Biased proportional navigation applicable for infrared guidance munitions

Considering trajectory shaping guidance is unavailable for the constraint of the impact angle of infrared guidance munitions which could not supply time-to-go information, a kind of biased proportional navigation guidance, without time-to-go for its input, is proposed. Based on the established munitions-target relative motion model and collision triangle, the relationship between the desired impact angle and the demand bias integral quantity is derived. Then, the differential equation of engagement kinematics is solved and the stable region is obtained. The influence of some relevant factor on guidance performance of the proposed guidance is studied. The biased proportional guidance performance is also compared with that of the trajectory shaping guidance. Simulation results show that the biased proportional navigation is competitive with the trajectory shaping guidance in the key performance indexes, such as impact angle control precision, guidance and control precision and the maximum demand acceleration and that it could be used for the constraint of impact angle of infrared guided munitions.