Research On Longitudinal Control Of Aircraft With Thrust Vectoring

This thesis works mainly on the problem of nonlinear control method of the new generation fighter with thrust vectoring. With a brief review of the development history of aircraft and detail discussion of main technique features of the new generation fighter, brings forward the research topic of super-maneuver flight control and analyses the latest study status.Firstly, a mathematical model is presented, which is based on the features of the new generation fighter. A flight control law is designed with singular perturbation theory and nonlinear dynamic inversion method, and the general aerodynamic deflection and the thrust deflection is alloted by progressive increase method. Then in order to reflect the effectiveness of the control law at high-angle-of-attack, the numerical simulation of longitudinal maneuver at high-angle-of-attack is done with the NDI method. By discussing the application of dynamic inversion theory to nonlinear flight control, illustrates the limitations of this method.Secondly, Sliding mode control(SMC) shows a strong vigor on controlling an uncertain nonlinear system for its excellent robustness and complete adaptability to matching uncertainties and external perturbations,a discussion is devoted to the design of the control systems of the new generation fighter based on the sliding mode control. Then, in order to eliminate the chattering that exist in the sliding mode control system, a fuzzy controller is designed; To solve the problem of enable to establish accurate mathematical model, combining the advantages of RBF neural networks(RBFNN)and SMC, and introducing RBFNN into SMC. In the end, an adaptive sliding mode control based on is designed. It uses RBF neural network to approximate the system uncertain dynamic, designs the weights adaptive laws, The stabilities of this method are proved strictly based on Lyapunov’s direct method. at the last, the longitudinal maneuver at high-angle-of-attack is simulated under the designed integrated flight/propulsion control system. Through the analysis of simulation results, this scheme can promise that the tracking errors converge to zeros in finite time, and can improve the response speed of the system rapidly. The designed control system is effective.