Second Order Sliding Mode-Based Intercept Guidance with Uncertainty and Disturbance Compensation

This paper focuses on a missile intercept guidance method taking account of uncertainty and disturbance. The proposed guidance law are developed using a second order sliding mode approach, along with an uncertainty and disturbance estimator. A novel sliding surface is developed for the second order sliding mode-based missile guidance. The proposed sliding surface is unified both for non-impact angle constraint and an impact angle constraint. The proposed sliding surface guarantees the finite time convergence of the lineof- sight rate and (if specified) the LOS angle error associated with a simple function of a time-to-go like the case of using the proportional navigation against a non-maneuvering target while the proposed strategy can also be effective even against a maneuvering target. The line-of-sight rate convergence property can be adjusted using only one parameter that makes the design process simple. Moreover, the guidance law is unified also for the missile intercept guidance with a specified impact angle constraint. The potential of the proposed guidance laws is demonstrated with some simulations.