A Novel Demodulation Method Based on Partial Period Curve-fitting for FM Signal in Impact Acceleration Calibration by Using Laser Interference Methods

FM signals in acceleration calibration by laser interference, a demodulation method based on partial periodic sine wave fitting is proposed. By using a sine wave model with about 1/5 cycles, FM demodulation is realized. It has good adaptability to the laser Doppler impulse signal waveform, and can perform operations without signal interception, and has good algorithm stability and one sampling interval resolution. Experiments on a set of actual measured waveforms verify the correctness and feasibility of the algorithm, and provide an effective method for impact acceleration calibration. The method herein can also be used for demodulation of heterodyne laser interference vibration signals.