Accuracy evaluation method and system for vibration measurement based on fmcw radar

Abstract

The invention provides a vibration measurement accuracy evaluation method and system based on an FMCW radar. The method comprises the steps that the initial phase and amplitude of a baseband complex beat signal in each sweep frequency cycle are estimated; the sequence of discrete points (R[i], I[i)] on a complex plane is acquired from the estimated initial phase time sequence and amplitude time sequence spanning multiple sweep frequency cycles; center estimation and circular trajectory fitting are carried out on the sequence of the discrete points (R[i], I[i)] in the complex plane; the sequence of the distance d[i] of the sequence of the discrete points (R[i], I[i)] and the estimated center is calculated; the standard deviation sigma d of the sequence of the distance d[i] is calculated; and the measurement accuracy evaluation parameter Ma is acquired. According to the invention, the method is based on the representation of extracted phase complex vectors in the complex plane and circular trajectory fitting; approximate quantitative evaluation of the vibration measurement accuracy is carried out by determining the standard deviation of the distance of each phase complex vector discrete point and the estimated center; and the method has the advantages of low computational complexity, visual result, clear indicator and high reliability.

Description

technical field [0001] The present invention relates to the technical field of vibration measurement, in particular to an accuracy evaluation method and system for vibration measurement based on FMCW radar. Background technique [0002] In the field of engineering technology, vibration measurement plays an important role, for example, it is an important means and method to realize equipment fault diagnosis and structural health monitoring. According to different sensing methods, vibration measurement techniques and methods can be divided into contact and non-contact types. Among them, contact vibration measurement needs to install corresponding sensors on the monitored object, which will affect the monitoring of dynamic performance of lightweight structures, and there is a problem of inconvenient installation and networking for vibration measurement of large structures. Commonly used technologies for non-contact vibration measurement include eddy current sensing measurement...

AI Technical Summary

Problems solved by technology

The evaluation of the signal-to-noise ratio of the target component of the baseband signal has a certain reference for the evaluation of the measurement accuracy, but due to the possible interference of adjacent components and background clutter components, it is difficult to estimate the signal-to-noise ratio more accurately, and due to the noise composition There is no quantitative correspondence between complexity, signal-to-noise ratio and measurement accuracy

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