JP2008292222A - Rotational vibration phase detection apparatus and method - Google Patents

Abstract

A signal phase shift until a vibration signal is output from a sensor for detecting rotational vibration can be corrected, a rotation reference position can be detected, a DC signal level can be canceled, and a vibration signal at a desired rotational speed can be obtained. It is to provide a rotational vibration phase detection device capable of
A vibration sensor for detecting a vibration displacement of a rotating part of a rotating device, a rotation reference sensor for detecting a rotation reference signal of the rotating part of the rotating device, and a signal processing of the vibration displacement detected by the vibration sensor. And a phase detector for correcting a signal phase shift generated in the process and outputting a vibration signal.
[Selection] Figure 1

Description

  The present invention relates to a rotational vibration phase detection apparatus and method for detecting vibration generated in a rotating part of a rotating device and evaluating a rotational unbalance component.

  In a rotating device such as a turbine, a generator, or an electric motor, the rotating shaft may vibrate greatly due to imbalance of the rotating portion. Therefore, the rotational vibration of the rotating device is detected and abnormality due to vibration is diagnosed. As a bearing diagnosis device for a rotating machine, there is one that can accurately read a vibration signal and corresponding diagnosis information from a plurality of files to perform bearing diagnosis (see, for example, Patent Document 1).

  In order to detect the unbalance of the rotating part of the rotating device, the vibration displacement of the rotating device is detected. As a measurement example, a vibration sensor and a rotation reference sensor are attached to a rotating device, the vibration displacement is obtained from the vibration signal detected by the vibration sensor, and the phase of the vibration displacement is calculated from the rotation reference signal detected by the rotation reference detection sensor. To do.

  As the vibration sensor, a displacement sensor that directly detects vibration displacement, a speed sensor that detects vibration speed, and an acceleration sensor that detects vibration acceleration are used. When the speed sensor is used, the vibration displacement is obtained by integrating the detected vibration speed signal once. When the acceleration sensor is used, the vibration displacement is obtained by integrating the detected vibration acceleration signal twice. Yes.

  An eddy current type sensor is often used as the displacement sensor. Generally, a negative power source is used, and the output signal is also a negative signal (a state in which a displacement vibration signal is superimposed on a DC negative voltage). . In addition, an acceleration sensor with a built-in amplifier is often used as the acceleration sensor, and a constant current as a power source is supplied to the amplifier built in the sensor, so the signal output of the acceleration sensor is always a positive signal ( A state in which a displacement vibration signal is superimposed on a positive DC voltage).

  As the rotation reference sensor, a photoelectric sensor or an eddy current sensor is used. In the photoelectric sensor, a reflective material is attached to the rotation reference position of the rotating unit, and the photoelectric sensor is installed at a position where the reflective material rotates to detect the rotation reference signal. In the eddy current type sensor, the same sensor as the displacement sensor is used, a step is provided at the rotation reference position of the rotating part, and the sensor is installed at this position to detect the rotation reference signal.

Then, the rotational displacement vibration is calculated based on the signal input from the vibration sensor, and the vibration phase is calculated based on the cycle and timing of the signal input from the rotation reference sensor. Normally, measurement is performed at the rated rotational speed of the rotating device to be measured. Measurements may be taken at certain rotation speed intervals while reaching the rotation speed. For example, when measuring at a rated rotation speed of 3600 min-1 every 300 min-1 from startup, measurement is performed at intervals of 600 min-1, 900 min-1, ... 3000 min-1, 3300 min-1, 3600 min-1. Then, based on the obtained vibration phase, a counterweight or the like is attached to the rotating body to correct the unbalance of the rotating device.
JP 2003-149090 A

  However, the conventional devices have the following problems. First, problems relating to rotational vibration phase correction, displacement sensor signal bias correction, and rotational vibration phase correction will be described. Rotational vibration phase is important as information necessary to detect rotational vibration imbalance. Especially, the vibration phase in the low rotational speed range from the start of large rotating equipment to the rated rotational speed is accurately detected. However, when an acceleration sensor or eddy current displacement sensor is used as the vibration sensor, a DC component is superimposed on the input signal, so it is necessary to remove this component. Use a high pass filter to cut out.

  However, when a high-pass filter is used, the signal phase after passing through the high-pass filter is shifted in a low rotation speed region as shown in FIG. 17, so it is desirable to set the cutoff frequency of the high-pass filter to be low. On the other hand, in order to remove low vibration components other than the rotation component, it is desirable to set the cutoff frequency of the high-pass filter high, and the cutoff frequency of the high-pass filter is determined in consideration of the trade-off between the two. In any case, there is a problem in that an error in the detected value of the vibration phase in the low rotational speed region is unavoidable with respect to the true value.

  Next, the problem about the rotation reference signal automatic detection will be described. The rotational vibration phase detection device includes a fixed type that is permanently installed for a measurement target and a portable type that is installed with a vibration sensor and a rotation reference sensor in a target device each time. In a fixed rotational vibration phase detector, an eddy current sensor is often installed in the vibration sensor and the rotation reference sensor, and the signal interface is also adapted to this. In a portable rotational vibration phase detection device, in many cases, a speed sensor and an acceleration sensor are used as the vibration sensor, a photoelectric sensor is used as the rotation reference sensor, and a signal interface has a specification corresponding to this.

  However, in actual field measurements, if you want to measure the vibration phase of a rotating device with a fixed sensor installed using a portable device, you can use a fixed rotation reference sensor to match the detection phase reference. Although it is desirable to input an output signal, there is a problem that the signal cannot be used because the signal level is different.

  Next, the problem about the measurement timing prediction at the time of rotational acceleration and deceleration will be described. When measuring at a certain rotation speed interval from the start until the rated rotation speed is reached, measure at regular intervals with a fixed measurement period and use the measured value when approaching the desired measurement rotation speed. ing. For example, when the desired measurement rotation speed is 600 min-1 and the allowable range is ± 100 min-1, when the measurement rotation speed reaches the range of 500 min-1 to 700 min-1, the measurement value is adopted as the measurement value at 600 min-1. is doing.

  However, in the conventional measurement method, since the measurement cycle is constant, in order to measure at a rotational speed as close as possible to the desired rotational speed, the measurement period must be shortened or the allowable range must be narrowed. Considering that there is a limit to shortening the measurement cycle. If the allowable range is too narrow, if the speed of rotation of the rotating body (the rate at which the rotation speed increases) is large, rotation will exceed the allowable range within the period of the measurement cycle. There is a risk that the number will rise and the measurement time will be missed.

  An object of the present invention is to correct a signal phase shift until a vibration signal is output from a sensor that detects rotational vibration, to detect a rotation reference position, to cancel a DC signal level, and to generate a vibration signal at a desired rotational speed. It is an object of the present invention to provide a rotational vibration phase detection apparatus and method that can be obtained.

  The present invention relates to a rotational vibration phase detection device that detects rotational vibration of a rotating device and detects an imbalance of the rotating portion of the rotating device, a vibration sensor that detects vibration displacement of the rotating portion of the rotating device, A rotation reference sensor for detecting a rotation reference signal of the rotation unit, and a phase detection device for correcting a signal phase shift generated in a signal processing process of vibration displacement detected by the vibration sensor and outputting a vibration signal. It is characterized by.

  According to the present invention, it is possible to correct a signal phase shift until a vibration signal is output from a sensor that detects rotational vibration, to detect a rotation reference position, to cancel a DC signal level, and to generate vibration at a desired rotational speed. It is possible to provide a rotational vibration phase detection device capable of acquiring a signal.

  FIG. 1 is a block diagram of a rotational vibration phase detection apparatus according to an embodiment of the present invention. As shown in FIG. 1, the rotational vibration phase detection device 11 includes a vibration sensor 12 that detects a vibration displacement of a rotating unit of a rotating device, a rotation reference sensor 13 that detects a rotation reference signal of the rotating unit of the rotating device, and a vibration. It comprises a phase detector 14 that corrects a signal phase shift generated in the signal processing process of the vibration displacement detected by the sensor 12 and outputs a vibration signal.

  The phase detector 14 includes a sensor input unit 15, a RAM 16, a flash ROM 17 that stores data and programs, an input unit 18 such as a touch panel, a keyboard, and a mouse, an output unit 19 such as an LCD display, an input unit 18, and the like. It comprises a man-machine interface (MMI) 20 that controls the output means 19 and a CPU 21 that performs processing operations for phase detection. The sensor input unit 15 includes a vibration sensor input unit 22 and a rotation reference sensor input unit 23.

  The detection signal of the vibration sensor 12 is input to the vibration sensor input unit 22 of the sensor input unit 15, and the detection signal of the rotation reference sensor 13 is input to the rotation reference sensor input unit 23 of the sensor input unit 15.

  FIG. 2 is a configuration diagram of an example of the vibration sensor input unit 22 of the sensor input unit 15 when the vibration sensor 12 is the acceleration sensor 12a. A sensor power supply 24 is connected to the acceleration sensor 12 a, and a detection signal from the acceleration sensor 12 a is input to the vibration sensor input unit 22 of the sensor input unit 15. The vibration sensor input unit 22 includes high-pass filters 25a, 25b, and 25c, integrators 26a and 26b, a multiplexer 27, an amplifier 28, a low-pass filter 29, and an analog / digital converter 30.

  FIG. 3 is a configuration diagram of an example of the vibration sensor input unit 22 of the sensor input unit 15 when the vibration sensor 12 is the displacement sensor 12b. The displacement sensor 12 b is connected to the vibration sensor input unit 22 of the sensor input unit 15 through the transducer 31. The vibration sensor input unit 22 includes a high pass filter 25 a, an amplifier 28, a low pass filter 29, and an analog / digital converter 30.

The sensor output signals of the acceleration sensor 12a in FIG. 2 and the displacement sensor 12b in FIG. 3 are input to the high-pass filter 25a, and the DC component of the sensor output signal is cut. The phase characteristic of the high-pass filter 25a at this time is, for example, As shown in FIG. 4, the phase shift increases as the rotational speed decreases. Table 1 shows the relationship between the rotational speed and the phase in this case.

  Therefore, in the embodiment of the present invention, data on the relationship between the rotation speed and the phase shown in Table 1 is stored in advance in the data storage flash ROM 17 as a rotation speed / phase data table.

Then, the vibration waveform and the rotation reference signal are sampled, and the CPU 21 calculates the number of rotations from the period of the rotation reference signal, extracts the rotation period component from the signal of the vibration sensor, and calculates the phase with the rotation reference signal. Thereafter, the phase characteristic corresponding to the calculated rotational speed is extracted from the rotational speed / phase data table stored in the data storage flash ROM 17, and the phase characteristic amount is subtracted from the phase quantity calculated from the rotation reference signal and the vibration sensor signal. This cancels out the phase shift caused by the high-pass filter 25a.

  Accordingly, when a signal on which a DC component such as the acceleration sensor 12a or the eddy current displacement sensor 12b is superimposed is input, the phase shift can be corrected even if the high-pass filter 25a is configured. Therefore, the true value of the vibration phase Can be obtained, and the measurement accuracy of the vibration phase is improved.

FIG. 5 is a configuration diagram illustrating an example of the rotation reference sensor input unit 23 of the sensor input unit 15 according to the embodiment of the present invention. The rotation reference sensor input unit 23 includes a limiter circuit 32 and a window comparator 33. In FIG. 5, the limiter circuit 32 limits the amplitude of the input sensor signal to a certain width for circuit protection. The window comparator 33 is set with an “upper limit threshold value” and an “lower limit threshold value”, compares the input signal with the upper and lower limit threshold values, and outputs them under the conditions shown in Table 2.

  For example, in the case of the rotation reference sensor 13 using a photoelectric sensor, a rotation reference sensor input signal as shown in FIG. When the rotation reference sensor input signal is at a high level, the upper limit threshold of the window comparator 33 is exceeded, so the output of the window comparator 33 is at a high level.

  In the case of a rotation reference sensor using an eddy current displacement sensor, a rotation reference sensor input signal as shown in FIG. 6B is input. When the rotation reference sensor input signal is at the low level, the lower limit threshold value of the window comparator 33 is exceeded, so that the output of the window comparator 33 is at the high level.

  Next, FIG. 7 is a configuration diagram illustrating another example of the rotation reference sensor input unit 23 of the sensor input unit 15 according to the embodiment of the present invention. The rotation reference sensor input unit 23 includes a limiter circuit 32, an absolute value circuit 34, and a comparator 35.

In FIG. 7, the limiter circuit 32 limits the amplitude of the input sensor signal to a certain width for circuit protection. The absolute value circuit 34 outputs the absolute value of the signal regardless of the polarity (+, −) of the input signal. The comparator 35 compares a preset “threshold value” with the signal input to the comparator, and outputs the result under the conditions shown in Table 3.

  For example, in the case of the rotation reference sensor 13 using a photoelectric sensor, a rotation reference sensor input signal as shown in FIG. The signal after passing through the absolute value circuit 34 has the same waveform as the input signal, and is compared with a threshold value by a comparator. When the rotation reference sensor input signal is at a high level, the threshold value of the comparator 35 is exceeded, so that the output of the comparator 35 is at a high level.

  In the case of the rotation reference sensor 13 using an eddy current displacement sensor, a rotation reference sensor input signal as shown in FIG. 8B is input. The signal after passing through the absolute value circuit 34 has a waveform whose polarity is inverted from that of the input signal, and is compared with a threshold value by the comparator 35. When the rotation reference sensor input signal is at the low level, the threshold value of the comparator 35 is exceeded, so that the output of the comparator 35 is at the high level.

  Next, FIG. 9 is a block diagram showing another example of the rotation reference sensor input unit 23 of the sensor input unit 15 according to the embodiment of the present invention. The rotation reference sensor input unit 23 includes a limiter circuit 32, a high level peak hold circuit 36, a low level peak hold circuit 37, an adder circuit 38, a ½ voltage divider circuit 39, and a comparator 35.

In FIG. 9, the limiter circuit 32 limits the amplitude of the input sensor signal to a certain width for circuit protection. The high level peak hold circuit 36 holds the highest level among the inputted signals, and the low level peak hold circuit 37 holds the lowest level among the inputted signals. The adder circuit 38 adds the peak-hold level, and the 1/2 voltage divider circuit 39 sets the added level to a 1/2 level. As a result, an intermediate level between the high-side peak level and the low-side peak level is obtained as the output of the ½ voltage dividing circuit 39, and this is input as the threshold value of the comparator 35. The comparator 35 compares the sensor signal with the generated threshold value, and outputs it under the conditions shown in Table 4.

  In FIG. 10, when the rotation reference sensor input signal is input, the highest level among the signals input by the high level peak hold circuit 36 is held, and the highest among the signals input by the low level peak hold circuit 37. A low level is maintained. These two signals are added by the adder circuit 38, and a signal at an intermediate level between the high-side peak level and the low-side level is obtained via the 1/2 voltage dividing circuit 39. This is the threshold value of the comparator 35. The comparator 35 compares the sensor signal with the threshold value generated thereby.

  As a result, the rotational vibration phase detection device with different signal levels can be applied as the rotation reference sensor 13 without distinguishing between a fixed type that is permanently installed on the measurement target and a portable type that has a vibration sensor and a rotation reference sensor installed on the target device each time. As a result, the availability of the phase detector 14 is greatly improved.

  FIG. 11 is a configuration diagram of another example of the vibration sensor input unit 22 of the sensor input unit 15 when the vibration sensor 12 is the displacement sensor 12b. The displacement sensor 12 b is connected to the vibration sensor input unit 22 of the sensor input unit 15 through the transducer 31. The vibration sensor input unit 22 includes a low-pass filter 29a, an amplifier 28, a subtraction circuit 40, a low-pass filter 29b, and an analog / digital converter 30.

  The low-pass filter 29a of the vibration sensor input unit 22 in the sensor input unit 15 removes the vibration component of the input vibration signal and outputs only the superimposed DC component. The subtracting circuit 40 subtracts the signal generated by the low-pass filter 29a from the vibration sensor signal. Thereby, the vibration component of the vibration sensor is obtained. The signal obtained by the subtracting circuit 40 is input to the analog / digital converter 30 through the amplifier 28 and the low-pass filter 29b that removes aliasing.

  When an eddy current displacement sensor is used as the vibration sensor, as shown in FIG. 12, the waveform is such that the vibration signal component is superimposed on the negative DC voltage, and only the DC component superimposed by the low-pass filter 29a is obtained. Is output. Then, the signal generated by the low-pass filter 29a is subtracted from the vibration sensor signal by the subtraction circuit 40, and the vibration component of the vibration sensor is obtained.

  FIG. 13 is a configuration diagram of another example of the vibration sensor input unit 22 of the sensor input unit 15 when the vibration sensor 12 is the acceleration sensor 12a. The acceleration sensor 12 a is connected to the sensor power supply 24 and is connected to the vibration sensor input unit 22 of the sensor input unit 15. The vibration sensor input unit 22 includes a low-pass filter 29a, a subtracting circuit 40, high-pass filters 25b and 25c, integrators 26a and 26b, a multiplexer 27, an amplifier 28, a low-pass filter 29b, and an analog / digital converter 30.

  Here, when the acceleration sensor 12a is used, the sensor power supply 24 supplies a constant current to supply power to the acceleration sensor 12a. Therefore, the signal output of the acceleration sensor 12a has a waveform in which a vibration signal component is superimposed on a + DC voltage as shown in FIG. Therefore, only the superimposed DC component is output from the low-pass filter 29a as shown in FIG. Then, the signal generated by the low pass filter 29a is subtracted from the vibration sensor signal by the subtraction circuit 40, and the vibration component of the vibration sensor is obtained.

  As a result, even when a signal in which a DC component is superimposed, such as the acceleration sensor 12a or the eddy current displacement sensor 12b, can be removed without using a high-pass filter, even in a low rotational speed region. A vibration phase shift does not occur, and a value closer to the true value of the vibration phase can be obtained, thereby improving measurement accuracy.

  Next, measurement timing prediction at the time of rotational acceleration / deceleration will be described. FIG. 15 is a characteristic diagram of an example of a time / rotational speed transition when the rotating device according to the embodiment of the present invention is activated to increase the speed to the rated rotational speed.

  As shown in FIG. 15, a situation is assumed in which the rotational speed increases with the passage of time. In FIG. 15, the vibration signal and the rotation reference signal are sampled at a constant time interval ΔT, and the rotation speed is calculated from the interval of the rotation reference signal. The rotation speed at the n-th sampling time Tn is Rn, the target rotation speed is Rt, and the time to reach the target rotation speed Rt is Tt. When the sampling interval is ΔT, the sampling time is expressed by the following relational expression.

Tn−Tn−1 = ΔT
FIG. 16 is a flowchart showing the procedure of the vibration signal capturing operation. When the sampling at time Tn−1 is completed and the next sampling time Tn is set, sampling is waited until the time is reached. In this state, it is determined whether or not the scheduled sampling time is reached (S1).

  When the scheduled sampling time Tn is reached, the vibration signal and the rotation reference signal are sampled (S2), and the rotation speed is calculated from the rotation reference signal (S3).

  Then, the next sampling scheduled time Tn + 1 is set (S4), and the preset target rotational speed Rt is compared with the calculated rotational speed Rn (S5). If they are equal or within a preset tolerance, the vibration phase is calculated from the rotation reference signal and vibration signal (S6), the next target rotation speed is set (S7), and the next scheduled sampling time Tn + 1 is reached. Wait to do.

  On the other hand, if it is determined in step S5 that the target rotational speed Rt does not match the calculated rotational speed Rn or exceeds a preset tolerance, the rotational speed Rt calculated at the time Tn sampled this time is The rotational speed change rate ΔR / ΔT is calculated from the rotational speed Rt-k at the time Tn-k sampled in the past by the following formula (S8).

ΔR / ΔT = (Rn−Rn−k) / (Tn−Tn−k)
However, k is an integer value equal to or greater than 1. Then, the rotational speed change rate ΔR / ΔT and the rotational speed at the next sampling scheduled time Tn + 1 from the current sampling time are predicted by the following formula (S9).

Rn + 1 = Rn + (ΔR / ΔT)
The predicted value Rn + 1 thus obtained is compared with the target rotational speed Rt (S10), and when the predicted value Rn + 1 exceeds the target rotational speed Rt, the time interval ΔT ′ until reaching the target rotational speed Rt is expressed by the following equation. presume.

ΔT ′ = (Rt−Rn) / (ΔR / ΔT)
Then, the target rotational speed arrival time Tt is estimated by the following equation (S11).

Tt = Tn + ΔT ′
Then, the estimated time is set as the next scheduled sampling time (S12), and the process waits until the next scheduled sampling time is reached. If the predicted value Rn + 1 does not exceed the target rotational speed Rt, the process waits until the next scheduled sampling time Tn + 1 is reached.

  As a result, in the case of measuring at a constant rotation speed interval after reaching the rated rotation speed from startup, it is possible to measure the desired rotation speed without missing the measurement time even if it is difficult to shorten the measurement cycle. Excellent effect.

The block diagram in the rotational vibration phase detection apparatus concerning embodiment of this invention. The block diagram of an example of the vibration sensor input part of the sensor input part in case the vibration sensor in embodiment of this invention is an acceleration sensor. The block diagram of an example of the vibration sensor input part of the sensor input part in case the vibration sensor in embodiment of this invention is a displacement sensor. The characteristic diagram of the rotation speed-phase characteristic by the high-pass filter of the vibration sensor input part in embodiment of this invention. The block diagram which shows an example of the rotation reference sensor input part of the sensor input part in embodiment of this invention. FIG. 6 is an operation waveform diagram of the rotation reference sensor input unit shown in FIG. 5. The block diagram which shows another example of the rotation reference | standard sensor input part of the sensor input part in embodiment of this invention. FIG. 8 is an operation waveform diagram of the rotation reference sensor input unit shown in FIG. 7. The block diagram which shows another example of the rotation reference sensor input part of the sensor input part in embodiment of this invention. FIG. 10 is an operation waveform diagram of the rotation reference sensor input unit shown in FIG. 9. The block diagram of the other example of the vibration sensor input part of the sensor input part in embodiment of this invention. FIG. 12 is an operation waveform diagram of the vibration sensor input unit illustrated in FIG. 11. The block diagram of another example of the vibration sensor input part of the sensor input part in embodiment of this invention. FIG. 12 is an operation waveform diagram of the vibration sensor input unit illustrated in FIG. 11. The characteristic view of an example of time and a rotation speed transition at the time of the rotation apparatus in embodiment of this invention starting and speeding up to a rated rotation speed. The flowchart which shows the procedure of the taking-in operation of the vibration signal in embodiment of this invention The characteristic figure of the rotation speed-phase characteristic by the conventional high pass filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Rotation vibration phase detection apparatus, 12 ... Vibration sensor, 12a ... Acceleration sensor, 12b ... Displacement sensor, 13 ... Rotation reference sensor, 14 ... Phase detection apparatus, 15 ... Sensor input part, 16 ... RAM, 17 ... Flash ROM, DESCRIPTION OF SYMBOLS 18 ... Input means, 19 ... Output means, such as LCD display, 20 ... Man-machine interface, 21 ... CPU, 22 ... Vibration sensor input part, 23 ..., 24 ..., 25 ... High pass filter, 26 ... Integrator, 27 ... Multiplexer 28 ... Amplifier, 29 ... Low-pass filter, 30 ... Analog / digital converter, 31 ... Transducer, 32 ... Limiter circuit, 33 ... Window comparator, 34 ... Absolute value circuit, 35 ... Comparator, 36 ... High level peak hold circuit, 37 ... Low level peak hold circuit, 38 ... adder circuit, 39 ... / 2 voltage dividing circuit, 40 ... subtracting circuit

Claims (6)

In a rotational vibration phase detection device that detects rotational vibration of a rotating device and detects an unbalance of the rotating portion of the rotating device, a vibration sensor that detects vibration displacement of the rotating portion of the rotating device, and rotation of the rotating portion of the rotating device A rotation reference sensor for detecting a reference signal, and a phase detection device for correcting a signal phase shift generated in a signal processing process of vibration displacement detected by the vibration sensor and outputting a vibration signal are provided. Rotational vibration phase detector. 2. The rotational vibration phase detecting device according to claim 1, wherein the phase detecting device identifies a polarity or level of a rotation reference signal detected by the rotation reference sensor and detects a rotation reference position. The phase detection device outputs a vibration signal in which the DC signal level is canceled when a DC signal level is superimposed on the vibration displacement detected by the vibration sensor. The phase detection device is characterized in that when the vibration sensor is an acceleration sensor and a DC signal level is superimposed on a vibration acceleration signal detected by the acceleration sensor, a vibration signal that cancels the DC signal level is output. Rotating vibration phase detector. 5. The phase detection device according to claim 1, wherein the phase detection device predicts a timing at which a desired rotation speed is reached from a history of rotation speeds acquired in the past, and acquires a vibration signal at the desired rotation speed. The rotational vibration phase detector described. In a rotational vibration phase detection method for detecting rotational vibration of a rotating device and detecting an unbalance of the rotating portion of the rotating device, a rotation reference signal of the rotating portion of the rotating device is detected, and vibration displacement of the rotating portion of the rotating device is detected. A rotational vibration phase detection method comprising: detecting and correcting a signal phase shift generated in a signal processing process of the detected vibration displacement and outputting a vibration signal.

Images