Adaptive optimal control for hypersonic morphing vehicles considering performance constraints

To address the strong nonlinearity, large uncertainties and multi-source external disturbances during the morphing process, an adaptive optimal control method with performance constraints for hypersonic morphing vehicles is proposed. Firstly, the steady-state controller is designed based on adaptive performance-prescribed control. The singularity problem of fixed performance function is solved by designing an adaptive scaling strategy. Furthermore, the optimal compensation controller is designed based on adaptive dynamic programming. Online optimal control is realized through offline-online policy iteration scheme, where offline policy iteration enhances the stability of the network in the initial stage of online updates, and online policy iteration enhances the robustness of the optimal compensation controller by introducing the zero-sum game. Finally, the stability of the closed-loop system is analyzed based on Lyapunov stability theorems. Simulation results show that the proposed method improves the transient and steady-state performance of the vehicle system. The results also illustrate that the proposed method improves the robustness and adaptability to uncertainties and external disturbances during morphing flight process.