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 the process of span morphing, which means that it is highly sensitive to flight states. An antisaturation coupling-triggered controller (ASCTC) is investigated to deal with transient performance constraints of tracking errors and angle-of-attack constraint for the NSMV, including a barrier-based antisaturation performance function (BAPF) and a multisource coupling-triggered strategy (MCTS). First, a BAPF comprising a prescribed-time benchmark function, an antisaturation term, and a nonsingular term is designed to satisfy performance constraints of a tracking error. The antisaturation term with a barrier function can expand the boundary of the BAPF to solve the saturation problem. The barrier function is used to avoid unlimited growth within the BAPF so as to limit the angle of attack within the available range. The nonsingular term can guarantee that the tracking error is always enveloped within the BAPF to solve the singular problem. Second, an MCTS is devised to evaluate the 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 multisource coupling to enhance stability and accelerate the convergence rate. Based on the BAPF and the MCTS, the ASCTC can achieve fast and high-precision convergence of attitude during the process of span morphing. Finally, numerical simulations for the NSMV demonstrate the effectiveness of the proposed method.