Improving wheelchair-driving using a sensor system to control wheelchair-veer and variable-switches as an alternative to digital-switches or joysticks

Purpose – The purpose of this paper is to present powered-wheelchair transducers and systems that provide more control, reduced veer on slopes, and improved energy conservation, while reducing effort. They are especially significant for people with movement disorders who lack sufficient hand-grasp and release ability or sufficient targeting skill to use joysticks.

Design/methodology/approach – Laboratory test rigs are created to test proportional switches and teach potential users. Then, trials are conducted with a rolling road and in real situations. Caster angle-measurement is selected to provide feedback to minimize drift away from a chosen course and an electronic solution was created to match driver control to caster-steering-position. A case study is described as an example.

Findings – Results and advantages are presented from changing from using a set of digital-switches to a set of new variable-switches and then adding a sensor system to prevent veer on slopes. Systems have been tested for nearly two years and shown to assist powered-wheelchair-users with poor targeting skills.Research limitations/implications – The research used wheelchairs with caster-wheels but the systems could easily be used on other wheelchairs.

Practical implications – Simple input-devices are presented that isolate gross motor function and are tolerant to involuntary movements (proportional-switches). A sensor system is presented that assists users in steering across sloping or uneven ground.

Originality/value – Proportional-switches and sensors are shown to reduce veer and provide more control over turn and forward speed and turn radius while reducing frustration and improving energy conservation. The simple and affordable systems could be created and attached to many standard powered-wheelchairs in many organisations.