Seyyed Sajjad Moosapour , Ghasem Alizadeh , Sohrab Khanmohammadi and Seyyed Hamzeh Moosapour
International Journal of Aeronautical and Space Sicences, vol. 13, no. 3, pp.369-376, 2012

Abstract : A nonlinear robust guidance law is designed for missiles against a maneuvering target by incorporating sliding-mode and optimal control theories based on the state dependent Riccati equation (SDRE) to achieve robustness against target accelerations. The guidance law is derived based on three-dimensional nonlinear engagement kinematics and its robustness against disturbances is proved by the second method of Lyapunov. A new switching surface is considered in the sliding-mode control design. The proposed guidance law requires the maximum value of the target maneuver, and therefore is opposed to the conventional augmented proportional navigation guidance (APNG) law, where complete(Ed. note: Do you mean, ‘where complete’? Please clarify: Agreed) information about the target maneuver is not necessary, and hence it is simple to implement in practical applications. Considering different types of target maneuvers, several scenario simulations are performed. Simulation results confirm that the proposed guidance law has much better robustness, faster convergence, and smaller final time and control effort in comparison to the sliding-mode guidance (SMG) and APNG laws.

Keyword : guidance, optimal control, robustness, sliding-mode