Nonlinear Differential Game Guidance Law for Guarding a Target

three-body engagement scenario is considered where a unmanned combat air vehicles (target) fires a defending missile (defender) to intercept the attacking missile (attacker). Firstly, the nonlinear model of target-defender-attacker engagement is built. Considering the miss distance between defender and attacker, the miss distance between attacker and target, and the control energy of three adversaries, the function index is established. Then a nonlinear differential game guidance law for three adversaries is derived based on differential game theory. When the attacker adopts the optimal strategy for pursuing the target and evading the defender, the feasible launch angle region of defender and the feasible region of penalty coefficient under the available overload constraints are analyzed when given initial condition. Simulation results show that the defender can intercept the attacker with less maneuverability by cooperating with the target, which shows the superiority of the cooperation.