Structure of distributed control system in Seimei telescope

Abstract

A segmented mirror control system is indispensable for operating an astronomical telescope which is equipped with a segmented primary mirror. In this study, we focus on the distributed control system (DCS) proposed for Seimei telescope. An interesting hierarchical structure is found by analysing its zero–nonzero structure in the DCS, and then, 54 gains are reasonably classified into 4 groups. Design examples for selecting gains of the DCS are presented so that the closed loop pole locations are similar to those of the centralized control system (CCS). The freedom in the selections of gains by taking account of the hierarchical structure is shown to be effective by numerically evaluating the stability region and by optimizing the maximum distance between the closed loop poles of DCS and CCS.