Doppler radar-based non-contact type vibration measuring method

Abstract

The invention discloses a Doppler radar-based non-contact type vibration measuring method. The method includes the following steps: S1. directly facing a measured vibration object to emit single-frequency microwaves in the form of continuous waves, and receiving radar echoes after modulation by vibration motion; S2. performing amplifying, filtering and quadrature mixing on echo signals and taking down conversion signals to obtain two paths of baseband signals I(t) and Q(t); S3. performing data collection on the baseband signals to obtain discrete digital signals; and S4. performing phase demodulation processing on the discrete baseband signal I[n] and Q[n], and extracting vibration amplitude and frequency information. The Doppler radar-based non-contact type vibration measuring method provided by the invention uses a microwave radar to perform non-contact type vibration measurement based on a Doppler effect, has good low frequency measurement sensitivity, is high in environmental adaptation, and can perform accurate vibration measurement under the condition of containing a barrier. The microwave radar used by the method is compact in structure and low in cost and has relatively low power consumption, thereby providing a solution to integration of a large-scale vibration measuring system.

Description

technical field [0001] The invention relates to the technical field of vibration measurement and analysis, in particular to a non-contact vibration measurement method based on Doppler radar. Background technique [0002] Vibration is a ubiquitous physical phenomenon in nature. Vibration measurement has been widely used in many fields of engineering technology, such as condition monitoring and fault diagnosis of various mechanical systems, low-frequency vibration monitoring of large flexible structures, and vibration and noise testing and analysis. Inhibition etc. In order to meet various vibration measurement needs, various sensors have been developed, and various vibration measurement technologies have been developed. The current vibration measurement methods can be divided into contact and non-contact measurement, among which acceleration sensors are widely used in contact measurement. The acceleration sensor measures the acceleration of the contact target and obtains th...

AI Technical Summary

Problems solved by technology

The acceleration sensor measures the acceleration of the contact target and obtains the relative displacement of the measured object after integration. However, the commonly used accelerometers have poor low-frequency response capabilities and cannot be used effectively in special environments such as weightlessness. There are often many limitations in the application

In non-contact measurement, the laser vibrometer has high test accuracy, but there are limitations such as high equipment cost, calibration and narrow detection range, and it has relatively high requirements for test environment conditions, which cannot adapt to vibration monitoring in complex environments.

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