Method for working out the eccentricity and the angular position of a rotating element and device for carrying out such a method

摘要

A method for working out the angular position of a rotating element, by using at least one fixed light source emitting a light beam in the direction of a fixed sensor, arranging the light source with respect to the rotating element and sensor to induce an interaction between the beam and sensor, and providing a value of the angular position dependent of the sensor's output signal. The method including:
arranging on the path of the beam a code-disc presenting a two-dimensional pattern of transparent and opaque areas and an absolute code integral with the rotating element,using the image casted by the code-disc on the sensor for determining the eccentricity of the code-disc in dependence of the angular position of the rotating element,using the eccentricity for compensating the value of the computed angular position, andcomputing a corrected angular position of the rotating element.

主权项

1. A method for determining at least the eccentricity of a rotating element which is mounted in a fixed frame, said method comprising:
using at least one fixed light source emitting a light beam in the direction of a fixed sensor; arranging the light source with respect to the rotating element and with respect to the sensor in a way so as to induce an interaction between the light beam and the sensor, which depends on the angular position and the radial position of the rotating element; using computing and processing means for providing a value of the radial position dependent on the output signal of the sensor; arranging on the path of the light beam a code-disc which comprises a two dimensional regular pattern interlaced with an absolute code and which is integral in rotation with the rotating element; and using an image cast by said code-disc on the sensor for determining the eccentricity of the code-disc dependent on the angular position of the rotating element.