An adaptive proportional navigation guidance law for guided mortar projectiles

Mortar projectiles have large launch angles and curved trajectories, which bring new problems to the application of proportional navigation guidance (PNG). In this article, the ballistic characteristics of mortar projectiles and their impact on the application of PNG are analyzed, and an adaptive proportional navigation guidance (APNG) scheme with a variable coefficient is proposed. The guidance performance of two guidance laws is compared through simulation. Results of the simulation show that the path command angle with PNG is different from the mortar path angle, which leads to poor guidance. On the other hand, the path command angle with APNG is similar to the mortar path angle and easy to track for the guided mortar projectiles, so the application of APNG can significantly improve the firing precision of guided mortar projectiles. The result of an example trajectory and Monte Carlo simulations testifies to the effectiveness of the APNG scheme.