Research on model reference sliding mode control in roll stabilization of aerocraft

Abstract

Aimed at aerospace roll stabilization, control arithmetic based on model reference sliding mode variable structure theory and chattering reduction arithmetic are formulated. Correctness and validity of arithmetic are analyzed. With flight dynamics, the roll-loop mathematic model and reference model are established. Sliding hyperplane is deduced based on model reference sliding mode variable structure theory. Combing with reaching law, control law is derived, and stability of roll-loop is analyzed. Chattering of aileron instructions is alleviate by using boundary layer approach. Digital flying simulation result shows that variable structure control arithmetic realized roll stabilization control, the roll angle is less than 5.3° under powered flight, and that of unpowered flight is less than 0.5°, respectively. The command fin angle is less than 1.5°. High frequency chattering of fin command nearby the minimum velocity was trailed off by chattering reduction arithmetic. The sliding mode control arithmetic show good performance when aerodynamic coefficients varies 20%. The control arithmetic is easy to be implemented for its simplicity.