Application of pseudo-random code in miniature absolute encoder chip

作者：Yin Jing Zhi; Yu Zhi Shuai; Peng Can; Mu Yu Song; Chang Yu Chun^*

来源：Optics and Precision Engineering, 2016, 24: 169-174.

DOI：10.3788/OPE.20162413.0169

• Absolute encoders
• Chip
• Compensation algorithm
• Engineering applications
• Photoelectric encoders
• Pseudo random codes
• Pseudo random coding
• Pseudo-random binary sequences

To solve the problem of large volume and low precision for traditional absolute encoder, an absolute encoder chip based on the M-code pseudo-random binary sequence was designed. With overall consideration of advantages and disadvantages of absolute encoding mode, the sing M-code track was designed for avoiding the multi-track and large size of the traditional multi-loop absolute encoder track, thus realizing the miniaturization of absolute encoders. Subjected to the interpolation of the internal ACD, the combination of the M-code channel with the incremental precise-code channel can highly improve the resolution of the absolute encoder to 19 bit with a rather low external noise. Finally, an error compensation algorithm based on the neural-network were adopted to reduce the subdivision error by twice or three times, thus the system precision of the encoder was greatly improved. After compensation, the standard deviation of the encoder system is 8.4″. The absolute encoder can basically meet the requirements for small volume, high precision and high reliability, with certain engineering application values.

• 出版日期2016