Research on fuzzy variable structure guidance law for passive homing missiles against maneuvering targets

A fuzzy variable structure guidance law is proposed for the passive homing guidance in which only LOS angular rate can be measured when a target maneuvers. The proposed guidance law is based on the sliding-mode variable structure guidance law which regards the target maneuvering as interference. In order to reduce chattering, it selects the gain of the switching term according to the target maneuver estimation by means of fuzzy control. When the guidance law is implemented, the angle-of-attack is estimated by the method that the guidance command passes through a low-pass filter. At last, the proposed guidance law is applied to the computer simulation of the video-guided bomb, and compared with traditional proportional navigation and sliding-mode variable structure guidance law. The simulation results show that the proposed guidance law against a maneuvering target has stronger robustness to estimation errors and smaller miss distance than the others.