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A digital whole-body vibration exposure recorder for monitoring heavy equipment in the field Kindsvater, André 1982

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DIGITAL WHOLE-BODY VIBRATION EXPOSURE RECORDER FOR MONITORING HEAVY EQUIPMENT IN THE FIELD by ANDRE KINDSVATER B.C.S., Concordia U n i v e r s i t y , 1976 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department of E l e c t r i c a l E ngineering) We accept t h i s t h e s i s as conforming to the r e q u i r e d standard THE UNIVERSITIY OF BRITISH COLUMBIA. August 1982 ©Andre' K i n d s v a t e r 1982 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. I t i s understood that copying or publication of t h i s thesis f o r f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of ^LB^T/Z-I^AIL- E u&/K>££ JZ/AJq The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date 29. JUL.? 19 BZ 11 ABSTRACT A s e l f - c o n t a i n e d v i b r a t i o n a n a l y z e r f o r the e v a l u a t i o n of whole-body v i b r a t i o n exposure of heavy equipment o p e r a t o r s has been developed, using d i g i t a l f i l t e r i n g t e c h n i q u e s . Two s e t s of d i g i t a l f i l t e r s were designed: a) a set of weighting f i l t e r s a c c o r d i n g to the ISO 2631 standard (Guide f o r the E v a l u a t i o n of Human Exposure to Whole-body V i b r a t i o n ) b) a set of second order octave band f i l t e r s c o v e r i n g the range from 1 t o 80 Hz. The implementation was based on a low power 8 b i t micro-p r o c e s s o r , supported by a s t a c k - o r i e n t e d a r i t h m e t i c p r o c e s s o r . The instrument processes 3 analogue i n p u t s from a t r i a x i a l s t r a i n g a g e accelerometer and outputs the f i l t e r e d rms (10 sec) s i g n a l f o r analogue r e c o r d i n g . The f i l t e r s can be s e l e c t e d i n the f i e l d as e i t h e r conforming to the ISO 2631 standard or to be 1 of 6 octave f i l t e r s . The instrument was e v a l u a t e d i n the l a b o r a t o r y and used f o r f i e l d measurements under p r o d u c t i o n c o n d i t i o n s i n f o r e s t h a r v e s t i n g . On the p a r t i c u l a r machine i n v e s t i g a t e d , i t was found that the operator v i b r a t i o n exposure i s w e l l below the l i m i t s set by the ISO 2631 standard. But high v a r i a t i o n s i n the measured rms v i b r a t i o n l e v e l s i n d i c a t e the presence of a l a r g e energy c o n t r i b u t i o n from shock impulses, which are o u t s i d e the scope of the standard. i i i TABLE OF CONTENTS 1 . I n t r o d u c t i o n 1 2. Whole-Body V i b r a t i o n And I t s E f f e c t s On Man 3 I n t r o d u c t i o n 3 V i b r a t i o n Measurements 5 The Human Body As A Mechanical System .. 7 C o n s i d e r a t i o n s Of F i e l d Measurements 11 Standards 16 ISO 2631 Standard 16 VDI 2057 17 E f f e c t s Of WBV 19 Mechanical Behaviour of P a r t s of the Body 19 P h y s i o l o g i c a l Reactions 20 Damage To Health 23 Conc l u s i o n 23 3. System Design 25 Hardware 25 Software 27 4. D i g i t a l F i l t e r Design 32 ISO Whole-Body F i l t e r s , 32 Octave Bandpass F i l t e r s 34 Design 35 S c a l i n g 38 BILIN.C 41 C o e f f i c i e n t Q u a n t i s a t i o n 41 A r i t h m e t i c Noise 41 L i m i t C y c l e s 44 5. Performance 46 Laboratory T e s t s 46 Performance Improvement 58 F i e l d T r i a l s 67 Data E v a l u a t i o n 67 Re s u l t s 72 6. Con c l u s i o n 83 Future Work And Recommendations 84 7. References 86 Appendix A 89 Hardware 89 Software 115 Appendix B 148 I n t e r n a t i o n a l Standard ISO 2631 148 LIST OF FIGURES F i g . 2.1 Simple Model of the Human Body 8 F i g . 2.2 S i m p l i f i e d Mechanical System Representing the Human Body 8 F i g . 2.3 Impedance of one Subject S i t t i n g and Standing .... 10 F i g 2.4 Impedance of 8 Subjec t s S i t t i n g E r e c t (median, 20th and 80th P e r c e n t i l e ) 10 F i g . 2.5 Equipment and Methods For Recording and A n a l y z i n g Random V i b r a t i o n 13 F i g 2.6 V i b r a t i o n i n Three D i r e c t i o n s of Two T r a c t o r Seats While D r i v i n g on a bad Road 14 F i g . 2.7 K-values a f t e r VDI 2057 18 F i g . 2.8 ISO 2631 vs. VDI 2057 18 F i g 3.1 V i b r a t i o n A n a l y s i s System 29 F i g 3.2 Flow Chart 30 F i g 3.3 S t r u c t u r e of a 2nd Order F i l t e r S e c t i o n 31 F i g 3.4 Data Flow w i t h i n a 2nd-order F i l t e r S e c t i o n 31 F i g 4.1a ISO 2631 Whole-Body F i l t e r ; x- and y - d i r e c t i o n ... 33 F i g 4.1b ISO 2631 Whole-Body F i l t e r ; z - d i r e c t i o n 33 F i g 4.2 Octave Bandpass F i l t e r a f t e r ANSI S1.11 34 F i g 4.3a Design Parameters i n the s-Plane 37 F i g 4.3b Design Parameters i n the z-Plane 37 F i g 4.4 S i m p l i f i e d Gain Model of a Second Order F i l t e r .... 40 F i g 4.5 D e t a i l e d Model f o r S c a l i n g of a Second Order F i l t e r 4 0 F i g 4.6 I d e a l F i x e d Point M u l t i p l i c a t i o n and T r u n c a t i o n ... 43 F i g 4.7 F u l l w o r d T r u n c a t i o n i n Integer M u l t i p l i c a t i o n 43 F i g . 5.1 ISO(x,y) F i l t e r Response from Function Generator Input 48 F i g 5.2 ISO(z) F i l t e r Response from F u n c t i o n Generator Input 49 F i g . 5.3 #1 F i l t e r Response from Function Generator Input . 50 F i g . 5.4 #2 F i l t e r Response from Function Generator Input . 51 F i g . 5.5 #3 F i l t e r Response from Function Generator Input . 52 F i g . 5.6 #4 F i l t e r Response from Function Generator Input . 53 F i g . 5.7 #5 F i l t e r Response from Function Generator Input . 54 F i g . 5.8 #6 F i l t e r Response from Function Generator Input . 55 F i g . 5.9 A c c e l e r a t i o n Range of Scotch Yoke 56 F i g . 5.10 #4 F i l t e r Response With Shaker Input 56 F i g . 5.11a Sample Waveform of Scotch Yoke 57 F i g . 5.11b Frequency Content of Scotch Yoke 57 F i g . 5.12a Zero-Pole-Zero-Pole S t r u c t u r e 60 F i g . 5.12b Zero-Pole-Pole-Zero S t r u c t u r e 60 F i g . 5.13a F i l t e r #1 Z-P-Z-P 61 F i g . 5.13b F i l t e r #1 Z-P-P-Z 61 F i g . 5.14a F i l t e r #2 Z-P-Z-P 62 F i g . 5.14b F i l t e r #2 Z-P-P-Z ..' 62 F i g . 5.15a F i l t e r #3 Z-P-Z-P 63 F i g . 5.15b F i l t e r #3 Z-P-P-Z 63 F i g . 5.16a F i l t e r #4 Z-P-Z-P 64 F i g . 5 . 1 6 b F i l t e r #4 Z-P-P-Z .. 64 F i g . 5.17a F i l t e r #5 Z-P-Z-P 65 F i g . 5.17b F i l t e r #5 Z-P-P-Z 65 F i g . 5.18a F i l t e r #6 Z-P-Z-P- 66 F i g . 5.18b F i l t e r #6 Z-P-P-Z 66 V F i g . 5.20 Madill-044 Grapple Yarder 69 F i g . 5.21 I n s t a l l a t i o n of the F u l l Data A c q u i s i t i o n System 69 F i g . 5.22 Attachment of the Sensor to the Cab S t r u c t u r e ... 70 F i g . 5.23 Attachment of the Sensor to the Seat 70 F i g . 5.24 E q u i v a l e n t Exposure Times 71 F i g . 5.25a X-Axis V i b r a t i o n Measurement Day #1 74 F i g . 5.25b X-Axis D i s t r i b u t i o n Day #1 74 F i g . 5.26a Y-Axis V i b r a t i o n Measurement Day #1 75 F i g . 5.26b Y-Axis D i s t r i b u t i o n Day #1 75 F i g . 5.27a Z-Axis V i b r a t i o n Measurement Day #1 76 F i g . 5.27b Z-Axis D i s t r i b u t i o n Day #1 76 F i g . 5.28a X-Axis V i b r a t i o n Measurement Day #2 77 F i g . 5.28b X-Axis D i s t r i b u t i o n Day #2 . ' — 77 F i g . 5.29a Y-Axis V i b r a t i o n Measurement Day #2 78 F i g . 5.29b Y-Axis D i s t r i b u t i o n Day #2 78 F i g . 5.30a Z-Axis V i b r a t i o n Measurement Day #2 79 F i g . 5.30b Z-Axis D i s t r i b u t i o n Day #2 79 F i g . 5.31a X-Axis V i b r a t i o n Measurement Day #3 80 F i g . 5.31b X-Axis D i s t r i b u t i o n Day #3 80 F i g . 5.32a Y-Axis V i b r a t i o n Measurement Day #3 81 F i g . 5.32b Y-Axis D i s t r i b u t i o n Day #3 81 F i g . 5.33a Z-Axis V i b r a t i o n Measurement Day #3 82 F i g . 5.33b Z-Axis D i s t r i b u t i o n Day #3 82 v i LIST OF TABLES Table 2.1 Frequency Ranges Produced by Common Sources of V i b r a t i o n 4 Table 2.2 Items Measured i n F i e l d T e s t s 11 Table 2.3 Mean Value of Oxygen Uptake 22 Table 2.4 Mean Value of Heart Rate 22 Table 4.1 ANSI S1.11 F i l t e r s 34 Table 4.2 M u l t i p l i c a t i o n Noise 44 Table 4.3 C a l c u l a t e d DC L i m i t C y c l e L e v e l s ..- 45 Table 5.1 C a l c u l a t e d and Measured DC L i m i t C y c l e L e v e l s ... 59 Table 5.2 E q u i v a l e n t Exposure Times 72 v i i ACKNOWLEDGEMENT I would l i k e to thank my s u p e r v i s o r Dr. P.D. Lawrence f o r h i s support and pat i e n c e throughout the course of t h i s work. I would a l s o l i k e to thank Dr. P.L. C o t t e l l f o r h i s support and the o p p o r t u n i t y to conduct t h i s work in the context of the on-going ergonomic r e s e a r c h i n f o r e s t h a r v e s t i n g . I a l s o thank Amaury De Souza f o r h i s h e l p with the f i e l d wor k. I am g r a t e f u l to MacMillan B l o e d e l f o r the use of t h e i r f o r e s t h a r v e s t i n g f a c i l i t i e s . T h i s work has been supported by the Science C o u n c i l of B r i t i s h Columbia (Grant No. 79 RC-3) and the N a t u r a l Sciences and E n g i n e e r i n g Research C o u n c i l of B r i t i s h Columbia (Grants A 6422 and A 9341). 1 1. INTRODUCTION In Canada, the F o r e s t I n d u s t r i e s are the l a r g e s t s i n g l e c o n t r i b u t o r to export earnings ($6.4 B i l l i o n or 31% of t o t a l manufacturing i n 1976). R e g i o n a l l y t h i s c o n t r i b u t i o n can be even h i g h e r , as i n B r i t i s h Columbia, where the percentage was 51% of t o t a l manufacturing. O v e r a l l p r o d u c t i v i t y has been s t e a d i l y improving with an i n c r e a s e d l e v e l of mechanisation, but t h i s development seems to be s l o w i n g 1 . The trend to higher mechanisation not only improves p r o d u c t i v i t y , but a l s o demands continued i n c r e a s e s i n e f f i c i e n c y to compensate for the l a r g e r investment c o s t s . One area to achieve the more e f f i c i e n t use of machinery, which has been l a r g e l y ignored thus f a r , i s the human f a c t o r i n man-machine i n t e r a c t i o n . To gain more i n s i g h t and i d e n t i f y p o t e n t i a l areas f o r improvement a recent p r o j e c t was undertaken to measure and assess a wide v a r i e t y of ergonomic v a r i a b l e s (operator environment, c o n t r o l l a yout) r e l a t i n g to p r o d u c t i v i t y and human f a c t o r s i n f o r e s t h a r v e s t i n g using heavy equipment. A system was developed to monitor and r e c o r d 'environmental' v a r i a b l e s such as noise, temperature, v i b r a t i o n , and humidity along with operator task e x e c u t i o n , r e l a t i n g each measurement to a s i n g l e time r e f e r e n c e 2 . One of the v a r i a b l e s , v i b r a t i o n (or more s p e c i f i c a l l y Whole-Body V i b r a t i o n ) , has been widely i n v e s t i g a t e d and i t s r o l e as a s t r e s s - i n d u c i n g agent e x t e n s i v e l y documented (see chapter 2). I t s importance i s a l s o r e f l e c t e d i n d e f i n i t e standards such as ISO 2631 3 and VDI 2057", which s t a t e frequency-dependent l i m i t s with respect to 'reduced comfort', ' f a t i g u e - d e c r e a s e d 2 p r o f i c i e n c y ' and 'hazard to h e a l t h and s a f e t y ' . In the ergonomic s t u d i e s 5 , of which t h i s work forms a p a r t , the simultaneous r e l a t i o n s h i p s between measured v i b r a t i o n l e v e l s and measured pr o d u c t i o n v a r i a b l e s ( i n - h a u l time, out-haul time, et c . ) and s t r e s s v a r i a b l e s (e.g. heart r a t e ) are being i n v e s t i g a t e d . The o b j e c t i v e of t h i s t h e s i s work i s to c o n s i d e r the measurement of v i b r a t i o n exposure of humans, to design a s u i t a b l e v i b r a t i o n a n a l y s i s system and use the system to gather whole-body v i b r a t i o n data i n the f i e l d . The system had to i n t e r f a c e e a s i l y with an a l r e a d y e x i s t i n g data-logger and p rovide compatible data to be recorded s i m u l t a n e o u s l y with other ergonomic v a r i a b l e s . A l s o , to be u s e f u l i n a f o r e s t h a r v e s t i n g environment the instrument had to be rugged, compact and independent of an e x t e r n a l power supply. A survey of commercially a v a i l a b l e equipment i n d i c a t e d some systems that c o u l d meet some of the requirements, but none that c o u l d f u l f i l l a l l . The most s o p h i s t i c a t e d instrument commercially a v a i l a b l e ( s i n c e 1981) i s the 2512 Human Response V i b r a t i o n Meter by B r u e l and K j a e r . The b a t t e r y powered instrument processes only one a x i s at a time and i s analogue based, except f o r a d i g i t a l d i s p l a y and IEC-625 bus i n t e r f a c e . 3 2. WHOLE-BODY VIBRATION AND ITS EFFECTS ON MAN  INTRODUCTION Awareness of the e f f e c t s of mechanical shock and v i b r a t i o n i s i n c r e a s i n g i n our t e c h n o l o g i c a l s o c i e t y . Ground, water, a i r and space t r a n s p o r t a t i o n v e h i c l e s , as w e l l as machinery at the workplace c r e a t e v i b r a t i o n s that can i n t e r f e r e with comfort, working e f f i c i e n c y and, i n extreme circumstances, h e a l t h and s a f e t y ( T a b l e l 2.1). The problem of whole-body v i b r a t i o n (WBV) exposure has been noted i n the l i t e r a t u r e q u i t e r e g u l a r l y s i n c e the e a r l y 1930's 6. Most v i b r a t i o n encountered i n an i n d u s t r i a l environment i s of a random nature w i t h i n a broad frequency band, but f o r the sake of determining and q u a n t i f y i n g v i b r a t i o n e f f e c t s the m a j o r i t y of i n v e s t i g a t i o n s have d e a l t with s i n u s o i d a l v i b r a t i o n under l a b o r a t o r y c o n d i t i o n s . Complementing the l a b o r a t o r y data are data d e r i v e d from a v a r i e t y of f i e l d measurements under r e a l i s t i c working c o n d i t i o n s . 4 SOURCE icr 1 i o ° Frequency (Hz) 10 1 10 2 10 3 _ i 1 1 1,0" i n f r a s o n i c a u d i b l e u l t r a s o n i c k— WBV—H A i r c r a f t manoeuvers gust responses p i s t o n engines p r o p e l l e r s r o t a t i n g wings j e t engines A i r c u s hion c r a f t s u r f a c e responses power sources B r i d g e s s t r u c t . r e s p o n s e s to wind and t r a f f i c i Land v e h i c l e s earthmoving, a g r i -c u l t u r a l + m i l i t a r y i road t r a n s p o r t r a i l t r a n s p o r t i -Machine t o o l s s t a t i o n a r y t-Table 2.1 Frequency ranges produced by common sources of v i b r a t i o n p o r t a b l e Ships sea movement power sources Space v e h i c l e s aerodynamic e f f e c t s power sources 5 T h i s survey i s r e s t r i c t e d to the phenomena and the e f f e c t s of whole-body v i b r a t i o n only, i n the range from 1 to 100 Hz. Frequencies below 1 Hz are u s u a l l y a s s o c i a t e d with motion s i c k n e s s , which i s not an apparent problem i n heavy equipment o p e r a t i o n . Not d i s c u s s e d are r e p o r t s on a c c e l e r a t i o n s above 5g which are more r e l e v a n t to m i l i t a r y and accident-damage s t u d i e s . WBV produces a r a t h e r s p e c i f i c c l i n i c a l p i c t u r e (see E f f e c t s of WBV), one that d i f f e r s from that formed when, for example, pneumatic t o o l s are o p e r a t e d 7 . Hence l o c a l v i b r a t i o n s with frequency contents to 1000 Hz and a c c e l e r a t i o n s of up to 1Og are not i n c l u d e d . In the range 1-20 Hz n o i s e and v i b r a t i o n o v e r l a p .(infrasound). No e f f e c t on h e a r i n g occurs, but f o r i n t e n s i t i e s of more than 140dB there i s evidence of v e s t i b u l a r d i s t u r b a n c e ( d i s o r i e n t a t i o n , l o s s of balance and nausea), a u r a l p a i n , and induced chest w a l l and whole-body v i b r a t i o n 6 . Due to the high l e v e l s r e q u i r e d t h i s seems of minor importance in the case of heavy equipment o p e r a t o r s . VIBRATION MEASUREMENTS Sine-wave and other p e r i o d i c v i b r a t i o n s are easy to v i s u a l i z e because they can be d e s c r i b e d g r a p h i c a l l y or by simple mathematical equations. They can be completely d e f i n e d by s p e c i f y i n g frequency, amplitude, and phase c h a r a c t e r i s t i c s . Thus, maximum a c c e l e r a t i o n , an important parameter f o r t e s t purposes, i s c a l c u l a b l e . The instantaneous a c c e l e r a t i o n produced by a sine-wave can be determined by t a k i n g the second d e r i v a t i v e of the sine-wave equation: 6 A= 4 i r 2 f 2Dsin2fff t from t h i s , maximum a c c e l e r a t i o n can be c a l c u l a t e d as: a=0.04024f 2D where: a=max a c c e l e r a t i o n i n g f=frequency i n Hertz D=displacement i n cm Random v i b r a t i o n s 8 , however, are d i f f i c u l t to p i c t u r e because they have nonperiodic wave forms that change magnitude u n p r e d i c t a b l y . A random v i b r a t i o n , though o f t e n l i m i t e d to a s p e c i f i c frequency band, c o n t a i n s s e v e r a l f r e q u e n c i e s s i m u l t a n e o u s l y , and a l l f r e q u e n c i e s i n the band are p o s s i b l e . N e i t h e r instantaneous v e l o c i t i e s nor instantaneous displacements can be p r e d i c t e d f o r random v i b r a t i o n s . Thus, maximum a c c e l e r a t i o n i s indeterminate, and s t a t i s t i c a l theory must be used to c a l c u l a t e rms a c c e l e r a t i o n and to p r e d i c t the p r o b a b i l i t y f o r any s p e c i f i c instantaneous a c c e l e r a t i o n . I f the a c c e l e r a t i o n produced by a random v i b r a t i o n i s observed over a long p e r i o d , the mean, the v a r i a n c e , and the standard d e v i a t i o n can be measured and c a l c u l a t e d . 7 THE HUMAN BODY AS A MECHANICAL SYSTEM From a p u r e l y mechanical p o i n t of view the human body might be c o n s i d e r e d as a complex system c o n s i s t i n g of s p r i n g s , dampers and masses. E a r l y i n v e s t i g a t i o n s of the mechanical impedance of a standing or s i t t i n g man under v e r t i c a l whole body v i b r a t i o n l e a d to a simple mass-spring system 9. Below 2 Hz the body a c t s as a u n i t mass. Resonant peaks appearing between 4 and 5 Hz ( F i g . 2.3a, 2.3b) suggest the damped s i n g l e s p r i n g - s i n g l e mass system of F i g . 2.1. Higher order systems were d e v e l o p e d 1 0 to account f o r m u l t i p l e resonances ( F i g . 2.2), but the s i n g l e s p r i n g - s i n g l e mass model can be used as a f a i r l y good approximation. Moreover the approximation f i t s best f o r v i b r a t i o n s below 10 Hz which c o i n c i d e s with the range of primary i n t e r e s t . Apart from the 4 Hz resonance f o r the thorax-abdomen system there i s a f u r t h e r resonance i n the 20 - 30 Hz range from the head-neck-shoulder system. Other resonant f r e q u e n c i e s f o r p a r t s of the body have been e x p e r i m e n t a l l y determined: Hand: 30 to 40 Hz Arm,leg: 2 to 6 Hz Jaw: 100 to 200 Hz E y e b a l l : 60 to 90 Hz 8 m r F i g 2.1 Simple model of the human body M M -SHOULDER SYSTEM STIFF ELASTICITY^ or SPINAL COLUMM LEGS UPPER TORSO THORAX-ABDOMEN SYSTEM (SIMPLIFIED) HIPS • FORCE APPLIEO I TO SITTING * SUBJECT FORCE APPLIED TO STANDING SUBJECT F i g 2.2 S i m p l i f i e d mechanical system representing the human body at low frequencies 9 I t was found d i f f i c u l t to a s s i g n d e f i n i t e numerical v a l u e s to the elements of the model, s i n c e they depend c r i t i c a l l y on the body type, posture and muscle tone of the s u b j e c t under t e s t . A homogeneous sample of 8 he a l t h y young males a l r e a d y e x h i b i t s f a i r l y l a r g e v a r i a t i o n s as shown by the upper and lower graph i n F i g . 2.3b. Estimates f o r the values of the elements i n the s i n g l e mass model are: Mass: 75.2 kg Spring constant: 32.7 N/cm Damper: 12.8 Nsec/cm Damping f a c t o r : 0.258 10 Frequency (Hz) F i g 2.3 Impedance of one s u b j e c t s i t t i n g and standing Frequency (Hz) F i g 2.4 Impedance of 8 s u b j e c t s s i t t i n g e r e c t (median, 20th and 80th p e r c e n t i l e ) 11 CONSIDERATIONS OF FIELD MEASUREMENTS An e x t e n s i v e study on WBV was conducted through the N a t i o n a l I n s t i t u t e f o r Occ u p a t i o n a l Safety and H e a l t h (NIOSH) 1 1. Using a s p e c i a l l y equipped ex-Ambulance truck, v i b r a t i o n l e v e l s at 5 p o i n t s , p h y s i o l o g i c a l parameters and t e s t v e h i c l e motion (Table 2.2) were recorded through a FM telemetry l i n k . The data was then analysed ( o f f - l i n e ) i n blocks of 1024 samples and over a range of 0-25 Hz with a Hewlett-Packard D i g i t a l F o u r i e r A n a l y z e r . V i b r a t i o n a c c e l e r a t i o n a t : Target v e h i c l e f l o o r [ v e r t i c a l a x i s ) Man/seat i n t e r f a c e ( i . e . worker's buttocks, a l l three axes) Worker's k n e e ' ( v e r t i c a l a x i s ) Worker's shoulder ( v e r t i c a l a x i s ) Worker's head ( v e r t i c a l a x i s ) Environment Noise Tat the worker's ear l e v e l ) Temperature and r e l a t i v e humidity (manually obtained) P h y s i o l o g y E l e c t r o c a r d i o g r a m (EKG) Electromyogram (EMG, 2 channels, b i l a t e r a l s a c r o -s p i n a l i s muscles) Other: Road p r o f i l e s t r a v e r s e d by the t a r g e t v e h i c l e and continuous o b s e r v a t i o n of the operator and h i s v e h i c l e motion (video tape) T a r g e t - v e h i c l e speed (Doppler radar) T a r g e t - v e h i c l e t i r e p ressure (where a p p l i c a b l e ) Two-way r a d i o communication between t a r g e t - v e h i c l e operator and mobile r e c o r d i n g u n i t Table 2.2 Items measured i n f i e l d t e s t s From 21 runs by one of four d r i v e r s on 22 machines (of 11 d i f f e r e n t types) about 150 s p e c t r a l p l o t s were generated. 1 2 The main c o n c l u s i o n s drawn from the data are: - the m a j o r i t y of high l e v e l v i b r a t i o n appears i n the z-d i r e c t i o n ( v e r t i c a l ) , - there i s l i t t l e d i f f e r e n c e i n the measured v i b r a t i o n l e v e l s between operat o r s of d i f f e r e n t body mass (weights: 180-230 l b s ) - i t appears that there i s a s i n g l e t r a n s m i s s i o n path to the o p e r a t o r ' s upper t o r s o from the v e h i c l e through the seat. - f o r a l o g s k i d d e r , v i b r a t i o n o c c u r r e d mostly between 1.0 and 15Hz with l e v e l s from 0.07 to 0. 130g (peak). U n f o r t u n a t e l y no e v a l u a t i o n was made of the p h y s i o l o g i c a l data (EKG and EMG's were r e c o r d e d ) . At the Norwegian I n s t i t u t e of A g r i c u l t u r a l E n g i n e e r i n g , S j o f l o t and coworkers have c a r r i e d out a s e r i e s of i n v e s t i g a t i o n s with p a r t i c u l a r r e f e r e n c e to the WBV caused by s e l f - p r o p e l l e d machines i n a g r i c u l t u r e and f o r e s t r y 1 2 1 3 . T h e i r main aims were: a) to develop methods of measuring, a n a l y s i n g and e v a l u a t i n g the v i b r a t i o n exposure of machine op e r a t o r s i n p r a c t i c a l work and b) to evaluate v i b r o t e c h n i c a l aspects i n l a b o r a t o r y i n v e s t i g a t i o n s concerning i r r e g u l a r and random o s c i l l a t i o n s . The v i b r a t i o n a c c e l e r a t i o n was recorded at the pl a c e of a c t i o n , i . e on the seat j u s t under the d r i v e r . In some experiments where d i f f e r e n t types of seats were ev a l u a t e d , v i b r a t i o n a c c e l e r a t i o n was a l s o measured on the v e h i c l e body beneath the s e a t s . The a c c e l e r a t i o n was measured i n three d i r e c t i o n s a c c o r d i n g to ISO 2631. The v i b r a t i o n d u r i n g p r a c t i c a l d r i v i n g experiments with v a r i o u s types of machinery, v a r i o u s 13 speeds, e t c . , was recorded on magnetic tape and analyzed i n the l a b o r a t o r y . The frequency a n a l y s i s was c a r r i e d out over the range 0.3 to 110 Hz. The frequency s p e c t r a showed the average a c c e l e r a t i o n amplitude i n frequency bands 0.06 Hz wide f o r an experimental p e r i o d of 2.8 minutes. A technique of frequency t r a n s f o r m a t i o n was used, i . e . r e c o r d i n g on a tape loop at a low tape speed and using a speed 100 times higher when r e p l a y i n g f o r a n a l y s i s . A computer c a l c u l a t i o n of the frequency s p e c t r a , f o r f r e q u e n c i e s up t o 25 Hz, was a l s o made with a r e s o l u t i o n of 0.1 Hz and a sample frequency of 1OOsamples/sec f o r the analogue r e c o r d i n g s . T < Dote transport, I recorcwq on top* loop, To.pt recorder O—D FM MAS H •Amplifier frequence tronfformotton lAmplltler tope recorder FM PI 6200 Colibrotion  '/ana control \ V.100, 4 Nolte frequ«cj| anotfter ; A. Anotoooui Compen-sol ion poper recorder i i * Amplitude -j spectrum O i r tc l paprr recorder 1 Acceleration F i g 2.5 Equipment and methods f o r r e c o r d i n g and a n a l y z i n g random v i b r a t i o n 1 2 . 1 4 Vehicle II 12 km/h •Vehicle body beneath the seat Seat B | O o & e s e a t u n a e r th«> driver -Seat C Z-axis RMS —1,87 m / s 2 —1 ,40 m / s , — 1.33 m / s ' '29 40 60 80 ICO H Z 120 X-axis RMS o . • r t •if • III i 1 s2 J2 1' i A , i M A. 2 * 6 Y - a x i s 10 >1 1* IS '8 20 OA 0.2 0.2 RMS .—-1.90 m/s?1 U-K-4 l , 5 0 m / s . 0 r , ~ 1 0.90 m/'s 20 K»1S_ • 40 a m y 60 00 100 11 >3Hx20 Frequency F i g 2.6 V i b r a t i o n i n three d i r e c t i o n s of two t r a c t o r seats while d r i v i n g on a bad r o a d 1 2 . 1 5 The frequency s p e c t r a were i n t e r p r e t e d i n r e l a t i o n to the German VDI - g u i d e l i n e s 2057 (K- v a l u e ) " . The main c o n c l u s i o n s drawn: - v i b r a t i o n s above 20 Hz, measured on the seat, d i d not i n t e r f e r e with v e h i c l e o p e r a t i o n . - on p n e u m a t i c a l l y t i r e d v e h i c l e s the dominating f r e q u e n c i e s f o r v e r t i c a l (z) d i r e c t i o n appeared between 2.5 and 4.5 Hz. V i b r a t i o n in the h o r i z o n t a l d i r e c t i o n s are u s u a l l y 1/4 to 1/2 of the v e r t i c a l with dominant f r e q u e n c i e s from 1 to 4 Hz ( r i g h t - t o - l e f t d i r e c t i o n ) and from 0.3 to 2.5 Hz (chest-to-back d i r e c t i o n ) . - v a r i a t i o n i n d r i v i n g speed (8,12,16 km/h) had no i n f l u e n c e on the frequency d i s t r i b u t i o n , however the amplitude i n c r e a s e d with speed, p a r t i c u l a r l y at the dominant f r e q u e n c i e s - l i g h t w e i g h t d r i v e r s appeared to be exposed to g r e a t e r v i b r a t i o n s t r e s s e s than heavier ones. A study to c o l l e c t r e p r e s e n t a t i v e v i b r a t i o n data f o r front-end l o a d e r s i n the f i e l d was conducted by the F o r e s t E n g i n e e r i n g Research I n s t i t u t e of Canada 1" (FERIC). Data was c o l l e c t e d , i n the v e r t i c a l d i r e c t i o n only, from three o p e r a t o r s working on four d i f f e r e n t l o a d e r s . The weighted s i g n a l (ISO) was analyzed with a B r u e l and Kjaer (B+K) S t a t i s t i c a l L e v e l A n a l y z e r . Peak a c c e l e r a t i o n s of more than 2g (rms) were observed. More commonly (about 70%) the values c l u s t e r e d around 0.05 to 0.3g rms. 1 6 STANDARDS ISO 2631 Standard The standard d e f i n e s and g i v e s numerical values f o r l i m i t s of exposure f o r v i b r a t i o n t r a n s m i t t e d from s o l i d s u r f a c e s to the human body i n the frequency range from 1 to 80 Hz (see Appendix B). I t d e f i n e s the three major axes i n which to measure the v i b r a t i o n i n r e l a t i o n to s i t t i n g and standing s u b j e c t s , x - a x i s : l a t e r a l (back to chest) y - a x i s : a n t e r o p o s t e r i o r ( r i g h t to l e f t ) z - a x i s : l o n g i t u d i n a l , v e r t i c a l ( f o o t to head) Separate l i m i t s are s p e c i f i e d a c c o r d i n g to whether the v i b r a t i o n i s i n the v e r t i c a l (z) d i r e c t i o n or the h o r i z o n t a l (x,y) d i r e c t i o n . The c h a r a c t e r i s t i c s f o r two weighting networks, one for x- and y-axes and one f o r the z - a x i s , are gi v e n . The networks allow the ex p r e s s i o n of the l e v e l of v i b r a t i o n with r e s p e c t to i t s e f f e c t s on man by a s i n g l e q u a n t i t y . Three l i m i t s as a f u n c t i o n of frequency are set ac c o r d i n g to the three main human c r i t e r i a : - reduced comfort boundary; r e l a t e s to i n t e r f e r e n c e with b a s i c o p e r a t i o n s such as e a t i n g , reading, w r i t i n g . - f a t i g u e - d e c r e a s e d p r o f i c i e n c y boundary; above which the working e f f i c i e n c y may be impaired. - exposure l i m i t s ; exceeding these l i m i t s can pose a t h r e a t to the s a f e t y and/or h e a l t h of the s u b j e c t . 17 VDI 2057 The K-Factor as developed by Dieckmann p r o v i d e d the b a s i s f o r a German n a t i o n a l standard (VDI 2057) concerned with the harmful e f f e c t s of v i b r a t i o n . K i s d e f i n e d as the c o e f f i c i e n t of the amount ( i . e . power) of the p h y s i o l o g i c a l s t r e s s d u r i n g exposure to v i b r a t i o n . Thus: K=0.1 t h r e s h o l d of s e n s i t i v i t y to v i b r a t i o n K=0.3-1.0 v i b r a t i o n a c t i n g over a long p e r i o d may be unpleasant K=1.0-3.0 v i b r a t i o n i s unpleasant but bearable K=3.0-10 s e r i o u s d i s o r d e r s appear duri n g s e v e r a l hours exposure K=l0-30 work i s ha r d l y p o s s i b l e K=30-100 human presence i s impossible The K - f a c t o r i s c a l c u l a t e d from amplitude (d, i n cm) and frequency ( f , i n Hz) as: v e r t i c a l to 5Hz R=d*f 2 5 - 4 0 H Z K=5*d*f 40-100Hz K=200*d For simultaneous a c t i o n s h o r i z o n t a l to 2Hz K=2*d*f 2 2 - 2 5 H Z K=4*d*f 25-100HZ K=l00*d K=(K 2+K 2+K] + . . . ) y>2 «* o tt Pa-te prion loteroricc H efiretnety Travel in vehicles for short time G Physical work with longer interruptions. Travel in ve-hicles during longer lime F Physical' work with short interruptions K strong!/ perceptable Physical work vrithaul interruptions O definitely perrephbl* Present* in housings with longer interruptions • c perceptebte Presence in housings with short or no interruptions t B hordly percepletii A hot perctprable F i g 2.7 K-values a f t e r VDI-2057 1.0 0.1 t—\ in E 00.1 — J / / r / / / / / f J / / f y 0.001 10 25 Hz 50 80 F i g 2.8 ISO 2631 vs. VDI 2057 19 EFFECTS OF WBV As with most other s t r e s s e s WBV concerns not only the p h y s i o l o g i c a l f i e l d , i t may a l s o l e a d to d i f f e r e n t psycho-emotional s i t u a t i o n s 1 5 . These p s y c h o l o g i c a l r e a c t i o n s together may s t r a i n the human organism and i n f l u e n c e p r o f i c i e n c y . I t i s d i f f i c u l t to d i v i d e m e t h o d i c a l l y the e f f e c t s i n t o the p h y s i o l o g i c a l - o b j e c t i v e and the p s y c h o l o g i c a l - s u b j e c t i v e f i e l d . In s p i t e of t h i s , most of the experimental r e p o r t s d e s c r i b e only s i n g l e p h y s i o l o g i c a l , p s y c h o l o g i c a l , p a t h o l o g i c a l or p h y s i c a l react i o n s . The r e p o r t e d e f f e c t s f a l l mostly i n t o the f o l l o w i n g c l a s s e s : Acute: a) mechanical behaviour of p a r t i c u l a r p a r t s of the body b) p h y s i o l o g i c a l r e a c t i o n s of c i r c u l a t i o n , r e s p i r a t i o n , muscular system or nervous system c) s u b j e c t i v e i n t e n s i t y of v i b r a t i o n p e r c e p t i o n d) decrease i n performance C h r o n i c : e) damages to h e a l t h Mechanical Behaviour of P a r t s of the Body The d i f f e r e n t resonances of s e l e c t e d limbs have a l r e a d y been noted. The input f o r c e i s a l s o t r a n s m i t t e d to the heart and other l a r g e body organs. Because of the arrangement of the heart i n the t h o r a c i c c a v i t y , which al l o w s i t to " r e c o i l " , the heart i s h i g h l y s u s c e p t i b l e to v i b r a t i o n 1 6 . Resonances at 3-4 Hz and 8-10 Hz have been observed. The swing of the heart i n response 20 to v i b r a t i o n may a l s o a f f e c t l e f t v e n t r i c u l a r e j e c t i o n , thereby producing f u r t h e r changes in blood pressure and flow. A lumped parameter c l o s e d - l o o p analogue computer model of the hydrodynamic aspects of the p a s s i v e c a r d i o v a s c u l a r system was used to estimate the r e l a t i v e c o n t r i b u t i o n of the f l u i d and vessel' system to changes i n the a r t e r i a l p r e s s u r e s and flows as measured in dogs. The a n a l y s i s of the data suggested that of the change in mean a o r t i c flow, approximately 25% was due to dynamics of the f l u i d and v e s s e l s and the remaining 75% was due to r e a c t i o n of the organism, i . e . mechano-receptors v i a the c e n t r a l nervous system, the hormonal metabolic system and p s y c h o - p h y s i o l o g i c a l mechanisms. These f i n d i n g s were confirmed to a f i r s t approximation from experiments with a n a e s t h e t i z e d animals. P h y s i o l o g i c a l Reactions The most t y p i c a l consequences of WBV i n the high frequency range are d i s o r d e r s i n the c e n t r a l nervous system and, i n p a r t i c u l a r , v e g e t a t i v e d y s f u n c t i o n with a n g i o d y s t o n i c , c e r e b r a l and c a r d i a c symptoms with a neurasthenic background 5. An e l e c t r o - e n c e p h a l o g r a p h i c examination of p a t i e n t s a f f e c t e d by WBV shows predominant changes in the b i o e l e c t r i c a c t i v i t y of the b r a i n ; i . e . c o n s i d e r a b l e d e p r e s s i o n of the alpha-rhythm, lower amplitude of the waves and prevalence of a c t i v i t y with h i g h frequency/low amplitude. Confirming other r e p o r t s , Sharp et a l . 1 7 recorded a s i g n i f i c a n t i n c r e a s e i n oxygen uptake under constant displacement (0.625 cm) s i n u s o i d a l v i b r a t i o n . As Table 2.3 21 shows, no s i g n i f i c a n t d i f f e r e n c e was obtained with the s u b j e c t at r e s t and d u r i n g v i b r a t i o n at 2 and 4 Hz. At 6, 8 and 10 Hz, however, there was an i n c r e a s e which was f a i r l y l i n e a r with i n c r e a s i n g frequency. S i m i l a r r e s u l t s were found by measuring heart r a t e , with the d i f f e r e n c e that the heart r a t e seems to adapt somewhat ( T a b l e l 2.4). The observed i n c r e a s e was g r e a t e s t a f t e r 5 minutes and d e c l i n e d towards the end of the v i b r a t i o n p e r i o d . At a l l f r e q u e n c i e s the heart r a t e d u r i n g recovery was lower than in the c o n t r o l r e s t p e r i o d . 22 Frequency of at a f t e r 5 min a f t e r 10 min Recovery 1 v i b r a t i o n (Hz) Rest v i b r a t ion v i b r a t ion RESTRAINED 2 0.299 0.301 0.270 0.302 4 0.278 0.274 0.271 0.274 6 0.280 0.388 0.390 0.272 8 0.317 0.472 0.476 0.292 10 0.277 0.525 0.505 0.260 UNRESTRAINED 2 0.313 0.283 0.278 0.272 4 0.287 0.270 0.274 0.261 6 0.282 0.372 0.332 0.269 8 0.302 0.476 0.509 0.272 10 0.278 0.518 0.531 0.274 Table 2.3 Mean value of oxygen uptake Frequency of at a f t e r 5 min a f t e r 10 min Recovery v i b r a t i o n (Hz) Rest v i b r a t i o n v i b r a t ion RESTRAINED 2 84. 1 82.5 81 .3 80. 1 4 79. 1 78.0 75.5 76.7 6 81.2 86.3 78.9 77.5 8 84.6 89.2 85.2 79.5 10 84.8 97.0 92.3 82.6 UNRESTRAINED 2 82.2 84.6 80. 1 79.5 4 81.0 79.5 80.2 77.4 6 83.4 86.0 79.2 78.4 8 85.0 89.3 84.7 80.0 10 84.0 96.2 92.2 80. 1 Table 2.4 Mean value of heart r a t e 23 Damage To H e a l t h It appears that common (low l e v e l ) exposure to WBV poses l i t t l e or no d i r e c t r i s k to h e a l t h 1 8 . On the other hand, v i b r a t i o n of l a r g e magnitude can produce annoyance and p a i n , and l e a d to f u n c t i o n a l a l t e r a t i o n s such as muscular weakness, high blood p r e s s u r e , f a t i g u e and decreased nerve conducting v e l o c i t y . As noted before, i t i s d i f f i c u l t to e s t a b l i s h d e f i n i t e cause and e f f e c t r e l a t i o n s h i p s i n WBV, as a complex s t a t i s t i c a l a n a l y s i s of approximately 3900 h e a l t h s e r v i c e s c l a i m s of heavy equipment o p e r a t o r s 1 9 showed. The study c o u l d e x t r a c t only t e n t a t i v e i n d i c a t i o n s of a p a t t e r n ( p r i m a r i l y with p r o s t a t i t i s ) , but i t could show that the o p e r a t o r s w i l l switch to l e s s exposed jobs with the onset of d i s c o m f o r t due to the v i b r a t i o n a l d i s e a s e 2 0 2 1 . A study of 78 Russian co n c r e t e workers exposed to WBV showed marked changes in bone s t r u c t u r e i n v o l v i n g s p o n d y l i t i s deformations, i n t e r v e r t e b r a l o s t e o c h o n d r i t i s and c a l c i f i c a t i o n of the i n t e r v e r t e b r a l d i s c s and Schmorl's n o d e s 2 2 . "A w e l l designed German p r o j e c t suggests that t r a c t o r v i b r a t i o n c o n t r i b u t e s to g a s t r i c d i s o r d e r s and premature bone changes in the t h o r a c i c and lumbar v e r t e b r a e . " 2 3 CONCLUSION The s i m u l a t i o n s and l a b o r a t o r y experiments show that the range of i n t e r e s t f o r WBV i s from 1 to 80 Hz, and i t s e f f e c t s on the human are complex and not merely mechanical, i . e . the e f f e c t s r e s u l t p a r t l y from the energy input and p a r t l y from the r e a c t i o n of the n e u r o - p h y s i o l o g i c a l system. 24 Therefore an instrument f o r the measurement of WBV must be f l e x i b l e i n order to provide f o r computation of v i b r a t i o n i n d i c e s r e l a t i n g to frequency, exposure-duration and amplitude and at the same time r e l a t e i t to changes i n other ergonomic q u a n t i t i e s and p o s s i b l e s t r e s s i n d i c a t o r s . The e f f e c t s on the human are frequency dependent and i t would be advantageous i f the v i b r a t i o n s c o u l d be examined w i t h i n narrower frequency bands. As a r e s u l t of t h i s study three primary requirements were determined f o r the v i b r a t i o n monitor system: a) I t should measure v i b r a t i o n s along a l l three axes si m u l t a n e o u s l y ; b) i t should meet the' ISO 2631 whole-body f i l t e r requirements; c) i t should be able to be reprogrammed to a new v i b r a t i o n exposure index (set of frequency weighting f i l t e r s ) as a r e s u l t of i n v e s t i g a t i o n s on the e f f e c t s of whole-body v i b r a t i o n . 25 3. SYSTEM DESIGN HARDWARE To be compatible with the a l r e a d y e x i s t i n g data-logger the v i b r a t i o n a n a l y z e r had to have analogue outputs and i n c o r p o r a t e some p r e p r o c e s s i n g . The data-logger works with ' d i f f e r e n c e -based' sampling, r a t h e r than the more usual time-based sampling; i . e . a value and i t s corresponding time are recorded only i f the new value d i f f e r s by a p r e s e t amount from the p r e v i o u s v a l u e . T h i s allows one to r e c o r d slowly v a r y i n g s i g n a l s over a longer time p e r i o d , but would n e c e s s i t a t e p r e p r o c e s s i n g higher frequency i n p u t s such as raw v i b r a t i o n data. For p r o c e s s i n g the v i b r a t i o n s i g n a l the rms-value was chosen i n accordance with the ISO 2631 standard. The rms a c c e l e r a t i o n i s d i r e c t l y p r o p o r t i o n a l to the f o r c e , and hence energy, d e l i v e r e d to the o p e r a t o r . To measure the a c c e l e r a t i o n , a t r i a x i a l , p i e z o r e s i s t i v e transducer was chosen with a 1Og c a p a c i t y to a t t a i n s u f f i c i e n t l i n e a r i t y over the frequency range. The r e l a t i v e high c a p a c i t y a l s o gave some p r o t e c t i o n a g a i n s t d e s t r u c t i v e o v e r l o a d s . The r e s u l t i n g v o l t a g e s from a c t u a l a c c e l e r a t i o n s were q u i t e small (0.125 mV/lOg) and had to be a m p l i f i e d u s i n g a d i f f e r e n t i a l i n s t r u m e n t a t i o n a m p l i f i e r with a gain of 2000. To implement the f i l t e r i n g and s i g n a l p r o c e s s i n g (rms) the d i g i t a l route was chosen. The advantages were low power, f l e x i b i l i t y , freedom from d r i f t and i n s e n s i t i v i t y to e x t e r n a l n o i s e . The v o l t a g e s , p r o p o r t i o n a l to the a b s o l u t e a c c e l e r a t i o n , from the a c c e l e r a t i o n t r a n s d u c e r s ( F i g . 3.1) are band l i m i t e d to 26 the Nyquist frequency by a 3rd order Butterworth f i l t e r . A f t e r f i l t e r i n g , the s i g n a l s are sampled at 160 Hz and h e l d f o r the analogue to d i g i t a l c o n v e r s i o n . The co n v e r s i o n with 8 b i t r e s o l u t i o n r e s u l t s i n a conver s i o n n o i s e of -59 dB(rms) r e l a t i v e to f u l l s c a l e , which i s s u f f i c i e n t f o r t h i s a p p l i c a t i o n . The p r o c e s s i n g of the d i g i t a l s i g n a l i s handled by a dual processor system: an 8 b i t CMOS micro-processor f o r the c o n t r o l and data flow, and a 16 b i t s t a c k - o r i e n t e d a r i t h m e t i c processor (APU) f o r the a r i t h m e t i c o p e r a t i o n s . A 2 K byte EPROM serves as storage f o r the program and the f i l t e r c o e f f i c i e n t s and 1/4 K of random access memory holds the data and intermediate values that cannot be h e l d on the APU stack. An e x t e r n a l switch allows the s e l e c t i o n of one of seven d i f f e r e n t f i l t e r s e t s . The computed rms values (over 10 sec) are converted to analogue s i g n a l s with an 8 b i t d i g i t a l - a n a l o g u e c o n v e r t e r and presented to the dat a - l o g g e r , which records the changing samples and the corresponding time on an incremental c a s s e t t e tape r e c o r d e r . The f u l l data c a s s e t t e , which can hold the combined data of a complete working day, can be removed and f u r t h e r analyzed i n the l a b o r a t o r y with a computer to produce s t a t i s t i c s and graphs.(Also see Appendix A: Hardware) 27 SOFTWARE The program implements the d i g i t a l f i l t e r s f o r a l l three channels (x-, y- and z - d i r e c t i o n ) s e q u e n t i a l l y ( F i g . 3.2). A l l implemented f i l t e r s are of the same general form with a cascaded s t r u c t u r e : z 2-1 z 2-1 G(z) = * z 2+pz+q z 2+rz+s Having the same form a l l o w s the use of the same program f o r a l l f i l t e r s and the f i l t e r frequency response can then e a s i l y be changed by s e l e c t i n g d i f f e r e n t c o e f f i c i e n t s . The a p p r o p r i a t e f i l t e r c o e f f i c i e n t s are s e l e c t e d at i n i t i a l i z a t i o n time depending on the s e t t i n g of the e x t e r n a l s e l e c t i o n switch. Due to the low speed of the A/D con v e r t e r the conver s i o n and f i l t e r - c a l c u l a t i o n s are i n t e r l e a v e d ; that i s , the conver s i o n f o r the next channel i s s t a r t e d at the beginning of a f i l t e r c a l c u l a t i o n . By the time the c a l c u l a t i o n i s f i n i s h e d the converted value f o r the f o l l o w i n g channel i s ready. The task of c a l c u l a t i n g the f i l t e r s i s d i v i d e d between the CPU and the APU. The CPU handles the c o n t r o l of the a u x i l i a r y hardware (such as A/D's and DAC's) and the data flow (delay-s h i f t s ) , while the APU executes the a r i t h m e t i c o p e r a t i o n s ( F i g . 3.3). At the end of a f i l t e r c a l c u l a t i o n the outputs are squared and summed f o r the rms c a l c u l a t i o n . A f t e r a f u l l sequence the CPU waits f o r an i n t e r r u p t from the sampling c l o c k . On ' i n t e r r u p t ' the program f a l l s through and checks i f a f u l l rms-i n t e r v a l has e l a p s e d . I f not, the program loops back to the beginning of the f i l t e r c a l c u l a t i o n s . 28 If a f u l l i n t e r v a l has passed, the rms valu e s are c a l c u l a t e d and the r e s u l t s output to the DAC's; then the e x t e r n a l switch i s scanned f o r a change i n s e t t i n g and i f a change has o c c u r r e d , the program branches to the i n i t i a l i s a t i o n segment of the program; i f not, the f i l t e r c a l c u l a t i o n s are resumed with the same c o e f f i c i e n t s . (Also see Appendix A: Software) 29 i i F i g 3 . 1 V i b r a t i o n A n a l y s i s System 30 Reset I n i t i a l i z e Convert x-input Scan e x t . Switch Set Coeff.1 1—I F Set Coeff .7 3 _ i t L E Convert y - i n p u t 1 x - f i l t e r Square and Sum Convert z-input 1 y - f i l t e r Square and Sum Convert x-input z - f i l t e r Square and Sum , 1 vf" <T > lOsec ?/— T RMS c a l c u l a t i o n Output wait i n t e r r u p t . LI V T <(change of e x t . Switch ? / — F i g . 3.2 Flow Chart F i g . 3 . 3 S t r u c t u r e of a 2nd order F i l t e r S e c t i o n < x(n) t J Data J } Constant Operation F i g . 3.4 Data flow w i t h i n a 2nd order F i l t e r S e c t i o n 32 4. DIGITAL FILTER DESIGN The design goal was to implement two s e t s of f i l t e r s : a) whole body f i l t e r s f o r the v e r t i c a l and h o r i z o n t a l axes as d e f i n e d i n the ISO 2631 standard. These f i l t e r s are used to a r r i v e at a v i b r a t i o n exposure index. b) a set of octave bandpass f i l t e r s , which would allow the f i e l d examination of the v i b r a t i o n i n narrower bands. As a g u i d e l i n e the ANSI S1.11 standard was chosen. ISO WHOLE-BODY FILTERS The ISO 2631 standard c a l l s f o r two f i l t e r s ; a lowpass f i l t e r with c u t - o f f frequecy of 2 Hz and a -20 dB/dec r o l l - o f f f o r the h o r i z o n t a l axes (x+y) and a bandpass f i l t e r with a -1OdB/dec r o l l o f f f o r f r e q u e n c i e s l e s s than 4 Hz and -20dB/dec f o r f r e q u e n c i e s g r e a t e r than 8 Hz. For both f i l t e r s , d e v i a t i o n s of ±1dB and ±2dB i n the passband and the t r a n s i t i o n band, r e s p e c t i v e l y , are allowed i n the standard ( F i g . 4.1). 0.1 02 0.5 1 2 5 10 2 0 50 Hz F i g 4.1a ISO 2631 Whole-Body F i l t e r ; x- and y - d i r e c t i o n Q1 02 0.5 1 2 5 10 20 50 Hz F i g 4.1b ISO 2631 Whole-Body F i l t e r ; z - d i r e c t i o n 34 OCTAVE BANDPASS FILTERS S p e c i f i c a t i o n s f o r octave bandpass f i l t e r s are set out i n the ANSI S1.1l Standard "Octave, Half Octave and T h i r d Octave Band F i l t e r S e t s " 2 " . The recommended center f r e q u e n c i e s were e x t r a p o l a t e d f o r the low frequency range r e s u l t i n g i n 6 f i l t e r s c o v e r i n g the range from 0.1 to 80 Hz ( t a b l e 4.1). The upper and lower l i m i t s of a standard octave f i l t e r are reproduced i n graphic form i n f i g 4.2. F i l t e r f l fu #1 0.71 1 .0 1 .41 #2 1.41 2.0 2.82 #3 2.82 4.0 5.60 #4 5.60 8.0 1 1.2 #5 11.2 16.0 22.4 #6 22.4 32.0 44.7 Table 4.1 ANSI SI. 11 F i l t e r s -45dB F i g 4.2 Octave Bandpass F i l t e r a f t e r ANSI S1.11 35 DESIGN The B i l i n e a r Transform (BLT) was chosen over other transforms such as "the matched z" and impulse i n v a r i a n t method. The BLT i s v e r s a t i l e and easy to use from an a l g e b r a i c p o i n t of view. I t guarantees a s t a b l e analogue f i l t e r i f s t a r t e d from a s t a b l e d i g i t a l f i l t e r 2 5 s i n c e the f u l l l e f t hand s-plane i s mapped i n t o the u n i t c i r c l e of the z-plane. I f the BLT i s used to p r o j e c t the l i n e s c orresponding to the design parameters, namely the break frequency (t^.) and the damping f a c t o r ( s ) from the s-plane onto the z-plane ( f i g 4.3a and f i g 4.3b) the d i g i t a l f i l t e r c o e f f i c i e n t s can be found to a f i r s t approximation by i n s p e c t i o n . The mapping f u r t h e r allows the i n s p e c t i o n of the f i n a l design i n terms of pole s and zeroes and to a c e r t a i n extent p r e d i c t the behaviour of the d i f f e r e n t d i g i t a l f i l t e r stages as to overshoot, gain and c o e f f i c i e n t q u a n t i s a t i o n . As a l r e a d y mentioned i n the pre v i o u s chapter, i t was decided to have the same general form z 2-1 z 2-1 G(z)= * z 2+pz+q z 2+rz+s f o r a l l f i l t e r s to keep the program l o g i c simple (and the run time low). Hence the same approach was taken i n the design of both f i l t e r s e t s . The ISO low pass f i l t e r (x- and y-axes) was implemented as a band pass f i l t e r , but having the lower corner frequency f a r o u t s i d e the range s p e c i f i e d by the standard. The band pass f i l t e r ( z - a x i s ) was transformed by p l a c i n g the lower corner 36 frequency, using t r i a l and e r r o r , so as to r e s u l t i n the s p e c i f i e d r o l l - o f f of 10/dB w i t h i n the s p e c i f i e d range. The ANSI bandpass f i l t e r s were found i n a s t r a i g h t f o r w a r d way from the analogue form by prewarping and then a p p l y i n g the BLT. 37 38 SCALING Because of the l i m i t e d dynamic range of f i x e d p o i n t a r i t h m e t i c , s p e c i a l a t t e n t i o n was p a i d to the s c a l i n g of the d i g i t a l s i g n a l at each p o i n t w i t h i n the s t r u c t u r e . On one hand the l a r g e s t p o s s i b l e s i g n a l was d e s i r e d to keep the s i g n a l to n o i s e r a t i o high, on the other hand overflow had to be avoided due to i t s l a r g e d i s t o r t i o n and n o i s e c o n t r i b u t i o n . To f i n d the optimal s c a l i n g f a c t o r s the input to each a r i t h m e t i c o p e r a t i o n was examined. As a f i r s t approximation the numerator and denominator f o r each stage was represented as an a m p l i f i e r with a gain equal to the maximum gain ( G ^ G ™ ) w i t h i n the band 0<u<u^(fig. 4 . 4). Then, i f at any p o i n t the d i g i t a l s i g n a l must be l e s s than the l a r g e s t e x p r e s s i b l e number M: w(n), y(n) < M ( 4 . 1 ) where: w(n)=cfj*x(n) ( 4 . 2 ) y(n)=GJy*w(n) (4.3) The numerator stage poses no problem, s i n c e i t i n v o l v e s only the d i f f e r e n c e of two c l o s e l y f o l l o w i n g s i g n a l s . Further i t r e p r e s e n t s a d i f f e r e n t i a t o r with a max. gain of 1/2 at 0 = 0 ^ / 2 . Hence the s c a l i n g was i n s e r t e d between the numerator and denominator stage. In the denominator stage p o t e n t i a l p o i n t s f o r overflow were a f t e r summation and a f t e r m u l t i p l i c a t i o n . The summation again was q u i t e safe s i n c e i n r e a l i t y i t c o n s i s t s of a l t e r n a t e a d d i t i o n s and s u b t r a c t i o n s and as long as the inputs were l i m i t e d so was the output. The m u l t i p l i c a t i o n i n v o l v e s known constants ( r , s ) and only the input has to be l i m i t e d . 39 Thus (with r e f e r e n c e to f i g . 4 . 5 ) : 4*y(n)*max(p,q) < M * ; ( 4 . 4 ) y(n)=x(n)*G^*c *G™ ( 4 . 5 ) c=M/[x(n)*G^*G™*max(p,q ) *4 ] ( 4 . 4 + 4 . 5 ) where: M=max. e x p r e s s i b l e number= 2 - 2 " 1 " x(n)=max. input (^max.(G(o) ); O^o^u^ r,s=denominator c o e f f i c i e n t s A s i m i l a r argument holds f o r a l l f o l l o w i n g stages ( k ) , only that the input x(n) i s a l r e a d y a t t e n u a t e d by k-1 'Di i = 1 IT «£!* c. * G':: ) ( 4 . 6 ) ^A c o r r e c t i o n f a c t o r of 4 i s r e q u i r e d because of the use of i n t e g e r m u l t i p l i c a t i o n f o r f i x e d p o i n t m u l t i p l i c a t i o n (see A r i t h m e t i c Noise) 40 w ( n ) Y(n) Fig.4.4 S i m p l i f i e d Gain Model of a Second Order F i l t e r points of overf low Fig.4.5 D e t a i l e d Model f o r S c a l i n g of a Second Order F i l t e r 41 BILIN.C To c a l c u l a t e the c o e f f i c i e n t s and s c a l i n g f a c t o r s a FORTRAN program was w r i t t e n . The program f i r s t c a l c u l a t e s the analogue c o e f f i c i e n t s f o r a second order f i l t e r from the given break f r e q u e n c i e s ( a f t e r prewarping). Using the b i l i n e a r transform the d i r e c t d i g i t a l f i l t e r c o e f f i c i e n t s are found, which are then s o l v e d f o r the zeroes and p o l e s . The zeroes and p o l e s are 'reassembled' in 2 second order stages and the maximum gain f o r each stage i s c a l c u l a t e d to f i n d the s c a l i n g f a c t o r s . The c o e f f i c i e n t s and s c a l i n g f a c t o r s are converted to b i n a r y and as a general check the f i n a l frequency response i s c a l c u l a t e d . COEFFICIENT QUANTISATION A f t e r the c o e f f i c i e n t s are expressed with a l i m i t e d word l e n g t h the s o l u t i o n of the numerator and denominator c h a r a c t e r i s t i c equation, i . e . the zeroes and p o l e s , r e s p e c t i v e l y , can only access the l o c a t i o n s given by a g r i d c o rresponding to the q u a n t i z e d v a r i a b l e s r 2 and 2 r c o s ( o ) . 2 6 The e r r o r introduced a p p l i e s only to the f i l t e r shape. I t i s q u i t e small f o r most of the region w i t h i n the u n i t c i r c l e (0.5%), but i n c r e a s e s to a p p r e c i a b l e l e v e l s i n the band c l o s e to the r e a l a x i s . ARITHMETIC NOISE The e f f e c t s of f i n i t e wordlength are most n o t i c e a b l e i n the execution of a r i t h m e t i c o p e r a t i o n s . The f i x e d - p o i n t a d d i t i o n s and s u b t r a c t i o n s are accurate as long as no over- or underflow 42 occu r s . In m u l t i p l i c a t i o n the 2N-bit product of two N - b i t numbers i s t r u n c a t e d to N b i t s . The e r r o r was evident as m u l t i p l i c a t i o n noise and i n c r e a s e d as the p o l e s approached 2 = 1 . 2 7 show that f o r a second order f i l t e r the v a r i a n c e of the e r r o r i s : 2q 2 1+b gl  12 ( ! - b ) [ ( b + l ) 2 - a 2 ] (4.7) The m u l t i p l i c a t i o n n o i s e i s compounded by an e f f e c t t h a t reduces the e f f e c t i v e wordlength by 2 b i t s . In f i x e d - p o i n t a r i t h m e t i c the bi n a r y p o i n t i s only imagined by the user, while the p r o c e s s o r a c t u a l l y processes i n t e g e r s . T h i s leads to the dis c r e p a n c y that the b i n a r y p o i n t i s assumed f i x e d r e l a t i v e to the word, but the mechanics of b i n a r y m u l t i p l i c a t i o n set the bin a r y p o i n t r e l a t i v e to the number. Thus from the m u l t i p l i c a t i o n of two r e a l numbers Rt,R^we expect the product E E=R, *R2 =I*2-b *I*2" b =1,1/2" 2 b ( f i g 4.5) yet the product returned by the processor i s P=I*I*2- b *2"" ( f i g 4.6) Hence the product returned i s too small by a f a c t o r of E/P E I I * 2 " 2 b _L - _ 2 N ' b P i i _ * 2 - b * 2 - N A3 0 0 0 0 0 0 0 0 0 0 0 0 N N 0 0 0 0 0 0 0 0 0 0 0 0 N truncate (b) F i g 4.6 I d e a l f i x e d p o i n t m u l t i p l i c a t i o n and t r u n c a t ion b 1 1 0 0 0 0 0 0 N 1 0 0 0 0 0 0 N 0 0 0 0 0 0 0 0 0 0 0 0 0 N truncate (N) error F i g 4.7 Fu l l w o r d t r u n c a t i o n i n i n t e g e r m u l t i p l i c a t i o n 44 T h i s ' i m p l i c i t d i v i s i o n ' can be c o r r e c t e d by m u l t i p l y i n g the r e s u l t by 2 , but the i n f o r m a t i o n of the N-b l e a s t s i g n i f i c a n t b i t s are l o s t and the e f f e c t i v e m u l t i p l i c a t i o n e r r o r t h e r e f o r e i n c r e a s e s to q=2" 1 2. Table 4.2 shows the m u l t i p l i c a t i o n noise fo r the v a r i o u s f i l t e r s implemented. damped • I coef f i c i e n t s n o i s e f req. r s [dB] 0.8 -1 .984795 0.985682 -37.1 1.2 -1 .973893 0.976332 -43.7 1 .6 -1 .968009 0.971518 -46.0 2.4 -1 .943436 0.953066 -52.6 3.2 -1 .930540 0.944346 -54.9 4.9 -1.872726 0.909841 -61 .2 6.4 -1.837728 0.890938 -63.6 9.8 -1.686829 0.827710 -69.7 13.0 -1.590760 0.788489 -72.0 19.9 -1.184247 0.688553 -77.3 26.3 -0.918180 0.585946 -79.4 39.9 0.065113 0.515266 -81.7 Table 4.2 M u l t i p l i c a t i o n Noise (Equation 4.7) LIMIT CYCLES A f t e r an i n i t i a l d i s t u r b a n c e f o l l o w e d by a zero input the f i l t e r s d i s p l a y e d a l a t c h i n g behaviour, which was due to t r u n c a t i o n i n the m u l t i p l i c a t i o n s and again i n c r e a s e d as the poles approached z=1. By s o l v i n g the c h a r a c t e r i s t i c equation at steady s t a t e [y(n-2)=y(n-1)=y(n)] and assuming an average q u a n t i s a t i o n of q/2, the l e v e l of the l i m i t c y c l e output ^ was determined as: y(n)=6(n)-Q[r*y(n-1)]-Q[s*y(n-2)] y(n)=[r*y(n-1)-q/2]-[s*y(n-2)-q/2] y(n)(1+r+s)=q q y = 1 1+r+s (4.8) 45 The DC l i m i t c y c l e outputs are s t a b l e with respect to the i n t r o d u c t i o n of small inputs to the f i l t e r . That i s , with small inputs the output remains e s s e n t i a l l y the same as f o r the zero input l i m i t c y c l e . As the input i s i n c r e a s e d the output remains unchanged u n t i l the i d e a l f i l t e r output approaches the magnitude of the DC l i m i t c y c l e . Above t h i s l e v e l the f i l t e r output approaches the i d e a l output more and more c l o s e l y as the e f f e c t of t r u n c a t i o n becomes r e l a t i v e l y smaller and s m a l l e r . Table 4.3 shows the c a l c u l a t e d ( q = 2 - 1 2 ) l e v e l s f o r the two stages of the implemented bandpass f i l t e r s . damped i coef f i c i e n t s c a l c f req. r s [dB] 0.8 -1 .984795 0.985682 -17. 2 1 .2 -1 .973893 0.976332 -26. 0 1 .6 -1 .968009 0.971518 -29. 2 2.4 -1 .943436 0.953066 -38. 0 3.2 -1 .930540 0.944346 -41 . 1 4.9 -1 .872726 0.909841 -49. 7 6.4 -1 .837728 0.890938 -52. 8 9.8 -1 .686829 0.827710 -61 . 3 13.0 -1 .590760 0.788489 -64. 2 19.9 -1 .184247 0.688553 -72. 3 26.3 -0 .918180 0.585946 -74. 8 39.9 0 .065113 0.515266 -82. 2 Table 4.3 C a l c u l a t e d DC L i m i t C y c l e L e v e l s (Equation 4.8) 46 5. PERFORMANCE LABORATORY TESTS No s u i t a b l e shake-table (pure, s i n u s o i d a l a c c e l e r a t i o n with constant amplitude over the range from 0.1 to 80 Hz) c o u l d be found i n the u n i v e r s i t y and the t e s t i n g had to be done i n two phases. F i r s t the d i g i t a l system (A/D, p r o c e s s o r s , DAC's and software) and the d i g i t a l f i l t e r performance were t e s t e d using a s i n u s o i d a l input from a f u n c t i o n generator. The r e s u l t s show that the performance of the ISO whole-body f i l t e r s meet the s p e c i f i c a t i o n s ( F i g . 5.1, 5.2). The octave f i l t e r s conform to the ANSI standard w i t h i n the passbands, the stopband performance however f a l l s s h o r t , e s p e c i a l l y f o r the low frequency f i l t e r s #1 to #3 ( F i g . 5.3 to 5.7). Although judged s u i t a b l e f o r f i e l d use, the f i l t e r s would have to be m o d i f i e d to give b e t t e r stopband performance. An a n a l y s i s of the noise sources i n d i c a t e d that the primary p o i n t f o r improvement were the d i g i t a l f i l t e r s (see Performance Improvements). Noise Source Magnitude Sensor (thermal noise) -88 dB rms D i f f . A m p l i f i e r (output noise) -68 dB Op Amp (output noise) -130 dB Sample/Hold ( i n j e c t i o n noise) -72 dB A/D (conversion noise) -59 dB rms D i g i t a l F i l t e r (DC L i m i t C y c l e) -17 to -82 dB DAC (conversion noise) -59 dB rms The second phase t e s t e d the complete system (accelerometer to output) at some p o s s i b l e f r e q u e n c i e s . A Scotch yoke shaking 47 apparatus was a v a i l a b l e from the UBC Mechanical E n g i n e e r i n g Department which had only one l a r g e , f i x e d displacement, r e s u l t i n g i n an e x p o n e n t i a l i n c r e a s e i n a c c e l e r a t i o n with frequency ( F i g . 5.9). I t was p o s s i b l e to use t h i s apparatus by changing the f i x e d gain of the i n s t r u m e n t a t i o n a m p l i f i e r s by a f a c t o r of 10. The r e s u l t s tended to be higher at the lower f r e q u e n c i e s than with the f u n c t i o n generator input due to the harmonic content of the shaking apparatus ( F i g . 5.11a, 5.11b). The harmonic content allowed the use of the shaker f o r q u a l i t a t i v e t e s t i n g of the f u l l system only and rendered i t i n a p p l i c a b l e f o r c a l i b r a t i o n purposes. Thus the f u l l system c o u l d not be c a l i b r a t e d and the c a l i b r a t i o n c o n s t a n t s were found from the manufacturer's s p e c i f i e d transducer s e n s i t i v i t y and the gains of the analogue a m p l i f i e r s and d i g i t a l f i l t e r s . dB dB F i g 5.4 #2 F i l t e r Response from F u n c t i o n Generator Input F i g . 5.10 #4 F i l t e r Response with Shaker Input 57 Q33 s i 1 F i g 5.11a Sample Waveform of Scotch Yoke 4Hz 8Hz 12 Hz F i g 5.11b Frequency Content of Scotch Yoke 58 PERFORMANCE IMPROVEMENT To i n v e s t i g a t e the c h a r a c t e r i s t i c s and e f f e c t s of the inher e n t , d i g i t a l n oise-sources more c l o s e l y , a s i m u l a t i o n of the a c t u a l f i x e d p o i n t a r i t h m e t i c implementation was w r i t t e n i n F o r t r a n and run on the UBC Amdahl 470 (SIMI16 and SIMI16D). The s i m u l a t i o n programs covered the f u l l d i g i t a l system i n c l u d i n g the A/D con v e r s i o n and the rms c a l c u l a t i o n . The analogue input was represented by the F o r t r a n SIN(X) f u n c t i o n . The 8 b i t A/D con v e r t e r was simulated by m u l t i p l y i n g the input by 2 8-1 and c o n v e r t i n g the r e s u l t to i n t e g e r , which r e s u l t e d i n the d e s i r e d t r u n c a t i o n . T h e r e a f t e r a l l o p e r a t i o n s were executed in the in t e g e r domain, as they would be with the a r i t h m e t i c p r o c e s s o r . The t r u n c a t i o n from m u l t i p l i c a t i o n was handled through byte e x t r a c t i o n and a l l op e r a t i o n s were checked f o r over- and underflow. The f i l t e r outputs were converted to r e a l numbers and rms values were c a l c u l a t e d . Done. The r e s u l t s ( F i g . 5.13a to 5.20a) i n d i c a t e d that the i n s u f f i c i e n t a t t e n u a t i o n o u t s i d e the passband was due to the l i m i t c y c l e behaviour of the l a s t stage. Examining the output a f t e r a one-sample impulse input showed that the output locked on to a DC l i m i t c y c l e with the steady s t a t e l e v e l c o r r e l a t e d to the d i s t a n c e of the poles from z=1 and i n c l o s e agreement with the l e v e l s c a l c u l a t e d i n the pr e v i o u s chapter (Table 5.1). 59 Damped i coef f i c i e n t s c a l c . found Freq. r s [dB] [dB] 0.8 -1.984795 0.985682 -17.2 -17.3 1 .2 -1.973893 0.976332 -26.0 -25.8 1 .6 -1.968009 0.971518 -29.2 -27.4 2.4 -1.943436 0.953066 -38.0 -37.7 3.2 -1.930540 0.944346 -41 . 1 -41 . 1 4.9 -1.872726 0.909841 -49.7 -48.2 to -51.0 6.4 -1.837728 0.890938 -52.8 -44.5 9.8 -1.686829 0.827710 -61 .3 -64.3 13.0 -1.590760 0.788489 -64.2 -66.2 19.9 -1.184247 0.688553 -72.3 -70.2 to -78.3 26.3 -0.918180 0.585946 -74.8 -78.3 39.9 0.065113 0.515266 -82.2 (-inf.) Table 5.1 C a l c u l a t e d and Measured DC L i m i t C y c l e L e v e l s Reasoning that a d i f f e r e n t i a t o r would remove any r e s i d u a l DC, the stages were rearranged i n the s i m u l a t i o n such that the l a s t stage was a numerator implementation (= d i f f e r e n t i a t o r ) . The s i m u l a t i o n with the z e r o - p o l e - p o l e - z e r o showed a marked improvement f o r the low frequency f i l t e r s ( F i g . 5.12b to 5.19b) over the p r e v i o u s implementation with a z e r o - p o l e - z e r o - p o l e order. The stopband performance of the improved s t r u c t u r e d i d not improve beyond the 50-55 dB l i m i t . I t seems that a f l o o r i s e s t a b l i s h e d by the A/D co n v e r s i o n n o i s e . The t h e o r e t i c a l l i m i t set by the A/D co n v e r t e r i s at -59 dB (rms), but i t should be kept i n mind that t h i s i s f o r u n c o r r e l a t e d , random input, an assumption which does not hol d completely f o r pure sine wave i n p u t s . F i g 5.12a Zero-Pole-Zero-Pole S t r u c t u r e F i g 5.12b Zero-Pole-Pole-Zero S t r u c t u r e dB F i g 5.14a F i l t e r #2 Z-P-Z-P F i g 5.14b F i l t e r #2 Z-P-P-Z dB 0--10-,20' -?0--AO--50-QI 02 , 1 1 — — — i — — i 1 1— 05 1 2 5 10 20 F i g 5.18a F i l t e r #6 Z-P-Z-P dB 0--10--20--30--AO--50-I 0.1 Q2 05 1 5 10 20 F i g 5.18b F i l t e r #6 Z-P-P-Z 67 FIELD TRIALS The v i b r a t i o n a n a l y z e r together with the data logger was used to o b t a i n some data under a c t u a l f i e l d c o n d i t i o n s . The complete system was i n s t a l l e d i n a Madill-044 Grapple Yarder ( F i g . 5.20, 5.21), which i s a track-mounted f o r e s t h a r v e s t i n g machine used to haul the cut and de-branched logs from the f e l l i n g s i t e to an access road. During measurements the h a r v e s t i n g machine operated w i t h i n a normal p r o d u c t i o n environment, h a u l i n g logs at the Shawnigan Logging D i v i s i o n (MacMillan B l o e d e l Ltd.) near Duncan on Vancouver I s l a n d . The h a r v e s t i n g s i t e was l o c a t e d i n a mountainous area (800-1000 m a . s . l . ) and y a r d i n g during a working s h i f t was done in both the u p h i l l and d o w n h i l l d i r e c t i o n s . The operator cab was i s o l a t e d from the tower s t r u c t u r e by a one-inch rubber mat and the operator seat had an i n t e g r a l damper-spring suspension that c o u l d be a d j u s t e d to the o p e r a t o r ' s weight by p r e - t e n s i o n i n g the s p r i n g . V i b r a t i o n measurements were taken with the sensor a t t a c h e d to the cab s t r u c t u r e ( F i g . 5.22) or to the operator seat a f t e r the suspension ( F i g . 5.23). Data was c o l l e c t e d with the ISO weighting f i l t e r s d u r i n g three f u l l working s h i f t s of 8 h r s , i n c l u d i n g a 1/2 hr r e s t p e r i o d . DATA EVALUATION The c o l l e c t e d v i b r a t i o n data showed widely v a r y i n g a c c e l e r a t i o n l e v e l s , which p e r o d i c a l l y exceeded the exposure l i m i t s v a l i d at that time. Comparing the s t r a i g h t v i b r a t i o n measurements a g a i n s t the ISO Standard exposure l i m i t s would 68 i n d i c a t e that the exposure l i m i t s have been exceeded, but t h i s does not take i n t o account the ' r e s t p e r i o d s ' of lower v i b r a t i o n l e v e l s . A b e t t e r procedure i s to convert the v a r y i n g l e v e l s to a r e f e r e n c e l e v e l and c a l c u l a t e the 'equivalent exposure time' as o u t l i n e d i n the ISO standard (paragraph 4.4.3). The procedure i s based on the assumption that a v i b r a t i o n exposure at l e v e l Aj f o r a time tj i s e q u i v a l e n t to an exposure at a s e l e c t e d r e f e r e n c e l e v e l A' f o r a time t' ; where t'=t( V<j-') and Tj" and T a r e the exposure l i m i t s v a l i d f o r the l e v e l s Aj and A', r e s p e c t i v e l y ( F i g . 5.24). For the e v a l u a t i o n of the a c q u i r e d data A' was s e l e c t e d as 0. 03g (the 8 hr exposure l i m i t ) and hence i f the t o t a l ' e q u i v a l e n t exposure time' was g r e a t e r than 8 h r s , then the operator v i b r a t i o n exposure exceeded the standard. Being e s s e n t i a l l y a weighted averaging method the 'eq u i v a l e n t exposure time' e n t a i l e d some l o s s of i n f o r m a t i o n . For i n s t a n c e , short b u r s t s of high v i b r a t i o n l e v e l s , that c o u l d exceed the standard l i m i t s , are l o s t . A second method f o r the e v a l u a t i o n was used to give a more d e t a i l e d p i c t u r e : the cumulative d i s t r i b u t i o n of the t o t a l time the measured v i b r a t i o n l e v e l exceeded a given l e v e l was c a l c u l a t e d and p l o t t e d a g a i n s t that l e v e l , together with the time l i m i t s v a l i d f o r the v i b r a t i o n l e v e l s . The data can then be e v a l u a t e d v i s u a l l y 1 . e. the cumulative exposure time should be below the exposure l i m i t s set by the ISO Standard f o r a l l l e v e l s i-f the standard i s to be f u l f i l l e d . F i g . 5.20 Madill-044 Grapple Yarder Data Logger Recording Unit •Vibration Analyzer F i g . 5.21 I n s t a l l a t i o n of the F u l l Data Acquisition System 7 0 F i g . 5.23 Attachment of the Sensor to the Seat 71 F i g 5.24 E q u i v a l e n t Exposure Times 72 RESULTS Figures 5.25a to 5.33a show the acceleration l e v e l s in the x-, y- and z-direction for each of the three days with the ISO 'fatigue decreased proficiency boundary' and exposure l i m i t s superimposed on the graphs. The 10 sec rms acceleration levels vary widely (from O.Olg to 0.l2g rms) and p e r i o d i c a l l y exceed the 8 hr exposure l i m i t . The sudden v a r i a t i o n s indicate a p o s s i b i l i t y of s i g n i f i c a n t energy contribution to the rms value from shock impulses. The results from the 'equivalent exposure time' cal c u l a t i o n s are tabulated in Table 5.2. The values from d i f f e r e n t days vary due to d i f f e r e n t machine-down times, but a l l are well below the 8 hr l i m i t . A l l values are approximately in the same range, except for the higher value from the z-direction measured at the cab, which indicates the effectiveness of the seat in that d i r e c t i o n . Date Sensor X y z Day #1 Day #2 Day #3 @ Seat @ Seat <§• Cab 168.9 171.6 17 1.4 181 .7 . 175.0 184. 1 1 66.0 1 66.6 203.7 Table 5.2 Equivalent Exposure Times [min] The cumulative d i s t r i b u t i o n of the t o t a l time the measured vib r a t i o n l e v e l exceeded a given l e v e l (Fig. 5.25b to 5.33b) shows that the exposure time i s well below both the exposure l i m i t and the fatigue decreased proficiency boundary, for a l l l e v e l s . • • A comparison of the d i s t r i b u t i o n s from measurements taken 73 at the cab and at the seat show that the seat e f f e c t i v e l y removes the low l e v e l v i b r a t i o n (0.001 to 0.005 g) i n a l l three d i r e c t i o n s . 0 3 0 6 0 90 130 150 180 2 1 0 240 2 ? 0 3 0 0 3 3 0 360 390 420 450 480 T I M E C m l n ] F i g 5.25a x-Axis V i b r a t i o n Measurement Day #1 0 Crres] F i g 5.25b x-Axis D i s t r i b u t i o n Day #1 F i g 5.26a y-Axis V i b r a t i o n Measurement Day #1 F i g 5.26b y-Axis D i s t r i b u t i o n Day #1 F i g 5.27a z-Axis V i b r a t i o n Measurement Day #1 F i g 5.27b z-Axis D i s t r i b u t i o n Day #1 0 3 0 6 0 90 120 150 180 2 1 0 240 2 ? 0 3 0 0 3 3 0 3 6 0 390 420 450 4 30 T I M E C m i n ] F i g 5.28a x-Axis V i b r a t i o n Measurement Day #2 g [rms] F i g 5.28b x-Axis D i s t r i b u t i o n Day #2 .200 r 0 3 0 6 0 90 120 15B 180 2 1 0 240 2 ? 0 3 0 0 3 3 0 3 S 0 390 420 458 480 T I M E Cmin] F i g 5.29a y-Axis V i b r a t i o n Measurement Day #2 F i g 5.29b y-Axis D i s t r i b u t i o n Day #2 F i g 5.30a z-Axis V i b r a t i o n Measurement Day #2 g [rmsD + F i g 5.30b z-Axis D i s t r i b u t i o n Day #2 F i g 5.31b x-Axis D i s t r i b u t i o n Day #3 • 2 B 0 r 0 3 0 6 0 90 120 150 160 2 10 340 2 7 0 3 0 0 3 3 0 3 6 0 390 4 2 0 4 5 6 490 T I M E Cmtn] i F i g 5.32a y-Axis V i b r a t i o n Measurement Day #3 g [rms] F i g 5.32b y-Axis D i s t r i b u t i o n Day #3 F i g 5.33a z-Axis V i b r a t i o n Measurement Day #3 F i g 5.33b z-Axis D i s t r i b u t i o n Day #3 83 6. CONCLUSION A whole-body f i l t e r , meeting the ISO 2631 whole-body f i l t e r i n g standard has been developed and t e s t e d , using d i g i t a l f i l t e r s as opposed to c u r r e n t l y a v a i l a b l e analogue f i l t e r systems. The advantages of d i g i t a l p r o c e s s i n g are that i t can be l e s s expensive to manufacture and i s s m a l l e r i n s i z e . The present implementation has a l s o the f l e x i b i l i t y of being programmable and the system can be changed as the standard i s m o d i f i e d as a r e s u l t of ongoing r e s e a r c h . The system was t e s t e d i n the l a b o r a t o r y and a p p l i e d under a c t u a l f i e l d c o n d i t i o n s i n a p r o d u c t i o n environment; and i t demonstrated i t s u s e f u l n e s s as a r e s e a r c h t o o l f o r whole-body v i b r a t i o n measurements in c o n j u n c t i o n with the r e c o r d i n g of other ergonomic v a r i a b l e s . Since the f u l l system i s s e l f -c o n t a i n e d , i t i s s u i t a b l e f o r measurements on moving v e h i c l e s and e l i m i n a t e s the need f o r expensive telemetry l i n k s . The same system c o u l d as e a s i l y be used 'stand alone' f o r long-term ' i n d u s t r i a l h e a l t h ' m o n i t o r i n g . The r e s u l t s obtained d u r i n g the i n i t i a l f i e l d work showed three r e s u l t s . F i r s t , on the p a r t i c u l a r machine i n v e s t i g a t e d , the operator v i b r a t i o n exposure i s w e l l below the l e v e l s allowed by the I n t e r n a t i o n a l Standard. Secondly, the r e s u l t s a l s o showed that the seat a t t enuates the v i b r a t i o n l e v e l s along the z - a x i s . F i n a l l y , the sudden v a r i a t i o n s i n the measured rms v i b r a t i o n l e v e l s (and observed shock behaviour i n the f i e l d ) i n d i c a t e a l a r g e c o n t r i b u t i o n from shock impulses (high c r e s t f a c t o r ) , which may i n themselves play an important r o l e as s t r e s s inducing f a c t o r s . The ISO Standard i s v a l i d only f o r c r e s t 84 f a c t o r s of l e s s than 3 and, i n the instance of heavy equipment operator exposure i n f o r e s t h a r v e s t i n g , the problem i s o u t s i d e the scope of the standard. The problem of the e x i s t i n g rms method showing ' l e t h a l a c c e l e r a t i o n s from shock impulses as p e r f e c t l y safe (and v i c e v e r s a ) ' has appeared i n the case of high speed boat t r a v e l and a l t e r n a t e e v a l u a t i o n s have been proposed 2 8 . An estimate of the DC l i m i t c y c l e (zero order) was c a l c u l a t e d and a technique was found to minimize i t by p o l e - z e r o r e o r d e r i n g . I t was found that f o r p r a c t i c a l purposes the lowest break frequency should exceed 20% of the Nyquist frequency. FUTURE WORK AND RECOMMENDATIONS There are a number of ongoing i n v e s t i g a t i o n s using the v i b r a t i o n a n a l y z e r . These w i l l be reported i n an forth-coming Ph.D. T h e s i s 5 and i n c l u d e : - Measurements under d i f f e r e n t working c o n d i t i o n s , such as d i f f e r e n t o p e r a t o r s , v e h i c l e s and t e r r a i n s . - Examination of the v i b r a t i o n l e v e l d i s t r i b u t i o n i n r e l a t i o n to the work c y c l e . - I n v e s t i g a t i o n of the c o r r e l a t i o n between v i b r a t i o n l e v e l s and m a i n - l i n e cable t e n s i o n . A l s o the v i b r a t i o n w i t h i n the octave bands can be evaluated, using the system, to p i n p o i n t the e f f e c t i v e n e s s of the seat with regard to a t t e n u a t i o n . M o d i f i c a t i o n s to the present system are recommended to in c o r p o r a t e aspects of o n - s i t e v i b r a t i o n a n a l y s i s which came to l i g h t d u r i n g the development and e v a l u a t i o n of the system: 85 - Recording of peak v i b r a t i o n l e v e l s : measurement of the peak values would allow an i n v e s t i g a t o r to decide i f the problem of operator v i b r a t i o n exposure in f o r e s t h a r v e s t i n g i s r e a l l y one of whole-body v i b r a t i o n , or i f i t r e l a t e s more to the f i e l d of shock measurements. - Use of p i e z o e l e c t r i c i n s t e a d of s t r a i n gage tran s d u c e r s ( s u b j e c t to the a v a i l a b i l i t y of a sensor with s u f f i c i e n t l y low frequency response), which, having a l a r g e r dynamic range, w i l l accommodate high, t r a n s i e n t peak valu e s without c l i p p i n g . - D i s p l a y of input peak l e v e l s together with v a r i a b l e gains f o r the p r e a m p l i f i e r s to monitor the inputs while o n - s i t e and to a d j u s t the gains a c c o r d i n g l y . T h i s would allow to a t t a i n the best p o s s i b l e S/N r a t i o s under d i f f e r e n t measurement c o n d i t i o n s . A l a r g e p r o p o r t i o n of processor time i s used fo r data h a n d l i n g ; w i t h i n a second order f i l t e r s e c t i o n about 35% of a l l i n s t r u c t i o n s are r e l a t e d to the delay s h i f t s and 25% to moving data to and from the A/D and APU. A r e - d e s i g n would p o s s i b l y be based on d e v i c e s which have become commercially a v a i l a b l e s i n c e the i n c e p t i o n of t h i s p r o j e c t , such as d e d i c a t e d s i g n a l processor (INTEL 2920), which would a v o i d the problem of time consuming I/O and memory r e f e r e n c e o p e r a t i o n s . Another approach c o u l d be the use of a 'switched c a p a c i t o r ' d e v i c e . Other improvements c o u l d be the a d d i t i o n of a r e a l time c l o c k and automatic shut-down for week-long, unattended o p e r a t i o n . 86 7. REFERENCES 1 P.L. C o t t e l l and P.D. Lawrence E l e c t r o n i c Datalogger f o r Man-Machine Studi e s i n F o r e s t r y A paper presented at the Annual Meeting of the Human F a c t o r s A s s o c i a t i o n of Canada at Lake of Bays, O n t a r i o , Sep. 1980. Human F a c t o r s A s s o c i a t i o n of Canada,1980 2 K. Hu s c r o f t F o r e s t H a r v e s t i n g Operations Data Logger I n t e r n a l Report Dept. of E l e c . E n g i n e e r i n g U n i v e r s i t y of B r i t i s h Columbia, 1979 3 ISO 2631-1978 Guide f o r the E v a l u a t i o n of Human Exposure to Whole-body V i b r a t i o n I n t e r n a t i o n a l Standards O r g a n i s a t i o n , Geneva, 1978 • VDI 2057 B e u r t e i l u n g der Einwirkung mechanischer Schwingungen auf den Menschen DIN V e r z e i c h n i s , Normen und Normentwuerfe Beuth V e r l a g GmbH, B e r l i n , 1976 5 A. De Souza Study of Production and Ergonomic F a c t o r s i n Grapple Yarding Operations using a Data Logger System Ph. D. T h e s i s ( i n progress) F a c u l t y of F o r e s t r y , U n i v e r s i t y of B r i t i s h Columbia 6 C. Zenz O c c u p a t i o n a l Medicine Yearbook Medical P u b l i s h e r s , Chicago, 1975 [WA 400 023; Woodw] 7 T.P. Asanova C l i n i c a l Aspects of V i b r a t i o n Diseases V i b r a t i o n and Work Proc. of the F i n n i s h - S o v i e t - S c a n d i n a v i a n V i b r a t i o n Symposium, 1 975 I n s t , of Occupa t i o n a l H e a l t h , H e l s i n k i , 1976 8 R.R. Coermann The Mechanical Impedance of the Human Body i n S i t t i n g and Standing P o s i t i o n at Low Frequencies Human F a c t o r s 4:227,1962 [BF1 H8; Main] 9 D. Dieckmann Mechanische Modelle fuer den schwingenden menschlichen Koerper I n t . Z e i t s c h r i f t fuer angew. P h y s i o l o g i e 17:67,1958 [QP1 168; Woodw] 87 1 0 C. H a r r i s and C. Crede Shock and V i b r a t i o n Handbook McGraw-Hill, 1976 [TA355 H35; MechR] 1 1 D.E. Wasserman et a l . Whole-body V i b r a t i o n Exposure of Workers d u r i n g Heavy Equipment Operat ion US Dept. of Health, Education and Welfare, C i n c i n n a t i , 1978 1 2 L. S j ^ f i o t Measuring and E v a l u a t i n g Low Frequency V i b r a t i o n s A c t i n g on Machine Operators i n A c r i c u l t u r e and F o r e s t r y Report No. 19 Norwegian I n s t i t u t e of A g r i c u l t u r a l E n g i n e e r i n g , A, 1970 1 3 i b i d Some Methods and R e s u l t s from T r a c t o r V i b r a t i o n S t u d i e s Methods i n Ergonomic Research i n F o r e s t r y INFRO D i v i s i o n 3, Publ. No. 2, 1973 1• M.G. Mowat Exposure of Front-end Log Loader Operators to Whole-body V i b r a t ion FERIC Tech. Note TN 25, December 1978 1 5 H. Dupuis Human Exposure to Whole-body V i b r a t i o n i n M i l i t a r y V e h i c l e s and E v a l u a t i o n by A p p l i c a t i o n of ISO 2631 AGARD (NATO) Conference Proceedings No. 145 on V i b r a t i o n and Combined S t r e s s e s i n Anvanced Systems, Oslo, A p r i l 1974 [WD735 N67; WCB] 1 6 C.F. Knapp Models of the C a r d i o v a s c u l a r System under Whole Body V i b r a t i o n S t r e s s AGARD (NATO) Conference Proceedings No. 145 on V i b r a t i o n and Combined S t r e s s e s in Anvanced Systems, Oslo, A p r i l 1974 1 7 G.R. Sharp The R e s p i r a t o r y and Metabol i c E f f e c t s of Constant Amplidude Whole-body V i b r a t i o n i n Man AGARD (NATO), Oslo, 1976 1 8 Report of Working Group 79 The E f f e c t s of Whole-body V i b r a t i o n on Health N a t i o n a l Academy of Science, Washington DC, 1979 1 9 T.H. M i l b y et a l . R e l a t i o n s h i p s between Whole-body V i b r a t i o n and M o r b i d i t y P a t t e r s among Heavy Equipment Operators NIOSH, 1974 88 2 0 R.C. Spear M o r b i d i t y S t u d i e s of Workers exposed to Whole-body V i b r a t i o n A r c h i v e s of Environmental Health ( C a l i f o r n i a ) , May 1976 2 1 R.C. Spear et a l . M o r b i d i t y P a t t e r n s among Heavy Equipment Operators exposed to Whole-body V i b r a t i o n (Follow-up Study to 1") NIOSH, 1975 2 2 D.E. Wasserman et a l . V i b r a t i o n and i t s R e l a t i o n to Oc c u p a t i o n a l H e a l t h and Safety B u l l e t i n of the New York Academy of Medicine, V o l 49, Oct 1973 2 3 E d i t o r i a l Whole-Body V i b r a t i o n The Lancet, May 1977 2 W ANSI SI.11-1966 Octave, H a l f - o c t a v e and T h i r d - o c t a v e F i l t e r Sets American N a t i o n a l Standards I n s t i t u t e , Inc., 1979 2 5 K. S t e i g l i t z The Equivalence of D i g i t a l and Analog S i g n a l P r o c e s s i n g Information C o n t r o l , Vol.8, pp. 455-467, 1965 2 6 0. Herrmann On the Accuracy Problem i n the Design of Non-recursive D i g i t a l F i l t e r s D i g i t a l S i g n a l P r o c e s s i n g , IEEE Press, pp. 385-386,1972 2 7 A. Oppenheim and R.W. Shaefer D i g i t a l S i g n a l P r o c e s s i n g P r e n t i c e - H a l l , p. 246, 1975 2 8 P.R. Payne Method to Q u a n t i f y Ride Comfort and Allowable A c c e l e r a t i o n s A v i a t i o n , Space, and Environmental Medicine, 49(1), pp 262-269, Jan 1978 APPENDIX A HARDWARE 90 Layout [DRWG #13 CHIP # PART # FUNCTIONS SOURCE I 1 D i s c r e t e - -12 LH0038CD D i f f . Amp NS 13 LH0038CD D i f f . Amp NS 14 LH0038CD D i f f. Amp NS 15 LM324 Op-Amp NS 16 LM324 Op-Amp NS 17(D) D i s c r e t e - -I8(D1) D i s c r e t e - -I9(D2) D i s c r e t e — — 110 IH5111-JE S/H I n t e r s i l I 1 1 IH5111-JE S/H I n t e r s i l 112 IH5111-JE S/H I n t e r s i l I 1 3 HD14011-BP Quad (2)NAND H i t a c h i 114 HD14016-BP Hex I n v e r t e r H i t a c h i I 1 5 MC14023-BC T r i (3)Nand Motorola I 1 6 AD0808-CCN A/D Converter NS 117 MC14020B-PC F r e q . D i v i d e r F a i r c h i l d 118 MC14520 CP Di v i d e by N Motorola 119 MC14001B-CP Quad (2)NOR Motorola 120 MC14504B-CP L e v e l s h i f t Motorola 121 D271 6 EPROM(2K) INTEL 122 MC14528B-CP Dual One-shot Motorola 123 MC14584B-CP Schmitt T r i g g e r Motorola 124 D i s c r e t e - -125 CD4012-BE Dual (4)NAND RCA 126 D i s c r e t e - -127 CD4012-BE Dual (4)NAND RCA 128 AM9511-1DC A r i t h . P r o c . U n i t AMD 129 — Spare — 130 CDP1802-D CPU RCA 131 CD4042-BE Quad Latch RCA 132 HD14011-BP Quad (2)NAND H i t a c h i 134 MWS5101-DL RAM RCA 135 MWS5101-DL RAM RCA 136 MCI4028-CP Port S e l e c t Motorola 137 MWS5101-DL RAM RCA 138 MWS5.101-DL RAM RCA 139 AD558KN DAC Analog Devices 140 AD558KN DAC Analog Devices 141 AD558KN DAC Analog Devices 142 UA7805 +5V Regulator F a i r c h i l d 143 UA7810 +10V Regulator F a i r c h i l d 145 D i s c r e t e - -42 A3 DRWG #1 Layout 92 Analogue Inputs and S i g n a l C o n d i t i o n i n g [DRWG #2; #2A] The a c c e l e r a t i o n i s measured with a t r i a x i a l accelerometer (KYOWA AS-TB, lOg). The sensor c o n s i s t s of 3 l i n e a r t r a n s d u c e r s arranged o r t h o g o n a l l y . The s t r a i n gage based t r a n s d u c e r s convert the v i b r a t i o n / a c c e l e r a t i o n i n t o a p r o p o r t i o n a l e l e c t r i c a l s i g n a l . Each of the three transducer outputs has i t s own s i g n a l c o n d i t i o n i n g c i r c u i t up to the A/D converter a f t e r which p o i n t the s i g n a l s are m u l t i p l e x e d . The transducer outputs are AC-coupled to a d i f f e r e n t i a l i n s t r u m e n t a t i o n a m p l i f i e r with a f i x e d gain of 2000. The AC-c o u p l i n g i s necessary to e l i m i n a t e output due to g r a v i t y . The p r e - a m p l i f i e d s i g n a l i s band l i m i t e d to the Nyquist frequency (80 Hz) with a 3rd order Butterworth f i l t e r . The f i l t e r i s implemented i n two stages, where the f i r s t order stage a l s o i n c l u d e s an o f f s e t input to o f f s e t the s i g n a l by 2.5 v o l t s for the u n i p o l a r A/D c o n v e r t e r . DRWG # 2 A Transducers 95 Analogue to D i g i t a l Conversion [DRWG #3; #4] The sample and h o l d f o r each channel i s c o n t r o l l e d by a sample c l o c k pulse (SCLK) which i s d e r i v e d d i r e c t l y from the system c l o c k . On the p o s i t i v e going edge the analogue s i g n a l s are sampled and l a t c h e d at the negative edge of the p u l s e . The sampled s i g n a l s are converted with an 8 - b i t A/D c o n v e r t e r , which c o n t a i n s an i n t e g r a l 8 channel m u l t i p l e x e r . The a p p r o p r i a t e channel i s s e l e c t e d under CPU c o n t r o l from the data l i n e s D0-D2, which are l a t c h e d i n t o the channel s e l e c t r e g i s t e r through the ALE p u l s e . The ALE pulse i s decoded from the N - l i n e s (OUT CHANL) and gated with the TPB pulse f o r proper t i m i n g . The s e r i a l data l i n e (Q) c o n t r o l s the s t a r t of the c o n v e r s i o n . Conversion takes up to 100 micro-sec, a f t e r which time the converted value i s ready i n the data r e g i s t e r . The data i s t r a n s f e r r e d to memory through INP DATA, which decoded as SEL4 enables the A/D t r i - s t a t e d r i v e r s . pi-z) (svt)-L •»| 7-n 7 J 2 xsn Ui-zc) -t/f -ri ft" _ ->r 2f» L -If 2,-SJ: J'J>-DRWG #3 Sample and Hold cn 136-1} (M-W • f p * 2 t ZC / — — — *•$» I* Z-SH It 1 7 0&-O SoaHx. lo raisr aw b a. JM>A AW* VOL-»» If Di 23 Ate l i t EX Lib 7 • T»o n J» • * , if Ti 1 if A K • » s T it 3y A Ii 3 V 2t> Jfr - CUL use. V 6*& ty Kl-t) (Zi-zo) (21-H? tw-/*••> "77777-DRWG #4 A/D Conversion ^1 98 C e n t r a l Processor [DRWG #5] The c o n t r o l of data and program flow i s handled by a CD1802E microprocessor . Within i t s a r c h i t e c t u r e the user can access and modify 16 general r e g i s t e r s (16 b i t ) each of which can be desig n a t e d as index r e g i s t e r or program counter, an 8 b i t accumulator, a F l i p - F l o p (Q) to c o n t r o l a s e r i a l output l i n e , and an i n t e r r u p t - e n a b l e F l i p - F l o p . To a c e r t a i n extent the tim i n g can be c o n t r o l l e d , s i n c e the f u l l o p e r a t i o n of the CPU can be suspended and resumed to w i t h i n a c l o c k c y c l e . To i n t e r f a c e with e x t e r n a l systems the f o l l o w i n g l i n e s are a v a i l a b l e : 8 Data L i n e s (D0-D7) An 8 b i t b i - d i r e c t i o n a l data bus. These l i n e s are used f o r data t r a n s f e r between the memory, the processor and the I/O d e v i c e s . 8 Addresss L i n e s (A0-A7) The higher order byte of a 16 b i t memory address appears on the address bus f i r s t . The b i t s r e q u i r e d f o r the memory space are s t r o b e d i n t o an e x t e r n a l address l a t c h by the t i m i n g p u l s e TPA. The lower order byte i s then presented a f t e r negation of TPA. Using a l l e i g h t high order address b i t s a l l o w s a d d r e s s i n g of up to 65K bytes. I/O S e l e c t i o n L i n e s (N0 -N2 ) These l i n e s allow the s e l e c t i o n of up to 7 I/O d e v i c e s . The N - l i n e s are low u n t i l an I/O i n s t r u c t i o n i s executed, at which time they r e f l e c t i n b i n a r y form the numerical operand of the I/O i n s t r u c t i o n ( i . e . INP 3, OUT 7). The d i r e c t i o n of the data flow i s i n d i c a t e d by the MRD l i n e . E x t e r n a l F l a g s (EF1-EF4) The four l i n e s are intended f o r e x t e r n a l s t a t u s - or c o n t r o l i n p u t s . The i n s t r u c t i o n set i n c l u d e s c o n d i t i o n a l branches depending on the s t a t u s of the l i n e s . The l i n e s are a c t i v e low and are i n t e r n a l l y i n v e r t e d , i . e . BN3 w i l l cause the program to branch i f the E F 3 - l i n e i s high. Timing Pulses (TPA,TPB) P o s i t i v e p u l s e s that occur every machine c y c l e . They are used to time the i n t e r a c t i o n with the data- and address bus. TPA s i g n a l s that the high order byte i s a v a i l a b l e on the address bus. During TPB high, data i s t r a n s f e r r e d from the data bus to the CPU. 99 Memory Write (MWR) During execution of a memory-write or output i n s t r u c t i o n , a f t e r the address l i n e s have s t a b i l i z e d , a negative pulse on the MWR-l i n e i s used to l a t c h data from the data bus i n t o memory or the s e l e c t e d d e v ice r e g i s t e r Memory Read (MRD) MRD goes low during a memory read c y c l e , i t a l s o i n d i c a t e s the d i r e c t i o n of the data t r a n s f e r d u r i n g I/O i n s t r u c t i o n s : MRD=0: Data from I/O to CPU and memory MRD=1: Data from memory to I/O It should be noted that the MRD-line i s always high d u r i n g the f i r s t 2 c l o c k p e r i o d s of an execute c y c l e , which can l e a d to g l i t c h e s . S e r i a l output (Q) A s i n g l e b i t output that can be set and re s e t under software c o n t r o l . The s t a t e t r a n s i t i o n occurs about halfway d u r i n g the execute c y c l e . S tate Codes (SC0,SC1) The l i n e s i n d i c a t e i n what s t a t e ( c y c l e ) the processor i s ope r a t i n g Cycle SCO SC1 Fetch(SO) 0 0 Execute(S1) 0 1 DMA(S2) 1 0 Interupt(S3) 1 1 C o n t r o l (WAIT,CLR) The l i n e s p r ovide 4 modes to c o n t r o l the CPU o p e r a t i o n : CLEAR WAIT Mode 1 1 Run 1 0 Pause 1 0 Reset 0 0 Load *Reset: R e g i s t e r s I and N and the Q f l i p - f l o p are r e s e t , i n t e r r u p t i s enabled and a l l O's are put on the data bus. A f t e r l e a v i n g the res e t mode, the f i r s t machine c y c l e i s an i n i t i a l i s a t i o n c y c l e , d u r i n g which the CPU remains i n a S1 s t a t e and X, P and RO are set to 0. I n t e r r u p t s and DMA requests are suppressed. The next c y c l e i s SO i f no DMA requests are pending. *Pause: A l l i n t e r n a l CPU o p e r a t i o n s are suspended, but the c l o c k continues to run. *Run: The run mode can be entered e i t h e r from the pause or wait mode. If i n i t i a t e d from pause the CPU resumes o p e r a t i o n on 100 the f i r s t h i - l o t r a n s i t i o n of the c l o c k . From the r e s e t mode the f i r s t c y c l e w i l l be an i n i t i a l i s a t i o n c y c l e , f o l l o w e d by a DMA c y c l e or a f e t c h from l o c a t i o n OOOO(HEX). *Load: The CPU i s h e l d i n an IDL execute loop and allows an I/O device to l o a d memory. Asynchronous I/O (INT, DMA-IN, DMA-OUT) A s s e r t i o n of e i t h e r l i n e w i l l cause the CPU to enter S2 or S3 s t a t e upon execution of the present i n s t r u c t i o n . * I n t e r r u p t : X and P (the index and program counter d e s i g n a t o r s ) are s t o r e d in T; X and P are then set to 2 and 1, r e s p e c t i v e l y . Further i n t e r r u p t s are d i s a b l e d (IE=0) and the next i n s t r u c t i o n i s f e t c h e d from M[R1]. *DMA: A f t e r f i n i s h i n g the c u r r e n t i n s t r u c t i o n , data i s t r a n s f e r r e d between the bus and the memory l o c a t i o n p o i n t e d to by RO, then RO i s incremented. The p r i o r i t i e s f o r simultaneous requests are i n d e c r e a s i n g order: DMA-IN, DMA-OUT, i n t e r r u p t . Address- and I/O Decode Four of the 8 high order address b i t s (PA0-PA3) are d e m u l t i p l e x e d with the TPA pulse i n t o a quad D-type r e g i s t e r [1-31] r e s u l t i n g i n address b i t s A8-A11. The usable address space of 2048 bytes c o n t r o l the data access i n the EPROM and RAM. Bytes Type S t a r t End 00 - 511 ROM 0000 01FF 512 - 1024 ROM 0200 03FF 1024 - 1535 ROM 0400 06FF 1536 - 2047 ROM 0600 07FF 2048 - 2559 RAM 0800 09FF Table 2 Memory Map The three I/O l i n e s N0-N2 are decoded in a binary-to-BCD decoder, g i v i n g the device c o n t r o l l i n e s SEL1 to SEL7. The s e l e c t l i n e s are used to enable, together with MRD and MWR the a p p r o p r i a t e I/O d e v i c e d u r i n g execution of an INP or OUT i n s t r u c t i o n . 101 Port F u n c t i o n Mnemonic 0 i l l e g a l ; q uiescent s t a t e -1 not used INP 1 2 not used INP 2 3 not used INP 3 4 enable converted data to bus INP DATA 5 not used INP 5 6 r e t r i e v e r e s u l t s from APU INP APU 7 read APU st a t u s INP CMND 0 i l l e g a l ; q uiescent s t a t e -1 s e l e c t 1st DAC OUT DAC 1 2 s e l e c t 2nd DAC OUT DAC 2 3 s e l e c t 2rd DAC OUT DAC 3 4 not used OUT 4 5 s e l e c t 1 of 8 A/D Channels OUT CHANL 6 load data onto APU stack OUT APU 7 is s u e APU command OUT CMND Table 3 I/O Port Assignments The wait l i n e i s c o n t r o l l e d by a s i n g l e - s t e p c i r c u i t and the PAUSE l i n e from the APU. A pulse from the s i n g l e step button r i p p l e s through two f l i p - f l o p ' s , p u t t i n g the CPU i n t o run mode. The TPB pulse at the end of an i n s t r u c t i o n r e s e t s the second f l i p - f l o p , which i n turn negates the wait l i n e and causes the CPU to suspend execution without stopping the c l o c k . The CPU i s d r i v e n by a 4 MHz c l o c k , which r e s u l t s i n an i n s t r u c t i o n c y c l e of 4 micro-seconds (6 micro-seconds f o r long branches and NOP's). A pulse d e r i v e d from the processor c l o c k (see Clock C i r c u i t ) d r i v e s the i n t e r r u p t l i n e and p r o v i d e s the exact s y n c h r o n i s a t i o n of the program execution to the sampling frequency. The Q - l i n e i s t i e d to the START pin of the A/D co n v e r t e r and i s used to i n i t i a t e the c o n v e r s i o n . It.-I* m 1 At te <**-»»> s J e t * r* tex.i Z » J ' S*d.<l t SuC » * «*» <»-») DRWG #5 C e n t r a l P r o c e s s i n g U n i t o to 1 03 The A r i t h m e t i c P r o c e s s i n g U n i t (APU) [DRWG #6] A l l a r i t h m e t i c o p e r a t i o n s are handled by a AM9511A A r i t h m e t i c P r o c e s s i n g U n i t (APU). The stack o r i e n t e d processor executes 16 b i t and 32 b i t i n t e g e r s and 32 b i t f l o a t i n g p o i n t numbers depending on the i n s t r u c t i o n s . The data i s loaded, i n bytes over an 8 b i t data bus, d i r e c t l y onto the stack. The r e s u l t of the l a s t o p e r a t i o n i s a v a i l a b l e on top of the stack. The data stack i s 8 words deep f o r 16 b i t i n t e g e r s and 4 words f o r 32 b i t i n t e g e r s and f l o a t i n g p o i n t numbers. By p l a c i n g the operands i n the proper sequence, the proce s s o r can execute m u l t i p l e operand o p e r a t i o n s ( l i m i t e d to the depth of the stack) a c c o r d i n g to the r u l e s of reverse p o l i s h n o t a t i o n . The APU i s c o n f i g u r e d as an I/O device with the command/status r e g i s t e r and the data stack accessed as two separate p o r t s . The data i s entered i n bytes over an 8 b i t data bus, with the l e a s t s i g n i f i c a n t byte entered f i r s t . The i n s t r u c t i o n OUT APU w i l l s e l e c t the c h i p and enable the data r e g i s t e r (C/D low). The data i s then c l o c k e d with the shortened MRD pulse (SHMRD) i n t o the r e g i s t e r . A f t e r the operands are loaded the a r i t h m e t i c o p e r a t i o n i s i n i t i a t e d with an OUT CMND, which w i l l t r a n s f e r the a p p r o p r i a t e command to the command r e g i s t e r (C/D h i g h ) . THE APU i s d r i v e n by a 2MHz c l o c k r e s u l t i n g i n the f o l l o w i n g execution times: Mnemonic and Fun c t i o n Time (usee) FIXMULLO: l o byte of i n t e g e r m u l t i p l i c a t i o n 42-47 FIXMULHI: h i - b y t e of i n t e g e r m u l t i p l i c a t i o n 40-48 FIXADD: i n t e g e r a d d i t i o n 8-9 104 FIXSUB: i n t e g e r s u b t r a c t i o n 15-16 FIXFLT: convert i n t e g e r to f l o a t i n g p o i n t 31-78 FIXCOPY: d u p l i c a t e top of stack ( i n t e g e r ) 8 FLTMUL: m u l t i p l y f l o a t i n g p o i n t 73-82 FLTADD: add f l o a t i n g p o i n t 27-184 FLTDIV: f l o a t i n g p o i n t d i v i s i o n 77-92 FLTCOPY: d u p l i c a t e top of stack (f.p.) 10 SQRT: f l o a t i n g p o i n t square root 391-435 FLTFIX: convert f l o a t i n g p o i n t to i n t e g e r 45-107 No p a r a l l e l p r o c e s s i n g c a p a b i l i t i e s are p r o v i d e d , s i n c e i n most cases the r e s u l t s from the APU are immediately needed as inputs to the next o p e r a t i o n . For o p e r a t i o n s , where the time f o r an a r i t h m e t i c o p e r a t i o n exceeds the CPU i n s t r u c t i o n c y c l e time, the CPU execution i s suspended. The suspension of the CPU i s under hardware c o n t r o l from the APU (PAUSE). T h i s makes the o p e r a t i o n of the APU completely t r a n s p a r e n t and the time d i f f e r e n c e between a CPU and an APU execution c y c l e can be ignored i n the software. AcUK (ti- »•) -'T) -IV- »»)• <*-'*> /A /2 an 1 T A X2g 18 OK. PAUSE v.Ese.r  \22~~ Zl ze> IS CS k _ J L T P S -carl*; DRWG #6 Ari t h m e t i c Processing Unit (APU) 106 Clock C i r c u i t [DRWG #7] The processor c l o c k , which i s d e r i v e d from a 4 MHz c r y s t a l , i s d i v i d e d down to give the proper c l o c k s i g n a l s f o r the APU, the A/D co n v e r t e r and the ti m i n g f o r the i n t e r r u p t and S/H p u l s e . The APU c l o c k i s obtained by a simple d i v i s i o n by 2. A f u r t h e r d i v i s i o n by 8 g i v e s the A/D c l o c k of 500 KHz. The S/H and i n t e r r u p t pulse are c r e a t e d by a " d i v i d e by 2 1 3 " , f o l l o w e d by a "modulo 3" counter; the r e s u l t i n g frequency i s 4 MHz/(2 1 3*3)=162.76 Hz. An 8 micro-second one-shot i s i n s e r t e d i n t o the SCLK l i n e to g i v e the needed pulse width and p o l a r i t y . *£</ *fr tTAC US-2V +1* Ui 0, em 0<L I" u r Ol J/8 3 / « < b I 1 f*>k»t 1 r ZfOkJh. 6 xsr DRWG #7 Clock C i r c u i t 108 Memory [DRWG #8] The addressable memory space c o n s i s t s of 2048 bytes of EPROM and 256 bytes of RAM. The 2K EPROM (121) holds the program and the f i l t e r c o e f f i c i e n t s . A11 A10 s e l e c t s the c h i p and AO to A9 access a byte w i t h i n the ROM. For the v a r i a b l e s , 516 bytes of RAM (1-34 to 1-37) are implemented with four 256 by 4 b i t c h i p s . A11 A8 addresses the lower 256 bytes (2 c h i p s i n p a r a l l e l ) , while A11 A8 addresses the upper 256 bytes. The data i s c l o c k e d i n t o the memory by MWR going low; the reading of data i s enabled by the MRD l i n e . (CM 2±- 1111 s\ >J »1 ni al iw *A n\ JL ex.1 upnvt 'At*. LT _u_ L T 3< Ob*?. h . . i n »l al al « U I ( J M ) 4r * T'8 <9 *l *l "\a\a\^\"] /*\ DRWG #8 Random Access Memory 4Sr <M-<«3 L ' DRWG #8A Read Only Memory 111 D i g i t a l to Analogue Conversion [DRWG #9] Each of the three channels has i t s own DAC (139-141) to i n t e r f a c e with the data logger. A converter i s s e l e c t e d by the a p p r o p r i a t e s e l e c t l i n e (SEL1,SEL2,SEL3) and the value i s c l o c k e d i n with the TPB p u l s e . The corresponding analogue value i s almost immediately (20 nsec) a v a i l a b l e . The DAC's c o n t a i n an i n t e g r a l output d r i v e r and connect d i r e c t l y to the output connectors. (it-*) TP/i lf-12) -lO -(to-io) • {*>-*) Sen •flV Sett a if 0.1/if Hi— . MSB DRWG #9 D i g i t a l to Analogue Conversion NJ 1 1 3 F u n c t i o n S e l e c t i o n [DRWG #10] The e x t e r n a l f l a g s EF1-EF3 are c o n t r o l l e d by a r o t a r y switch, whose 8 p o s i t i o n s are b i n a r y encoded [127]. The e x t e r n a l f l a g i n puts are then software decoded and used f o r the s e l e c t i o n of the d i f f e r e n t f i l t e r s . 1 I 7*7T BXT. SW" MS Mi Hi. £ 2 0 2ifc j i 22 k i£j_G J 13 BfZ *F3 DRWG #10 Function S e l e c t i o n 115 SOFTWARE The program implements the f i l t e r s i n s e q u e n t i a l order ( x , y , z ) . Due to the long c o n v e r s i o n time (100 usee), the analogue to d i g i t a l c o n v e r s i o n runs concurrent with the program e x e c u t i o n and the c o n v e r s i o n f o r the next channel i s always i n i t i a l i z e d at the beginning of a f i l t e r sequence. By the time the c a l c u l a t i o n s f o r the present channel are executed, the conver t e d value i s ready f o r the f o l l o w i n g channel ( f i g . 1). Sample Pulse A/D Conversion Program F i g 1 A/D and Program S y n c h r o n i z a t i o n For most e f f i c i e n t use of the i n s t r u c t i o n set and the 16 b i t memory address r e g i s t e r s , the data (delayed samples, c o e f f i c i e n t s and APU commands) are s t o r e d in contiguous b l o c k s . The data can then be accessed through d e d i c a t e d p o i n t e r s using the i n d i r e c t , auto-increment memory r e f e r e n c e and I/O i n s t r u c t i o n s . At i n i t i a l i z a t i o n , the program s t a r t s at memory l o c a t i o n 0000 and the f i r s t i n s t r u c t i o n d i s a b l e s the i n t e r r u p t with a 'fake r e t u r n ' . Then the workspace i n RAM i s c l e a r e d and the 1 16 p o i n t e r s common to a l l f i l t e r s are s e t . A b i n a r y t r e e (with input from the e x t e r n a l f l a g s ) i s t r a v e l l e d , which determines the f i l t e r s e l e c t e d and se t s the c o e f f i c i e n t p o i n t e r (R6) to the f i r s t c o e f f i c i e n t of the a p p r o p r i a t e c o e f f i c i e n t b l ock ( f i g . 2 ) . EF3 EF2 EF2 EF 1 EF1 EF1 EF 1 °/\ °l\ ° | \ ° l \ CHECK #6 #5 #4 #3 #2 #1 ISO F i g 2 F i l t e r S e l e c t i o n Tree In case 'CHECK' i s s e l e c t e d (EF1-EF3=111) the program runs a small r o u t i n e , which puts the va l u e s from the A/D s t r a i g h t through to the DAC's and branches back to the s t a r t . T h i s allows the checking of the sensors and the o f f s e t adjustments of the input a m p l i f i e r s . The f i l t e r i n g program proper reads the data from the A/D (INP DATA) and s t o r e s i t i n memory f o r the d e l a y - s h i f t s and the D - r e g i s t e r . From the r e g i s t e r the value i s loaded on to the APU stack (OUT APU). Then the x(n-2) value i s a l s o loaded and s u b t r a c t e d , the r e s u l t ( s t i l l on the stack) i s m u l t i p l i e d by C1. Before f u r t h e r f i l t e r c a l c u l a t i o n s the c o n v e r s i o n f o r the next channel i s i n i t i a l i z e d . 1 17 The denominator c a l c u l a t i o n s [ d1*y(n-1)+d2*y(n-2) ] are executed i n a s i m i l a r manner and the r e s u l t i s m u l t i p l i e d by 4 fo r c o r r e c t placement of the b i n a r y p o i n t . The r e s u l t , which i s the output of the f i r s t stage, i s saved (INP APU) f o r the delay-s h i f t s . The second stage i s executed as above. Using R8 and R9 the samples are s h i f t e d by one l o c a t i o n (2 bytes) to e f f e c t the time delay, i . e . x(n-1) to x(n-2), x(n) to x(n-1), e t c . The output of the f i l t e r (second s t a g e ) , which i s s t i l l on the APU stack, i s converted to f l o a t i n g p o i n t , squared, added to the running sum (SSQX) and the new value r e - s t o r e d i n memory. Two more, i d e n t i c a l sequences implement the f i l t e r i n g f o r the y- and z-channel. A f t e r a l l three f i l t e r i n g sequences the p o i n t e r s (R6,R12,R14) are r e s e t to the beginning of each data block. If the 10 sec rms i n t e r v a l has not elapsed the rms c a l c u l a t i o n s are skipped and the sample p o i n t e r (R7) i s r e s e t . The program i s synchronized to the sample c l o c k by e n a b l i n g the i n t e r r u p t and w a i t i n g f o r the c l o c k p u l s e . On i n t e r r u p t the program ' f a l l s through' and branches back to the beginning of the program. In case that a f u l l rms i n t e r v a l has passed, the 'sum of squares' are r e t r i e v e d from memory and the rms values c a l c u l a t e d . A f t e r the rms values have been output to the DAC's (OUT DAC1 - DAC3), the program checks f o r a change of the f i l t e r s e l e c t i o n . I f no change has o c c u r r e d the program branches to the 'wait f o r i n t e r r u p t ' sequence, otherwise i t branches to the beginning of the program. 1 2 3 4 5 6 7 8 9 10 1 1 12 TITLE ; * RCA.2B * , * * * * * * * * * * ' * * RCA.2B * * 06.NOV 1981' ;* 4MHZ CLOCK 4MICSEC/INSTR (6MICSEC/LBR+N0P) ;* DOUBLE PRECISION, 2 S COMPLEMENT, AM9511 ARITHM.PROCESSING UNIT ;* EXT.FLAGS 1 TO 3 SELECT 1 OF 8 FILTERS ;* 3 CHANNELS LABELED X,Y & Z ; CASCADED FORM ;W = = = = ( 1 ) = >< + > = (C1)=>< + > = = = (4) = = = = = = = = = = ( 1 ) = = >.< + > = (C2)=>< + } = = = (4) = = = = = > V 14 ; I 15 ; [T] <=(-d1)=[T] [T] 1 <=(-d1)=[T] 16 ; 1 17 ; | 18 ; [T]=(-1)=> <=(-d2)=[T] [T]=(-1)=> <=(-d2)=[T] ' 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 DEFINITIONS ; APU COMMANDS FIXMULLO EOU 6EH FIXMULHI EOU 76H FIXADD EOU 6CH F i ' x S U B E O U 6 D H FIXFLT EOU 1DH FIXCOPY EOU 77H FLTCOPY EOU 17H FLTMULT EOU 12H FLY ADD E O U 1 0 H FLTDIV EOU 13H SORT EOU 01H FLT F I X E O U 1FH I/O PORT DEFINITIONS 41 DAC 1 EOU 1 42 DAC2 EOU 2 43 DAC3 EOU 3 44 DATA EOU 4 45 CHANL EOU 5 46 APU EOU 6 47 CMND EOU 7 48 49 ; REGISTER DEFINITIONS 50 51 PC EOU 0 ;PROGRAM COUNTER 52 ISPC EOU 1 ;INTRPT-SERVICE PC 53 SP EOU 2 ;STACK POINTER 54 TIMER EOU 3 55 COUNT EOU 4 ' 56 ;R5 EOU 5 GENERAL PURPOSE 57 ;R6 EOU 6 SAMPLE PTR 58 ;R7 EOU 7 COEFFICIENTS PTR 59 ;R8 EOU 8 DELAY POINTER 60 ;R9 EOU 9 DELAY POINTER 1 oo 61 R10 EOU 0AH 62 R11 EOU 0BH 63 R12 EOU 0CH ;SUM SQUARES PTR 64 R13 EOU ODH 65 R14 EOU OEH ;COMMAND-POINTER 66 R15 EOU OFH :GENERAL PTR 67 68 ; CONSTANTS 69 70 INTRV.HI EOU 06H 7 1 INTRV.LO EOU 5CH ;SUMMING INTERVAL FOR 10 SEC 72 WASTE.HI EOU 3H 73 WASTE.LO EOU 2EH ;WASTE INTERVAL FOR 5 SEC 74 ; 75 === START OF PROGRAM ======================= 76 77 ; INITIALISATION 78 79 ; ON POWER-UP RO IS PC AND RX 80 DIS ;DISABLE INTERUPTS BYTE 10H ;[X,P]-ARGUMENTS FOR FAKE-RETURN 82 REO 83 J POINTERS 85 . 86 START LDI HI (W01X.LO) 88 LDI L0(WO1X.LO) 89 PLO R6 ;R6 > LO BYTE OF FIRST X-SAMPLE 91 LDI HI(CHSEL) 92 PHI R5 94 PLO R5 ;R5 > CHANEL SELECTED 95 ; 97 PHI R12 98 LDI LO(SSQX) ;R12 > LSB OF SUM OF SQUARES ACCUMULATOR 100 ; 101 LDI HI (BAND) PHI RIO 103 LDI LO(BAND) 104 PLO R10 ;R10 > BAND SELECTED 106 LDI HI(SCRTCH) 107 PHI R1 1 108 LDI LO(SCRTCH) 109 PLO R1 1 ;R11 > SCRATCH PAD 1 10 LDI HI(INSTR) 1 12 PHI R14 1 13 LDI LO(INSTR) 1 14 PLO R14 ;R14 > THE FIRST APU-INSTR 115 ; 1 16 LDI HI(ENDWS) 117 PHI R15 118 LDI LO(ENbWS) 1 19 PLO R15 ;R15 > END OF WORKSPACE 120 ; vO 121 122 123 ; SET COUNTERS LDI INTRV.HI 125 126 LDI PLO INTRV.LO . 128 129 LDI PHI WASTE.HI 131 132 PLO TIMER ;TIMER=(495*SAMPLING)=3 SEC 134 135 ; INITIAL: R15 137 138 L00P1 LDI STXD 0 140 141 XRI BNZ 08H 143 144 XRI BNZ 01H 146 147 ; START FIRST CONVERSION 149 150 LDI 0 STR R5 152 153 DEC R5 155 156 REO ;START CONVERSION 158 159 ; DEPENDING ON 161 162 ; CORRESPONDING FILTER SEQUENCE.(FLAGS LOW ACTIVE) 164 165 BN2 BN1 F10X FILTR1 • 167 168 F10X BN1 FILTR3 170 171 FOXX BN2 FOOX 173 174 BR FILTR4 176 177 BR FILTR6 179 180 ISO LDI HKC1XI.L0) 18 1 PHI R7 182 LDI L0(C1XI.LO) 183 PLO R7 ;R7 > FIRST COEFFICIENT 184 J 185 LDI 1 186 STR R10 ;BAND = 1 187 BR OFILTER 188 ; 189 ; SET FILTER #2 COEFF-POINTERS 190 191 FILTR1 LDI HI(CIX1.LO) 192 PHI R7 193 LDI L0(C1X1.LO) 194 PLO R7 ;R7 > FIRST COEFFICIENT 195 196 LDI 2 197 STR R10 ;BAND = 2 198 BR OFILTER 199 J 200 ; SET FILTER #3 COEFF-POINTERS 201 202 FILTR2 LDI HI(C1X2.LO ) 203 PHI R7 204 LDI L0(C1X2.LO) 205 PLO R7 ;R7 > FIRST COEFFICIENT 206 ; 207 LDI 3 208 STR R10 ;BAND = 3 209 BR OFILTER 210 ; 21 1 ; SET FILTER #4 COEFF-POINTERS 212 213 FILTR3 LDI HI (C1X3.LO) 214 PHI R7 215 LDI L0(C1X3.L0) 216 PLO R7 ;R7 > FIRST COEFFICIENT 217 218 LDI 4 219 STR R10 ;BAND = 4 220 BR OFILTER 221 222 ; SET FILTER #5 COEFF-POINTERS 223 224 FILTR4 LDI HI(C1X4.LO) 225 PHI R7 226 LDI L0(C1X4.L0) 227 PLO R7 ;R7 > FIRST COEFFICIENT 228 229 LDI 5 230 STR RIO ;BAND = 5 231 BR OFILTER 232 233 ; SET FILTER #6 COEFF-POINTERS 234 235 FILTR5 LDI HI(C1X5.Lbj 236 PHI R7 237 LDI L0(C1X5.L0) 238 PLO R7 ;R7 > FIRST COEFFICIENT 239 ; 240 LDI 6 24 1 STR R10 ;BAND = 6 " 242 BR OFILTER 243 ; 244 ; SET FILTER #7 COEFF- POINTERS 245 246 FILTR6 LDI HI (C1X6 .LO) 247 PHI R7 248 LDI L0(C1X6 .LO) 249 PLO R7 ;R7 > FIRST COEFFICIENT 250 251 LDI 7 252 STR R10 ;BAND = 7 253 BR OFILTER 254 J 255 ; CHECK 256 257 J 258 CHECK LDI 00 259 PHI R15 260 LDI 25 261 PLO R15 ;SET TIMER TO ABOUT 120 uSEC 262 ; 263 C0N1 DEC R15 264 GLO R15 265 BNZ C0N1 266 ; 267 SEX R1 1 268 INP DATA ;GET DATA 269 OUT DAC 1 ;AND DUMP IT 270 DEC R1 1 271 LDI 1 272 STR R5 273 274 SEX R5 ;SELECT Y-CHANNEL 275 OUT CHANL 276 DEC R5 277 278 SEO 279 REQ 280 281 LDI 00 282 PHI R15 283 LDI 30 284 PLO R15 ;SET TIMER TO ABOUT 120 uSEC 285 286 C0N2 DEC R15 287 GLO R15 288 BNZ C0N2 289 290 . SEX R11 291 INP DATA ;GET DATA 292 OUT DAC2 ;AND DUMP IT 293 DEC R1 1 294 LDI 2 295 STR R5 296 ; 297 SEX R5 ;SELECT Z-CHANNEL 298 OUT CHANL 299 DEC R5 300 ; 301 SEO 302 REO 303 304 LDI 00 305 PHI R15 306 LDI 30 307 PLO R15 ;SET TIMER TO ABOUT 120 uSEC 308 C0N3 DEC R15 310 GLO R15 31 1 LBNZ C0N3 313 SEX R1 1 314 INP DATA ;GET DATA DAC3 ;AND DUMP IT 316 DEC R1 1 317 * LBR RECHCK 319 J 320 ; X-CHANNEL 322 ********************* 323 ; -(Y1*D1)-(Y2*D2) 325 326 ; V=OUTPUT; W= INPUT D=DENOMINATOR 328 ; 329 ; INITIAL: R5 > CHAN2 331 ; R7 > C1X LO 332 ' ; R14 > FIXSUB 334 ; INPUT 335 » v 337 LDI 0 338 STR R6 ;SET LO BYTE TO ZERO 340 INC R6 ;R6 > HI BYTE 341 INP DATA ;READ SAMPLE FROM ADC 343 SHR ;SHIFT RIGHT 344 STR R6 ;STORE AT HI BYTE ;R6 > LO BYTE 346 BNF NEXTX ;IF NO OVERFLOW LEAVE LO BYTE = 0 347 LDI 80H ;ELSE SET LO BYTE TO 80H STR R6 349 ; 350 ; SUM=(W01-W21)*C1 352 NEXTX SEX R7 353 OUT APU •;LOAD C1 354 OUT APU 355 ; 356 SEX R6 APU ;LOAD W01X LO-BYTE 358 OUT APU ; " W01X HI-BYTE 359 360 IRX to 361 IRX ; SKIP OVER W11X 362 OUT APU ; LOAD W21X LO BYTE 363 OUT APU ; LOAD W21X HI BYTE 364 365 SEX R14 366 OUT CMND ;SUBTRACT 367 OUT CMND :MULT I PLY 368 369 : START NEXT CONVERSION 370 37 1 LDI 1 372 STR R5 373 SEX R5 374 OUT CHANL ; SELECT A/D CHANNEL tt\ 375 DEC R5 376 ; 377 SEQ 378 REQ 379 380 ; SUM = SUM-(V11*D11) 381 382 SEX R6 383 IRX 384 IRX ;SKIP OVER V01X HI&LO 385 OUT APU ;LOAD V11X LO BYTE 386 OUT APU ;LOAD V11X HI-BYTE 387 388 SEX R7 389 OUT APU ;LOAD D11X LO-BYTE 390 OUT APU ;LOAD D11X HI-BYTE 391 392 . SEX R14 393 OUT CMND ;MULTIPLY 394 OUT CMND ;SUBTRACT 395 * 396 ; SUM= SUM-(V21*D21) 397 398 SEX R6 399 OUT APU ;LOAD V21X LO-BYTE 400 OUT APU ;LOAD V21X HI-BYTE 401 ; 402 SEX R7 403 OUT APU ;LOAD COEFFICIENT LO BYTE 404 OUT APU ; " " HI BYTE 405 ; 406 SEX R14 407 OUT CMND ;MULTIPLY 408 OUT CMND ;SUBTRACT 409 410 ; MULTPLY BY 4 41 1 . 412 OUT APU ;LOAD 4 413 OUT CMND ;MULLO 414 415 ; SAVE 1ST STAGE OUTPUT 416 417 ; INITIAL: R6 > V12X LO-BYTE 418 ; 419 LDI L0(VWOX.HI) 420 PLO R6 ;R6 > V01X HI-BYTE 421 J 422 NOTE DATA BLOCK MUST NOT LIE ACROSS A PAGE BOUNDARY 423 ; 424 SEX R6 425 INP APU ;GET HI-BYTE 426 ; 427 DEC R6 428 INP APU ;GET LO-BYTE 429 ; 430 ; 2ND STAGE (X) 431 432 ; 433 ; SUM =(W02-W22)*C2 434 435 ' ; INITIAL: R7 > C2X 436 J R6 > W02X( =V01X) LO-BYTE 437 438 SEX R7 439 OUT APU ;LOAD C2 440 OUT APU 441 j 442 SEX R6 443 OUT APU ;LOAD W02X LO-BYTE 444 OUT APU ; " W02X HI-BYTE 445 446 IRX 447 IRX ;SKIP OVER W12X 448 OUT APU ;LOAD W22X LO BYTE 449 OUT APU ;LOAD W22X HI BYTE 450 j 451 SEX R14 452 OUT CMND ;SUBTRACT 453 OUT CMND ;MULTIPLY 454 j 455 ; SUM =SUM-(V12*D12) 456 457 SEX R6 458 OUT APU ;LOAD V12X LO BYTE 459 OUT APU ;LOAD V12X HI BYTE 460 ; 461 SEX R7 462 OUT APU ;LOAD D12X LO-BYTE 463 OUT APU ;LOAD D12X HI-BYTE 464 j 465 SEX R14 466 OUT CMND ;MULT I PLY 467 OUT CMND ;SUBTRACT 468 ; 469 ; SUM =SUM-(V22 *D22) 470 471 SEX R6 472 OUT APU ;LOAD V22X LO-BYTE 473 OUT APU ;LOAD V22X HI-BYTE 474 ; 475 SEX R7 476 OUT APU ;LOAD D22X LO-BYTE 477 OUT APU ;LOAD D22X HI-BYTE 478 j 479 SEX R14 480 OUT CMND ;MULTIPLY 481 OUT CMND ; SUBTRACT - — 482 J 483 ; MULTPLY BY 4 485 OUT CMND ;FIRST COPY FOR SSOX 486 OUT APU ;LOAD 4 488 ; 489 ; DELAY-SHIFT THE SAMPLES 491 ; V12 TO V22 492 . 494 • LDI HI (V12X.HI ) 495 PHI R8 497 PLO R8 ;R8 > V12X.HI 498 ; 500 PHI R9 501 LDI L0(V22X.HI) 503 j 504 SEX R9 506 STXD ;STORE IT, R9-1 507 DEC R8 509 STXD ;STORE IT, R9-1 510 DEC R8 512 ; V02 (ON TOS) TO V 12 513 515 ; INITIAL.R9 > V12X HI-BYTE 516 ; 518 DEC R9 519 INP APU ;GET LO BYTE 521 522 ; INITIAL: R9 > V12X LO-BYTE 524 ; RX = R9 525 ; 527 DEC R8 ;R8 > VW1X HI-BYTE 528 DEC R9 ;R9 > VW2X HI-BYTE 530 • LDN R8 ;GET VW1X HI-BYTE 531 STXD ;STORE @ VW2X HI-BYTE 533 LDN R8 ;GET VW1X LO-BYTE 534 STXD ;STORE @ VW2X LO-BYTE 536 537 ; VWO TO VW1 539 LDN R8 ; GET VWOX HI-BYTE 540 STXD ;STORE @ VW1X HI-BYTE 541 DEC R8 542 LDN R8 ;GET VWOX LO-BYTE 543 STXD ;STORE 9 VW1X LO-BYTE 544 DEC R8 545 * 546 ; W1 1 TO W21 547 548 DEC R8 549 DEC R8 ;R8 > W11X HI-BYTE 550 DEC R9 551 DEC R9 ;R9 > W21X HI-BYTE 552 LDN R8 ;GET W11X HI-BYTE 553 STXD ;STORE 9 W21X HI-BYTE 554 DEC R8 555 LDN R8 ;GET W11X LO-BYTE 556 STXD ;STORE 9 W21X LO-BYTE 557 DEC R8 558 559 ; W01 TO W1 1 560 561 LDN R8 ;GET W01X HI-BYTE 562 STXD ;ST0RE 9 W1IX HI-BYTE 563 DEC R8 564 LDN R8 ;GET W01X LO-BYTE 565 STXD ;ST0RE 9 W11X LO-BYTE 566 DEC R8 567 568 ; FOR START-UP (TIMER.GT .0) SKIP SUM OF SQUARES 569 570 GHI TIMER 571 BNZ YYY 572 GLO TIMER 573 BNZ YYY 574 ; 575 ; SUM OF SQUARES (X) 576 577 ; INITIAL: R14 > CONVERT 578 R12 > SUM OF SQUARES; (SSQX) 579 580 SEX R14 581 OUT CMND ;CONVERT TO FLOATING POINT 582 OUT CMND ;COPY TOS (FLOATING) 583 OUT CMND ;FLOATING MULT (SQUARE) 584 585 SEX R12 586 OUT APU 587 OUT APU 588 OUT APU 589 OUT APU ;LOAD PREVIOUS SUM 590 DEC R12 ;R12 > MSB OF SSQX 591 592 SEX R14 593 OUT CMND ;FLOATING ADD 594 595 SEX R12 596 INP APU ;STORE NEW SSQX AND CONTINUE 597 DEC R12 598 INP APU 599 DEC R12 600 INP APU 601 DEC R12 602 INP APU ;R12 > LSB OF SSOX 603 ; 604 ; FILTER FOR Y-CHANNEL 605 ********************* 606 ; 607 ; 1ST STAGE V0=(W0-W2)*C1 -(Y1*D1)-(Y2*D2) 608 609 ; V=OUTPUT; W= INPUT 610 ; N=NUMERATOR; D=DENOMINATOR 61 1 J 612 ; INITIAL: R5 > CHAN3 613 ; R6 > W01Z.L0 614 ; R7 > D22X.HI+1 615 R14 > FIXSUB 616 617 ; SET POINTERS 618 619 YYY GLO R7 620 SMI 12 ;OFFSET BACK 621 PLO R7 ;R7 > C1X.L0 622 623 ; ** NOTE! COEFFICIENT BLOCK MUST NOT LIE ACROSS A PAGE BORDER 624 625 LDI HI(INSTR) 626 PHI R14 627 LDI LO(INSTR) 628 PLO R14 ;R14 > FIRST OF COMMANDS 629 * 630 ; INPUT 631 632 SEX R6 633 LDI 0 634 STR R6 ;SET LO BYTE TO ZERO 635 636 INC R6 ;R6 > HI BYTE 637 INP DATA ;READ SAMPLE FROM ADC 638 639 SHR ;SHIFT RIGHT 640 STR R6 ; STORE AT HI BYTE 641 DEC R6 ;R6 > LO BYTE 642 BNF NEXTY ;IF NO OVERFLOW SKIP TO N4 643 LDI 80H ;ELSE SET LO BYTE TO 80H 644 STR R6 645 646 ; SUM=(Wbl-W2i)*C1 647 648 NEXTY SEX R7 649 OUT APU ; LOAD CI 650 OUT APU 651 652 SEX R6 653 OUT APU ;LOAD W01Y LO-BYTE 654 OUT APU ; " W01Y HI-BYTE 655 656 IRX 657 IRX ;SKIP OVER W11Y 658 OUT APU ;LOAD W21Y LO BYTE 659 OUT APU ;LOAD W21Y HI BYTE 660 ; 661 SEX R14 662 OUT CMND ;SUBTRACT 663 OUT CMND ;MULT IPLY 664 J 665 ; START NEXT CONVERSION 666 667 LDI 2 668 STR R5 669 SEX R5 670 OUT CHANL ; SELECT A/D CHANNEL Ir2 671 DEC R5 672 ; 673 SEO 674 REO 675 676 ; SUM = SUM-(V11*D11) 677 678 SEX R6 679 IRX 680 IRX ;SKIP OVER V01Y HI&LO 681 OUT APU ;LOAD V11Y LO BYTE 682 OUT APU ;LOAD V11Y HI-BYTE 683 ; 684 SEX R7 685 OUT APU ;LOAD D1 IY LO-BYTE 686 OUT APU ;LOAD D11Y HI-BYTE 687 688 SEX R14 689 OUT CMND ;MULTIPLY 690 OUT CMND ;SUBTRACT 691 ; 692 ; SUM = SUM-(V21*D21) 693 694 SEX R6 695 OUT APU ;LOAD V21Y LO-BYTE 696 OUT APU ;LOAD V21Y HI-BYTE 697 ; 698 SEX R7 699 OUT APU ;LOAD COEFFICIENT LO BYTE 700 OUT APU ; " " HI BYTE 701 j 702 SEX R14 703 OUT CMND ;MULTIPLY 704 OUT CMND ;SUBTRACT 705 j 706 ; MULTPLY BY 4 707 708 OUT APU ;LOAD 4 709 OUT CMND ;MULLO 710 71 1 ; SAVE 1ST STAGE OUTPUT 712 713 ; INITIAL: R7 > V12Y LO-BYTE 714 715 LDI L0(VWOY.HIj 716 PLO R6 ;R6 > V01Y HI-BYTE 717 ; 718 ; * * NOTE DATA BLOCK MUST NOT LIE ACROSS A PAGE BOUNDARY 719 ; 720 SEX R6 7 2 1 I N P A P U ; G E T H I - B Y T E 7 2 2 7 2 3 D E C R 6 7 2 4 I N P A P U ; G E T L O - B Y T E 7 2 5 7 2 6 ; 2 N D S T A G E ( Y ) 7 2 7 ; — ~ ~ — 7 2 8 j 7 2 9 ; S U M = ( W 0 2 - W 2 2 ) * C 2 7 3 0 7 3 1 ; I N I T I A L : R 7 > C 2 Y 7 3 2 R 6 > W 0 2 Y ( = V 0 1 Y ) L O - B Y T E 7 3 3 ; 7 3 4 S E X R 7 O U T A P U ; L O A D C 2 7 3 6 O U T A P U 7 3 7 ; 7 3 8 S E X R 6 7 3 9 O U T A P U ; L O A D W 0 2 Y L O - B Y T E 7 4 0 O U T A P U ; " W 0 2 Y H I - B Y T E 7 4 1 7 4 2 I R X 7 4 3 I R X ; S K I P O V E R W 1 2 Y 7 4 4 O U T A P U ; L O A D W 2 2 Y L O B Y T E 7 4 5 O U T A P U ; L O A D W 2 2 Y H I B Y T E 7 4 6 ; 7 4 7 S E X R 1 4 7 4 8 O U T C M N D ; S U B T R A C T 7 4 9 O U T C M N D ; M U L T I P L Y 7 5 0 7 5 1 ; S U M = S U M - ( V 1 2 * D 1 2 ) 7 5 2 7 5 3 S E X R 6 7 5 4 O U T A P U ; L O A D V 1 2 Y L O B Y T E 7 5 5 O U T A P U ; L O A D V 1 2 Y H I B Y T E 7 5 7 S E X R 7 7 5 8 O U T A P U ; L O A D D 1 2 Y L O - B Y T E 7 5 9 O U T A P U ; L O A D D 1 2 Y H I - B Y T E 7 6 0 7 6 1 S E X R 1 4 7 6 2 O U T C M N D ; M U L T I P L Y 7 6 3 O U T C M N D ; S U B T R A C T 7 6 4 ; 7 6 5 ; S U M = S U M - ( V 2 2 * D 2 2 ) 7 6 6 7 6 7 S E X R 6 7 6 8 O U T A P U ; L O A D V 2 2 Y L O - B Y T E 7 6 9 O U T A P U ; L O A D V 2 2 Y H I - B Y T E 7 7 0 J 7 7 1 S E X R 7 7 7 2 O U T A P U ; L O A D D 2 2 Y L O - B Y T E 7 7 3 O U T A P U ; L O A D D 2 2 Y H I - B Y T E 7 7 4 • 7 7 5 S E X R 1 4 7 7 6 O U T C M N D ; M U L T I P L Y 7 7 7 O U T C M N D ; S U B T R A C T 7 7 8 J 7 7 9 ; M U L T I P L Y B Y 4 7 8 0 . o oo oo 03 00 00 00 00 00 00 00 co CO 00 00 00 oo co oo co co 00 oo oo oo oo oo co co 00 00 oo co oo oo oo co 00 00 03 00 00 ^1 ~1 ~4 -J ~4 ^1 ^1 ^1 ~J -~l -J -J -J -J -J -J U CO CO CO CO CO CO CO CO to to to to to to to to to to o o o o o o o o O O CO CO CO CO CO CO CO CO CO CO 00 oo 00 CO co oo 00 O CO CO -J cn Ul CO IO -•• o CO 00 -J cn Ol •b CO to -* o CO 00 ^1 cn Ul u CO to O CO CO cn oi A CO to -» O (D 00 ~4 cn Ol CO to -- o CO 00 ~1 CT) Ol CO CO r~ o t o r - 1 < O CO r - O CO r - o o o •• 1 < HH o 1—< ^ 1 O CO r - o CO r - oo TI I- T3 I - T3 r-H a m H o 1 £ -m H o m —1 o m m m 1 £ z m z TO J> 1 -1 m - i o m -1 O m r- O X o r- a x o X z O X Z 1 ^ n x z n X z o o o 70 70 1 tO TI o CO CO 1 o O X z o X Z X o « »H ,—1 o 1—1 o o o o 00 CO 1 C/l o • V CO 1 w V V C I 70 TO 70 TO TO 70 7} 71 73 > 70 > < 2 i -1 73 73 73 7) 73 r - 70 I 73 r - 73 I 00 oo oo oo oo CO oo CO oo oo < < •o CO TJ i a 00 00 00 03 CO co a CO (—1 oo o 00 l-H o c c to 1 • .—. to ro -< O 1 < < < < < •< -< Z 1 ro ro L. I 1 M ro ro to ro X I - 1—1 H -< -< < < (—1 o 1 o 1 1 00 CO I X X I CO 00 < l-H l-H t—1 l-H -< < H a -1 -1 m -n m m > • • •. -o »• * • »* »• »• -• -• -• -• -• CD CD c CO CD CO CD 73 7) 00 CD CO CD CO CD CO CD TO 70 m m H m -1 m CO 00 -1 m -I m H m H m CO CO H -1 o -1 o -1 o H O -1 o -1 o —1 Ta TO V V TO TO 70 TO V V I - I m r - m I m < m < m < m < o 1—< a 1—f < < £ £ £ £ < < 1 HH \ to © o © o •© — t £ £ CO CO -1 CO —1 00 to to X X -< •< to — * -< < - -c » -< -< < < < < < -< < - ( -1 -1 H £ r~ £ I £ P" £ I m m 73 m 7) m X X - k o 1—1 to o to *-H X I CO CO 1—1 l-H < 1 -< 1 -< 1 < 1 1—1 l-H 1 1 CO CO CO CO 1 r™ -< X < r~ -< X -< •3 00 o -1 1— -1 o H »—1 -1 -< -< m m • H i < Z i £ O O O C C C 2 TI 2 z c z o o 2 r- oo c o > r - > < r - o m O o 71 00 CO O 841 ; 842 ; W1 1 TO W21 • 843 844 DEC R8 845 DEC R8 ;R8 > W11Y HI-BYTE 846 DEC R9 847 DEC R9 ;R9 > W21Y HI-BYTE 848 LDN R8 ;GET W11Y HI-BYTE 849 STXD ;STORE 0 W21Y HI-BYTE 850 DEC R8 851 LDN R8 ;GET W11Y LO-BYTE 852 STXD ;STORE 0 W21Y LO-BYTE 853 DEC R8 854 ; 855 ; W01 TO W1 1 856 857 LDN R8 ;GET W01Y HI-BYTE 858 STXD ;ST0RE 0 W11Y HI-BYTE 859 DEC R8 860 LDN R8 ;GET W01Y LO-BYTE 861 STXD ;STORE 0 W11Y LO-BYTE 862 DEC R8 863 ; 864 ; FOR START-UP (TIMER.GT .0) SKIP SUM OF SQUARES 865 866 ,GHI TIMER 867 BNZ zzz 868 GLO TIMER 869 BNZ ZZZ 870 871 ; SUM OF SQUARES (Y) 872 873 ; INITIAL: R14 > CONVERT 874 ; R12 > LSB OF SUM OF SQUARES; (SSQX) 875 ; 876 SEX R14 877 OUT CMND ;CONVERT TO FLOATING POINT 878 OUT CMND ;COPY TOS (FLOATING) 879 OUT CMND ;FLOATING MULT (SQUARE) 880 j 881 SEX R12 882 IRX 883 IRX 884 IRX 885 IRX ;R12 > LSB OF SSQY 886 OUT APU 887 OUT APU 888 OUT APU 889 OUT APU ;LOAD PREVIOUS SUM 890 DEC R12 ;R12 > MSB OF SSQY 891 ; 892 SEX R14 893 OUT CMND ;FLOATING ADD 894 ; 895 SEX R12 896 INP APU ;STORE NEW SSQX AND CONTINUE 897 DEC R12 898 INP APU 899 DEC R12 900 INP APU 901 DEC R12 902 INP APU ;R12 > LSB OF SSQY 903 904 ; FILTER FOR Z-CHANNEL 905 . * * * * * * * * * * * * * * * * * * * * * 906 907 ; 1ST STAGE V0=(W0-W2)*C1- (Y1*D1 )-(Y2*D2) 908 909 ; V=OUTPUT; W= INPUT 910 ; ENUMERATOR; D=DENOMINATOR 91 1 J 912 ; INITIAL: R5 > CHAN3+1 913 ; R6 > W01X LO 914 ; R7 > D22X.HI+1 = C1Z.L0 915 ; R14 > FIXSUB 916 917 ; SET POINTERS 918 919 ZZZ LDI HI(INSTR) 920 PHI R14 921 LDI L0(INSTR) 922 PLO R14 ;R14 > FIRST OF COMMANDS 923 J 924 ; INPUT 925 926 SEX R6 927 LDI 0 928 STR R6 ;SET LO BYTE TO ZERO 929 930 INC R6 ;R6 > HI BYTE 931 INP DATA ;READ SAMPLE FROM ADC -932 ; 933 SHR ;SHIFT RIGHT 934 STR R6 ;STORE AT HI BYTE 935 DEC R6 ;R6 > LO BYTE 936 BNF NEXTZ ;IF NO OVERFLOW SKIP TO NEXTZ 937 LDI 80H ;ELSE SET LO BYTE TO 80H 938 STR R6 939 940 ; SUM=(W01-W21)*C1 941 942 NEXTZ SEX R7 943 OUT APU ;LOAD C1 944 OUT APU 945 946 SEX R6 947 OUT APU ;LOAD W01Z LO-BYTE 948 OUT APU ; " W01Z HI-BYTE 949 950 IRX 951 IRX ;SKIP OVER W1 1Z 952 but APU ;LOAD W21Z LO BYTE 953 OUT APU ;LOAD W21Z HI BYTE 954 ; 955 SEX R14 956 OUT CMND ;SUBTRACT 957 OUT CMND ;MULTIPLY 958 ; 959 ; START NEXT CONVERSION 960 ; 961 LDI 00 962 STR R5 963 SEX R5 964 OUT CHANL ;SELECT A/D CHANNEL #0 965 DEC R5 966 967 SEQ 968 REO 969 970 ; SUM=SUM-(V11 *D1 1 ) 971 972 SEX R6 973 IRX 974 IRX ;SKIP OVER V01Z HI&LO 975 OUT APU ;LOAD V11Z LO BYTE 976 OUT APU ;LOAD V11Z HI-BYTE 977 978 SEX R7 979 OUT APU ;LOAD D11Z LO-BYTE 980 OUT APU ;LOAD D11Z HI-BYTE 981 982 SEX R14 983 OUT CMND ;MULTIPLY 984 OUT CMND ;SUBTRACT 985 986 ; SUM=SUM-(V21 *D21 ) 987 988 SEX R6 989 OUT APU ;LOAD V21Z LO-BYTE 990 OUT APU ;LOAD V21Z HI-BYTE 991 992 SEX R7 993 OUT APU ;LOAD COEFFICIENT LO BYTE 994 OUT APU ; " " HI BYTE 995 R14 997 OUTv CMND ;MULTIPLY 998 OUT CMND ^SUBTRACT 1000 ; MULTIPLY BY 4 1001 1002 OUT APU ; LOAD 4 1003 OUT CMND ;MULLO 1004 ; 1005 : SAVE 1ST STAGE OUTPUT 1006 1007 ; INITIAL: R7 > V12Z LO-BYTE 1008 1009 LDI L0(VWOZ.HI) 1010 PLO R6 ;R6 > V01Z HI-BYTE 101 1 ; NOTE DATA BLOCK MUST NOT LIE ACROSS A PAGE BOUNDARY 1012 ; 1013 SEX R6 1014 INP APU ;GET HI-BYTE 1015 ; 1016 DEC R6 1017 INP APU ;GET LO-BYTE 1018 J 1019 ; 2ND STAGE (Z) 1020 ; ====-======= 1021 1022 SUM=(W02-W22)*C2 1023 1024 INITIAL: R7 > C2Z 1025 R6 > W02Z(=V01Z) LO-BYTE 1026 1027 SEX R7 1028 OUT APU ;LOAD C2 1029 OUT APU 1030 1031 SEX R6 1032 OUT APU ;LOAD W02Z LO-BYTE 1033 OUT APU ; " - W02Z HI-BYTE 1034 1035 IRX 1036 IRX ;SKIP OVER W12Z 1037 OUT APU ;LOAD W22Z LO BYTE 1038 OUT APU ;LOAD W22Z HI BYTE 1039 1040 SEX R14 1041 OUT CMND ;SUBTRACT 1042 OUT CMND ;MULTIPLY 1043 1044 SUM=SUM-(V12*D12) 1045 1046 SEX R6 1047 OUT APU ;LOAD V12Z LO BYTE 1048 OUT APU ;LOAD V12Z HI BYTE 1049 1050 SEX R7 1051 OUT APU ;LOAD D12Z LO-BYTE 1052 OUT APU ;LOAD D12Z HI-BYTE 1053 1054 SEX R14 1055 OUT CMND ;MULTIPLY 1056 OUT CMND ;SUBTRACT 1057 1058 SUM=SUM-(V22*D22) 1059 1060 SEX R6 1061 OUT APU ;LOAD V22Z LO-BYTE 1062 OUT APU ;LOAD V22Z HI-BYTE 1063 1064 SEX R7 1065 OUT APU ;LOAD D22Z LO-BYTE 1066 OUT APU ;LOAD D22Z HI-BYTE 1067 1068 SEX R14 1069 OUT CMND ;MULTIPLY 1070 OUT CMND ;SUBTRACT 1071 1072 MULT if PLY' BY 4 1073 1074 OUT CMND ;FIRST SAVE FOR SSOZ 1075 OUT APU ; LOAD 4 1076 OUT CMND ;MULLO 1077 1078 DELAY-SHIFT THE SAMPLES 1079 1080 V12 TO V22 1081 1082 1084 1085 PHI LDI P.8 L0(V12Z.HI) 1087 1088 LDI HI(V22Z HI) 1090 1091 LDI PLO L0(V22Z.HI ) R9 ;R9 > V22Z.HI 1093 1094 SEX LDN R9 R8 ;GET HI-BYTE 1096 1097 DEC LDN R8 R8 ;GET LO-BYTE 1099 DEC R8 1 100 1 102 1 103 • V02 IS {AS SUM} ON T0S;0F APU 1 105 1 106 INP APU ;GET HI BYTE 1 108 INP APU ;GET LO BYTE 1 109 1111 1112 ; INITIAL: R9 > V12Z LO-BYTE 1114 1115 DEC R8 1117 DEC R9 1 1 18 1 120 STXD ; STORE <a VW2Z HI-BYTE 1121 DEC R8 1 123 STXD 1 124 DEC R8 1 126 ; VWO TO VW1 1 127 1 129 STXD 1 130 DEC R8 1 132 sfxb 1 133 DEC R8 1 135 ; W11 TO W21 -1 136 1 138 DEC R8 1 139 1 140 DEC DEC R9 R9 . ;R9 > W21Z HI-BYTE UJ ON 1 141 LDN R8 ;GET W11Z HI-BYTE 1 142 STXD ;STORE 9 W21Z HI-BYTE 1 143 DEC R8 1 144 LDN R8 :GET W11Z LO-BYTE 1 145 STXD :STORE «> W21Z LO-BYTE 1 146 DEC R8 1 148 ; W01 TO W1 1 1 149 . LDN R8 ;GET WOiZ HI-BYTE 1151 STXD ;STORE # W11Z HI-BYTE 1 152 DEC R8 LDN R8 ;GET W01Z LO-BYTE 1 154 STXD ;STORE 9 W1 1Z LO-BYTE 1 155 DEC R8 1 156 ; 1 157 ; FOR START-UP (TIMER.GT .0) SKIP SUM OF SQUARES 1 158 GHI TIMER 1 160 LBNZ CDOWN 1 161 GLO TIMER BZ SQZ 1 163 ; 1 164 CDOWN DEC TIMER 1 165 LBR RESET 1 166 ; 1 167 ; SUM OF SQUARES (Z) 1 168 1 169 ; INITIAL: R14 > CONVERT 1 170 R12 > SUM OF SQUARES; (SSQX) 1 171 j 1 172 soz SEX R14 1 173 OUT CMND ;CONVERT TO FLOATING POINT 1 174 OUT CMND ;CbPY TOS (FLOATING) 1 175 OUT CMND ;FLOATING MULT (SQUARE) 1 176 ; 1 177 SEX R12 1 178 ; 1 179 IRX 1 180 IRX 1 181 IRX 1 182 IRX ;R12 > LSB OF SSQZ 1 183 OUT APU 1 184 OUT APU 1 185 OUT APU 1 186 OUT APU ;LOAD PREVIOUS SUM 1 187 DEC R12 ;R12 > MSB OF SSQZ 1 188 ; 1 189 SEX R14 1 190 OUT CMND ;FLOATING ADD 1 191 ; 1 192 SEX R12 1 193 INP APU ;STORE NEW SSQX AND CONTINUE 1 194 DEC R12 1 195 INP APU 1 196 DEC R12 1 197 INP APU 1 198 DEC R12 1 199 INP APU ;R12 > LSB OF SSQZ 1200 DEC COUNT 1201 1202 ; RESET ALL POINTERS 1203 1204 RESET LDI HI(WOIX.LO) 1205 PHI R6 LDI LO(WOIX.LO) 1207 PLO R6 ;R6 > FIRST SAMPLE 1208 J 1209 LDI HI(INSTR) -1210 PHI R14 1211 LDI L0(INSTR) PLO R14 ;R14 > THE FIRST APU-INSTR 1213 1214 LDI HI (SSQX) 1216 LDI LO(SSQX) 1217 PLO R12 ;R12 > LSB OF SSOX • 1219 ; CHECK FOR END OF INTERVAL 1220 1222 BNZ WAIT 1223 GLO COUNT ;IF NOT ZERO SKIP RMS CALCULATION 1225 ; 1226 ; RMS CALCULATION AND OUTPUT 1228 ; INITIAL: R12 > LSB OF SSOX 1229 RMSX SEX R12 1231 OUT APU 1232 OUT APU ; GET TOTAL SUM OF SQUARES (X) 1234 1235 SEX PC 1237 BYTE INTRV.LO ; LOAD INTERVALUb) 1238 OUT APU ;LOAD INTERVAL(HI) 1240 OUT CMND 1241 BYTE FIXFLT ;CONVERT TO FLOATING PT 1243 BYTE FLTDIV ;MEAN OF SQUARES 1244 OUT CMND 1246 SEX R7 1247 OUT APU -1249 OUT APU 1250 OUT APU ; LOAD FACTOR 1252 S E X PC 1253 OUT CMND 1255 OUT CMND 1256 BYTE FLTFIX ;CONVERT TO FIXPOINT 1258 SEX R1 1 1259 INP APU ;GET HI BYTE OF RMSX 1260 - OUT DAC 1 ;AND DUMP ON DAC1 1261 DEC R1 1 1262 INP APU ;WASTE LO BYTE 1263 1264 RMSY SEX R12 1265 OUT APU 1266 OUT APU 1267 OUT APU 1268 OUT APU ;GET TOTAL SUM OF SQUARES (Y) 1269 1270 SEX PC 1271 OUT APU 1272 BYTE INTRV.LO ;LOAD INTERVAL(LO) 1273 OUT APU 1274 BYTE INTRV.HI ;LOAD INTERVAL(HI) 1275 OUT CMND 1276 BYTE FIXFLT jCONVERT TO FLOATING PT 1277 OUT CMND 1278 BYTE FLTDIV ;MEAN OF SQUARES 1279 OUT CMND 1280 BYTE SORT 1281 SEX R7 1282 DEC R7 1283 DEC R7 1284 DEC R7 1285 DEC R7 ;RESET FOR CORRX 1286 OUT APU 1287 OUT APU 1288 OUT APU 1289' OUT APU ;LOAD FACTOR 1290 1291 SEX PC 1292 OUT CMND 1293 BYTE FLTMULT 1294 OUT CMND 1295 BYTE FLTFIX ;CONVERT TO FIXPOINT 1296 1297 SEX R1 1 1298 INP APU ;GET HI BYTE OF RMSX 1299 OUT DAC2 ;AND DUMP ON DAC2 1300 DEC R1 1 1301 INP APU ;WASTE LO BYTE 1302 • 1303 RMSZ SEX R12 1304 OUT APU 1305 OUT APU 1306 OUT APU 1307 OUT APU ;GET TOTAL SUM OF SQUARES (Z) 1308 • 1309 SEX PC 1310 OUT APU 131 1 BYTE INTRV.LO ; LOAD INTERVAL 1312 OUT APU 1313 BYTE INTRV.HI 1314 OUT CMND 1315 BYTE FIXFLT ;CONVERT TO FLOATING PT 1316 OUT CMND 1317 BYTE FLTDIV ;MEAN OF SQUARES 1318 OUT CMND 1319 BYTE SORT 1320 SEX R7 132 1 OUT APU 1322 OUT APU OUT APU 1324 OUT APU ;LOAD FACTOR 1325 1327 OUT CMND 1328 BYTE FLTMULT 1330 BYTE FLTFIX ;CONVERT TO FIXPOINT 1331 1333 INP APU ;GET HI BYTE OF RMSX 1334 OUT DAC3 ;AND DUMP ON DAC3 1336 INP APU ;WASTE LO BYTE 1337 1339 1340 LDI INTRV. HI 1342 LDI INTRV. LO 1343 PLO COUNT 1345 SEX R12 1346 LOUPE LDI 0 1348 GHI R12 1349 XRI HI(SSOBGN) 1351 GLO R12 1352 XRI LO(SSOBGN) 1354 IRX ;R12 > SSOX 1355 1357 . 1358 LDI 1 1360 ADI 4 ;D=D+4 1361 N3 B2 N2 1363 N2 B1 N1 1364 ADI 1 ;D=D+1 1366 SD ;PRESENT FILTER - PREVIOUS FILTER 1367 ;NEW FILTER: GO TO START 1369 1370 GLO R7 ;SAME FILTER, OFFSET FOR USED CORR.FACTORS ;OFFSET BACK 1372 PLO R7 ;R7 > LAST COEFF +1 1373 MSEC) TO SYNCRONIZE 1375 1376 WAIT GLO R7 ;R7 > LAST COEFF+1 ;RESET 1378 PLO R7 ;R7 > FIRST COEFF 1379 ; 1380 ; * * NOTE! COEFFICIENT BLOCKS MUST NOT LIE ACROSS PAGE BORDERS 138 1 1382 LDI HI (ISR) 1384 1385 LDI PLO LO(ISR) ISPC ;SET INTERUPT-PC (ON INPT ISPC BECOMES PC) 1387 1388 SEX RET PC 1390 IDL ;WAIT FOR INPTHS 1 39 1 1393 1394 PHI LDI PC LO(OFILTER) 1396 1397 SEX ISPC 1399 1400 BYTE OOH 1402 1403 PAGE 1405 1406 ; * DATA -AREA 1408 1409 ; ROM 1411 1412 SPAZE CHAN1 BYTE BYTE OOH OOH 1414 1415 CHAN3 BYTE 02H 1417 1418 INSTR BYTE BYTE FIXSUB FIXMULHI 1420 1421 BYTE BYTE FIXSUB FIXMULHI 1423 1424 BYTE BYTE 4H FIXMULLO 1426 1427 BYTE BYTE FIXSUB FIXMULHI 1429 1430 BYTE BYTE FIXSUB FIXMULHI 1432 1433 BYTE BYTE FIXCOPY 4H 1435 1436 BYTE FIXFLT 1438 1439 1440 BYTE BYTE ; COEFFICIENTS FLTMULT FLTADD FROM BILIN C16 OF NOV 3. 81 — 1441 1442 1444 ; ISO FILTER COEFFICIENTS 1445 C1XI.LO BYTE OCDH 1447 D11XI.LO BYTE OAEH 1448 D11X1.HI BYTE 85H ;-1 .91 12. . . 1450 D21XI.HI BYTE 3AH ;0.9150. . . 1451 1453 C2XI.HI BYTE 40H ; 1 0 1454 D12XI.LO BYTE OOH 1456 D22XI.LO BYTE OOH 1457 D22XI.HI BYTE OCOH ; -1.0 1459 C1ZI.LO BYTE OBH 1460 C1ZI.HI BYTE 09H ;0. 1413. . . 1462 D11ZI.HI BYTE 93H 1463 D21ZI.LO BYTE 0E8H 1465 1466 C2ZI.LO BYTE OOH 1468 D12ZI.LO BYTE OOH 1469 D12ZI.HI BYTE OOH ;0.0 1471 D22ZI.HI BYTE OCOH ;-1 .0 1472 1474 CORXI.MM BYTE 28H 1475 CORXI.MS BYTE 0B8H 1477 CORZI.LS BYTE OOH 1478 CORZI.MM BYTE 0D2H 1480 CORZI.EX BYTE 02H 1481 1483 1484 C1X1.LO C1X1.HI BYTE BYTE OEEH OOH ;2*0.007277 . . . 1486 D1 1X1.HI BYTE 80H 1487 D21X1.LO BYTE 15H 1489 1490 C2X1.LO BYTE OADH 1492 1493 D12X1.LO D12X1.HI BYTE BYTE OABH 81H ; - 1 .973 . . . 1495 D22X1.HI BYTE 3EH 1496 1498 C1Z1.HI BYTE OOH 1499 D11Z1.LO BYTE OF AH 1500 D11Z1.HI BYTE 80H ; -1 .984 . . . . — 1501 D21Z1.LO BYTE 15H 1502 D21Z1.HI BYTE 3FH ;0.9856. . . 1503 1504 C2Z1 .LO BYTE OADH ;0.0105 1505 C2Z1.HI BYTE OOH ;0 .0105. . . 1506 D12Z1 .LO BYTE OABH 1507 D12Z1.HI BYTE 81H ; -1 .9738. . . 1508 D22Z1 .LO BYTE 7CH 1509 D22Z1.HI BYTE 3EH ;0 .9763. . . 1510 1511 C0RX1.LS BYTE 1BH 1512 C0RX1.MM BYTE 42H 1513 C0RX1.MS BYTE 0D4H 1514 C0RX1.EX BYTE 04 H ; 13.266 1515 C0RZ1.LS BYTE 1BH 1516 C0RZ1.MM BYTE 42H 1517 C0RZ1.MS BYTE 0D4H 1518 C0RZ1.EX BYTE 04H ;13.266 1519 1520 ; FILTER 02 COEFFICIENTS ( 1 41-2 82 HZ) 1521 C1X2.LO BYTE ODFH 1522 C1X2.HI BYTE 01H ;2*0.0146. . . 1523 D1 1X2.LO BYTE OCH 1524 D1 1X2.HI BYTE 82H 1525 D21X2.L0 BYTE 2DH 1526 D21X2.HI BYTE 3EH 1527 1528 C2X2.LO BYTE 057H 1529 C2X2.HI BYTE 01H ;0 .4211. . . 1530 D12X2.LO BYTE 9EH 1531 D12X2.HI BYTE 83H 1532 D22X2.LO BYTE OFFH 1533 D22X2.HI BYTE 3CH 1534 1535 C1Z2.L0 BYTE ODFH 1536 C1Z2.HI BYTE 01H ;2*0.0146. . . 1537 D1 1Z2 . LO BYTE OCH 1538 D1 1Z2.HI BYTE 82H 1539 D21Z2.LO BYTE 2DH 1540 D21Z2.HI BYTE 3EH 1541 1542 C2Z2.L0 BYTE 057H 1543 C2Z2.HI BYTE 01H ;0.04211. . . 1544 D12Z2.LO BYTE 9EH 1545 D12Z2.HI BYTE 83H 1546 D22Z2.LO BYTE OFFH 1547 D22Z2.HI BYTE 3CH 1548 ; 1549 C0RX2.LS BYTE 54H 1550 C0RX2.MM BYTE 003H 1551 C0RX2.MS BYTE 0D2H 1552 C0RX2.EX BYTE 04H ;13.125 • 1553 C0RZ2.LS BYTE 54H 1554 C0RZ2.MM BYTE 03H 1555 C0RZ2.MS BYTE 0D2H 1556 C0RZ2.EX BYTE 04H ;13.125 1557 1558 ; FILTER 03 COEFFICIENTS (2 82-5 6 HZ) 1559 C1X3.LO BYTE OBAH 1560 C1X3.HI BYTE 03H ;0.02923. . . 1561 D11X3.LO BYTE 72H 1562 D11X3.HI BYTE 84H 1564 D21X3.HI BYTE 3CH 1565 1567 C2X3.HI BYTE 02H ;0.03844.. . 1568 D12X3.LO BYTE 25H 1570 D22X3.L0 BYTE 03AH 1571 D22X3.HI BYTE 3AH 1573 C1Z3.LO BYTE ODAH 1574 C1Z3.HI BYTE 03H ;0.02923 1576 D11Z3.HI BYTE 84H 1577 D21Z3.LO BYTE 070H 1579 1580 C2Z3.LO BYTE 075H 1582 D12Z3.LO BYTE 25H 1583 D12Z3.HI BYTE 88H 1585 D22Z3.HI BYTE 3AH 1586 1588 C0RX3.MM BYTE 0C7H 1589 C0RX3.MS BYTE 0D7H 1591 C0RZ3.LS BYTE OABH 1592 C0RZ3.MM BYTE 0C7H 1594 C0RZ3.EX BYTE 04H ;3.5587 1595 1597 C1X4.LO BYTE ODCH 1598 C1X4.HI BYTE 03H ;0.0603. . . 1600 D11X4.HI BYTE 8AH 1601 D21X4.LO BYTE OFEH 1603 1604 C2X4.LO BYTE OCDH 1606 D12X4.LO BYTE 25H 1607 D12X4.HI BYTE 94H ;-1.6852. . . 1609 D22X4.HI BYTE 34H 1610 1612 C1Z4.HI BYTE 03H 1613 D11Z4.LO BYTE 6AH 1615 D21Z4.LO BYTE OFEH 1616 D21Z4.HI BYTE 38H ;0 .8905. . . 1618 C2Z4.LO BYTE OCDH 1619 C2Z4.HI BYTE 09H ;0.1531 1620 D12Z4.L0 BYTE 25H 145 ••- CN co CM CN CN CD IP Id i in ID CM CM CN CD ID ID co 01 O O I I I I I I I I : I I I : CO o i O CM O iCJ CN CN: LU co o < :<_> o o it Q Oi o o ;o O i LU LU LU LU LU LU LU LU iLU LU LU H r- 1 - 1 - 1 - i i - 1 - 1 - i l - h h >- > > > > > > :> > > 03 CO CD CO 03 CO CO :C0 03 CO i o »-l (/) E ic/1 X (/) E cn x I - 1 I _ l E i s LU _1 j S S U i 1- i f •3-N IM N X X X N : N N N CM CM CM Or or :or or or i or or or CM CM o o i o o a i o o o Q Q Q i •- CJ cj iCJ CJ CJ iCJ CJ o r- co cn CM CM CM CD ID CD O »- CN CO CO CO CD CD CD Ni I I- I z < U i 03 O CJ O LU CJ K in co 0£ UJ O •~* in U- X co f in co co co CD CD CD I I I 00 t < O CO o CO t - 00 CO CO CO CD CO CD 01 O *-CD CO CD 1 1 • X I i T CM iio CO u . O CO i< — CO ;o CM CO f •* f CD CD CD I I I t o o co o CN o in CD i -t t t CO CD CO 1 1 < oo ca O O oo cn O •a- i- in CD CD CD in CD in CD CO O ro Ol CO CM cn O CO 01 CO CM CO CO Ol co CO oo CO CD 01 CO CD co 00 CD CO m CO o co CO LO co o ^~ CO o in t- CO CD ,_ i> CO r . co in 6 i O O i 6 O i O O i O CM CM • - •- •* * * •* I I I 1 < f CO 01 t-*- CM CO in in in CD CD CD in CD in in in CO CD co i l l CO U - T CO 00 O LU LU LU :LU LU LU LU UI iLU UJ LU UJ UJ iLU UJ LU LU UJ iLU UJ UJ iLU LU iLU UJ LU LU LU LU iLU LU i o LU :U1 LU UJ LU r- r- r- i l - H i l - 1— 1- i l - 1- H 1 - r- i l - 1 - 1 - i l — 1- i K 1 - i H t- i l - r- 1 - i l — K- 1— i l - 1- i O O h i l - 1- 1- i l ->->->- •>• > :> >- > ••>• > > > >- :> > > :>- > ••>• > > > > :> > > >- > > >- > or >- :> > V ;> 00 CO CO CO CO CO CO CO : 00 00 CO co ca ICQ co CO ica ca ica CO ca CO CO ica ca ca i CO CO 03 ica ca C^D O CO i n i CO CO CO CO O M i o i-< o O H H i o w o : i—I o •~i i o « il/) s 00 ix cn s t/> X :QT O " io l-t —I I i - J I i o - J i l - J I o « i — 1 1 —J i l o - J I i - J x i-> s E ;LU -1 E i E UJ :LU O - 1 1 : _ l I • i _ l I - i i _j i l i l - _ l i l • in in i m in in in in in iin in in iio in in iin in im LO in iin in in im in ; _ i CD CO iCD in x x i x X ;in in X X X X in in ;IM N N ; N in :in IM IM :|M N :x X X : X IM IM :|M N 10 iCD X X i X x *- X X CM : CM CM CM IM IM N :IM CM CM :CM CM :OT O. a. -.a a a. ioc or iu_ X i X iCM CM iCM CM i * - CN CM CN iCM CN iCM iCM CM i O O o i o o o i o o ~^ iCN CJ o o i O Q • iCJ CJ a i O O D : •- O CJ :o a O i o •- CJ iCJ O a ;a o • i o CJ o i U U O iCJ CJ • o io o o :o co oi in tn in CD co co I X o o O CM O — CM CD CD CO CD CD CD X X I o o oi o co f in CD CD CD CD CD CD I I I CN O 0) O O h CD t" 00 CD CD CD CD CO CO I X CO CN < o O 01 O *-CD IN t-10 CD CD in I- I I z o --LU O O M Id O CJ CM co t~ t~ f~ CD CD ID CO CO CM 00 CN IO CM 01 00 CM 6 in 6 O X X X CJ CO f O u . O o o in ID IN i-~ r— t— CD CO CD I I co in r~ CM co oi O i> r- co CD CD CD 1681 C2X6 . LO BYTE OOH 1682 C2X6 . HI BYTE 20H ;0.5 1684 D12X6 .HI BYTE 04H ;0.0644. . . 1685 D22X6 . LO BYTE ODBH 1687 1688 C1Z6 . LO BYTE 0D1H 1690 01 1Z6 . LO BYTE 0F3H 1691 D1 1Z6 .HI BYTE 0C4H ; -0 .9226 . . . 1693 D21Z6 .HI BYTE 25H ;0 .5851. . . 1694 1696 C2Z6 . HI BYTE 20H ;0.5 1697 D12Z6 . LO BYTE 20H ;0.0644. . . 1699 D22Z6 . LO BYTE ODBH 1700 D22Z6 .HI BYTE 20H ;0 .5133. . . 1702 C0RX6 . LS BYTE OOH 1703 C0RX6 .MM BYTE OOH 1705 C0RX6 .EX BYTE 01H ; 1 .5 1706 C0RZ6 .LS BYTE OOH 1708 C0RZ6 .MS BYTE OCOH 1709 C0RZ6 . EX BYTE 01H ; 1 5 1711 ; RAM 1712 ; — 1714 BAND BYTE 0 1715 SCRTCH BYTE 0 1717 1718 ; X-SAMPLES 1720 W01X. HI BYTE 0 1721 W1 1X . LO BYTE 0 1723 W21X. LO BYTE 0 1724 W21X . HI BYTE 0 1726 VWOX . LO BYTE 0 1727 VWOX . HI BYTE 0 ;V01 = W02 1729 VW1X . HI BYTE 0 ;VI 1 = W12 1730 VW2X . LO BYTE 0 1732 1733 V12X . LO BYTE 0 1735 V22X . LO BYTE 0 1736 V22X . HI BYTE 0 1738 ; Y-SAMPLES 1739 W01Y . LO BYTE 0 1740 W01Y . HI BYTE 0 1741 W1 1 Y LO BYTE 0 1742 W1 1Y HI BYTE 0 1743 W2 IY I n BYTE 0 1744 W21Y HI BYTE 0 1745 ; 1746 VWOY i n BYTE 0 1747 VWOY HI BYTE 0 ; V01 = W02 1748 VW1Y LO BYTE 0 1749 VW1Y HT BYTE 0 ; V1 1 = W12 1750 VW2Y LO BYTE 0 1751 VW2Y HI BYTE 0 ; V21 = W22 1752 1753 V12Y LO BYTE 0 1754 V12Y HI BYTE 0 1756 V22Y HI BYTE 0 1757 1759 W01Z LO BYTE 0 1760 W01Z HI BYTE 0 1762 W1 1Z HI BYTE 0 1763 W21Z LO BYTE 0 1765 1766 vwoz LO BYTE 0 ; V01 = W02 . 1768 VW1Z LO BYTE 0 1769 VW1Z HI BYTE 0 ; V1 1 = W12 1771 VW2Z HI BYTE 0 ;V21 = W22 1772 ; 1774 V12Z HI BYTE 0 1775 V22Z LO BYTE 0 1777 1778 SSQBGN BYTE 0 1780 SSQY BLOCK 4 1781 SSQZ BLOCK 4 1783 ENDWS BYTE 0 1784 LAST ORG 9FFH End of F i l e 4> 148 APPENDIX B  INTERNATIONAL STANDARD ISO 2631 For reasons of c o p y r i g h t the ISO standard 'Guide to the E v a l u a t i o n of Human Exposure to Whole-body V i b r a t i o n ' can not be reproduced here. Copies can be obtained from: I n t e r n a t i o n a l Standard O r g a n i s a t i o n C e n t r a l S e c r e t a r i a t 1 Rue de Varembe CH-1211 Geneva S w i t z e r l a n d In Canada c o p i e s can be ordered from: Standards C o u n c i l of Canada Fo r e i g n Standard Sales S e c t i o n 2000 Argentina Road S u i t e 2-401 Mis s i s s a u g a ONT L5N 1P7 

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