Abstract: In order to meet the high reliability requirements of the new model to launch vehicle, the angular displacement sensor is designed by using series, in parallel with three redundancy in a closed-loop used as measurement and feedback. For servo output shaft angle measurement, the mechanical angular signal is converted to electrical signal output to the controller, so as to realize electric servo closed-loop control. Three ultra-small, high-reliability redundant angular displacement sensor is in the form of three redundant rotary potentiometer, but with two-ring design, one of the rings as the single way,another ring for doubleredundant design, the resistance ring will be overlapped , the structure is the combination of the series and parallel, can  be used alone or in parallel electrically. This sensor using new brush structure, improving the environmental adaptability of the product, has significant social, economic benefits and promotional value.

Key words: Angular displacement sensor, Redundant, Environmental adaptability