Antisaturation Coupling- Triggered Controller for Near-Space Morphing Vehicle With Limited Angle of Attack

The near-space morphing vehicle (NSMV) is a strongly coupled and nonlinear system during process of span morphing, which means that it is highly sensitive to flight states. An anti-saturation coupling-triggered controller (ASCTC) is investigated to deal with transient performance constraints of tracking errors and angle-of-attack constraint for NSMV, including a barrier-based anti-saturation performance function (BAPF), and a multi-source coupling triggered strategy (MCTS). Firstly, a BAPF comprising prescribed-time benchmark function, anti-saturation term, and non-singular term, is designed to satisfy performance constraints of tracking error. The anti-saturation term with a barrier function can expand boundary of BAPF to solve saturation problem. The barrier function is used to avoid unlimited growth within BAPF, so as to limit angle of attack within available range. The non-singular term can guarantee that tracking error is always enveloped within BAPF to solve singular problem. Secondly, a MCTS is devised to evaluate influence of couplings on the convergence of attitude. By retaining beneficial couplings and eliminating harmful couplings, the coupling triggered strategy can fully utilize the complex and multi-source coupling to enhance stability and accelerate convergence rate. Based on BAPF and MCTS, the ASCTC can achieve fast and high-precision convergence of attitude during process of span morphing. Finally, numerical simulations for NSMV demonstrate effectiveness of the proposed method.