A navigation system for increasing the autonomy and the security of powered wheelchairs

Assistive technology is an emerging area where some robotic devices can be used to strengthen the residual abilities of individuals with motor disabilities or to substitute their missing function thus helping them to gain a level of independence at least in the activities of daily living. This paper presents the design of a navigation system and its integration with a commercial powered wheelchair. The navigation system provides the commercial wheelchair with a set of functions which increase the autonomy of elderly and people with motor disabilities. In general, a robot device must be adapted to assistive applications in such a way as to be easily managed by the user. Users, especially young ones, prefer to directly control the robotic device and this aspect of usability has to be managed without affecting the security and efficiency of the navigation module. These aspects have been considered as specifications for the navigation module of powered wheelchairs. Different autonomy levels of the navigation module and proper user interfaces have been developed. Two autonomy levels have been designed. Simple collision avoidance is also implemented in order to stop the mobile base when an obstacle is detected. The preliminary technical tests performed on the navigation system have shown satisfactory results in terms of security and response time. A modular solution for the navigation module was considered in order to simplify the adaptation of the module to different powered wheelchairs.