A joystick steering control system with variable sensitivity for stable high speed driving

This paper presents a steering-wheel control system with a joystick interface for stable car driving at a high speed. The joystick drive system allows a handicapped person to drive a car using a joystick interface with a small force and short stroke. However when a vehicle running at a very high speed, a wrong joystick operation, such as a sudden and wide steering, results in a car accident quite easily. The additional problem is that a car could not be controlled stable if joystick sensitivity is not appropriate especially at high speed. The other hand when parking a car, a large steering angle provides easy parking maneuvers to a driver. To realize these multiple requirements and solve some problems for the steering control, we propose a steering control system with a steering angle restriction and a variable sensitivity function based on vehicle velocity information. In this paper, some types of variable sensitivity methods are proposed and one of them is selected through driving tests by a human driver. By the variable sensitivity function, approx. 85km/h driving is realized.