KR20150035638A - Apparatus for error detecting of the rotary machine and Method for the same - Google Patents

Abstract

The present application relates to apparatus for error detecting of the rotary machine and method for the same. The rotary machine according to an embodiment of the present invention includes: a measuring unit that measures rotational displacement and rotational speed; a convertor which converts the rotational displacement and the rotational speed into digital signal; an analysis unit which order analyzes size and phase of component signals that have frequency with integer multiple of rotary frequency by conversion of transactional flourier from the rotary displacement and rotation speed.

Description

TECHNICAL FIELD [0001] The present invention relates to a rotating apparatus diagnostic apparatus and a rotating apparatus diagnostic method,

The present invention relates to a rotating device diagnostic apparatus and a rotating apparatus diagnosing method, and more particularly, to a measuring apparatus and method for measuring a displacement and a rotating speed of a rotating apparatus, and to provide an indication of abnormal operation of the rotating apparatus through a Fractional Fourier Transform And more particularly, to a diagnostic apparatus and a diagnostic method for a rotating apparatus.

The core of the rotating machine diagnosis is to characterize the malfunction and abnormal operation signs of the rotating machine through signal processing. The method used for diagnosing the rotating machine includes a method of analyzing the frequency of the vibration signal during the operation of the rotating machine and a method of analyzing the order of the rotating machine at the start and stop. Particularly, the method of analyzing the order is a key element in the diagnosis of the rotating machine by showing not only the dynamic characteristics of the rotating machine, but also the signs of other failures. In the case of order analysis, the risk rate associated with the natural frequency of the rotating machine can be identified and used as a Bode diagram.

Conventionally, as an order analysis method, a method using STFT (Short Time Fourier Transform), a resampling method in which sampling is resumed through interpolation according to the rotation angle of a rotating machine, and an adaptive filter Method was used.

However, the method using STFT (Short Time Fourier Transform) is a method of conducting frequency analysis for a short time and scaling the analyzed frequency spectrum in units of rotation frequency in order to analyze the order, There is a problem that smearing phenomenon is detected and it is difficult to accurately measure the order.

In addition, in the case of the resampling method, there is a problem that the speed of the calculation is slowed because the signal integration and interpolation operation are required.

An adaptive filter is a method of analyzing an order assuming that the rotating speed of the rotating device is constant within a short time. Therefore, the method using an adaptive filter has a problem that the accuracy is low when the rotation speed of the rotating device changes rapidly, slow computation speed and complicated parameter setting are required, and the user's convenience is poor.

Korean Patent Publication No. 10-2007-0037667 (Apr.

The present application is to provide a rotating apparatus diagnostic apparatus and a rotating apparatus diagnosing method capable of measuring a displacement and a rotating speed of a rotating apparatus and monitoring abnormal operation signs of the rotating apparatus through a FFT (Fractional Fourier Transform).

According to an aspect of the present invention, there is provided a device for diagnosing a rotating machine, comprising: a measuring unit for measuring a rotational displacement and a rotating speed of the rotating device; A converter for converting the rotational displacement and the rotational speed into a digital signal; And an analyzer for performing order analysis for obtaining a magnitude and a phase of component signals having a frequency that is an integral multiple of a rotational frequency of the rotating machine through a FFT using the rotational displacement and the rotational speed as variables.

Here, the analyzing unit may calculate the following equation

Can be used to calculate the fractal Fourier transform.

는 프랙셔날 푸리에 변환값,

은 윈도우 함수 보정계수,

는 윈도우 함수,

은 측정시간,

은 회전속도,

은 상기 회전기기의 오더, N은 한 커넬에서 취급하는 데이터 개수,

는 회전가속도를 의미한다.here,

Is a fractal Fourier transform value,

The window function correction coefficient,

Is a window function,

The measurement time,

The rotation speed,

Is the order of the rotating machine, N is the number of data handled in one kernel,

Means the rotation acceleration.

Here, the window function may be a Hanning window function.

Here, the analysis unit may generate a board diagram for each order using the order analysis result of the rotating machine.

A method for diagnosing a rotating machine according to an embodiment of the present invention includes diagnosing a rotating machine to diagnose an abnormal operation of the rotating machine, the method comprising: measuring a rotational displacement of the rotating machine; A signal conversion step of converting the rotational displacement and the rotational speed into a digital signal; And the rotational displacement converted into the digital signal and the rotational speed are expressed by the following equations

And an order analyzing step of performing order analysis for calculating a magnitude and a phase of component signals having a frequency that is an integral multiple of the rotational frequency of the rotating machine.

는 프랙셔날 푸리에 변환값,

은 윈도우 함수 보정계수,

는 윈도우 함수,

은 측정시간,

은 회전속도,

은 상기 회전기기의 오더, N은 한 커넬에서 취급하는 데이터 개수,

는 회전가속도를 의미한다.
here,

Is a fractal Fourier transform value,

The window function correction coefficient,

Is a window function,

The measurement time,

The rotation speed,

Is the order of the rotating machine, N is the number of data handled in one kernel,

Means the rotation acceleration.

In addition, the means for solving the above-mentioned problems are not all enumerating the features of the present invention. The various features of the present invention and the advantages and effects thereof will be more fully understood by reference to the following specific embodiments.

According to the rotary device diagnostic apparatus and the rotary device diagnostic method according to an embodiment of the present invention, it is possible to grasp the abnormal operation signs of the rotary device.

According to the apparatus for diagnosing a rotating device and the method for diagnosing a rotating device according to an embodiment of the present invention, the resonance frequency of the rotating device can be accurately analyzed even at a low frequency.

According to an embodiment of the present invention, it is possible to quickly and accurately analyze the order of a rotating machine.

1 is a block diagram showing a configuration of a rotating-apparatus diagnostic apparatus according to an embodiment of the present invention.
FIG. 2 is a view for explaining the operation of the rotating apparatus diagnostic apparatus according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating an example of a result of a board diagram generated by a rotating apparatus diagnostic apparatus according to an embodiment of the present invention.
4 is a flowchart showing a method of diagnosing a rotating machine according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order that those skilled in the art can easily carry out the present invention. In the following detailed description of the preferred embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In the drawings, like reference numerals are used throughout the drawings.

In addition, in the entire specification, when a part is referred to as being 'connected' to another part, it may be referred to as 'indirectly connected' not only with 'directly connected' . Also, to "include" an element means that it may include other elements, rather than excluding other elements, unless specifically stated otherwise.

1 is a block diagram showing a configuration of a rotating-apparatus diagnostic apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the apparatus for diagnosing a rotating machine according to an embodiment of the present invention may include a measuring unit 10, a converter 20, and an analyzing unit 30.

Hereinafter, a rotating apparatus diagnostic apparatus according to an embodiment of the present invention will be described with reference to FIG.

The measuring unit 10 can measure the rotational displacement and the rotational speed of the rotating equipment. The rotating device may be any device that includes a motor, a pump, a compressor, and a pump, and operates to obtain power through rotational motion.

The rotational displacement and the rotational speed may be in the form of a continuous analog signal. Specifically, the rotational displacement may be a signal measuring a displacement of the axis of the rotating machine. The measuring unit 10 may include a displacement sensor for measuring the rotational displacement. The displacement sensor can be any device capable of measuring the rotational displacement of a known rotating machine including a potentiometer displacement sensor, a differential transformer displacement sensor, a synchronous resolver, a rotary encoder, and a pulse generator.

The measuring unit 10 may include a tachometer for measuring the rotation speed. The tachometer may be any known one as long as it can measure the rotation speed of the rotating device.

The converter 20 may convert the rotational displacement and the rotational speed into a digital signal. The converter 20 may be any known one as long as it can convert an analog signal into a digital signal. The converter 20 may sample the continuous analog signal measured by the measuring unit 10 so as to enable discrete Fourier transform. In this case, the sampling period when the converter 20 samples the signal can be set by the user as desired.

The analyzer 30 can perform order analysis for obtaining the magnitude and phase of component signals having a frequency that is an integral multiple of the rotational frequency of the rotating machine through the FFT using the rotational displacement and the rotational speed as parameters.

Specifically, the analyzing unit 30 can calculate a fractal Fourier transform using the following equation (1).

는 프랙셔날 푸리에 변환값,

은 윈도우 함수 보정계수,

는 윈도우 함수,

은 측정시간,

은 회전속도,

은 상기 회전기기의 오더, N은 한 커넬에서 취급하는 데이터 개수,

는 회전가속도를 의미한다.here,

Is a fractal Fourier transform value,

The window function correction coefficient,

Is a window function,

The measurement time,

The rotation speed,

Is the order of the rotating machine, N is the number of data handled in one kernel,

Means the rotation acceleration.

Specifically, when the spectral characteristic of the Fractian Fourier transform value is analyzed, the window function can reduce the leakage of spectra that may occur when cutting into a spherical window having a sudden change (for example, a noise of a spectrum waveform Mixing and preventing distortion of the waveform).

Here, the window function may be any well-known window function including a Bartlett window, a Hamming window, a Hamming window, a Papulis window, a Blackman window, and a Pagen window. The window function correction coefficient may be set to a constant value corresponding to the window function to be used. For example, when the window function of the Hanning window is used as the window function, the window function correction coefficient value may be 1.63.

는 상기 측정부(10)가 측정한 회전 변위값을 디지털 신호로 전환한 신호의 함수 값일 수 있다.In the above equation (1)

May be a function value of a signal obtained by converting the rotational displacement measured by the measuring unit 10 into a digital signal.

The N value can be set arbitrarily according to the order resolution desired by the user. In this case, as the N value becomes larger, the order analysis is performed using more data, so that the number of calculation processes increases, while the resolution of the order increases.

)를 구하기 위하여 펄스 카운터 및 속도 계산기를 구비할 수 있다. 상기 펄스 카운터 및 속도 계산기는 주지의 카운터 또는 계산기라면 어떠한 것이라도 가능하다.The analysis unit (30) calculates the rotation acceleration

A pulse counter and a speed calculator may be provided. The pulse counter and the speed calculator can be any known counter or calculator.

The analyzer 30 may generate a result of comparing magnitudes and phases of component signals corresponding to respective orders by using the fractal Fourier transform values. In this case, the analyzer 30 may generate a graph that compares the magnitudes of the component signals.

The analyzer 30 may generate a board diagram or a Nyquist diagram for each order using the order analysis result of the rotating machine. Specifically, the diagnosis of the abnormality of the rotating devices can be made by checking the frequency characteristics of the rotating device through the board diagram. Accordingly, the user can immediately grasp the operating state of the rotating machine by using the board diagram generated by the analyzing unit 30. FIG.

The apparatus for diagnosing a rotating machine according to an embodiment of the present invention may further include a display unit (not shown) for displaying the fractal Fourier transform value, the order analysis graph, and the board diagram. The display unit can be any well-known display device as long as it can display the order analysis result on the screen.

FIG. 2 is a view for explaining the operation of the rotating apparatus diagnostic apparatus according to an embodiment of the present invention.

FIG. 2 is a graph showing an example of a relationship with a rotation speed of a rotating machine that changes with time.

)는 두 시간 사이의 회전속도의 차이값(

)을 두 시간의 차이값(

)으로 나눈 값일 수 있다. 즉, 상기 회전가속도는 두 개의 시간(

및

)에서의 회전속도 그래프의 기울기일 수 있다.Referring to FIG. 2,

) Is the difference value of the rotation speed between two hours

) To the difference value of two hours (

). ≪ / RTI > That is, the rotational acceleration is divided into two time periods

And

) ≪ / RTI >

Specifically, when the rotating machine is started and stopped, the rotation speed may increase or decrease in proportion to time. Therefore, the variation of the rotation speed may be analyzed for each predetermined interval, and the variation of the rotation speed for a certain section may be calculated and used for the FFT. In this case, the interval between the two hours can be set by the user as desired. The time interval may be the same as the sampling period of the rotational displacement and rotational speed measured by the signal converter.

FIG. 3 is a diagram illustrating an example of a result of a board diagram generated by a rotating apparatus diagnostic apparatus according to an embodiment of the present invention.

Referring to FIG. 3, the portion indicated by a dotted line represents a result of analyzing a rotating apparatus in a diagnostic apparatus according to an embodiment of the present invention, and a portion represented by a solid line represents a resampling method The results are shown in Fig. In the graph of FIG. 3, the axis of abscissas represents the revolution per minute (rpm) and the axis of ordinate represents the magnitude of the component signal whose order is four times the fundamental frequency of the rotating machine.

Referring to FIG. 3, in the case of the conventional resampling method, since the data at a large amount of time is required when the speed of the rotating machine is low, the peak value can not be tracked at a point of 500 rpm. On the other hand, it can be seen that, even in the case where the speed of the rotating machine is low, the accurate value can be tracked when analyzing the order of the rotating machine in the rotating machine diagnostic apparatus according to an embodiment of the present invention.

4 is a flowchart showing a method of diagnosing a rotating machine according to an embodiment of the present invention.

Referring to FIG. 4, a method for diagnosing a rotating device according to an exemplary embodiment of the present invention may include a rotating equipment measuring step (S10), a signal converting step (S20), and an order analyzing step (S30).

Hereinafter, a method of diagnosing a rotating machine according to an embodiment of the present invention will be described with reference to FIG.

In the rotating equipment measuring step (S10), the rotational displacement and the rotating speed of the rotating equipment can be measured. The rotational displacement and rotational speed may be in the form of a continuous analog waveform. In the rotating equipment measuring step (S10), the rotational displacement and the rotating speed may be transmitted to the converter (20).

In the signal conversion step (S20), the rotational displacement measured in the rotating equipment measuring step (S10) and the rotational speed may be converted into digital signals. In the signal conversion step (S20), the rotational displacement and the rotational speed may be sampled at a specific sampling period. Here, the sampling period can be arbitrarily set by the user. In the signal conversion step (S20), the rotation displacement and the rotation speed converted into digital signals may be transmitted to the analysis unit (30).

In the order analysis step S30, the analysis unit 30 calculates a fractal Fourier transform using Equation (1), calculates an order for obtaining the magnitude and phase of component signals having an integer multiple of the rotational frequency of the rotary device, Analysis can be done. In the order analysis step S30, a board diagram indicating the magnitude and phase of the component signals may be generated. In the order analysis step S30, the display unit can display the order analysis result and the board diagram on the outside. In the order analysis step S30, when the order analysis result is different from the preset reference value, the user can be notified that an abnormality has occurred in the rotating equipment.

The present invention is not limited to the above-described embodiments and the accompanying drawings. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

10:
20: Converter
30: Analysis department
S10: Rotating machine measurement step
S20: Signal conversion step
S30: order analysis step

Claims (5)

A measuring unit for measuring a rotational displacement and a rotational speed of the rotating machine;
A converter for converting the rotational displacement and the rotational speed into a digital signal; And
And an analyzer for performing order analysis for obtaining a magnitude and a phase of component signals having a frequency that is an integral multiple of a rotational frequency of the rotating machine through fractal Fourier transform using the rotational displacement and the rotational speed as variables.
The apparatus of claim 1, wherein the analyzing unit
The following equation

To calculate a fractal Fourier transform.
here,

Is a fractal Fourier transform value,

The window function correction coefficient,

Is a window function,

The measurement time,

The rotation speed,

Is the order of the rotating machine, N is the number of data handled in one kernel,

Means the rotation acceleration.
3. The method of claim 2,
A rotating device diagnostic device which is a Hanning window function.
The apparatus of claim 1, wherein the analyzing unit
And generates a board diagram for each order using the order analysis result of the rotating equipment.
A method for diagnosing an abnormal operation of a rotating machine,
A rotating machine measuring step of measuring a rotating displacement and a rotating speed of the rotating machine;
A signal conversion step of converting the rotational displacement and the rotational speed into a digital signal; And
The rotation displacement and the rotation speed converted into a digital signal are expressed by the following equations

And an order analyzing step of performing order analysis for calculating a fractal Fourier transform using the frequency component and a phase and a magnitude and a phase of component signals having a frequency that is an integral multiple of the rotational frequency of the rotating device.
,

Is a fractal Fourier transform value,

The window function correction coefficient,

Is a window function,

The measurement time,

The rotation speed,

Is the order of the rotating machine, N is the number of data handled in one kernel,

Means the rotation acceleration.

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