Identification and adaptive control of a high-contrast focal plane wavefront correction system

作     者：Sun, He Kasdin, N. Jeremy Vanderbei, Robert 

作者机构：Princeton Univ Dept Mech & Aerosp Engn Princeton NJ 08544 USA Princeton Univ Dept Operat Res & Financial Engn Princeton NJ 08544 USA 

出 版 物：《JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS》 (J. Astron. Telesc. Instrum. Syst.)

年 卷 期：2018年第4卷第4期

核心收录：

学科分类：07[理学] 0804[工学-仪器科学与技术] 070401[理学-天体物理] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：AWD1004079 AWD1004730 

主　　题：exoplanet direct imaging coronagraph wavefront correction E-M algorithm system identification adaptive control reinforcement learning 

摘      要：All coronagraphic instruments for exoplanet high-contrast imaging need wavefront correction systems to reject optical aberrations and create sufficiently dark holes. Since the most efficient wavefront correction algorithms (controllers and estimators) are usually model-based, the modeling accuracy of the system influences the ultimate wavefront correction performance. Currently, wavefront correction systems are typically approximated as linear systems using Fourier optics. However, the Fourier optics model is usually biased due to inaccuracies in the layout measurements, the imperfect diagnoses of inherent optical aberrations, and a lack of knowledge of the deformable mirrors (actuator gains and influence functions). Moreover, the telescope optical system varies over time because of instrument instabilities and environmental effects. We present an expectation- maximization (E-M) approach for identifying and real-time adapting the linear telescope model from data. By iterating between the E-step (a Kalman filter and a Rauch smoother) and the M-step (analytical or gradientbased optimization), the algorithm is able to recover the system even if the model depends on the electric fields, which are unmeasurable hidden variables. Simulations and experiments in Princeton s High Contrast Imaging Lab demonstrate that this algorithm improves the model accuracy and increases the efficiency and speed of the wavefront correction. (c) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.