Differential type laser-measuring-impact method and device based on partial period demodulation

Abstract

The invention relates to a differential type laser-measuring-impact method and device based on partial period demodulation, and belongs to the technical field of photoelectric measurement. The method is characterized by comprising the following steps: performing optimal estimation of sine parameters by using a model section smaller than one carrier period; applying an estimation result to differential type laser-measuring-impact data processing, so as to complete instantaneous frequency demodulation of a laser Doppler signal and further acquire impact speed waveforms and impact acceleration waveforms. The device provided by the invention consists of a laser 1, a beam splitter prism 2, a focusing lens 3, a measuring surface (a grating) 4, an impact table 5, a reflecting mirror 6, a reflecting mirror 7, a focusing lens 8, a photoelectric converter 9 and a data acquisition system 10. The impact measurement carried out by utilizing the method and the device provided by the invention has the advantages that the temporal resolution is high, the algorithm is absolutely convergent, the high adaptation and robustness for non-stable laser Doppler time-domain signals are achieved, and traceable calibration can be conveniently carried out.

Description

technical field [0001] The invention relates to a differential laser shock measurement method and device, in particular to a differential laser shock measurement method and device based on residual period demodulation, and belongs to the field of photoelectric measurement technology. Background technique [0002] In the measurement of mechanical quantities such as vibration and impact, in order to avoid the impact of installing sensors on the measured object, people generally use non-contact measurement methods such as photoelectric measurement. For the purpose of waveform measurement, the photoelectric measurement technology based on the Doppler principle is one of the most important methods, and the core technology is the frequency modulation signal demodulation technology. [0003] Both modulation and demodulation are processes of spectrum change: since the output signal of the nonlinear element has more abundant frequency components than the input signal, the frequency c...

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Problems solved by technology

[0006] The purpose of the present invention is to solve the problem of poor quality of the laser Doppler signal waveform obtained during ultra-high shock measurement calibration and testing, and propose a differential laser shock measurement method and device based on residual period demodulation

By using the present invention, when both the median value and the amplitude of the oscillating waveform change sharply, it presents a violent irregular and non-stationary feature, and overcomes the shortcomings and deficiencies of the existing shock laser measuring device

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