Passive Homing Missile's Variable Structure Proportional Navigation with Terminal Angular Constraint

The objective is to design a variable structure proportional navigation law for the passive homing missile so that the missile can hit the target with a minimum miss-distance and desired impact attitude angle within the required overload when it flies at a lower trajectory. This paper utilized the variable structure proportional navigation with terminal impact attitude angular constraint, and made estimation about the distance rate and distance between the missile and target, which broke the limitation of a passive homing seeker. Furthermore, the paper let the switch gain vary adaptively with time to avoid any larger initial overload. The mathematical simulation was completed by some studied passive homing missile's dynamic model, and the simulation results showed that the navigation law of the passive homing missile can make the missile get the required miss-distance and desired impact attitude angle against tanks at lower trajectories and within the maximum overload; also this guidance law is much robust to the estimation error of distance and distance rate.