Pre-research on arithmetic for facing control of segmented-mirror in LAMOST

Hanjie Miao; Yongjun Qi

doi:10.1117/12.786507

18 July 2008 Pre-research on arithmetic for facing control of segmented-mirror in LAMOST

Hanjie Miao, Yongjun Qi

Proceedings Volume 7019, Advanced Software and Control for Astronomy II; 70192A (2008) https://doi.org/10.1117/12.786507
Event: SPIE Astronomical Telescopes + Instrumentation, 2008, Marseille, France

Abstract

Main mirror in LAMOST is a spherical mirror with 4 meters effective aperture, it is assembled by 37 hexagonal segments, and the orientations of these segments were adjusted by actuators to achieve optical co-focal status. Arithmetic for facing control of segmented-mirror was pre-researched in this paper, based on present condition in LAMOST. To maintain the main mirror in a facing figure and preserve it during the track is the core of this control. To achieve the facing figure, the unique method in segmented-mirror technology nowadays is that sensors working with actuators to form closed loop. Firstly, relationship between the measurement results of sensors and the movements of actuators was calculated and the figure control equation set was founded. Secondly, the characteristic of the coefficient matrix of this equation set was analyzed. Finally, several methods to solve this equation system were comprehensively analyzed. Damped Least-Squares Solution (DLS) was selected as the best for this paper, and this method was programmed to apply on the experiment of sub system, finer result was got. Petal-effect in the experiment was noticed, analysis was given to show the control of whole main mirror would get rid of petal-effect.

Citation Download Citation

Hanjie Miao and Yongjun Qi "Pre-research on arithmetic for facing control of segmented-mirror in LAMOST", Proc. SPIE 7019, Advanced Software and Control for Astronomy II, 70192A (18 July 2008); https://doi.org/10.1117/12.786507

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available