Development of power wheelchair chin-operated force-sensing joystick

An chin-operated force sensing powered wheelchair joystick was developed. Because of stick displacement of conventional position joystick, it is difficult for the chin-operated wheelchair users to operate a powered wheelchair. Compared to the conventional position sensing joystick, people using a chin-operated force sensing joystick do not need to move their head quickly and accurately. They just need to give a little different direction force to the joystick stick. The force sensing joystick shaft is made of case hardened steel, the area for strain gages was machined flat. The length and diameter of the shaft was designed to exhibit a strain response in the linear operating range of the strain gauges. The forces needed to control a powered wheelchair is 0.2∼0.8 pounds. The hardware and software design method for the chin-operated force sensing joystick were introduced in this paper.