Integrated Guidance And Control Design Method For Hypersonic Vehicle

Hypersonic vehicle has the characters that its flight speed is fast,reachable zone is wide and it is difficult to be intercepted,so there are so much value in business and military field.However,because of its nonlinearity,coupling,fast varying character of states and in-flight multi-constraints and uncertainties,it brings about much difficulties to the design of guidance and control systems.In view of design of guidance and control systems in dive phase,this dissert ation puts forwards some kinds of integrated guidance and control alg orithms for this particular type of object and solves the prominent problems in hypersonic flight condition reasonably.With the help of establishing a coordinating relationship between guidance and attitude control system,the terminal accuracy and r obustness can be improved.Main contents of this dissertation are as fo llows:Firstly,the mathematical model of hypersonic vehicle is built and then analyze the characteristics of hypersonic vehicle.By analyzing the changing trend of coupling and nonlinearity factors and so on,design difficulties of guidance and control systems for this type of vehicle are clarified.On account of the fast varying character of hypersonic vehicle,the error caused during obtaining line-of-sight(LOS)rate and uncertainties of system have much more significant influence on system performance.A iming at solving this problem,the novel state observer and extended state observer(ESO)design method is proposed,which can guarantee high-order observer system to achieve global finite-time stability,and on this basis observers based integrated guidan ce and control design method is proposed.With considering high-order observer system integrally and strengthening the relationship among the observer su bsystems,the proposed design method of observer can improve the observer pe rformance effectively.Combining finite-time state observer and ESO with integrated guidance and control design method respectively can estimates the line-of-sight rate and system uncertainties quickly,thus reduce the influences from the LOS rate error and system uncertainties that can improve the robustness of system.To solve the saturation problem on account of the fast varying character and physical restrictions of hypersonic vehicle,a kind of integrated guidance and control design method which can guarantee the system avoid the saturation globally is proposed.Based on the longitude design model of integrated guidance and control,a novel global finite-time integrated guidance and control design method is proposed.The proposed method can establish the coordinated relationship in subsystems that reduces excessive control process and guarantees the system states convergence to the equilibrium point in a short time.Then introducing factors of the system states and control input saturation,the design method is further improved to meet the anti-windup requirement.The improved method drives the subsystems to remove the saturation together by introducing the nested anti-windup method,which realizes the global anti-windup performance and improves the robustness of system.Against the problem that three-dimensional guidance and control design method has a poor precision,the three-channel respectively and considering the control channel coupling integrated guidance and control design methods are investigated.Considering the coupling between position movement and attitude movement adequately,neglect the control channel coupling in nonlinear vehicle model,then propose the nonlinear integrated guidance and control design method in pitch,roll and yaw control channel respectively.On the basis of foregoing method,three-dimensional integrated guidance and control design method considering control channel coupling is proposed by combining back-stepping control method and dynamic inversion control method based on the complete nonlinear mathematic model of hypersonic vehicle.Both the proposed design method can solve the problem that the control precision is poor.It can reduce the excessive control process and improve the terminal accuracy with much more consideration the coupling factors of system.The design solution of guidance and control system usually requires to be evaluated by a group of experts that assists in optimization.In order to solve the problem that multi-experts evaluate the design solution together,a novel performance evaluation method for guidance and control system is investigated.Meanwhile,a software platform with the function of modeling,simulation and performance evaluation is established,which is convenient to analyze the design solution.The proposed performance evaluation method can fuse the evaluation information fully,reduce the influence of singular individual conclusions and obtain a more objective evaluation conclusion.With regard to the design solution of guidance and control system,modeling,experi ment designing,simulation,indexes system establishment and performance evaluation can realize quickly and conveniently with the help of software platform.It can attain eval uation conclusion by proposed evaluation method based on simulation data.Three-dimensional integrated guidance and control design method and tradi-tional design method are set as example to verify the effectiveness of evaluation method and software platform.