Development of Robotic Fiber Positioner and Path Planning Algorithm for Multi-object Spectroscopy 다천체 분광 관측을 위한 Robotic Fiber Positioner 및 경로 계획 알고리즘 개발

Abstract

A robotic focal plane system using robotic fiber positioners enables multi-object spectroscopy for hundreds to thousands of galaxies by utilizing a dense array of positioners that are closely packed at the focal plane of a telescope. While this dense arrangement increases the number of observations, it also introduces the potential for collisions between adjacent positioners. A fiber positioner is designed similarly to a SCARA robot. It is driven by two series of BLDC motors. Each positioner is manufactured with an outer diameter of 16 mm. It operates within an annular workspace with an outer diameter of 33.6 mm and an inner diameter of 12.8 mm. As these positioners are arranged with a spacing of 16.8 mm, target assignment and motion planning are critical to avoid collisions caused by overlapping workspaces. To address this, we proposed an optimized step choice algorithm using a motion planning method based on optimization with the sequential quadratic programming algorithm. Simulation results demonstrated that paths for all positioners within a tile were successfully generated with a success rate of up to 93.75% across 80 tiles.