Low-cost smart electric wheelchair with destination mapping and intelligent control features

Wheelchairs provide immense impact for the physically challenged as they offer mobility with relative ease. But in cases like severe disability or seeking relief from physical exertion, there is a necessity for automated electric wheelchairs which are very expensive. In this paper, an innovative design and implementation of a robust and user-friendly smart electric wheelchair are presented, where the product cost is minimized considering the affordability of a large group of people. A notable feature of the proposed scheme is `Destination Mapping' by which the smart wheelchair learns the destinations accessed by the user and autonomously reaches those destinations afterward using speech recognition. There are also various smart features such as rough surface detection, torque adjustments, slope and obstacle detection which promise a comfortable and safe ride. The proposed system takes input from a joystick, microphone, rotary encoders and sonar sensors, processes them through a microcontroller and eventually drives the motors through a motor driver. After much study on selecting suitable motors for implementation, windshield wiper motors were used as they produce quite enough torque at low rpm and are locally available as recycled parts. Experimentation has been carried out with 50 disabled persons of various age groups and subsequent improvements were undertaken based on their feedback over the timeframe of 1 year. Satisfactory results were obtained which implies that the proposed wheelchair can really serve as a low-cost smart alternative to aid the physically challenged, which has a tremendous potential impact on society.