Abstract:

The digital phase-locked loop is used to improve the accuracy of the encoder.First,the sine and cosine of the original signal and the feedback of the cosine and sine signals are input to the same phase detector  for multiplication and subtraction to remove the high frequency components,thus a better dynamic range of the PLL.The "reversible counter+digital sine/cosine wave table" approach is adopted to generate cosine/sine signals containing direction information,which achieves the static or transient position detection.This method improves the detection accuracy of conventional encoder,grating and other conventional detection device s by at least two orders of magnitude.

Key words: digital phase locked loop;encoder;detection accuracy