Safe driving algorithm of the electric wheelchair with model following control

Abstract

The wheelchair motion has propulsion and rotation components and the x-y axis signals of the joystick also can be expressed as the control command of these components. Using this phenomenon, the torque distribution method of two driving wheels and the model following control algorithm based on the propulsion and the rotation model of the electric wheelchair is proposed. The proposed torque distribution method gives smooth and precise driving performance on the land because the torque references of each wheel are continuous and sinusoidal according to the joystick position. Moreover, comfortable control performance can be obtained by adjusting the sensitivity coefficients of the joystick. On the various road conditions, it is possible to move safely because the model following controller gives the compensated torque to each wheel to track the model speed and direction even if one wheel is fixed by an obstacle. The feasibility of the proposed safe driving algorithm is verified through digital simulations.