Shared control strategies for human-machine interface in an intelligent wheelchair

Selecting a Best Compromise Direction for a Powered Wheelchair Using PROMETHEE

Research is described that determines the direction that a powered wheelchair will take, using the preference ranking organization method for enrichment of evaluations II (PROMETHEE II). This is the first time that this sort of decision making has been used in this type of application. A user suggests a desired direction and speed, and the decision-making system suggests a safe direction for a wheelchair. The two are mixed, and the wheelchair then tends to avoid obstacles. The inputs come from a powered wheelchair joystick and two ultrasonic transducers fixed onto the wheelchair, and the final direction is a simulation of the desired direction and a direction that moves the wheelchair away from obstacles. The arrangement assists a disabled driver to steer their wheelchairs. It uses a systematic decision-making process, and this paper presents the process and a new way of selecting a best compromise direction. Sensitivity analysis is employed to explore potentially suitable directions as uncertainty and risk may be present. A suitable direction is selected that provides a robust solution. The user would be able to override the suggestions by the PROMETHEE II system by holding the joystick in a position.