Control architecture for increased performance in pointing lasers

An overview of a control's architecture for pointing a laser in a track loop that performs with low frequency, type II, error rejection without the use of two free integrators in the forward path is presented. The method uses a stabilization loop on the outgoing laser to follow the residual error of the track loop. The cost of this loop is the addition of a position sensor and correction mirror. These components are normally used in high-performance pointing systems, thus the cost is only the delta increase in requirements from a conventional loop to that proposed. Additional effort is needed to calibrate the track sensor and stabilization sensor such that errors can be cross referenced. This capability allows for the additional error rejection between the two loops. The ability to accurately calibrate these detectors limits the performance of the total loop interaction. Initial simulation results show excellent type II error rejection without the overshoot typical in classical type II error rejection loops.