Fig. 1. Angular frequency waveforms of different signals

Fig. 2. Schematic of three-channel FMCW laser interference system

Fig. 3. Control circuit of three-channel FMCW laser interferometer

Fig. 4. Schematic of laser drive circuit

Fig. 5. Circuit board for three-channel FMCW laser interference system

Fig. 6. Execution sequence of each chip program

Fig. 7. Flowchart of phase detection of beat signal

Fig. 8. Experimental device

Fig. 9. Beat signal before and after adding synchronization signal. (a) Before adding; (b) after adding

Fig. 10. Correlation of feature points before and after adding synchronization signal. (a) Before adding; (b) after adding

Fig. 11. Scatter points of displacement errors of different channels. (a) Channel 1; (b) channel 2; (c) channel 3

Fig. 12. Linearity curves of three channels