Robust extended state observer-based three dimensional integrated guidance and control design for interceptors with impact angle and input saturation constraints

Abstract

In this paper, a new three-dimensional integrated guidance and control (IGC) scheme, considering impact angle and actuator saturation constraints, is presented for a skid-to-turn interceptor. The proposed method is based on backstepping, command filter, sliding mode control (SMC), and super-twisting extended state observer (STESO). To this end, a six-degrees-of-freedom realistic model, including errors between line-of-sight and interceptor velocity angles, model uncertainties, external disturbances, and limits for actuators, is constructed. Command filters effectively solve the explosion of complexity related to the derivative of virtual control signals in the backstepping method, and saturation limits for actuators. A combination of SMC and finite-time STESO guarantees strong robustness of the proposed IGC against lumped disturbances and target accelerations. System stability and uniformly ultimately boundedness of all states are proven using the Lyapunov stability theory. Finally, extensive numerical simulations are conducted to illustrate the effectiveness of the proposed IGC method.