An absolute rotary position sensor based on cylindrical coordinate color space transformation

Abstract

In this paper, a novel, very simple and low-cost absolute rotary position sensor is presented. The sensor operation is based on the RGB to cylindrical coordinate color space transformation. A very simple experimental setup based on optical reflective sensors for absolute rotary position sensing in order to demonstrate proof of concept is given. Instead of using complex solution consisting of color sensor and printed color wheel, a much simpler solution that uses three optical reflective sensors and grayscale wheel is proposed. The proposed sensor has linear characteristics with accuracy below ±1°, resolution of 0.1° and linearity with R2 of 0.99998, within the measurement range from 0° to 360°. © 2014 Elsevier B.V.