Abstract
A power-assisted cart for stair-climbing with planetary wheels is proposed. The planetary wheel is composed of planetary arm whose rotation is power-assisted by a motor and free wheels on the ends of planetary arm. With proportional power-assist control algorithm which commands motor by proportional torque to sensed drag force by human, reduction of the drug force up to 30% is observed. Speed of stair-climbing become faster for higher power-assist gain. So it is considered that the operator controls horizontal motion while vertical motion is assisted by the motor. Two planetary wheels with different dimensions are experimentally compared and better design or power-assist control is selected.
