Design and Implementation of Variable Structure Guidance Law for Maneuvering Target Interception

The design and implementation problem of terminal guidance law for a missile is investigated in consideration of targets maneuvering and the body dynamics of the missile.In the design of switching function,an augmented proportional navigation method is utilized to make compensation for target's evading maneuvers.For attenuating the influence of missile dynamics on guidance accuracy,a variable structure guidance law is designed to ensure that the missile's real lateral acceleration must be the form of augmented proportional navigation.In the implementation of the guidance law,a high-gain observer is used to estimate the line-of-sight rate.In the meantime,the observer is extended twice to provide rapid estimation of the target's maneuvering acceleration and its rate.Numerical simulation is conducted,and the simulation results show effectiveness of the proposed method.