JP2005106639A - Method and system for measuring rotation vibration of rotating body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and system for measuring rotation vibration of a rotating body capable of measuring torsional vibration of the rotor of a main motor by frequency analyzing the rotation vibration by frequency analyzing the interval variation of the zero-cross point of AC output with a simple constitution. <P>SOLUTION: The system comprises: an A/D converter 11; a time serial data recorder 12; an interpolation part 13; a zero-cross point determination and zero-cross point time interpolation acquisition part 14; a zero-cross point time serial recorder 15; a zero-cross point time mean value calculation part 16; a zero-cross point time mean value successively integration part 17; a zero-cross point time variance calculation part 18; a zero-cross point time variance time serial recorder part 19; a digital low pass filter part 20; a fast Fourier transform (FFT) part 21; a frequency/amplitude normalizing part 22; and a information process unit 10 composed of a record display part 23. By the simple and easy units, the torsional vibration of the rotor of the main motor is measured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for measuring rotational vibration of a rotating body, and more particularly to a method and apparatus for measuring rotational vibration of a rotor of a main motor of a vehicle.

  FIG. 4 is a schematic diagram of a conventional railway vehicle drive device.

  In this figure, 101 is a main motor, 102 is an output rotating shaft of the main motor 101, 103 is a joint connected to the output rotating shaft 102, 104 is a small gear fixed to the joint 103, and 105 is a small gear 104. , 106 is a gear box, 107 is an axle driven by the large gear 105, 108 is a wheel fixed to the axle 107, 109 is an axle box provided at both ends of the axle 107, and 110 is a main motor. 101 is a speed generator provided at 101.

For example, when a train running on a Shinkansen vehicle equipped with such a railway vehicle drive device is traveling at high speed, noise of a low frequency (about 250 Hz) may be heard in the vehicle, and the noise level may increase by about 3 dB. The cause of this noise is not yet clear, but the torsional vibration of the system of the main motor rotor (not shown) from the small gear 104 is swung around the gear-type flexible shaft joint 103 between the main motor 101 and the gear devices 104 and 105. (Rotational vibration), and vibrations including the bogie frame and the drive system are estimated as causes. Among these presumed causes, the torsional vibration (rotational vibration) of the main motor rotor needs to be measured in a non-contact manner because the object to be measured is a rotating body, and it is difficult to select a measurement method and to measure in a running test.
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  As described above, the rotational vibration of the main motor rotor of the vehicle needs to be measured in a non-contact manner because the object to be measured is a rotating body. However, it is difficult to select a measurement method, and measurement in a running test is also difficult. Therefore, paying attention to the output of the speed generator attached to the main motor, an attempt was made to measure the torsional vibration of the main motor rotor based on the output.

  However, the frequency fluctuation of the AC voltage output from the speed generator is very small, and since the DC voltage is smoothed after normal FV conversion, it is difficult to measure this minute frequency fluctuation. .

  In view of the above situation, the present invention performs frequency analysis of rotational vibration by frequency analysis of interval variation of the zero cross point of AC output, and measures torsional vibration of the main motor rotor with a simple configuration. An object of the present invention is to provide a method and apparatus for measuring the rotational vibration of a rotating body.

In order to achieve the above object, the present invention provides
[1] In a method for measuring rotational vibrations of a rotating body, (a) A / D conversion is performed at regular intervals on an AC voltage output of a speed generator provided on a measurement object having the rotating body, and the converted digital data is processed by an information processing device. (B) When the cycle of the AC voltage of the speed generator is as short as 10 times the sampling interval of the A / D conversion, interpolation (interpolation) is performed on the input data, (C) The time of each zero cross point of AC voltage output is obtained by interpolation from the positive and negative sampling times before and after each zero cross point, and (d) obtained in (c) above. The average interval of the zero cross points is calculated from the time of each zero cross point, and this value is used as the sampling interval. (E) The average time interval of the zero cross points is sequentially integrated. And the time difference between each zero cross point obtained in (c) and time-series data of time-varying components due to torsional vibration components superimposed on the AC voltage output of the speed generator, (f) e) Reduces aliasing by applying a digital low-pass filter to the time-series data of the time-varying component obtained in e), and (g) performs a fast Fourier transform of the time-series data of the time-varying component, and includes frequency components included in the time-varying component. The size is obtained, and the frequency and size are normalized and displayed based on the sampling interval.

  [2] In a rotational vibration measuring device for a rotating body, a speed generator provided on a measurement object having the rotating body, an information processing apparatus connected to the speed generator via an insulation amplifier, and the information processing apparatus Comprising at least an A / D converter, an interpolation unit, a digital low-pass filter unit, and a fast Fourier transform unit, amplifying the AC voltage output of the speed generator with an insulation amplifier, and inputting it to the information processing device, If the A / D converter has no digital data, and the AC voltage cycle of the speed generator is as short as 10 times the sampling interval of the A / D conversion, the input data is interpolated by the interpolator. The sampling interval is shortened, and the zero cross point time of the AC voltage output is obtained by interpolating from the positive and negative sampling times before and after the zero cross point. The average interval of the zero cross points is obtained from the time of the lo-cross point, this value is used as the sampling interval, the time difference between the value obtained by sequentially integrating the average time intervals of the zero cross points and the respective zero cross points is obtained, and the speed generator Time-series data of time-varying components due to torsional vibration components superimposed on AC voltage output is obtained, aliasing of the time-varying component time-series data is reduced through the digital low-pass filter section, and time-varying components are converted into the fast Fourier transform section. The time series data is subjected to fast Fourier transform to obtain the magnitude of the frequency component included in the time variation component, and the frequency and magnitude are normalized based on the sampling interval and displayed.

  [3] The rotational vibration measuring apparatus for a rotating body according to [2], wherein the measurement target having the rotating body is a main motor of a vehicle.

  [4] The rotational vibration measuring apparatus for a rotating body according to [3], wherein the vehicle is a railway vehicle.

  According to the present invention, in order to analyze the torsional vibration of the main motor rotor, it is only necessary to analyze the output of the existing speed generator in the main motor of the vehicle, and the temporary work for measurement can be expected to be reduced. Therefore, it is not necessary to use a highly accurate rotation measuring instrument, and the rotational vibration of the rotating body can be measured with a simple configuration.

  An AC voltage output of a speed generator provided in a measurement object having a rotating body is input to an information processing device via an insulation amplifier, where A / D conversion is performed at regular intervals to obtain converted digital data, When the cycle of the AC voltage of the speed generator is as short as 10 times the sampling interval of the A / D conversion, the input data is interpolated to shorten the sampling interval, and the information The zero cross point time of the AC voltage output is obtained by interpolating from the positive and negative sampling times before and after the zero cross point in the processing device, and the average interval of the zero cross points is obtained from the time of each zero cross point. No sampling interval, time difference between each zero cross point and the value obtained by sequentially integrating the average time intervals of the zero cross points Calculated, obtaining the time-series data of the time-varying component due to the torsional vibration component superimposed on the AC voltage output of the tachometer generator. Further, the time-varying component time-series data is subjected to a digital low-pass filter to reduce aliasing, and the time-varying component time-series data is subjected to fast Fourier transform to obtain the magnitude of the frequency component included in the time-varying component. The frequency and size are normalized and displayed based on the sampling interval. Therefore, it is only necessary to analyze the output of the existing speed generator in the main motor of the vehicle, and the temporary work for measurement can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a configuration diagram of a rotational vibration measuring apparatus for a rotating body according to an embodiment of the present invention, FIG. 2 is a diagram illustrating an output waveform of a speed generator of a railway vehicle according to the present invention, and FIG. It is explanatory drawing of the interpolation of a point. In FIG. 2, the thick line is the output waveform of the speed generator when the main motor is rotating at a constant speed, while the zero cross point has a constant interval, while the thin line is the fluctuation when the main motor is coasting This is the output waveform of the speed generator when it is rotating, and has an interval in which the zero cross point fluctuates.

  In FIG. 1, 1 is a main motor, 2 is a speed generator provided in the main motor 1, 3 is an insulation amplifier, 10 is an information processing device connected to the insulation amplifier 3, and this information processing device 10 is A / D conversion unit 11, time series data recording unit 12, interpolation unit 13, zero cross point discrimination and zero cross point time interpolation acquisition unit 14, zero cross point time series recording unit 15, zero cross point time average value calculation unit 16, zero cross point time Average value sequential integration unit 17, zero cross point time variation calculation unit 18, zero cross point time variation time series recording unit 19, digital low-pass filter unit 20, fast Fourier transform (FFT) unit 21, frequency / amplitude normalization unit 22, recording / recording unit The display unit 23 is included.

Generally, as described above, an AC voltage is output from a speed generator attached to a main motor of a vehicle, and is converted into a DC voltage proportional to the speed by performing FV conversion. If it is assumed that the main motor 1 rotor is torsionally vibrated (rotational vibration), it is considered that slight fluctuations occur in the output frequency proportional to the rotational speed of the AC voltage output from the speed generator 2. However, the frequency fluctuation of the AC voltage is very small, and it is difficult to measure the minute frequency fluctuation because the DC voltage is smoothed after normal FV conversion. Therefore, in the present invention, in order to measure torsional vibration (rotational vibration) from the AC output of the speed generator, frequency analysis of the interval variation of the zero cross point of the AC output of the speed generator 2 was performed. The measurement flow is shown below.
(1) The AC voltage output of the speed generator 2 is A / D converted at regular intervals in the A / D converter 11 and digital data is captured.
(2) When the cycle of the AC voltage of the speed generator is as short as 10 times or less of the sampling interval of the A / D conversion, the interpolation (interpolation) unit 13 performs interpolation on the input data, Reduce the sampling interval.

For example, as shown in FIG. 3, when the actual sampling data is sampling points S ₁ , S ₂ , S ₃ , S ₄ , S ₅ , S ₆ , S ₇ , S ₈ , S ₉ . The unit 13 causes S ₁₁ , S ₁₂ , S ₂₁ , S ₂₂ , S ₃₁ , S ₃₂ , S ₄₁ , S ₄₂ , S ₅₁ , S ₅₂ , S ₆₁ , S ₆₂ , S ₇₁ , S ₇₂ , S ₈₁ , S _82. , S ₉₁ ,... Are interpolated to shorten the sampling interval.
(3) In order to improve the time accuracy of the zero cross point, the time of each zero cross point of the AC voltage output in the information processing apparatus 10 is determined by the zero cross point discrimination and zero cross point time interpolation acquisition unit 14 before and after each zero cross point. It is obtained by interpolation from the sampling time of the value and the negative value, and recorded in the zero cross point time series recording unit 15.
(4) From the time of each zero cross point obtained in the above (3), the zero cross point time average value calculation unit 16 obtains an average interval of zero cross points, and considers this value as a sampling interval. Depending on the target frequency, only a zero cross point from a positive value to a negative value or from a negative value to a positive value may be used.
(5) Zero cross point time average value sequential integration unit 17 obtains the time difference between the value obtained by sequentially integrating the average time interval of the zero cross points obtained in (4) above and each zero cross point obtained in (3) above. The zero cross point time fluctuation calculating unit 18 obtains time series data of time fluctuation components due to torsional vibration components or the like superimposed on the AC voltage output of the speed generator 2, and the obtained time series data is used as the zero cross point time fluctuation time series recording unit 19. To record.
(6) Aliasing is reduced by passing the time-series data of the time variation component obtained in (5) above through the digital low-pass filter unit 20.
(7) The fast Fourier transform (FTT) unit 21 performs fast Fourier transform (FFT) on the time-series data of the time-varying component to obtain the magnitude of the frequency component included in the time-varying component, and obtained by (4) above. Based on the sampling interval, the frequency / amplitude normalizing unit 22 normalizes the frequency and size and displays the normalized values on the recording / display unit 23.

  In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.

  The method and apparatus for measuring rotational vibration of a rotating body according to the present invention is particularly effective for measuring torsional vibration of a main motor rotor of a vehicle, and is suitable for a measuring apparatus for a main motor of a railway vehicle.

It is a block diagram of the rotational vibration measuring apparatus of the rotary body which shows the Example of this invention. It is a figure which shows the output waveform of the speed generator of the railway vehicle concerning this invention. It is explanatory drawing of the digital sampling data and zero cross point interpolation of the speed generator concerning this invention. It is a schematic diagram of the drive device of the conventional railway vehicle.

Explanation of symbols

1 Main motor 2 Speed generator 3 Insulation amplifier 10 Information processing device (PC)
DESCRIPTION OF SYMBOLS 11 A / D conversion part 12 Time series data recording part 13 Interpolation part 14 Zero cross point discrimination | determination and zero cross point time interpolation acquisition part 15 Zero cross point time series recording part 16 Zero cross point time average value calculation part 17 Zero cross point time average value sequential integration part 18 Zero cross point time variation calculation unit 19 Zero cross point time variation time series recording unit 20 Digital low-pass filter unit 21 Fast Fourier transform (FFT) unit 22 Frequency / amplitude normalization unit 23 Recording / display unit

Claims (4)

(A) A / D conversion is performed at regular intervals on an AC voltage output of a speed generator provided on a measurement object having a rotating body, and the converted digital data is input to an information processing device,
(B) When the cycle of the AC voltage of the speed generator is as short as 10 times or less of the sampling interval of the A / D conversion, the input data is interpolated to shorten the sampling interval. And
(C) The time of each zero cross point of AC voltage output is obtained by interpolating from positive and negative sampling times before and after each zero cross point,
(D) An average interval of zero cross points is obtained from the time of each zero cross point obtained in (c), and this value is set as a sampling interval.
(E) Time variation due to a torsional vibration component superimposed on the AC voltage output of the speed generator by obtaining a time difference between a value obtained by sequentially integrating the average time intervals of the zero cross points and each zero cross point obtained in (c) Find time-series data of components,
(F) A digital low-pass filter is applied to the time-series data of the time variation component obtained in (e) to reduce aliasing,
(G) Performing fast Fourier transform of time-series data of time-varying components, determining the size of frequency components included in the time-varying components, and normalizing and displaying the frequency and size based on the sampling interval. A method for measuring rotational vibration of a rotating body. (A) a speed generator provided on a measurement object having a rotating body;
(B) an insulation amplifier connected to the speed generator;
(C) an information processing apparatus connected to the insulation amplifier;
(D) The information processing apparatus includes at least an A / D converter, an interpolation unit, a digital low-pass filter unit, and a fast Fourier transform unit.
(E) The AC voltage output of the speed generator is amplified by an insulation amplifier and input to the information processing apparatus, the digital data is generated by the A / D converter, and the AC voltage cycle of the speed generator is A When the sampling interval of the / D conversion is as short as 10 times or less, interpolation is performed on the input data by the interpolation unit, the sampling interval is shortened, and the time of the zero cross point of the AC voltage output is set to the zero cross point. Interpolated from the positive and negative sampling times before and after, obtained the average interval of zero cross points from the time of each zero cross point, made this value a sampling interval, and integrated the average time interval of the zero cross points sequentially The time difference between the value and each zero cross point is obtained, and the time variation due to the torsional vibration component superimposed on the AC voltage output of the speed generator is determined. Time-series data of the component is obtained, the time-series data of the time-varying component is reduced through the digital low-pass filter unit, the time-varying component is fast Fourier-transformed by the fast Fourier transform unit, An apparatus for measuring rotational vibration of a rotating body, characterized in that the magnitude of a frequency component included in a fluctuation component is obtained and the frequency and magnitude are normalized based on a sampling interval and displayed.   3. The rotational vibration measuring apparatus for a rotating body according to claim 2, wherein the measurement object having the rotating body is a main motor of a vehicle.   4. The rotational vibration measuring apparatus for a rotating body according to claim 3, wherein the vehicle is a railway vehicle.

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