Research On Method Of Vibration Target Measurement Based On Frequency Sweep Interference

Sweep frequency laser interferometry has obvious advantages,such as high measurement accuracy,no ranging dead zone,and no need to measure targets.It is a laser measurement techno logy with broad development prospects.In actual measurement,it is oft en necessary to measure moving objects.Sweep frequency interfero metry can also be applied in this measurement background.This paper mainly studies how to measure the vibration target using the swept frequency interfero metric ranging,and puts forward two measurement methods based on the single swept dynamic interferometric ranging method and the double swept dynamic interferometric ranging method.The topics discussed are all measuring the trajectory o f one-dimensio nal vibration in the direct ion of the opt ical axis.The measurement characterist ics of the two methods are analyzed through theoret ical derivat ion and simulat ion,and finally the vibrat ion target measurement experiment is carried outThis paper studies the basic principles of swept-frequency interferometric ranging,analyzes the effects of laser sweep nonlinearity,the Doppler effect brought by target vibrat ion,and the signal-to-no ise rat io o f the target signal o n the accuracy o f swept-interfero metric ranging.Laser frequency modulat ion nonlinear sweeping interfero metry ranging model.The dynamic interfero metric ranging method based on single-sweep frequency co mbines the advantages o f simple single-sweep interfero metric distance measurement opt ical path and linear Kalman filter algorithm wit h good opt imizat ion effect and fast efficiency.Data regressio n converges,restores the target’s trajectory,and analyzes the factors that affect its measurement accuracy and performs simulat ion verificat ion.Aiming at the shortco mings of high hardware requir ements and small measurement target range for single-sweep interferometric distance measurement,a dynamic interfero metric distance measurement method based on dual-sweep frequency is proposed.This method uses two lasers to scan frequency synchronously,using the gas chamber opt ical path,auxiliary interfero meter and The coordinated work of the measuring interfero meter solves the phase o f the beat signal and the time-frequency curve of the laser,then calculates the instantaneous distance o f the target,re stores the target’s trajectory,and analyzes and simulates the factors that affect its measurement accuracy.An experimental system was built to perform the vibrat ion target measurement experiment,and the movement trajectory o f the measured target can b e restored by two measurement methods: the single-sweep dynamic interference ranging system measures targets with different amplitudes and frequencies,and the amplitude measurement error is less than 1μm;The dual-sweep dynamic interfero metric ranging system measures targets with different amplitudes and frequencies,and the amplitude error measurement is less than 0.5 μm.The measurement uncertainty o f the two measurement methods is analyzed,and the mathemat ical model of the measurement uncertaint y o f t he two methods is determined.