Selecting a Best Compromise Direction for a Powered Wheelchair Using PROMETHEE

Abstract

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 mix 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 is able to override the suggestions by the PROMETHEE II system by holding the joystick in a position.

Initial Results from Using Preference Ranking Organization Methods for Enrichment of Evaluations to Help Steer a Powered Wheelchair

“…This paper described the successful use of a PROMETHEE II outranking method [3,4] for collision avoidance in wheelchairs [29]. The MCDM system [1,2] proved to be reliable and trustworthy.…”

“…MCDM assessed alternatives in an effort to select a suitable direction with regard to multiple and sometimes conflicting criteria [1][2][3][4].…”

“…A Multi-Criteria Decision Making (MCDM) system [1][2][3][4] is described that will assist in controlling a powered wheelchair [5][6][7][8][9][10][11]. Ultrasonic sensors [12,13] provide information about the surroundings of the wheelchair [5][6][7][8][9][10][11] and the systematic decision-making process [1][2][3][4] can help a disabled driver to avoid obstacles [14][15][16][17][18][19][20][21][22]. A desired direction is provided by the human wheelchair driver and the sensor system [23][24][25] suggests a new direction.…”

“…This paper presents an MCDM system [1][2][3][4] that can quickly react to obstacles to avoid them [6][7][8]. A best compromise direction is selected for collision avoidance.…”

“…A best compromise direction is selected for collision avoidance. A joystick provides a desired speed and direction and the MCDM system [1][2][3][4] modifies those inputs if an obstacle is detected. The user inputs are traded off against the detected distance to an obstacle.…”