Control Of Flexible Hypersonic Vehicle Research Articles

Improved finite-time command filtered backstepping fault-tolerant control for flexible hypersonic vehicle

The tracking control of a flexible hypersonic vehicle with system perturbation and actuator fault is investigated in this paper. A control-oriented model is constructed, which is composed of velocity loop and altitude loop. A double-layer fast adaptive-gain super-twisting disturbance observer (ASTDO) is designed to provide finite-time estimation of the lumped terms of external disturbances and actuator faults. The ASTDO has the property of the non-overestimation of adaptive gains and chattering reduction with higher precision. Based on the estimation of ASTDO, a novel finite-time command filtered backstepping (FCFB) scheme is proposed for the high-order altitude loop. The merit lies in the modified compensating signals and new virtual commands to compensate the command filter errors. The remarkable features of the developed algorithm include the finite-time convergence with higher accuracy and the chattering suppression. Finally, comparative simulation results are given to demonstrate the superiority of the proposed method.

Switched linear parameter-varying modeling and tracking control for flexible hypersonic vehicle

In this paper, the reference tracking problem for a class of flexible hypersonic vehicles, whose dynamics vary significantly as flight states changes, is investigated via a novel switched linear parameter-varying (LPV) framework. Specifically, ranges of velocity and altitude are divided into several partitions, and the flexible hypersonic vehicle dynamics is modeled as a LPV system in each partition. Then the switched LPV model for the underlying system is obtained over a wide range of operating conditions. Switched LPV tracking controllers based on the developed model are established under mode independent/dependent persistent dwell time (PDT/MPDT) switching signals, respectively. Compared with the conventional mode independent/dependent average dwell time (ADT/MADT) switching signals, the proposed PDT/MPDT switching signals can address some more general flight variations, such as slow maneuvers and frequent rapid maneuvers coexist in the same flight mission. Furthermore, stringent transient and steady-state performance and a guaranteed non-weighted H∞ performance are achieved with the aid of multiple Lyapunov-like functions. A simulation is used to illustrate the designed controller via two proposed switching signals.