Fast Nonsingular Terminal Sliding Mode to Attenuate the Chattering for Missile Interception with Finite Time Convergence

This paper proposed a new fast nonsingular terminal sliding mode to design terminal angle constraint guidance for intercepting maneuvering targets with attenuating the chattering of the command in the guidance law. A fast nonsingular terminal sliding mode (FNTSM) is established for dealing with the relationship between Line of sight (LOS) angle and the rate of LOS angle, the disturbance observer (DOB) is set up to calculate the compensation amount for counteracting the time-varying uncertainty produced by the design of guidance and targets' maneuver. Combining with FNTSM and DOB, an adaptive law and a compensated parameter are adopted to ease the coupling relationship between the convergence rate of sliding variable and initial parameters design. Furthermore, the chattering amplitude can be reduced, even can be eliminated in some cases. Theoretical analysis and numerical simulations verify the effectiveness of the proposed method.