The Design of Adaptive Sliding Mode Control Law on Reconfigurable Flight Control System

The flight environment of aircraft is very complex, it is necessary that the reconfigurable flight control system possesses a strong robust stability. The sliding mode variable structure control doesn't rely on accurate aircraft mathematic model, and can overcome inner model uncertainty and exterior disturbance in the system, to make the system to track reference model as high precision. A design method of reconfiguration flight control law based on adaptive sliding mode variable structure control is proposed in this paper. A unit vector approach is applied for sliding mode controller which is composed of linear and nonlinear components. A linear quadratic optimal controller is designed for the linear part, and adaptive gain in the nonlinear part is adapted for the different control surface damages. The simulation analyses are done for the reconfigurable flight control system of an aircraft lateral model. The results show that the effectiveness and feasibility of the proposed control law in the case of the aircraft control surface loss-of-effectiveness failures and the reconfigurable flight control system has better tracking performance for the reference signal.