Research on the Precision Improvement of Incremental Optical Encoder Based on FPGA and DSP
Luo Fu-yuan · Machinery & Electronics · 2012
To research on the method of the accuracy improvement of incremental optical encoder based on digital signal processor(DSP) and field programmable logic array(FPGA).Firstly,the output signals of low-precision(500 puls/r) and high-precision(2 500 puls/r) the incremental optical encoder were filtered and level shifted respectively,then the signal of low accuracy incremental optical encoder and DSP's output sampling pulse were input to FPGA,the time difference(error of 0.67ns) between the two pulses was calculated by time-to-digital converter(TDC),the time difference was input to the DSP by data bus real-timely,the position of sample was obtained by algorithm processing which compare with DSP's high-precision optical encoder position,the analysis showed that its accuracy increases five-fold.