New Modified Proportional Navigation Guidance with Several Constraints

It is well known that the Proportional Navigation Guidance (PN) is used as a terminal guidance law for missiles. It is also famous that PN is an optimal guidance under some conditions, but in the real world, PN is not always the ’optimal’ guidance especially when the missile accelerates. For the accelerating missiles, Modified Proportional Navigation Guidance (MPN) was proposed, although the axial acceleration of the missile was considered as constant. In fact, the missile will be accelerated nonlinearly, thus MPN is revisited and we proposed a new method (New MNP)[11]. In the control point of view, both MPN and our method are considered as double loop feedbacks based on the LOS angle and the LOS rate. They have to satisfy certain stability conditions and avoid the singularity[12]. In the new MNP, the objective function is considered and it is the traditional minimum squared lift coefficient integration in order to maintain the missile lift coefficient should be as small as possible. However, depending on the situation, they may encounter the load factor limitation as well as the stall limit. Under such circumstances, the missile may use the corner Mach number, where the turning rate is the maximum. With the new formulation, numerical analyses are performed. As a result, we succeeded to improve the MPN missile guidance.