Research On Parameter/Trajectory Optimization And On-board Guidance For Boost Complement Glide Vehicle

With the advantage of wide coverage,strong maneuverability and precise strike,the boost glide vehicle,which combines the advantages of conventional ballistic missiles and cruise missiles,has been the hot spots that global precious strike weapons primarily research on,and the target that missile defense system mainly focuses on.In order to increase the maneuver and penetration ability,reduce development risk and accelerate the use of weapons,a kind of boost complement glide vehicle with endoatmospheric lower trajectory and pulse thrust is becoming the focus in the research and development.In order to meet the new challenges and new requirements on the vehicle overall,trajectory and guidance technology caused by lower trajectory and especially power complement gliding,some key technologies of boost complement glide vehicle,such as the overall optimization design technique,trajectory optimization technique,trajectory planning and guidance technology,are studied in this paper.Under consideration of the coupling effects of various subsystems,booster overall design mathematical model including the engine,mass,aerodynamics and trajectory subsystem is established.Through the analysis of the data flow and the coupling relationship of the subsystems,the overall design variables are determined.And then,the minimum takeoff mass optimization design of the booster is carried out.Over the reduction in comprehensive optimization convergence caused by static overall parameters and dynamic trajectory parameters coupling,parameter / trajectory two level hierarchical optimization algorithm is proposed,in which random direction search algorithm is used for overall parameters optimization,and improved direct shooting + SQP algorithm is used for trajectory parameters optimization.The simulation results show that the algorithm is effective in solving the comprehensive optimization problem of various subsystems coupling and dynamic / static parameters coupling.In order to get the initial value of overall and trajectory design parameters conveniently and quickly,to improve the rate of convergence of booster comprehensive optimization design,using the uniform dispersation characteristic and neat comparison characteristic of orthogonal table,optimization initial value determination method based on multiple orthogonal test is proposed,and the specific test scheme design procedure and test result analysis method are given.To obtain the initial value with better test index,and reduce the design requirements of the orthogonal table and improve the level of the experimental factors,the multiple orthogonal test method is proposed to automatically update the new level.The simulation results show that the method not only obtains better initial values simply and efficiently,but also confirms the influence of factors on the test index.In order to improve the calculation speed and convergence efficiency of the two level hierarchical optimization algorithm,the optimization algorithm is improved from two aspects: control variables parameterization and balance coefficient SQP.The trajectory optimization control variable,program pitch angle,is characterized as intuition form of extreme angle of attack and linear pitch angle,instead of its direct discretation in time domain,which not only reduces the control variable number and NLP problem scale,but also makes initial variables determination relatively easier because of the practical significance of characterization parameters.Under consideration of the feasible solution to the optimal solution,the influence of the performance index and the constraint condition on the SQP penalty function is balanced by introducing the balance coefficient,to improve the optimization efficiency of SQP.Simulation results show that the balance coefficient SQP algorithm can improve optimization convergence efficiency,the search scope and the ability to adapt to the initial value.To resolve the time-varying discontinuous problem of power complement gliding dynamics model caused by pulse engine ignition,the piecewise dynamic trajectory optimization algorithm based on the Gauss pseudospectral method is put forward,which can automatically update the new fragment number and discrete point number.Different from the HP adaptive Gauss pseudospectral method,in which only the uniformity of discrete solution is considered,a new decision method of updating the segment and discrete points is determined,in which the deviation of the discrete solution and the real solution,and the satisfaction degree of the constraint conditions are both considered.And the analysis of the Jacobian matrix sparsity demonstrates that segmentation can improve the efficiency of the optimization.And using automatic differentiation techniques for derivative calculation further improves the calculation speed of the algorithm.The simulation results show that the algorithm is effective to deal with the time-varying discontinuous model optimization problem,and the range capability of power complement glide is obtained.In order to satisfy the quasi-equilibrium glide condition even in the case of the pulse engine working,a powered quasi-equilibrium glide condition is derived,and then a constrained on-board trajectory planning and guidance method with single parameter search of intermediate value of bank angle is established.In order to meet the requirements of online target changing task,attack area fast calculation method based on the interpolation coefficient of velocity-bank angle flight corridor adjustation,and pulse engine ignition time determination method based on firing table are proposed.Simulation results of different targets,different ignition times and different aerodynamic deviations show that the algorithm is rapid,effective,adaptive and robust.Through the research on optimization design and on-board guidance method of boost complement glide vehicle,some key technologies,such as parameter / trajectory comprehensive optimization,optimization initial value determination,balance coefficient trajectory optimization,time-varying discontinuous model trajectory optimization,powered quasi-equilibrium glide on-board trajectory planning and guidance,are mainly explored and improved.The related research results have certain reference significance for the overall design,trajectory optimization and on-board guidance schemes of the advanced vehicles,and they are conducive to promote the use of the boost glide vehicle.