Absolute position coding and decoding method for optical grating of absolute position displacement sensor

Abstract

The invention discloses an absolute position coding and decoding method for an optical grating of an absolute position displacement sensor. The absolute position coding and decoding method comprises the following steps that the optical grating with absolute position coding is divided into N code channels, wherein the first code channel is an absolute code channel, and the other n-1 code channels are equidistant increment code channels; the absolute code channel is composed of a parity bit cross-region identification code area, a gray code area, an interval code area (with or without) and an over-interval code area (with or without); the equidistant increment code channels comprise low-order equidistant increment code channels and high-order equidistant increment code channels which areprovided with evenly spaced scribing lines; the number of the scribing lines of the low-order equidistant incremental code channels is equal to the number of gray codes; the number of the scribing lines of the high-order equidistant incremental code channels can be arranged as required; the corresponding code is "1" when light passes through or reflects from an optical grating absolute code channel coding area to a photoelectric element, and the corresponding code is "0" is when light does not pass through or reflect to the photoelectric element; and during decoding, position data read by thecode channels are integrated through FPGA chips. The absolute position coding and decoding method can ensure that the absolute position coding within any coding length range is unique.

Description

technical field [0001] The invention belongs to the technical field of absolute position displacement sensors, in particular to a grating absolute position encoding and decoding method of an absolute position displacement sensor. Background technique [0002] The full-closed-loop direct position control scheme is the mainstream high-precision control scheme in applications such as high-precision robots and high-end CNC machine tools. Among them, the position displacement sensor is the key sensor in the high-precision full-closed-loop direct position control scheme. The position displacement sensor using the absolute position encoding grating can directly feed back the current absolute position information when it is powered on, and does not need to go back to zero to find the absolute reference point to confirm the absolute position. Therefore, this type of absolute position displacement sensor has a wider range of applications. [0003] At present, the commonly used absol...

AI Technical Summary

Problems solved by technology

The result is firstly that the manufacturing process of high-precision and high-resolution circular gratings is more difficult, and it also leads to an increase in the size of the encoder.

However, applications that require high precision and high resolution for encoders are often accompanied by strict restrictions on their installation space, which limits the high-precision performance of this type of circular grating that uses multi-turn Gray codes for absolute position coding and decoding. Application Promotion in Requested Application Areas

In addition, the increase in the code track width of this type of circular grating also requires corresponding adjustments in the shape of the photoelectric scanning sensor to ensure accurate reading of position data.

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