Abstract
Visually impaired (VI) people face many daily life challenges. It is often difficult for them to recognize where they are, and they may feel disoriented or completely isolated. Moreover, people who have other motor disabilities besides visual impairment face even more difficulty. For example, when using a wheelchair, they usually need a personal assistance to help them navigate to their destination, since they cannot use a cane or other manual assistive devices. To help these people, we aim to develop an indoor wheelchair navigation system. The system is divided into three components: a positioning system, a navigation system and a VI system interface. In the current research, we focus on the design of the navigation system, which will build the optimal path for a VI user on an electric wheelchair. To navigate, the user chooses a destination and their route preferences. A specially designed algorithm will construct an optimized path to the destination, by processing a map of the environment and the route preferences. The algorithm will take into account particular route features customized to the needs of the VI, such as: being free of obstacles, having few turns, being close to walls, and accommodating clues and landmarks. Our navigation system uses the A* shortest path algorithm for path construction, after adapting the objective function to take into account multiple criteria that fit the requirements of a visually impaired. The output of the algorithm is the moving directions, which will be fed back to the wheelchair as commands to direct its movement to the desired destination.