Comparative of disturbance suppression effect of Robust Steering control law by differential estimation methods

Abstract

Recently, in the steering control system based on the steer by wire and the automatic operation, it is possible to flexibly change the relationship between steering input and vehicle response characteristics. In the previous research, robust stabilization by H.inf. Control and model following control Automatic steering by LQG control optimal observer such as vehicle steering system considering uncertainty of vehicle dynamics model, improvement of vehicle performance by robust control rule, and inverted pendulum control by robust model matching Applied research has been applied. Based on such background, we extend the original state variables (yaw rate, transverse slip angle, and steering angle) of an optimal observer and add the disturbance model which models the frequency spectrum of the disturbance as a state variable, and estimate the disturbance value simultaneously with the estimation of the original state quantity. In this paper, we propose a new method of control law, which is based on the estimation of the disturbance value and to obtain the desired response by state feedback. This paper reports the effect of robust steering control law by combination of model matching and optimal observer capable of realizing robustness to input disturbance while realizing steering desired response by proposed steering control system. In the case of the robust control law for an automobile, it is assumed that the disturbance estimation by the optimal observer is suitable to suppress the whole disturbance energy. In this paper, we show the robust control effect of the steering control law on the real vehicle motion in the case where an optimal observer and an H∞filter are observers.