Actuator Fault Optimal Adaptive Compensation Control For A Class Of Nonlinear Systems

In this paper,we study how to solve the optimal tracking control problem for a class of multi-input multi-output(MIMO)affine nonlinear continuous-time systems with actuator failures.In the aspects of state tracking,output tracking and system uncertainty,a set of optimal adaptive compensation control methods are proposed for MIMO nonlinear systems based on adaptive dynamic programming,neural network and adaptive compensation control.Firstly,an optimal adaptive compensation control law is designed to solve the state tracking problem of a class of MIMO nonlinear systems with actuator failures.Considering stuck actuators and partial effectiveness failures,an adaptive parameter adjustment law is designed to estimate the actuator failure coefficients.An adaptive dynamic programming method is adopted to obtain the approximate optimal input by using neural network to approximate the cost function.It adjust the weights of the neural network by using an online adaptive algorithm.The proposed optimal adaptive compensation law can guarantee that the closed-loop system with actuator failures is stable and the given reference signals are effectively tracked.Secondly,in order to make the system can handle more engineering object,an optimal adaptive compensation control method is proposed to solve the output tracking problem of a class of MIMO nonlinear systems with actuator failures.Considering stuck actuators and partial effectiveness failures,an optimal adaptive output tracking control law based on neural network and adaptive dynamic programming is designed.The proposed optimal adaptive compensation law can guarantee that the closed-loop system with actuator failures is stable and that the given reference signals are effectively tracked.Furthermore,the output tracking control method simplifies state tracking algorithm in the previous chapter.Further,considering the system uncertainties and external disturbance,a state observer is designed by using neural network to estimate the uncertainty of the system.The optimal adaptive compensation control law based on adaptive dynamic programming is designed to solve the output tracking problem of a class of MIMO uncertain nonlinear systems with actuator failures.The control scheme is applied to the tailless flying wing aircraft longitudinal nonlinear dynamic model with unknown term.Finally,in this paper all the design methods of control law are verified by using the tailless flying wing aircraft longitudinal nonlinear dynamic model.MATLAB simulation software is used to realize the simulation of aircraft fault tolerant control and the simulation results demonstrate the effectiveness of the proposed method.