关键词: 相位差, 过零检测法, 数字相关法, FFT, NI FlexRIO, LabVIEW FPGA

Abstract:

To calculate the phase shift, zero-crossing detection, digital correlation method and FFT are commonly used. Tests on the three algorithms show that, they can obtain phase shift accurately in dozens of microseconds delay, but resources and time cost are different. Zero-crossing detection needs more resources, but less time. FFT has large resource occupancy and latency. Digital correlation method is just the opposite to FFT, but detecting phase reverse is difficult.

Key words: Phase shift, Zero-crossing detection, Digital correlation method, FFT, NI FlexRIO, LabVIEW FPGA