An on-line guidance algorithm for high L/D hypersonic reentry vehicles

An on-line guidance algorithm is presented for high L/D hypersonic reentry vehicles using plane-symmetry bank-to-turn control method. The proposed guidance algorithm can generate a feasible trajectory at each guidance cycle during the reentry flight. In the longitudinal profile, height-range (H-R) and height-velocity (H-V) joint design method is proposed to rapidly generate the reference trajectory and the controlled bank angle to satisfy all constraints. Then, the quasi-equilibrium glide phenomenon is employed to extract the other controlled angle of attack corresponding to the reference trajectory. In the lateral profile, the bank angle reversal strategy is designed according to the cross-range angle threshold and the proportional navigation approach to reduce heading error. Simulation results for nominal and dispersed cases show that the proposed guidance algorithm is capable of generating a feasible trajectory rapidly that satisfies both path and terminal constraints.