Study on nonlinear three-dimensional adaptive fuzzy variable structure guidance law

Three-dimensional relative motion model of missile and target is established in three dimensional spherical coordinates, 3-D adaptive fuzzy variable structure guidance law for homing missile based on zeroing speed of LOS(line-of-sight) angle is presented in intercepting the high maneuverable target. The fuzzy system is used to approximate the nonlinear function so as to overcome the influence of model uncertainty and external disturbance, and the maneuvering acceleration of target is regarded as a disturbance with boundary, which is estimated. Numerical simulation shows that the rates of LOS approach zero. The simulation result verifies the correctness and effectiveness of the presented guidance law.