Error analysis of friction drive elements

摘要

Friction drive is used in some large astronomical telescopes in recent years. Comparing to the direct drive, friction drivetrain consists of more buildup parts. Usually, the friction drive train consists of motor-tachometer unit, coupling, reducer,driving roller, big wheel, encoder and encoder coupling. Normally, these buildup parts will introduce somewhat errors tothe drive system. Some of them are random error and some of them are systematic error. For the random error, theeffective way is to estimate their contributions and try to find proper way to decrease its influence. For the systematicerror, the useful way is to analyse and test them quantitively, and then feedback the error to the control system to correctthem. The main task of this paper is to analyse these error sources and find out their characteristics, such as random error,systematic error and contributions. The methods or equations used in the analysis will be also presented detail in thispaper.