Cooperative Guidance Law for Targets Maneuvering in 3D with Multiple Constraints

This study focuses on the situation where multiple vehicles simultaneously intercept a maneuvering target with desired line-of-sight (LOS) angles and impact time in a three-dimensional environment. A predefined-time cooperative guidance law is proposed, which adapts to the switching communication topologies among the vehicles. To accomplish the task of adjusting the impact time by leveraging the multi-agent consensus principle, a novel adaptive predefined-time consensus protocol is designed in the LOS direction, which allows multiple vehicles to intercept the target at the desired impact time, while ensuring that the impact times of all vehicles converge within a predefined time. In the LOS normal direction, based on the error transformation function, a novel predefined-time non-singular fast terminal sliding mode guidance law is proposed to guarantee the convergence of the LOS angular rate within the predefined time, achieving the simultaneous interception of the target by multiple vehicles at different terminal angles and eliminating singularities. At the same time, the tracking error satisfies the prescribed performance constraint. In particular, for scenarios where the target acceleration is unknown, a predefined-time external state observer is employed to estimate disturbances and compensate within the guidance law. The simulation results validate the effectiveness and robustness of the proposed method.