Missile Guidance Law Considering Constraints on Impact Angle and Terminal Angle of Attack

This paper proposes a guidance law considering constraints on impact angle and terminal angle of attack for a homing missile. In the proposed structure, the guidance law generates angle of attack command and the controller tracks the generated command. For deriving the angle of attack command, the differential game problem with terminal boundary conditions is proposed and solved. Then, the sliding mode control is applied in order to derive the actual command input from the guidance command. Because the guidance command is the angle of attack, the terminal angle of attack constraint can be easily handled and the controller needs not deal with non-minimum phase characteristics. This capability to control the terminal angle of attack is the main contribution of the paper. The performance of the proposed law is evaluated using a two-dimensional nonlinear simulation. The result demonstrates that the proposed law allows the missile to intercept the maneuvering target with the constraints on impact angle and terminal angle of attack.