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UBC Theses and Dissertations
Improving the dynamic performance of multiply-articulated vehicles Rempel, Michael R.
Abstract
Current heavy vehicles having two or more trailers suffer from unique dynamic characteristics which limit both their stability and maneuverability at speed. The control of these characteristics in A-train vehicles is the objective of this work; specifically, the attenuation of rearward amplification and high-speed offtracking. Control is attained is through automatic steering of the A-dolly axle; the control system is localized entirely on the A-dolly, creating a modular and easily-implemented unit. The equations of motion were derived for a reference A-train vehicle, and the results simulated and compared to literature. A nonlinear two-dimensional yaw plane model with semi-static load transfer in the pitch and roll modes was found to adequately display the intended system characteristics. To apply control, a second linear state space model was created, based on the behavior of the A-dolly and the second semitrailer only. For high-speed, low amplitude maneuvers under feasible input frequencies, the results corresponded to the nonlinear simulation. Control was achieved using a state variable feedback controller to steer the dolly wheels; the gains were determined by moving the plant eigenvalues via Ackermann's method to the critically-damped locations of the "faster" mode. The controller was shown as to be robust to parameter estimation errors and to balance performance and required control inputs well. An Extended Kalman Filter (EKF) was employed to estimate the unknown tire cornering properties and states not measurable direcdy from the A-dolly. Through simulation, it was found that the controller was effective in reducing both the observed rearward amplification and the dynamic offtracking, although the effectiveness decreased with increasing forward velocity. At the nominal velocity for interstate highways in the United States (24.6 m/s), the peak improvement in rearward amplification under control was reduced to a minimum of 25 percent of the uncontrolled value; the peak value of offtxacking was reduced up to 50 percent.
Item Metadata
Title |
Improving the dynamic performance of multiply-articulated vehicles
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2002
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Description |
Current heavy vehicles having two or more trailers suffer from unique dynamic characteristics
which limit both their stability and maneuverability at speed. The control of these
characteristics in A-train vehicles is the objective of this work; specifically, the attenuation of
rearward amplification and high-speed offtracking. Control is attained is through automatic
steering of the A-dolly axle; the control system is localized entirely on the A-dolly, creating a
modular and easily-implemented unit.
The equations of motion were derived for a reference A-train vehicle, and the results simulated
and compared to literature. A nonlinear two-dimensional yaw plane model with semi-static
load transfer in the pitch and roll modes was found to adequately display the intended system
characteristics.
To apply control, a second linear state space model was created, based on the behavior of the
A-dolly and the second semitrailer only. For high-speed, low amplitude maneuvers under
feasible input frequencies, the results corresponded to the nonlinear simulation. Control was
achieved using a state variable feedback controller to steer the dolly wheels; the gains were
determined by moving the plant eigenvalues via Ackermann's method to the critically-damped
locations of the "faster" mode. The controller was shown as to be robust to parameter
estimation errors and to balance performance and required control inputs well. An Extended
Kalman Filter (EKF) was employed to estimate the unknown tire cornering properties and
states not measurable direcdy from the A-dolly.
Through simulation, it was found that the controller was effective in reducing both the
observed rearward amplification and the dynamic offtracking, although the effectiveness
decreased with increasing forward velocity. At the nominal velocity for interstate highways in
the United States (24.6 m/s), the peak improvement in rearward amplification under control
was reduced to a minimum of 25 percent of the uncontrolled value; the peak value of
offtxacking was reduced up to 50 percent.
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Extent |
6629777 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-08-14
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0090274
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2002-05
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.