Design And Application Of Laser Vibrometer Calibration Device

In recent years,laser vibrometer as a high-precision vibration measurement sensors have been widely used in defense and civilian fields,the demand for its calibration is also increasing.Paper studied the issue of laser vibrometer calibration,for different calibration requirements designed three calibration device,and through the experiment and the uncertainty calculation analyzed and evaluated performance of the device.Details as follows:(1)The paper analyzed the domestic and international situation and development trend of vibration calibration,proposed to use electrical calibration method,relative calibration method calibration and absolute calibration method to designe three laser vibrometer automatic calibration device.On this basis,the paper introduced measuring principle of laser vibrometer,and calibration principle of electrical calibrated method,relative calibration method,absolute calibration method.(2)The paper designed laser vibrometer electrical calibrated device hardware and software,could measure all frequency range and speed range of split type laser vibration,possessed the advantages of wide measuring range.The device adopts the signal generator for electric excitation source,simulated laser vibrometer photodetector output signals,used digital voltmeter and oscilloscope as measuring instruments,used Lab VIEW software developed calibration system on a PC,could be achieved input,transmission and display signals and other features.Repeated experimental tests using the device and analyzed of Uncertainty on this basis of experiments,thus evaluated the overall performance of the device.(3)For the problem that the electrical calibration method can only calibrate signal analysis and processing section of a laser vibrometer.The paper further designed laser vibrometer relative calibration device to achieve system calibration based on the relative calibration method,with advantage of simple assembly,low environmental requirements for calibration and so on.The means provides incentives by shaking table,uses accelerometer as a standard source,controls input signal and synchronously tests calibratedinstrument and the standard instrument in Lab VIEW Control Panel.Through several experiments to test different types of equipment and analysis of uncertainty determined that the device had good performance.(4)In certain situations that require high precision,relative calibration method is difficult to meet calibration requirements.To achieve high accuracy and reliability of the calibration,the paper designed a set of absolute calibration device.This means used interferometer as a standard source,connected each instrument with PC as a control system through the GPIB interface,formed automatic calibration device in Lab VIEW software control.Through experimental testing and uncertainty evaluation may proof device can realize laser vibration calibration as required.(5)Finally,the paper summarized research content and innovation,the same time prospected of the future study.