Document Type


Presentation Date



Mechanical and Aerospace Engineering


Approximately 180,000 persons who have a need for a powered wheelchair (PWC) suffer from Parkinson's’ hand tremor that makes it difficult, even potentially dangerous, for them to operate it. Persons with hand tremor that attempt to operate a PWC have to try to compensate for their tremor, which may not be realistically possible if the tremor is severe enough. Hand tremor can lead to sudden changes in PWC joystick commands that could result in unsafe PWC movements and collisions resulting in injury and/or property damage. These tremor sufferers are candidates for an assistive PWC. As a step toward assistive PWC, the tremor is measured in two axes using a joystick and data collection system. The peak tremor power frequency is used as the basis for a notch filter to mitigate the effect of the tremor on joystick commands to the PWC. To safely test the effectiveness of the tremor notch filter, a virtual reality system is developed that allows for physical PWC operation without actual movement. Hardware was successfully developed and tests conducted with non-tremor and tremor subjects to demonstrate the data collection gathering capabilities and tremor filter effectiveness. Further, the joystick and movement data from the PWC operation are used in the assessment of a human operator model for future PWC developments without human testing. The model is based on a predictive controller that considers the human planning horizon and muscular delay.