Three-Dimensional Prescribed-Time Hierarchical Cooperative Guidance Law for Head-On Interception

This paper proposes a three-dimensional prescribed-time hierarchical cooperative guidance law (3-D PTHCGL) for rapid and reliable head-on encirclement in cooperative interception of high-speed targets under incomplete directed communication topology, target maneuvers, and limited terminal engagement time. The proposed method consists of a distributed estimator layer (DEL) and a local controller layer (LCL), addressing three key issues in head-on encirclement formation: information acquisition, rapid convergence, and geometric configuration. In the DEL, a distributed prescribed-time estimator (DPTE) is developed to enable followers without direct communication with the leader to estimate the leader’s states from neighborhood information within a prescribed time. In the LCL, a prescribed-time extended state observer (PTESO) and a three-dimensional prescribed-time cooperative guidance law (3-D PTCGL) are designed to estimate target-maneuver-induced disturbances and unknown states, and to guarantee prescribed-time convergence of estimation and cooperative tracking errors. Furthermore, virtual line-of-sight (LOS) angles are introduced based on a three-dimensional head-on interception kinematic model to characterize the head-on encirclement configuration, and range-to-go together with radial relative velocity are adopted instead of time-to-go to reduce sensitivity to time-estimation errors. Simulation results demonstrate the effectiveness and robustness of the proposed method in achieving prescribed-time head-on encirclement and simultaneous attack without a speed advantage.