Research and development of a joystick car drive system for handicapped persons

This paper presents a system design of a joystick car drive system for safe and comfortable user interface. The joystick drive system allows a handicapped person to drive a car by using a joystick with small force and short stroke. However when a vehicle running in a very high speed, a wrong joystick operation, such as a sudden and wide steering, results in a car accident quite easily. The other hand, quite sensitive steering control is required around the center of steering angle when a car runs along a straight line. When parking a car, large steering angle provides easier parking maneuverings to a driver. To realize these multiple requirements and solve some problems for the steering control, we propose a steering control method with variable steering sensitivity and steering limitation based on a vehicle velocity. Addition to the steering control, pedal actuating system enables to controls acceleration or deceleration of a car by the joystick operation in back and forth direction. To reinforce the safety of a car in case of system fault, an emergency brake system is also developed which is actuated by accumulated high pressure air.