Improvement of laser pointing performance using a joint observer-based adaptive controller

Current classical tracking loops exhibit acceptable performance in certain regions; however, the uncertainties arising from system nonlinearities (i.e., acceleration limiters, laser dynamics, etc.) and multibody dynamics (interaction between the kill vehicle and the overall tracking system) demand a more robust controller design. Further, in a typical design, the commanded rate error signal is derived from a resolver (angle) sensor using a pseudo rate differentiator which could potentially produce undesirable performance. Two design modifications have been investigated to improve the performance of a laser pointing system for a kinetic kill vehicle. The first modification will improve the tracking performance of the laser system by using an adaptive controller scheme which was previously developed for a space-based attitude control system. The second modification will enhance the performance of the rate tracking loop by incorporating a dynamic observer to produce the optimal estimated angle and rate signals which can be used to compute a better actuating signal. The new design architecture has been implemented, tested, and evaluated in a six degree of freedom simulation environment.