Photoelectric encoder moire fringe subdivision method

Abstract

The invention provides a photoelectric encoder moire fringe subdivision method, wherein the method comprises the steps that: a signal of a latest moire fringe signal period is collected, and direct current level values of an SIN signal and a COS signal can be obtained according to a central point coordinate of the signal; according to the coordinates of the four vertexes of a moire fringe, the amplitude values of the SIN signal and the COS signal can be obtained; when an encoder performs subdivision, the actually acquired signals can be compensated according to the amplitude values and the direct current level values of the SIN signal and the COS signal so as to improve the precision of the encoder; and when the external environment is changed or a code disc of the encoder is locally stained, the moire fringe signal output by the encoder is an unstable signal, and the direct current levels and the amplitude values of the signals can be changed. When the system works, the direct currentlevels and signal amplitude values of the signals can be calculated in real time, so that moire fringe signals are compensated, and the subdivision precision of the encoder is improved.

Description

technical field [0001] The invention relates to the technical field of photoelectric encoders, in particular to a moiré fringe subdivision method of a photoelectric encoder. Background technique [0002] Photoelectric shaft encoder, also known as photoelectric angle position sensor, is a precision digital angle measuring device integrating light, mechanics and electricity. There are several concentric code tracks along the radial direction on the circular code disc of the absolute photoelectric shaft encoder, and each code track is composed of light-transmitting and opaque fan-shaped intervals. On one side of the code disc is a light-emitting element, and on the other side there is a photosensitive element corresponding to each code track. Each pair of light-emitting element and photosensitive element is called a reading head. When the code disc is in different positions, each photosensitive element outputs a different current signal according to whether it is illuminated o...

AI Technical Summary

Problems solved by technology

When the encoder is used for a period of time, its light-emitting element or photosensitive element will age, and its performance parameters will change, which will cause the amplitude values ​​of the amplified signal SIN and COS to be inconsistent, or the signal is not centered on 0V. When encoding When the code disc of the encoder falls into water droplets or dust, there will be a large error between the amplified signals SIN and COS output by the reading head and the standard sine wave signal when the encoder rotates, so the calculated encoder subdivision angle value does not It is not the real subdivision angle value, which will cause the encoder subdivision error to increase, or cause the encoder to be wrong and unusable

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