In order to improve the resolution of photoelectric shaft angle encoder

a method of subdividing high frequency-doubling Moire fringe signal is proposed and a frequency-doubling system of photoelectric potential shift signal based on FPGA is established. According to the mathematic model of ideal Moire fringe photoelectric signal

the original Moire fringe signal is deduced into

n

-fold high-order signal by using the function property of multi-angle sine-cosine signal. The different functions of the encoder are described

and

the frequency doubling technique of high resolution by using the amplitude subdivision lookup table is described respectively. Finally

an Omron E6B2-CWZ6C incremental photoelectric encoder with a diameter of 40 mm and a resolution of 2500 P/R is taken as the experimental object. Driven by a synchronous motor with a speed range of 200~3000 rpm

the output waveform frequency range of the encoder is about 8.3 kHz~125 kHz. Under the analog input signal with a frequency of 10 kHz

the subdivision scheme is adopted. In the quadruplicated frequency doubling experiment

the system can increase the frequency to 4 times of the original frequency. At the same time

based on the principle of 4 times frequency

the 128 times frequency experiment is designed and verified by experiments. The system can also be quickly increased to 128 times the input frequency. Compared with the traditional subdivision circuit

the design method and system have the characteristics of short development cycle

high integration

modularization and simple modification.