Cost-Effective Vision based Obstacle Avoidance System integrated Multi Array Ultrasonic sensor for Smart Wheelchair

Abstract

A smart wheelchair (SW) is a power wheelchair (PW) consist of microcontroller, actuators, sensor, and implement the assistive technology in system architecture. Users with severe motor impairment may realize the difficulty to operate a wheelchair when they are in a tight space such as passing a doorway or when avoiding obstacles since, they are unable to control the wheelchair. This project embarked on an obstacle avoidance system of a wheelchair. This project developed a cost-effective system that alarmed the user to avoid obstacle on its path. The prototype includes a Kinect camera and ultrasonic sensors. Kinect camera was placed at the right side of the wheelchair for real time video obstacle detection. Four of the ultrasonic sensors was used to detect obstacle at the front and one ultrasonic sensor for rear obstacle detection. Any obstacle detected by the ultrasonic sensors triggered the buzzer. Obstacle detected by Kinect camera was displayed with specific command for the user in attempt for obstacle avoidance. The performance of the obstacle avoidance system was tested indoor to detect obstacles in a controlled environment. The accuracy of the ultrasonic system was tested at a specific distance of 20mm to 200mm at 20mm intervals. Real time video received from the Kinect Camera was used to analyse the depth of the environment and the location of the object.