DEVELOPMENT OF A NOISE-FREE POSITION ENCODING DEVICE FOR SPACEFLIGHT USE

摘要

Conventional potentiometers both rotary and linear arerncommonly used in mechanisms for space flightrnapplications. Potentiometers offer simplicity, lowrnpower consumption and relatively low price for thernresolutions they offer; however, they frequently exhibitrn"noise" and "drop-outs" in signals after a few thousandrnrevolutions. Having any type of signal "drop-out" noiserncould become mission critical. The generated noise isrnmainly caused by wear particles lodging themselves inbetweenrnthe wiper contact and the resistive orrnconductive tracks. This phenomenon is common to allrntypes of conventional sliding contact potentiometers.rnThis paper addresses a rolling contact encoding devicerndeveloped jointly by H&K GmbH and Moog Inc. USA.rnThe device is based on a proven and patentedrnmembrane potentiometer technology design by H&Krnused in industrial, medical and aerospace applications.rnFor the commercial device to be used for space, specialrndevelopment was needed to address the materials andrnprocesses, hard vacuum, noise-free operation forrnextended life and linearity better than 0.25%.rnThis paper summarizes the design, development,rnqualification and life testing of this device. The devicerntrademarked as "Moog QuieSenseTM" noise-freernpotentiometer has undergone extensive developmentrntesting under different conditions and has proven thernnoise-free operation for over one million revolutions.