ELECTRIC POWER ASSIST SYSTEM INCLUDING ELECTRIC POWER ASSIST MODULE FOR WHEELCHAIR TRAVELING ON STAIRS AND STEPPED TERRAIN, AND CONTROL METHOD FOR ELECTRIC POWER ASSIST MODULE

摘要

The present invention provides an electric power assist system provided in a wheelchair frame, in which a seat part on which a rider sits is provided on a frame having a footrest and a handle, and driving wheels are provided on both sides of the frame. The electric power assist system is characterized by comprising: a caterpillar part in the form of an endless track-type traveling member which is mounted to the wheelchair frame to allow the wheelchair frame to ascend or descend stairs or stepped portions; a landing gear part which is provided in the caterpillar part and has front and rear free ends that ascend or descend about the center of gravity of the wheelchair frame; a three-axis acceleration sensor for measuring the x, y, and z-axis accelerations of the caterpillar part; and a control unit for calculating the roll angle and the pitch angle from data from the acceleration sensor, and estimating the yaw angle of the caterpillar part, wherein, when one end of the landing gear part ascends, the caterpillar part ascends and contacts a stair or stepped surface, and then the wheelchair frame is driven by the caterpillar part to travel on the stepped portions, thus allowing the wheelchair frame to ascend or descend the slope of the stair or stepped portion without an assistant.