Control of omni-directional intelligent wheelchair based on sitting postures

A large number of wheelchairs are manipulated via joysticks. But for the different degree of the handicapped, joystick does not fit for any disabled person and it will limit the users´ hand behaviour, especially in sport for them. This paper elaborates a more effective and hands-free method to control the intelligent wheelchair (IW), and describes the details of control algorithm on the omni-directional platform. The algorithm controls the IW´s directions and velocities according to user´s different sitting postures. Using the information from the force sensors under the seat surface, the different 2D position of gravity centre will be calculated out to control the intelligent wheelchair in response to the user´s leaning in different directions and velocities. Furthermore, it describes the motion mathematical model of the omni-directional wheelchair platform and provides control system hardware structure as well. Experiment results eventually indicate that the sitting postures control function is realized accurately, effectively in directions and velocities.