METHOD FOR MEASURING ANGLE OF ROTATION AND DEVICE REALIZING THEREOF Russian patent published in 2020 - IPC G01C1/02 G01B11/26 

FIELD: measuring equipment.

SUBSTANCE: invention relates to measurement equipment and can be used for non-contact determination of mechanical objects turning angles. Disclosed method of measuring shaft turn angle includes coaxial installation of circular scale on shaft with made on its periphery set of transparent and non-transparent strokes, illumination of the scale on one side by a parallel light beam and installation on the other side of the photodetector. Photodetector is made in the form of a precision one-dimensional matrix arranged on a tangential circular scale, and is equipped with a computer which enables recognition of lines, numbers of segments and position of the reference relative to the matrix with subpixel accuracy. Strokes on the circular scale are grouped in N approximately equal segments with angular width of 2*π/N radians, each segment has an allocated mark (reference), and the segments carry code denoting their number, wherein the minimum width of the stroke is not less than 3 pixels of the matrix photodetector. Length of the matrix photodetector device and the width of the segments are selected such that at least two segment lengths are laid on the length of the matrix, and it is possible to measure the distance in pixels of the photodetector between each two adjacent reference points L_i. Self-calibration procedure is carried out by measuring all values of interfiducial distances and normalizing the obtained results by the condition:

,

R is the photodetector setting radius, counted from the shaft rotation axis, δ is the pixel size of the photodetector device, based on the results of which the R value is updated and the absolute rotation angle is measured as the sum of the interfiducial distance integral values, expressed in the angular measure, and proportion of current segment counted by photodetector.

EFFECT: high accuracy of determining the angle of rotation and simple technique of making a code disc.

1 cl, 10 dwg