Study On Integrated Guidance And Control Design Approach For Hypersonic Vehicles

Due to the prospects for high speed transportation,affordable space access,and development of the next generation reusable launch vehicles,hypersonic vehicles attack an ever increasing attention in the world.Effective guidance and control(G&C)system design is essential for ensuring the feasibility and efficiency of hypersonic vehicles.However,because of the complex aerodynamic properties,high velocity,and complicated flight environment involved,the aerodynamic and motion models of hy-personic vehicles are highly nonlinear and rapidly vary in time,exhibit severe coupling and contain various uncertainties.As a result,realizing a G&C system design that assures excellent properties is still a key challenge for hypersonic vehicles.As an important trend in G&C design area,the integrated guidance and control(IGC)method can integrate the coupling terms between the translational and rotational dy-namics,improve the performance of the vehicles and reduce the design costs.In this paper,the guidance and control design problems of hypersonic vehicles are discussed,and the IGC design ideology is taken as a main line for the research of G&C design methods of hypersonic vehicles.For the purpose of solving the IGC application prob-lems and further developing the new theory and methods,this dissertation studies the integrated guidance and control design approaches systematically.The main results achieved in this dissertation are summarized as follows.Based on the spectral separation principle,the guidance and control design methods considering the couplings between the centroid and rotational loops are studied.The glide phase is guided by controlling the range and the lateral azimuth error to obtain the desired angle of attack and desired bank angle.The attitude con-troller is designed based on the back-stepping control theory.The couplings between the translational and rotational loops are all taken into account.Based on the three-dimensional relative motion model between the target and hypersonic vehicle,the commanded angle of attack and bank angle are obtained by controlling first-order derivatives of angles of Line-Of-Sight(LOS),the attitude controller is conducted based on the nonlinear dynamic inversion methods.The guidance subsystem and atti-tude control subsystem are combined and integrated to realize the six-degree-of-freedom(6DoF)numerical simulations.Finally,the flight constraints are converted into a magnitude constraint problem of control variables,the glide phase and dive phase are combined,and the 6DoF numerical simulation analysis of reentry phase of the hypersonic vehicle are performed.The full-state-coupling high-order strict feedback IGC design models are deduced and the integrated guidance and control methods of the glide phase and dive phase of hypersonic vehicles are proposed based on the back-stepping control theory.The state variables of the IGC design model of the glide phase involves the flight path angle,heading angle,angle of attack,sideslip angle,bank angle and three channel body rates,the IGC design model contains both the guidance controlled variables and the attitude controller variables.The LOS angles of relative motion,air-flow angles,and body rates are treated as state variables of IGC design model of the dive phase,the diving IGC design model including unmatched uncertainties are established.The IGC design models of the glide phase and dive phase are converted into strict feedback form,and the IGC algorithms are conducted and simulated based on the block back-stepping control theory and adaptive estimation method.Finally,the effectiveness and robustness of the proposed IGC scheme are verified and investigat-ed using the GHV and 6DoF nonlinear simulations.A novel analytic model between the three-channel body rates and components of acceleration in the ballistic frame is derived.The reduced-order integrated guidance and control methods of the glide and dive phase are proposed with the help of block dynamic surface control theory.The influence mechanism between the acceleration components and body rates is discussed.The gliding G&C problem is transformed into an iterative solution of the flight path angle.The strict feedback IGC design model containing the model uncertainties and aerodynamic uncertainties is established.The 3D coupling relative dynamics with bounded uncertainties is derived;the three-channel body rates are treated as pseudo-input variables,and the reduced-order strict feedback IGC design model is obtained.By estimating the upper magnitude of the bounded uncertainties,the IGC algorithms of the glide and dive phase are proposed based on the block dynamic surface control theory.A novel IGC design models of the glide and dive phase of the hypersonic vehicle are deduced.The direct relations between the translational variables and control surfaces are established,the time derivatives of centroid variables are the state variables,and the control surfaces are the input variables.For the glide phase,the IGC design model denoting direct relations between the first-order derivatives of components of velocity vector and the fin deflections is derived,the sliding mode vector is designed and the commanded control surfaces are directly obtained.For the dive phase,the IGC design model denoting direct relations between the second-order derivatives of LOS angles and the fin deflections is deduced,the sliding mode vector is conducted and the novel diving IGC algorithm is described.The system order and the tuning parameters of the 6DoF guidance and control system are reduced.The process of calculating the angle of attack and sideslip angle based on the desired overloads is omitted.In addition,the novel analytical model is applied to substitute for the compensated dynamics for the traditional tracking processes of the rotational control loops.Based on the HRT1000 real-time architecture,the design and implementation of a real-time simulation and test system with actuators in the closed-loop are preliminarily studied.The hardware components are completed according to the design specifications and technical requirements of the system.Based on the HRT1000 architecture,the hardware design and completion of the hardware-in-loop simulation and test system are established.The attitude controller algorithm,longitudinal IGC scheme and 6DoF diving IGC method are verified on the hardware-in-loop simulation and test system,the simulation results verify and validate the availability of the real-time simulation platform.This dissertation expands the research ideas of the IGC design of hypersonic vehicles,develops the modeling method of the IGC design model,which have both theoretical innovation and technique significance.The IGC scheme is not only suitable for hypersonic vehicles,but also can be applied to G&C design of different aircrafts.The IGC design models and IGC schemes enrich the research ideas of aircraft guid-ance and attitude control,and extend the IGC theory.The research work has high application value in hypersonic vehicles and other near space application projects.