Research On Control Of Hypersonic Vehicle Based On Active Disturbance Rejection Control Technology

Hypersonic vehicle has attracted wide attention all over the world because of its outstanding advantages such as extremely fast velocity speed,strong strike ability and fast response.Due to the complex flight environment and changeable aerodynamic traits of hypersonic vehicle,the dynamic model of hypersonic vehicle has the control difficulties of strong coupling,strong nonlinearity and strong uncertainty,which requires that the flight control system should have better control performance and stability.In this paper,aiming at the tracking control of hypersonic vehicle in cruise section,considering internal and external disturbances and actuator fault,the following aspects are studied based on active disturbance rejection control(ADRC)theory.The main contents are as follows:(1)Establishment of system model for ADRC.Firstly,the force acting on the body of the hypersonic vehicle during the cruise phase is analyzed,the longitudinal dynamics equations are established,and the specific definitions and values of each variable and parameter are given.Secondly,the equation group is deduced and sorted out,and the system model is divided into height subsystem and velocity subsystem,and each subsystem is analyzed preliminarily.(2)Design of sliding mode active disturbance rejection controller(SM-ADRC)for hypersonic vehicle.Aiming at the tracking control problem of hypersonic vehicle,firstly,the structure and specific algorithms of the traditional ADRC are introduced,and the shortcomings and defects of its rapidity and robustness are analyzed.Then,using the idea of sliding mode control method,based on the state error obtained by tracking differentiator and extended state observer,the exponential reaching law is used to design the sliding mode active disturbance rejection control law.Finally,the proposed algorithm is simulated and verified under the condition of model parameter perturbation and external interference,and compared with the traditional ADRC.Simulation results show that the algorithm is feasible.(3)Design of dynamic surface active disturbance rejection controller(DS-ADRC)for hypersonic vehicle.On the basis of the previous research,in view of the fact that the nonlinear function in the extended state observer is continuous but not smooth,the method of cubic spline interpolation is used to polish it,and the resulting function is smooth and derivable everywhere.The stability and estimation accuracy of the extended state observer are improved.In addition,based on the theory of dynamic surface control method,a DS-ADRC is designed to improve the chattering problem of hypersonic vehicle state variables under SM-ADRC.Considering the existence of model parameter perturbations and external disturbances,the effectiveness of the designed control algorithm is verified by simulation experiments,and compared with the SM-ADRC method,its superiority is verified by simulation results.(4)Design of intelligent active disturbance rejection and fault-tolerant control for hypersonic vehicle.Considering that the hypersonic vehicle carries out the mission with high maneuverability requirements in the complex environment,its actuator works frequently,which greatly increases the possibility of failure.In order to improve the safety and reliability of the system,the nonlinear state error feedback control law of the ADRC is optimized based on BP neural network,and the gradient descent method is used to adjust the weights of each neuron of the network,so that the controller can realize real-time on-line self-tuning and adjustment,thus completing the design of fault-tolerant controller.Through the simulation of the actuator in the case of random drift and partial failure,and by comparing with the control effect of no fault tolerance strategy,the effectiveness of the proposed algorithm is proved.