Research On Anti-disturbance Tracking Control Algorithm Based On Hypersonic Vehicle

In the research of various aircraft,hypersonic vehicle has many advantages of flight speed and concealment,which makes it to be the main research objective in the field of near space flight technology.Compared with the traditional aircraft,the propulsion system and dynamics of hypersonic vehicle has usually the characteristics of strong coupling and nonlinearity on account of the airframe/engine integrated design manner.At the same time,due to the complexity of the near space environment,how to design a controller with satisfactory performance under the influence of unknown disturbances has attracted extensive attention in the field of automatic control.Taking the hypersonic vehicle model published by NASA Langley research center as the objective,and by using intelligent disturbance modeling and disturbance observer(DO)design scheme,this paper designs a series of feasible anti-disturbance control algorithms and further systematically analyzes the dynamic performance under the influence of exogenous disturbances.The main contents of the paper are as follows:(1)By discussing the modeling process of longitudinal model of hypersonic vehicle,the anti-disturbance tracking control algorithm is studied under the framework of T-S disturbance modeling.The linearized model is obtained at a certain equilibrium point in the flight envelope by using small perturbation linearization method,and the rationality of the general hypersonic vehicle model is verified.Considering the influence of exogenous disturbances on system performance,the T-S fuzzy model is used to model the disturbances,and the DO is designed to estimate the unknown irregular disturbances.Furthermore,by combining PI control input with disturbance estimated value,a convex optimization-based composite controller is proposed to realize the dynamic compensation of disturbance and ensure the stability and the dynamic tracking performance of system.(2)The anti-disturbance tracking control problem for linear model of hypersonic vehicle is studied under the framework of neural network(NN)disturbance modeling.The NN model with adjustable parameters is introduced to model the irregular disturbances.Based on the exogenous model,a DO is proposed to estimate the unknown disturbances.Furthermore,by combining the designed adaptive parameter adjustment algorithm and the convex optimization theory,the PI controller gain and disturbance observer gain are calculated to realize the estimation and compensation of the irregular disturbances.Based on Lyapunov analysis method,it is proved that hypersonic vehicle has satisfactory stability and dynamic tracking performance under the influence of disturbances.Finally,the simulation example verifies the modeling ability of NNs for different disturbances,and further ensures good dynamic performance of the aircraft.(3)The anti-disturbance tracking control of longitudinal model of hypersonic vehicle is studied by using dynamic neural network(DNN)identification.In order to overcome the shortcoming of large modeling error caused by disturbance linearization,the longitudinal model of hypersonic vehicle with nonlinear term is directly considered.On this basis,the DNN model is introduced to identify the nonlinear dynamical model.By designing the nonlinear DO and the adaptive control algorithm and computing the observer gain,the objective of identification for aircraft model and the estimation for exogenous disturbance can be achieved simultaneously.Furthermore,the tracking controller is designed with Nussbaum function,and the corresponding Lyapunov function is constructed to verify that the dynamic model has good identification performance and dynamic tracking performance.Finally,a simulation example shows the feasibility and effectiveness of the proposed algorithm.