Second-order sliding mode control for passive ranging system in missile interception

A guidance law of the missile interceptor with passive ranging system (e.g. image IR seeker) based on second-order sliding mode is proposed in this paper. The missile system equipped with the passive ranging system can provide good stealth ability during its course of tracking the trajectory of a maneuvering target, therefore enhancing the probability of successful interception. The passive ranging system integrates the Extended Kalman Filter (EKF) with the Interacting Multiple Model (IMM) technique to minimize the errors of estimating the range and range rates incurred by the target´s maneuvers. By admitting the estimation error of the missile seeker, the guidance law is designed, applying Smooth Second-Order Sliding Mode (SSOSM) control technique so as to cope with the chattering and to hold against the maneuvering target. Finally, various simulation results are given to verify the proposed system performance.