A new piecewise predictive guidance for the long-range reentry vehicles

A new predictive guidance algorithm was presented for the long-range reentry vehicles to improve the real-time capability of the conventional predictive guidance. The equation of constraints in reentry flight was established. The bank angle curve of the reference trajectory was generated beforehand to supply the reference states for piecewise predictive guidance. The absolute value of the bank angle viewed as the control variable was designed to be a piecewise linear function of the energy parameter which consists of the velocity and the altitude. The reversal condition of the bank angle was gotten using the method of the azimuth error boundary. The predictive points were chosen according to the predictive time step and the predictive guidance equation which was used to generate the control corrections of the bank angel was designed. This approach avoids massive iterations of the conventional predictive guidance. Simulation results indicate that the method can decrease the time cost of the predictive guidance to a satisfying level and improve the guidance accuracy at the Terminal Area Energy Management (TAEM) interface.