关键词: 线性变参数控制, 切换系统, 高超声速飞行器, 大包线, 间隙度量, 滞后切换

Abstract: Hypersonic vehicles traverse a broad flight envelope with a wide parameter variation range and strong parameter uncertainties. Therefore it is important to improve the controller performance and robustness in a wide envelope. A new hysteresis switching linear parameter varying (LPV) control method using polytope theory and gap-metric is presented in this paper. The design envelope is firstly divided into several sub-regions in accordance with the time-varying parameters. A new LPV control method with the optimal gap-metric is proposed, and then a family of single LPV controllers are designed independently using the new method to improve the performance and robustness, each suitable for a specific sub-region. They are switched according to the time-varying parameter trajectories using the hysteresis switching strategy based on overlap regions to avoid chattering. The stability of the closed-loop switching system is also proved. Finally, the new switching LPV design approach is applied to a hypersonic vehicle. Simulation results show that this new method can improve the performance and enhance the robustness of the LPV controllers in a wide design envelope. The performance of command tracking and the robustness of the switching LPV control system are satisfactory. The stability of the system is also guaranteed.

Key words: linear parameter varying control, switching systems, hypersonic vehicle, wide flight envelope, gap-metric, hysteresis switching