Fig. 1. Function relationship under vibration small signal. (a) Relationship between D and P₀, P₁ , P₂ under small signal;(b) Relationship between ΔP_0-1 、ΔP_0-2、ΔP_1-2 and D under small signal

Fig. 2. Function relationship under vibration large signal. (a) Relationship between D and P₀, P₁ , P₂ under large signal;(b) Relationship between ΔP_0-1 、ΔP_0-2、ΔP_1-2 and D under large signal

Fig. 3. Spectrum of simulated Doppler signal. (a) Doppler signal spectrum at D=0.01 rad;(b) Partial enlargement of Doppler signal spectrum at D=200 rad

Fig. 4. Experimental setup diagram

Fig. 5. Time domain and spectral plots of the measured small amplitude heterodyne Doppler signal. (a) Time domain waveform of Doppler signal at 3 kHz with 30 mV excitation signal; (b)(c)(d) Spectrum of Doppler signal at different acquisition moments

Fig. 6. Spectrum of the measured large amplitude heterodyne Doppler signal. (a) Doppler signal spectrum at 80 Hz and 7 V excitation signal; (b) Doppler signal spectrum after local amplification centered on the carrier frequency

Fig. 7. Vibration measurement results of B&K shaker under different excitation conditions. (a) Measured amplitude and reference amplitude at 3 kHz vibration frequency with different voltages; (b) Measured amplitude and reference amplitude at 80 Hz vibration frequency with different voltages; (c) Measured B&K frequency response and reference frequency response at 0.5 V