Patent ID: 8847145
Filing Date: 2014-09-30
Classification: G01D

Abstract:
1. A method for working out the angular position of a rotating element which is mounted in a fixed frame, consisting in using at least one light source emitting a light beam in the direction of a fixed sensor and using processing and computing means for delivering an output signal of the sensor, consisting in: a) arranging the light source with respect to the rotating element and of the sensor in a way so as to induce an interaction between the light beam and the sensor which depends on the angular position of the rotating element, b) arranging on the path of the light beam, in a fixed position with respect to the sensor, a mask which presents a repetitive two dimensional pattern of transparent and opaque areas, c) detecting the image or shadows casted by the mask on the sensor, d) processing the output signal of the sensor for determining the position of the image or shadows on the sensor, and e) computing the angular position of the rotating element by using the position of the image or shadows on the sensor.