An Optimal Nonlinear Variable Structure Guidance Law Considering Missile Dynamics of Autopilot

A new nonlinear variable structure guidance law considering missile dynamics of autopilot against the space maneuver target is presented. Considering the target maneuverability as a disturbance with boundary, this guidance law constructs the switching surface by adding a nonlinear function which is confirmed by feedback optimization theory at the linear switching surface based on the proportional navigation law. Considering one order autopilot dynamic model, the actual guidance command is derived. Simulation results show that this designed guidance law has good trajectory performance, is robust for maneuver targets and overcomes the shortcoming of the linear switching surface that causes excessive overload at initial guidance phase. It is simple and more convenient for practical implementation.