Improved Adaptive Sliding Mode Cooperative Guidance Law with Multi-constraints

To address the issue of cooperative interception for maneuvering target with impact time and line of sight (LOS) angle constraints, an improved adaptive sliding mode cooperative guidance law (IASMCGL) based on the nonlinear disturbance observer (NDO) and adaptive sliding mode control is proposed in this paper. Firstly, by setting the time-to-go as the covariable, the time-coordinated guidance law in LOS direction is designed with sliding mode theory and multi-agent consensus theory, where the interference caused by the target’s maneuver is compensated by an adaptive law. Secondly, a guidance law considering terminal LOS angle constraint in normal LOS direction is designed based on the finite-time non-singular fast terminal sliding mode (NFTSM) surface with an NDO to estimate the target’s normal maneuver, and an improved three-stage reaching law is designed to speed up the reaching rate. The stability of the system is proved by Lyapunov stability theory. Finally, the effectiveness of the designed guidance law is verified by simulation.