Research On Robust And Adaptive Control Approach For Hypersonic Glide Vehicles

The hypersonic vehicle has the advantages of fast flight speed,long range,and strong penetration ability and so on.It has become a hotspot for many powerful countries.The dissertation aims at the hypersonic glide vehicles with strong coupling,nonlinearity and uncertainty of rotational dynamics model by presenting the composite control method of RCS(reaction control system)and pneumatic rudder,parameter adaptive sliding mode method and model autonomous identification based on nonlinear disturbance observer.The main contents are as follows:Firstly,aiming at the insufficient control of hypersonic glide vehicles in orbit-change stage,the composite control method of RCS(reaction control system)and pneumatic rudder is studied.To achieve the aircraft attitude control,the switching control law of RCS is designed based on phase plane method,and the allocation strategy on dynamic pressure switching between RCS and pneumatic rudder is given.What's more,a composite attitude control is put forward by using inversed dynamic approach and sliding mode method,and the simulation shows that the compound control strategy of dynamic pressure as the switching condition is reasonable.Secondly,in order to solve the problem of strong uncertainty in aerodynamic model,an adaptive sliding mode variable structure control method is studied.The method is based on the analysis of rotational dynamics,which is divided into three parts: the rudder deviation angle correlation,the non-rudder deflection angle correlation and the moment inertia correlation.The sliding mode variable structure control and self-adaptive control method are used to design the attitude control system,which realizes the online identification of the rudder angle correlation and the non-rudder angle correlation.The stability of the system is proved by Lyapunov stability theory and the effectiveness of the control method is proved by simulation.Finally,in order to improve the applicability and design an attitude control method without rotational dynamics mode,a model autonomous identification method of online identification of the moment inertia correlation using the nonlinear disturbance observer is proposed.The characteristics of nonlinear disturbance observer are analyzed,and sum of the non-rudder deflection angle correlation and the moment inertia correlation are regarded as the interference terms of the model.The nonlinear disturbance observer is used to estimate it,and the attitude control system is designed combined with the adaptive law of rudder deviation angle correlation And then,an attitude control method with strong robustness and adaptability is got,and the effectiveness of the control method is verified by numerical simulation.The composite control method of RCS and pneumatic rudder can track the guidance instruction in orbit-change stage.An adaptive sliding mode control method and a robust control method can solve the problem of large deviation of the aerodynamic parameters or even unknown parameters.And the research provides a theoretical basis and technical support for the study of strong coupling between aerodynamic coefficients and flight control system.