Anti-Saturation and Undecoupled Diving Attack Guidance Law for Impact Angle and Time Constraints

Aiming at the characteristics of the motion model of the dive attack segment of hypersonic vehicle, such as strong nonlinearity, strong coupling between channels, complex constraints and easy overload saturation under the limit condition, a kind of anti-saturation non-decoupled dive attack guidance law with angle and time constraints is designed. Firstly, based on the velocity front angular relative motion model and sliding mode control theory, a time-constrained non-decoupled sliding mode basic guidance law is designed. Subsequently, the three-dimensional undecoupled multi-angle constraint optimal guidance law based on geometric spinor is analyzed and the instruction item corresponding to the angle constraint is separated. Then, the instruction item is introduced into the sliding mode guidance law with time constraint as the bias item. A guidance law considering the terminal fall angle, azimuth angle and time constraint is constructed. Finally, a new approach law is designed to improve the guidance law reference term to suppress the saturation of guidance instructions, and an anti-saturation guidance law considering terminal angle and time constraints is obtained. The applicability and robustness of the proposed method are verified by numerical simulation.