Improved Predictor-Corrector Guidance with Hybrid Lateral Logic for No-fly Zone Avoidance

In this paper, an improved predictor-corrector algorithm with hybrid lateral logic is proposed to enhance the maneuverability during re-entry, which lets the reusable launch vehicle (RLV) possess the ability of avoiding a no-fly zone. First, the longitudinal guidance is converted to the quasi-equilibrium guidance algorithm once current states satisfy the joint point condition. During each guidance period in the gliding phase, a quadratic parametric model is devised to adjust the magnitude of the bank angle instead of utilizing the linear one. Then, an artificial potential field based lateral guidance law is designed for no-fly zone avoidance by transforming the problem into finding the reference heading angle. But the bank angle reverses while the RLV is approaching the target, which may aggravate the instability problem and increase the energy consumption. Aiming at above problem, the lateral guidance is combined with conventional heading angle deadband corridor, which works when the RLV leaves the influence area of the no-fly zone. Finally, numerical simulations show that the proposed lateral guidance logic not only is effective for no-fly zone, but also performs well in reducing the times of reversals. The Monte Carlo simulation results further demonstrate the robustness of the above guidance algorithm considering the random initial dispersions and errors.