Laser Doppler Vibration Signal Demodulation Algorithm and FPGA Implementation

The laser Doppler vibrometer has been widely used in many fields. Generally, the fast Fourier transform is widely used in vibration signal demodulation. However, this method has limitations in resolution, high computational complexity, requires high signal stability, and is non-real-time. To address the above problems in the laser Doppler vibrometer demodulation algorithm, this paper proposes a fast and real-time Doppler vibration signal demodulation algorithm, and designs a Doppler vibration signal acquisition and analysis system based on the FPGA platform. The pulse interleaved cancellation heterodyne method is used to achieve fast, real-time, and accurate laser Doppler demodulation. Through experiments on a standard vibration source, the feasibility of this method is verified. Compared with the fast Fourier transform, this method has lower computational complexity, higher real-time performance, and faster response.