Sliding Mode Robust Control for Maximum Allowable Vertical Tail Damage to Aircraft Based on Linear Matrix Inequality

Abstract

An adaptive sliding mode fault-tolerant control method is proposed for vertical tail damage. Firstly, the damaged aircraft model is introduced, and a novel nonlinear integral sliding surface is designed. Then, a sufficient condition is proposed to guarantee a damaged aircraft kinematic model with damage degree stability by using the linear matrix inequality (LMI) technique. Next, the damage-tolerant controller is designed based on an adaptive sliding mode control for analyzing damaged aircraft systems. Furthermore, the hyperbolic tangent function is utilized to replace the symbolic function in the controller; it is worth mentioning that it has been proven theoretically. Finally, an example for a Boeing-747 100/200 model is given to demonstrate the efficiency of the theoretical results by recognizing the structural fault of the aircraft. The numerical results show that the control law has a positive impact on the performance of the closed-loop system, but compared with the traditional damage aircraft stability control method, the control law has better fault tolerance and robustness to external disturbances.