Abstract
This paper presents an optimal control method which is based on a newly established framework of control problem and its application for steer-by-wire system. This framework is composed of obtaining the ideal characteristics of the system for a given criteria function and solving the equations of motion by using the inverse of ideal characteristics function as an optimal control law. The criteria function is defined as the combination of energy flow equation and performance measures. Minimization of the criteria function yields the ideal characteristics. In this paper, the necessary condition for optimality is given and the optimality is proven. Steer-by-wire system has the range of the front steer angle about ±30 deg. It is not easy to find the technique theoretically for controlling the control variable region in such a large steering angle. This control theory is applied to steer-by-wire and it is clarified that an emergence pattern was generated in the wave form of control signal and the performance was increased in the high-speed rapid lane change situation.
