JPH06207882A - Vibration analyzer - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to obtain a vibration analysis device capable of accurately analyzing frequency components of vibration of a rotating body. A vibration analysis device of the present invention inputs a vibration data through a vibration input device in synchronization with a rotation-synchronized trigger signal generator that generates a trigger pulse signal that is synchronized with the rotation of a rotating body. Sampling data input means for digitizing the input vibration data and saving it in a sampling data saving file, and discrete Fourier transform analyzing means for performing a discrete Fourier transform based on the saved sampling data to calculate the frequency component of the rotating body. And a frequency analysis result storage file for storing the frequency components calculated here.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration analyzer for analyzing vibration of a rotating body.

[0002]

2. Description of the Related Art In recent years, in various industrial plants, it has become important to monitor abnormal signs of a rotating body as the capacity and complexity of facilities increase. In plants with rotating bodies, the characteristics of various abnormalities are often found in vibration phenomena, but since vibration phenomena are high-speed phenomena, a huge amount of data is handled, and therefore various signal processing It was necessary to extract useful information for monitoring abnormal signs from a huge amount of data using. Further, since the characteristic of the vibration phenomenon is prominently seen in the frequency component, especially the specific frequency component such as rotation synchronization and the natural frequency component, the frequency analysis is the most useful means for monitoring abnormal signs, and these are monitored. In order to collect time series sampling data,
Discrete Fourier Transform (DFT: Discrete Fo)
Widely used are FFT analyzer devices that perform frequency analysis using the urierTransform method.

[0003]

However, in these conventional devices, since sampling data is input at constant time intervals and Fourier transform is performed, when the rotational speed of the rotating body is not constant, for example, When starting from a stopped state to the rated speed as in the start-up process, the frequency of rotation synchronization changes during sampling, so the specific frequency component of rotation synchronization cannot be obtained correctly. was there.

The present invention has been made in order to eliminate the drawbacks of the conventional device, and collects the sampling data in synchronization with the rotation of the rotating body instead of collecting the sampling data at constant time intervals. Accordingly, it is an object of the present invention to provide a vibration analysis device capable of accurately obtaining a frequency component synchronized with the rotation of a rotating body.

[0005]

A vibration analysis device of the present invention synchronizes with a rotation synchronization trigger signal generator for generating a trigger pulse signal synchronized with the rotation of a rotating body and a trigger signal of the rotation synchronization trigger signal generator. Based on the sampling data stored in the sampling data storage file and sampling data input means for digitizing the input vibration data and storing it in the sampling data storage file. It is provided with a discrete Fourier transform analysis means for performing conversion to calculate the frequency component of the rotating body, and a frequency analysis result storage file for storing the frequency component calculated by the discrete Fourier transform analysis means.

[0006]

According to the vibration analysis apparatus of the present invention, sampling data synchronized with the rotation can be obtained even when the rotation speed of the rotating body is not constant, and the spectrum analysis of the specific component of the vibration of the rotating body can be performed accurately. It becomes possible.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows a configuration example of a vibration analysis device according to the present invention. The vibration analysis device 1 is generated by a vibration input device 10 for inputting vibration data of a rotating body, a rotation synchronization trigger signal generating device 20 for generating a trigger pulse signal synchronized with the rotation of the rotating body, and a rotation synchronization trigger signal generating device. Sampling data input means 30 for converting (quantizing) the vibration data input by the vibration input device into a digital value in synchronization with the generated trigger signal, and a sampling data saving file 40 for saving the digitized sampling data. Discrete Fourier transform analysis unit 50 (hereinafter referred to as DFT analysis unit 50) that extracts an arbitrary number of data from the sampling data storage file and performs discrete Fourier transform, and frequency analysis result storage that stores the frequency component after the Fourier transform. And a file 60.

FIG. 2 shows an example of the configuration of a system incorporating the present invention. The present invention is generally incorporated in the electronic computer 3. The frequency analysis result of the vibration analysis device 1 is
The data is processed by the display processing means 4, and the display device 5
Is displayed in.

The vibration input device 10 converts a detection signal from the vibration sensor into an electric signal. The rotation synchronization trigger signal generator 20 adds markers at regular intervals (constant angle) in the circumferential direction of the rotating body, and generates a trigger signal every time the marker passes through one point on the circumference by the rotation of the rotating body. Occur. As a result, a periodic signal corresponding to the rotation speed of the rotating body is obtained.

The sampling data input means 30 converts the vibration data input by the vibration input device 10 into a digital value when the trigger signal is received from the rotation synchronizing trigger signal generator 20, and the sampling data saving file 4
Write to 0. Therefore, vibration data synchronized with the rotating body can be obtained.

FIG. 3 shows sampling data input means 30.
2 is a schematic process flow diagram of FIG. When the process is started, the process 301 waits for a trigger signal from the rotation synchronization trigger signal generator 20. When the trigger signal arrives, the process 302 then inputs the vibration data from the vibration input device 10. In the process 303, the vibration input device 10
The vibration data input from is converted (quantized) into a digital value. In process 304, the vibration data converted into the digital value is stored in the sampling data storage file 40.

The DFT analysis means 50 extracts an arbitrary number of sampling data from the sampling data stored in the sampling data storage file 40 and performs a discrete Fourier transform process on the resulting spectrum data, that is, frequency components. It is saved in the frequency analysis result save file 60.

Here, the discrete Fourier transform processing means that when the sampling time is T, the frequency (f = 1 / T) determined by the period T is the fundamental wave component, and the Fourier spectrum of the harmonic component of an integral multiple thereof. Is a process for obtaining. If this is replaced with the rotation-synchronous sampling of the present invention, the component determined by the sampling number is used as the fundamental wave component, and the Fourier spectrum of the harmonic component of an integral multiple thereof is obtained.

The frequency analysis result storage file 60 is a file in which harmonic components that are integral multiples of this fundamental wave component are sequentially stored.

FIG. 4 shows an example of the structure of the frequency analysis result storage file 60 when the number of data used for the discrete Fourier transform is 1024 and the number of trigger signal generation (the number of markers) per rotation is 64. Which data in the frequency analysis result storage file 60 the specific frequency component such as the rotation synchronization component is can be obtained by the following equation.

[0016]

[Equation 1]

As described above, in this embodiment, the sampling data is input at the timing of rotation synchronization and the discrete Fourier transform is performed, so that not the Fourier spectrum on a frequency basis but the Fourier spectrum synchronized with the rotation. It is possible to obtain the spectrum.

In the above embodiment, the markers are added at regular intervals (constant angle) in the circumferential direction of the rotating body, and the rotation synchronizing trigger is generated every time the marker passes through one point on the circumference by the rotation of the rotating body. Although the signal is generated, other means may be used as long as it generates a rotation synchronization trigger signal.

Further, in the above-mentioned embodiment, the discrete Fourier transform is performed on the vibration data synchronized with the rotation. However, if another analysis method is used as long as the data synchronized with the rotation is used. It is also applicable to.

[0020]

As described above, according to the present invention, even when the number of rotations changes during sampling by inputting sampling data at the timing of rotation synchronization and performing discrete Fourier transform. , The Fourier spectrum synchronized with the rotation can be accurately obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram when the vibration analysis device of the present invention is incorporated in a system.

FIG. 3 is a flowchart showing the function of sampling data input means of the present invention.

FIG. 4 is an explanatory diagram of a frequency analysis result storage file of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration analysis device 2 Rotating body 3 Electronic computer 4 Display processing means 5 Display device 10 Vibration input device 20 Rotation synchronization trigger signal generator 30 Sampling data input means 40 Sampling data storage file 50 DFT analysis means 60 Frequency analysis result storage file

Claims (1)

[Claims] 1. A vibration analyzer for inputting vibration data of a rotating body through a vibration input device and analyzing vibration of the rotating body based on the input data, wherein a trigger pulse signal synchronized with rotation of the rotating body is provided. A rotation synchronization trigger signal generating device to be generated, and vibration data is input through the vibration input device in synchronization with a trigger signal of the rotation synchronization trigger signal generating device, and the input vibration data is digitized into a sampling data storage file. Sampling data input means for saving, discrete Fourier transform analyzing means for calculating a frequency component of the rotating body by performing discrete Fourier transform based on the sampling data saved in the sampling data saving file, and the discrete Fourier transform A frequency analysis result storage file for storing the frequency components calculated by the analysis means. A vibration analysis device comprising: