A new nonlinear H∞ terminal guidance law design

For the case of intercepting maneuvering target, A new nonlinear terminal guidance law with robustness is proposed by adopting nonlinear H∞ control theory. The mathematic model was built according to nonlinear kinematics relationship between missile and target whose acceleration as disturbance was introduced. Based on the terminal guidance law's measure of zeroing the line-of-sight angular rate and zeroing the relative distance, a new nonlinear H∞ guidance law is designed by solving the Hamilton-Jacobi-Isaacs partial differential inequation, at the same time the parameter of guidance law is chosen according to weight parameter of measure and the different L2 gain values of nonlinear guidance system. Finally an illustrative example is given to show that nonlinear guidance law is more robust and suitable to the missile for intercepting the target with high velocity and high maneuver than proportional navigation law, and the better precision of guidance law is obtained.