Collision possibility analysis and collision avoidance for multi-object fibre-fed spectrographs with theta–phi positioners. Issue 1 (11th November 2020)

• Record Type: Journal Article
• Authors: Zhang, Feifan; Wang, Jianping; Liu, Zhigang; Zhai, Chao; Chu, Jiaru
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 500:Issue 1(2021)
• Page Start: 101
• Page End: 108
• Publication Date: 2020-11-11
• Subjects: instrumentation: spectrographs -- techniques: spectroscopic -- telescopes; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa1944
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Multi-object spectroscopy has become a valuable technique in numerous modern astronomical facilities. Most spectrographs have thousands of fibre positioners packed at a focal plane with shared working space. Therefore, positioners might collide with each other, which can lead to them being damaged. In this study, we first analysed the types of collisions between hexagonal patterned theta–phi positioners and the possibility of these collisions. Based on this, we proposed a motion planning method by deploying a proposed 'safety zone' within the positioner patrol area. Simulated experiments validated that our method could completely solve collisions between positioners with equal arms, such as the Large-sky-Area Multi-Object fibre Spectroscopic Telescope (LAMOST) and the Dark Energy Spectroscopic Instrument (DESI), or between positioners with unequal arms, such as the Multi-Object Optical and Near-infrared Spectrograph (MOONS).