Modelling and Simulation of an Ultrasonic Tethering Smart Wheelchair System for Social Following

Abstract

Distracted navigation causes 20% of all powered wheelchair accidents. In social situations, wheelchair users must divide their attention between navigating the chair and conversing with an accompanying person. These conversations could lead to increased mental stress and distractions from maneuvering the chair. This project aims to eliminate the need to manually control a powered wheelchair when moving and conversing with an accompanying person, by controlling the wheelchair’s path to follow beside a person. This includes identifying and determining the person’s pose to control wheelchair navigation. The proposed ultrasonic tethering system was developed and simulated on Matlab and Simulink using models for ultrasonic sensors, amplification and filtering circuits, and a processing unit. Unlike infra-red sensors and cameras that are highly dependent on environmental light conditions, ultrasonic sensors are inexpensive and independent of environmental conditions. Simulation results determined wheelchair direction based on the accompanying person’s position, suggesting that ultrasonic tethering can be used for side-by-side following. The simulation results can be used to determine circuit component parameters for developing an ultrasonic tethering prototype.