Advanced reentry guidance based on on-board reference trajectory reconstruction

Along with the growing demands of hypersonic vehicle reentry guidance in autonomy, robustness, and situation with insufficient performance of current methods, one compound reentry guidance method is proposed based on altitude-velocity reference profile on-board regeneration and tracking. Aiming at the vehicle reentry problem, overall guidance scheme and related key technologies are studied in this work, and vehicle feasible trajectory on-board planning subject to multiple constraints and adaptive trajectory tracking problem are specially focused on. On basic of reentry problem research and constraints analysis, a novel kind of compound altitude-velocity (short for HV) corridor is designed on-line, in consideration of current state, path constraints, vehicle flying capability and terminal condition constraints. New compound HV corridor provides feasible flight envelope with satisfying constraints. The tracking reference profile is obtained by weighting the upper and lower bounds of HV corridor and strict function monotone property between weighted coefficient and flyable range is also proved. Gauss-Newton method is introduced to solved the transformed single parameter and single constraint problem. For sake of avoiding integral in range prediction, the designed altitude-velocity profile is fitted with Lagrange polynomials and the Legendre primary functions help algorithm improve running speed significantly. Pole place and PID control methods are introduced to finish the tracker design of reference profile. The above researches constitute an autonomous, robust and reliable entry guidance scheme for hypersonic vehicles. Feasible trajectory validity test and Monte Carlo simulations illustate that the proposed compound guidance method performs well in reentry flight under conditions of initial launch deviation, parameter uncertainty and strong interference. New method has be proved with remarkable performance of autonomy, adaptability and robustness.