Voice controlled wheelchair.

A voice recognition and control system for use by quadriplegics and other severely physically disabled individuals in controlling a wheelchair has been developed and tested. Several wheelchair compatible features are included in the design--low power consumption (approximately 20 watts), small size (10"x11"x14"), low weight (approximately 22 lb), and no need for wheelchair modification (existing joystick control cable plugs directly into this system). The current system uses an eight word vocabulary (e.g., "forward," "slower," "right,") and a feedback control system to maintain the chair speed and direction. A recognition rate of more than 90% has been attained in laboratory tests with experienced speakers. Future system improvements are planned to increase the recognition rate and practical utility of the chair. The results of laboratory tests with normal and quadriplegic subjects indicate that voice commands are potentially a useful and practical means of wheelchair control. The effects of environmental noise are investigated and found to be minimally deleterious.