Designed Interface for Users of Powered Wheelchair with Arms or Hands Deficiency 2007-01-2867

Actually, wheelchair users with impairment or total lost of movements in arms or hands have many difficult to operate conventional motorized wheelchair. This project develop and integrate support systems having focus in a friendly user interface, like voice recognition, filters in joysticks, sonar for collision avoidance and motor drivers, all integrated by a hierarchic control architecture. Voice recognition was developed in two different architectures and implementations methods: the first by using commercial voice recognition software and the second by a microcontroller firmware, allowing a significant cost and weight reduction. For wheelchair user with hands or arms impairment like repetitive strain injuries or muscular dystrophy a joystick filter must to be used to interpret the movements where oscillate around a desired position. Since different kinds of interfaces and inputs are used, a consistent integration is necessary between them. The integration system uses a hierarchical logic, meaning that are some inputs are predominant than others when used, and stays in an idle condition until an event occurs. Hierarchical logic can be used for input management or obstacle avoidance, when an unsafe command is performed, like to drive to close of a wall, when the navigation system will disable some movement's directions. To evaluate this project, a prototype was built in reduced scale, but conserving all sensors and navigation architecture characteristics.