TY - GEN
T1 - Laboratory testing and calibration of the upgraded MMT adaptive secondary mirror
AU - Vaz, Amali
AU - Morzinski, Katie M.
AU - Montoya, Manny
AU - Fellows, Chuck
AU - Ford, John
AU - Gardner, Andrew
AU - Durney, Olivier
AU - West, Grant
AU - Harrison, Lori
AU - Gacon, Frank
AU - Downey, Elwood
AU - Carlson, Jared
AU - Mailhot, Emily
AU - Anugu, Narsireddy
AU - Jannuzi, Buell
AU - Hinz, Phil
N1 - Funding Information:
The MAPS project is primarily funded through the NSF Mid-Scale Innovations Program, programs AST-1636647 and AST-1836008. This research has made use of NASA’s Astrophysics Data System. The University of Arizona sits on the original homelands of Indigenous Peoples who have stewarded this Land since time immemorial. Aligning with the university’s core value of a diverse and inclusive community, it is an institutional responsibility to recognize and acknowledge the People, culture, and history that make up the Wildcat community. At the institutional level, it is important to be proactive in broadening awareness throughout campus to ensure our students feel represented and valued.
Publisher Copyright:
© 2020 SPIE.
PY - 2020
Y1 - 2020
N2 - The MMT Adaptive optics exoPlanet characterization System (MAPS) is a broad overhaul and upgrade of AO instrumentation at the 6.5-m MMT observatory, from deformable secondary mirror, through pyramid wavefront sensors in both the visible and near-infrared, to improved science cameras. MAPS is an NSF MSIP-funded program whose ultimate goal is a facility optimized for exoplanet characterization. Here we describe the laboratory testing and calibration of one MAPS component: the refurbished MMT adaptive secondary mirror (ASM). The new ASM includes a complete redesign of electronics and actuators, including simplified hub-level electronics and digital electronics incorporated into the actuators themselves. The redesign reduces total power to ?300W, from the original system's 1800W, which in turn allows us to eliminate liquid cooling at the hub with no loss of performance. We present testing strategies, results, and lessons learned from laboratory experience with the MAPS ASM. We discuss calibrations first on the level of individual actuators, including capacitive position sensing, force response function, and individual closed-loop position control with an improved control law. We then describe investigations into the full ASM system-hub, actuators, thin shell, and human-to understand how to optimize interactions between components for dynamical shape control using a feedforward matrix. Finally, we present our results in the form of feedforward matrix and control law parameters that successfully produce a desired mirror surface within 1ms settling time.
AB - The MMT Adaptive optics exoPlanet characterization System (MAPS) is a broad overhaul and upgrade of AO instrumentation at the 6.5-m MMT observatory, from deformable secondary mirror, through pyramid wavefront sensors in both the visible and near-infrared, to improved science cameras. MAPS is an NSF MSIP-funded program whose ultimate goal is a facility optimized for exoplanet characterization. Here we describe the laboratory testing and calibration of one MAPS component: the refurbished MMT adaptive secondary mirror (ASM). The new ASM includes a complete redesign of electronics and actuators, including simplified hub-level electronics and digital electronics incorporated into the actuators themselves. The redesign reduces total power to ?300W, from the original system's 1800W, which in turn allows us to eliminate liquid cooling at the hub with no loss of performance. We present testing strategies, results, and lessons learned from laboratory experience with the MAPS ASM. We discuss calibrations first on the level of individual actuators, including capacitive position sensing, force response function, and individual closed-loop position control with an improved control law. We then describe investigations into the full ASM system-hub, actuators, thin shell, and human-to understand how to optimize interactions between components for dynamical shape control using a feedforward matrix. Finally, we present our results in the form of feedforward matrix and control law parameters that successfully produce a desired mirror surface within 1ms settling time.
KW - Adaptive optics
KW - Adaptive secondary mirrors
KW - Deformable mirrors
KW - Feedforward control
KW - MMTAO
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U2 - 10.1117/12.2576352
DO - 10.1117/12.2576352
M3 - Conference contribution
AN - SCOPUS:85100057927
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Adaptive Optics Systems VII
A2 - Schreiber, Laura
A2 - Schmidt, Dirk
A2 - Vernet, Elise
PB - SPIE
T2 - Adaptive Optics Systems VII 2020
Y2 - 14 December 2020 through 22 December 2020
ER -