Cross-coupling control of a powered wheelchair driven by rim motors

Abstract

This paper proposes a time-optimal path-tracking strategy of cross-coupling control for a wheelchair driven by dual power wheels. Each power wheel is integrated by a rim motor, a battery bank, a brake, and a controller. The control strategy is responsible for adjusting the speed ratio of dual power wheels to maintain a direction of motion that the driver commands under any road circumstance. Since the wheelchair motion is dynamically coupled with the left and right wheel speeds, the time-optimal path-tracking strategy is to compensate both wheel speeds with equal speed difference by predicting the intended path of motion. Experimental results show that the proposed cross-coupling control system is robust to driver's weight and road disturbances.