Robust Guidance Law with L2 Gain Performance

The guidance law design problem is formulated as a disturbance attenuation L2 gain control problem where target accelerations are regarded as unpredictable disturbances that are completely unknown, but bounded and guidance parameter errors are viewed as bounded control system parameter uncertainties. By using a Lyapunov-like approach to find the feedback control, a guidance law satisfying the L2 gain performance is derived from a linear time-varying mathematical model that describes the missile-target engagement. During the derivation of the guidance law, its robust stability is proved. Simulation results show that the presented guidance law provides strong robustness properties against heading error, guidance parameter errors, and target maneuvers; thus they obtain excellent miss-distance performance over the conventional realistic true proportional navigation guidance law.