Comparison of Different Guidance Laws for a Mortar Missile

With a Pulse Jet Control Mechanism

Danilo ćuk

Faculty of Mechanical Engineering, Belgrade, Serbia, cukd@eunet.rs

miloš Pavić

Military Technical Institute, Belgrade, Serbia, CNN@beotel.rs

Bojan Pavković

Military Technical Institute, Belgrade, Serbia, bjnpav@gmail.com

Abstract: Impact point dispersion of a mortar missile can be drastically reduced with a ring of lateral pulse jets located around the center of gravity and homing head measuring the target line-of-sight rate. Using a simulation model that includes missile as a vehicle with six-degree-of-freedom, jet pulse flight control system, and relative motion of missile-to-target, three guidance laws are compared, namely, proportional navigation guidance, augmented proportional navigation, and augmented proportional navigation and rendezvous. The proportional navigation guidance exhibits large miss distance due to undesired effect of the gravitational acceleration because the missile hits the ground before arriving to the target. The augmented proportional navigation gives slightly better performances than the augmented proportional navigation and rendezvous for the same design parameters. Dispersion reduction was studied in details for the augmented proportional navigation. The proper selection of the design parameters – the number of pulse jets, the pulse jet impulse, and the minimal frequency of the pulse jets, for a particular dispersion of flight parameters during ballistic phase and the instant of the start guidance, is required to achieve optimum dispersion reduction. The minimum value of the individual pulse jet impulse required for the pin point accuracy of the mortar missile, was determined for the maximal deflection of the mortar missile from the nominal trajectory.