Linear parameter-varying attitude controller design for a reusable launch vehicle during reentry

Abstract

Considering the perturbation within a wide range of flight parameter (such as height, mach), and the strong uncertainty of aerodynamic and atmospheric parameter, a LPV(Linear Parameter-Varying) control method is studied for a RLV(Reusable Launch Vehicle) during reentry, which can make the controller designed envelope-oriented and obtain the self-scheduled ability. A standard LPV controller design process is given first, and the problem of LPV controller's large data volume is studied especially, for it will perform an exponential growth with the increase of order and number of LPV vertex models. Then the longitudinal/lateral controller separate design method based on coupling analysis and the LPV vertex models construct method based on model characteristics analysis are introduced, to decrease the data volume and make the LPV controller more applicable. At last, a LPV controller is designed for some RLV during reentry using the methods introduced above, and the 6-degree nonlinear simulation results demonstrate that the methods can reduce the data volume remarkably, while guarantee the controller's adaptability, tracking performance and robustness good enough.