LQG/LTR Tilt and Tip Control for the Starfire Optical Range 3.5-meter Telescope's Adaptive Optics System

摘要

The Air Force Research Laboratory has sponsored research on the tracking control loop portion of the adaptive optics system in the Starfire Optical Range 3.5-meter telescope at Kirtland Air Force Base. The control loop includes two steering mirrors (Coarse Steering Mirror and Fine Steering Mirror) used to remove wavefront tilt and tip phase distortion from light entering the telescope. The objective of this research is to design a single Linear Quadratic Gaussian controller to control both steering mirrors in order to eliminate wavefront tilt and tip distortions induced by the earth's atmosphere, and to evaluate the stability robustness and performance of the controller through simulation and Monte Carlo analysis. Controller design elements and simulation parameters are varied to examine and compare resulting performance and robustness characteristics. The controller design is limited to the use of linear models even though components within the control loop have some nonlinear characteristics; however, consideration has been given to the nonlinear aspects of the system via the simulation environment in order to observe the linear controller in a near-real-world environment.