UBC Theses and Dissertations
Towards an affordable multi-DOF force feedback motion control input device Yu, Zhang
A novel multi-degree-of-freedom force feedback motion control input device design has been proposed for 3D human-machine applications. This haptic device utilizes a new electro-mechanical design to achieve a large translation range for each axis of motion, while remaining suitable for mass production at low cost. Parallelogram linkages have been used to obtain displacements along each axis. The current device prototype uses an orthogonal arrangement of three parallelogram linkages to obtain displacements along all axes in Cartesian space. Springs have been used to center the device and a slot-and-tab hinge structure has been designed and used as a practical joint. An affordable and compact microelectronic sensor that is based on a grayscale with varying reflectance has been employed in order to sense the end-effector position. The nonlinearity of the sensor has been addressed and linearly compensated. A Lorentz force-based linear actuator design has been proposed. The actuator consists of a stator and a slider. The equivalent magnetic circuit model has been derived to assist the design computations. Experimental results show that the magnetic flux density along the air gap is approximately uniform and that the actuating force, although its level needs to be increased for use in the commercial product, is a linear function of the current applied to the coil windings on the slider. The device kinematics and dynamics have been derived and simulations have been performed to investigate the relationship between joint trajectories and work space actuating forces.
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