Experimental comparison of torque balance controllers for power-assisted wheelchair driving

Abstract

A power-assisted wheelchair amplifies the user’s propulsion power. If the user’s arm strength is unbalanced, this can affect the driving balance. In order to correct this imbalance, a method of producing an assisting torque by cross-referencing the opposite input torque was developed. One proposed torque balance control scheme involves automatically controlling the cross-reference proportion according to the amplitude ratio of the left and right input torques. However, this scheme cannot improve the driving performance under all conditions because instability is inherent to the user’s propelling torque. To resolve this problem, a new torque balance control method is proposed that considers not only the proportion of input torques but also the temporal difference. This study examined the usefulness of the proposed torque balance control method based on the temporal difference through a comparison with the existing method via a driving simulation and experiment.