RLV Attitude Control System Design in Reentry Flight Phase

摘要

In reentry flight phase of reusable launch vehicle (RLV), its aerodynamic characters alter sharply, going with serious uncertainties and nonlinearities. These factors make the reentry attitude control technique be one of key technique for RLV. In this paper, the sliding mode variable structure control technique is used for reentry attitude control. A specific switch function is defined; specific exponential reaching law and continuous analogy of sign function are chosen to weaken the chattering brought by the variable structure control technique. RLV is equipped with aerosurfaces and reaction control system (RCS), the arithmetic based on dynamic pressure change is presented. Six-freedom nonlinear simulation with great gain and high frequency disturbance proves that the reentry attitude control technique performs very well, and its control accuracy and robustness are brilliant.