title: Robustness study of the pseudo open-loop controller for multiconjugate adaptive optics.
abstract: Robustness of the recently proposed "pseudo open-loop control" algorithm against various system errors has been investigated for the representative example of the Gemini-South 8-m telescope multiconjugate adaptive-optics system. The existing model to represent the adaptive-optics system with pseudo open-loop control has been modified to account for misalignments, noise and calibration errors in deformable mirrors, and wave-front sensors. Comparison with the conventional least-squares control model has been done. We show with the aid of both transfer-function pole-placement analysis and Monte Carlo simulations that POLC remains remarkably stable and robust against very large levels of system errors and outperforms in this respect least-squares control. Approximate stability margins as well as performance metrics such as Strehl ratios and rms wave-front residuals averaged over a 1-arc min field of view have been computed for different types and levels of system errors to quantify the expected performance degradation.
authors.affiliation: Department of Electrical and Computer Engineering, Michigan Technological University, Houghton, Michigan 49931-1295, USA.
authors.forename: Piotr
authors.initials: P
authors.lastname: Piatrou
authors.forename: Luc
authors.initials: L
authors.lastname: Gilles