An Electric Powered Wheelchair (EPW) is a key mobility device for people with disabilities providing mobility, independence, and improved quality of life. However, the design of current EPWs remains limited when driving in environments with architectural barriers and uneven terrain, making EPW users susceptible to safety issues - such as tipping or falling - which may lead to serious injury. To overcome these limitations, we developed a series of control algorithms for a novel mobility enhancement robotic wheelchair (MEBot).
MEBot consists of six wheels with pneumatic actuators to control the elevation and inclination of the wheelchair as well as electric actuators in the driving wheel carriage to change its driving wheel configuration. Its controller is comprised of a single board computer, and a sensor package that aids obstacle detection and provides information about joint movements to develop MEBOT’s control algorithms. The ability of the MEBot controller to perform control algorithms, such as the dynamic seat leveling, curb climbing, and descending applications, was evaluated and validated in both simulation and a controlled environment for broader accessibility in architectural barriers. A stability analysis showed that while the footprint of the wheelchair changed during the process of its control algorithms when overcoming architectural barriers such as curbs and slopes; MEBot maintained its center of mass within the wheelchair footprint.
Furthermore, a usability evaluation with ten power wheelchair users was conducted to compare the MEBot’s controller with that of their own power wheelchair in simulated indoor, outdoor, and advanced (architectural barriers) environments. Results show that MEBot was able to perform a significantly higher number of tasks than currently available commercial power wheelchairs in the advanced environment. In addition, participant’s feedback was obtained for further improvement of the device and its control algorithms
