A Single Code Track Absolute Position Encoder

Abstract

The invention discloses a single-code-channel absolute position encoder which comprises a grating ruler, a CCD photoelectric detector, a lighting source and a photoelectric signal processing module. The grating ruler is a single-code-channel absolute grating ruler and is provided with a coding engraved rail. The lighting source is arranged below the grating ruler. A microscopic imaging lens set, the CCD photoelectric detector, the lighting source and the photoelectric signal processing module are sequentially arranged above the grating ruler from bottom to top. An absolute encoding code value on the single-code-channel absolute grating ruler is read based on the CCD photoelectric detector; absolute position information of the single-code-channel absolute grating ruler is calculated according to the encoding-decoding algorithm; subdivision of the output absolute position is achieved based on signal output of different pixels of the CCD photoelectric detector. System codes are adopted and can express more grades with shorter code words; in addition, according to features of multi-system codes, fast encoding and fast decoding of system codes can be achieved, and the problem that absolute grating length measurement is limited is solved.

Description

Technical field: [0001] The invention relates to the field of precision measuring instruments, in particular to a single-track absolute position encoder. Background technique: [0002] Grating encoders are widely used in CNC machine tools, precision measuring instruments, automation equipment and other fields, and their performance directly affects the accuracy of machining, measurement testing, and positioning control. [0003] At present, grating encoders for precision displacement measurement mainly include two basic forms: incremental grating encoders and absolute grating encoders. Its measurement standard is a grating ruler with periodic lines, using cheap semiconductor lasers or LEDs as light sources, which has low requirements on the environment and reduces costs. [0004] The principle of the incremental grating encoder system is to use the relative movement of the light source and the grating ruler to modulate the light, and obtain the displacement information by r...

AI Technical Summary

Problems solved by technology

For the gray code, pseudo-random sequence, uniform distribution and other absolute position codes commonly used on absolute angle encoders, it is difficult to meet the requirement of infinitely long single code track of the position encoder, and it will be difficult to realize the large-travel measurement required by the factory workshop

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