Free-Will Arbitrary Time Cooperative Guidance for Simultaneous Target Interception With Impact Angle Constraint Based on Leader–Follower Strategy

This paper introduces a robust Free-Will Arbitrary Time (FWAT) cooperative guidance strategy for leader-follower interceptors, proposed to simultaneously attack maneuvering targets in Three-Dimensional (3D) space with impact angle constraints. The proposed method enables to adjust the convergence time of the state errors directly. FWAT consensus control is implemented for second-order nonlinear leader-follower Multi-Agent Systems (MAS). On the basis of the 3D relative motion equations, a cooperative space and time guidance model within a Line-of-Sight (LOS) framework for leader-follower interceptors is established. Employing FWAT consensus control and Sliding Mode Control (SMC) approach, a robust leader-follower consensus protocol is proposed that ensures FWAT consensus for multiple interceptors in the LOS direction. Also, two robust FWAT guidance laws with LOS angle constraints in elevation and azimuth directions are introduced. Lyapunov stability theorem validates the stability of all proposed guidance laws within arbitrary time. Comparative simulations confirm the efficiency of the designed methods. Furthermore, experimental results using a baseline real-time Speedgoat machine show the feasibility of the proposed control plan.