A capacitive finger-type angular-position and angular-speed sensor

A robust capacitive finger-type angular-position and angular-speed sensor for automotive and metrology applications is presented. The main advantages of this low-cost system are easy mounting and replacement, its simplicity, speed and high resolution (/spl plusmn/0.02/spl deg/) over the absolute measurement range of 180/spl deg/, compact sensor outlines, and insensitivity to dirt or condensation. The paper describes the working principle, the design and layout of a prototype sensor, if derives the required relationships for computing the angular rotor position, and discusses measurement results obtained from a prototype sensor.