Line-of-Sight Triangle-Based Prescribed-Time Guidance Law for 3-Player with Second-Order Lag Dynamics

This work concerns defense guidance problems for 3-player target–defender–attacker engagement scenarios, in which the defender is launched to capture the incoming attacker in advance of the target being hit; a line-of-sight (LOS) triangle-based prescribed-time guidance is derived as an interception strategy for the defender. Integrating both the attacker–target and defender–attacker perspectives into the relative engagement model, the 3-player nonlinear engagement model is deduced considering the second-order lag dynamics of the actuator. Next, to reduce the defender and attacker overload ratio, the LOS triangle-guidance concept is presented to keep the defender on the LOS frame between the attacker and the target, in which the lateral overloads of the defender and attacker cancel each other out. In addition, in order to achieve perfect capture of the attacker in advance, the prescribed-time control can preallocate convergence time such that the defender can be guided and kept at the LOS frame between the attacker and the target in the preset time. What is even more unique is that the proposed guidance law design ignores the maneuvering of the attacker; i.e., the overload of the attacker is unknown, which is treated as a disturbance and estimated by the improved adaptive law. Numerical simulations are executed to validate performance and superiority, which has potential application value.