IFF optimal control for missile formation reconfiguration in cooperative engagement

In this paper, an integral feedback and feed-forward (IFF) optimal controller with hard terminal constraints for missile formation reconfiguration is designed. The controller has quadric optimal performance for expected terminal errors, output, and control quantity. From the viewpoint of the kinematics relationship of a formation in the relative coordinate frame, the authors establish a precisely linearized relative motion model by transforming the control variables. This relative motion model can intuitively manifest the relationship of the relative motion in three directions in the relative coordinate frame. In order to solve the designed IFF optimal controller, detailed deductions for deriving the related Lagrange parameters are presented. A precise integration algorithm was adopted instead of using a traditional backward integration algorithm to calculate more precise solutions for the relevant parameters in the IFF optimal controller. A collision avoidance system with four spherical domains was proposed, and a modifying principle to avoid collision during formation reconfiguration was presented. Simulation results demonstrate that the presented IFF optimal controller is capable of implementing missile formation reconfiguration rapidly, stably, and accurately. It can additionally restrain invariant or slowly varying perturbations induced by the velocity of a leader missile. Furthermore, the collision avoidance system developed in this paper can enable missiles to avoid collision during formation reconfiguration.