JP2010271185A - Abnormality monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extract a vibration excited by abnormal conditions in the rotation system of a motor or the like, without using any dedicated instrument for measuring the excited vibration when the abnormal conditions arise. <P>SOLUTION: A disturbance component calculation unit 3 calculates a torque disturbance τd included in a motor current command si on the basis of the motor current instruction si and a motor velocity vm. A rotation-synchronous disturbance component extraction unit 4 extracts a magnitude of the torque disturbance τd whose period is synchronized with a rotation frequency of the motor 2 on the basis of the torque disturbance τd calculated by the disturbance component calculation unit 3. A rotation-frequency synchronous vibration increase decision unit 8 determines an increase of a rotation-frequency synchronous vibration when an output value from the rotation-synchronous disturbance component extraction unit 4 becomes equal to or more than a threshold. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an abnormality monitoring apparatus, and more particularly to an equipment diagnosis system for industrial robots, mounting machines, injection molding machines, machine tools, printing machines, semiconductor manufacturing apparatuses, packaging machines, elevators, air conditioners, on-vehicle equipment, and the like.

  When an abnormality occurs in a rotating machine used in industrial robots, mounting machines, injection molding machines, machine tools, printing machines, semiconductor manufacturing equipment, packaging machines, elevators, air conditioners, and in-vehicle equipment, vibrations synchronized with the rotation occur. It may occur or become larger. For this reason, it is sometimes performed to detect the vibration of the rotating machine that occurs with the abnormality, and to determine the occurrence of the abnormality of the rotating machine based on the detection result.

  For example, Patent Document 1 discloses a method of determining an abnormal site and an abnormal cause by detecting vibration of a rotary machine in a mechanical system including a rotary machine such as a motor. That is, the displacement, speed, and acceleration of vibration generated in a rotating system such as a motor are measured together with the rotating speed of the rotating system, and the measured vibration acceleration signal is passed through a high-pass filter to extract only the high-frequency region component. Is done. Then, after the measured vibration signal is rectified and envelope processing is performed, the envelope-processed vibration signal and rotation period signal are sampled at a constant sampling period. Subsequently, the time interval of the vibration signal sampled at the same time as the rotation period signal is changed based on the ratio between the preset standard rotation period and the rotation period of the rotation system, and the vibration signal subjected to this change process Based on the frequency analysis or autocorrelation analysis, the abnormal part or the cause of the abnormality is determined.

JP-A-4-279826

  However, in the method disclosed in Patent Document 1, not only the state quantity (rotation position, speed, applied current value, etc.) used for controlling the acceleration / deceleration operation of the motor, but also an abnormality has occurred in the rotating system such as the motor. A dedicated measuring device (sensor) for measuring vibrations excited at the time is required. For this reason, there existed a problem that the cost concerning the control system of a mechanical system became high.

  Further, in the method disclosed in Patent Document 1, it is necessary to perform frequency analysis or autocorrelation analysis, and it is necessary to record data sampled simultaneously with the rotation period signal. For this reason, in addition to requiring a memory for storing data sampled simultaneously with the rotation period signal, it is necessary to have a function for performing frequency analysis or autocorrelation analysis. There was also a problem of high costs.

  The present invention has been made in view of the above, and is excited by an abnormality without using a dedicated measuring instrument for measuring vibration excited when an abnormality occurs in a rotating system such as a motor. An object of the present invention is to obtain an abnormality monitoring device that can extract vibrations.

  In order to solve the above-described problems and achieve the object, the abnormality monitoring apparatus of the present invention calculates a disturbance component included in at least one of a motor current command, a motor current, a motor acceleration, and a motor speed. A component calculation unit, and a rotation synchronization disturbance component extraction unit that extracts, from the disturbance component calculated by the disturbance component calculation unit, a magnitude of a disturbance component having a period synchronized with the rotation speed of the motor. .

  According to the present invention, it is possible to extract vibration excited by the abnormality without using a dedicated measuring instrument for measuring vibration excited when abnormality occurs in a rotating system such as a motor. There is an effect.

FIG. 1 is a block diagram showing a schematic configuration of Embodiment 1 of an abnormality monitoring apparatus according to the present invention. FIG. 2 is a block diagram showing a schematic configuration of Embodiment 2 of the abnormality monitoring apparatus according to the present invention. FIG. 3 is a block diagram showing a schematic configuration of Embodiment 4 of the abnormality monitoring apparatus according to the present invention. FIG. 4 is a block diagram showing a schematic configuration of Embodiment 5 of the abnormality monitoring apparatus according to the present invention. FIG. 5 is a block diagram showing a schematic configuration of Embodiment 6 of the abnormality monitoring apparatus according to the present invention. FIG. 6 is a block diagram illustrating a schematic configuration example of the model speed calculation unit 10 of FIG.

  Hereinafter, embodiments of an abnormality monitoring apparatus according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a schematic configuration of Embodiment 1 of an abnormality monitoring apparatus according to the present invention. In FIG. 1, the abnormality monitoring device 11 is provided with a disturbance component calculation unit 3, a rotation synchronization disturbance component extraction unit 4, and a rotation speed synchronization vibration increase determination unit 8. The rotation synchronization disturbance component extraction unit 4 is provided with a rotation speed synchronization signal sampling unit 5, a rotation speed synchronization period bandpass filter 6, and an effective value calculation unit 7. In addition, a position / speed control unit 1 and a motor 2 are provided in a rotating system in which an abnormality is monitored by the abnormality monitoring device 11.

  Here, the disturbance component calculation unit 3 can calculate the torque disturbance τd included in the motor current command si from the motor current command si and the motor speed vm. The rotation-synchronized disturbance component extracting unit 4 can extract the magnitude of the torque disturbance τd having a period synchronized with the rotational speed of the motor 2 from the torque disturbance τd calculated by the disturbance component calculating unit 3. The period synchronized with the rotational speed of the motor 2 corresponds to a period corresponding to n (n is a positive integer) times the rotational speed of the motor 2 (for example, 2 times, 4 times the rotational speed of the motor 2). Period). The rotation speed synchronization vibration increase determination unit 8 can determine that the rotation number synchronization vibration has increased when the output value from the rotation synchronization disturbance component extraction unit 4 is equal to or greater than a threshold value.

  The rotation speed synchronization signal sampling unit 5 can sample the torque disturbance τd calculated by the disturbance component calculation unit 3 according to a predetermined motor displacement width sd. The rotation speed synchronization period bandpass filter 6 can extract a frequency component n times the rotation speed of the motor 2 from the torque disturbance τd sampled by the rotation speed synchronization signal sampling unit 5. For example, the rotational speed synchronization period band pass filter 6 can be configured to have a pass band corresponding to a frequency component n times the rotational speed of the motor 2. The effective value calculation unit 7 can calculate an effective value of the magnitude of the torque disturbance τd having a period synchronized with the rotation speed of the motor 2.

  When the position command sp is input to the position / speed control unit 1, a motor current command si corresponding to the position command sp is generated and sent to the motor 2 and the disturbance component calculation unit 3. When the motor current command si is sent to the motor 2, the motor 2 rotates based on the motor current command si. Further, the motor speed vm and the motor position pm are detected from the motor 2, the motor speed vm is sent to the disturbance component calculation unit 3, and the motor position pm is sent to the rotation speed synchronization signal sampling unit 5.

  When the motor current command si and the motor speed vm are sent to the disturbance component calculation unit 3, the torque disturbance τd included in the motor current command si is calculated from the motor current command si and the motor speed vm, and the torque disturbance τd is rotated. It is output to the number synchronization signal sampling unit 5.

Here, the torque disturbance τd can be obtained as follows. That is, if the torque constant of the motor 2 is Kt, the equivalent inertia totaling the motor 2 and the machine is J, the motor acceleration calculated from the difference of the motor speed vm is am, the viscous friction coefficient is fv, and the coulomb friction coefficient is fc, vm When> 0, the estimated value τh of the motor torque can be given by the following equation (1).
τh = J * am + fv * vm + fc (1)

On the other hand, when vm <0, the estimated value τh of the motor torque can be given by the following equation (2).
τh = J * am + fv * vm−fc (2)

Assuming that the actual torque τ is given by τ = Kt * i from the equations (1) and (2), the torque disturbance τd can be given by the following equation (3).
τd = τ−τh (3)

  Next, when the torque disturbance τd calculated by the disturbance component calculation unit 3 and the motor position pm detected from the motor 2 are input to the rotation speed synchronization signal sampling unit 5, the motor position pm becomes the motor displacement width sd. The value of the torque disturbance τd is output to the rotational speed synchronization period band pass filter 6 every time the step position determined on the basis is exceeded.

  For example, the torque disturbance τd in the k-th (k is a positive integer) cycle is τd [k], and the motor position pm is pm [k]. Further, it is assumed that the previous output to the rotation speed synchronization period band pass filter 6 is the j-th output, and the step position when the j-th output is performed is kpm [j].

  When vm> 0, when pm [k] −kpm [j] <sd, the step position is not exceeded. Therefore, the rotation speed synchronization signal sampling unit 5 does not sample the torque disturbance τd [k] input at this time, and the value of the torque disturbance τd is not output to the rotation speed synchronization period bandpass filter 6.

On the other hand, when pm [k] −kpm [j]> sd, the rotation speed synchronization signal sampling unit 5 calculates dp1 and dp2 according to the following equations (4) and (5).
dp1 = pm [k] −kpm [j] −sd (4)
dp2 = sd−pm [k−1] + kpm [j] (5)

  When dp1 <dp2, the torque disturbance τd [k] is output to the rotation speed synchronization period bandpass filter 6, and when dp1> dp2, the torque disturbance τd [k-1] is the rotation speed synchronization period bandpass. It is output to the filter 6.

  Then, when the value of the torque disturbance τd is output to the rotation speed synchronization period bandpass filter 6, the output is the (j + 1) th output, and therefore the step position kpm [j + 1] when the j + 1th output is performed. Is updated to kpm [j] + sd.

  In the above example, the method of outputting the value closer to the step position every time the motor position pm exceeds the step position determined based on the motor displacement width sd has been described. The weighted sum may be calculated and output according to the above. For example, a value of (dp2 * τd [k] + dp1 * τd [k−1]) / (dp1 + dp2) may be output to the rotation speed synchronization period bandpass filter 6. In the above example, the case of vm> 0 has been described as an example, but the same applies to the case of vm <0.

  The rotation speed synchronization period bandpass filter 6 performs a bandpass filter operation each time data is input from the rotation speed synchronization signal sampling unit 5. The parameter of the band pass filter is set to a value that allows the component of n times the designated rotation speed to pass. By doing so, a frequency component n times the rotational speed of the motor 2 is extracted from the value of the torque disturbance τd sampled by the rotational speed synchronization signal sampling unit 5. The output of the rotation speed synchronization period bandpass filter 6 is output to the effective value calculation unit 7.

  When a frequency component that is n times the rotation speed of the motor 2 is input to the effective value calculation unit 7, the absolute value thereof is calculated and further passed through a low-pass filter such as a first-order lag filter, whereby the motor 2 The effective value of the frequency component n times the number of rotations is calculated and output to the rotation number synchronous vibration increase determination unit 8.

  Then, in the rotational speed synchronous vibration increase discriminating unit 8, the effective value of the frequency component n times the rotational speed of the motor 2 is compared with the threshold value, and the effective value of the frequency component n times the rotational speed of the motor 2 is obtained. When the threshold value is exceeded, it is determined that the rotational speed synchronization vibration has increased.

  Thereby, the vibration excited by the abnormality can be extracted without using a dedicated measuring device for measuring the vibration excited when the abnormality occurs in the rotating system such as the motor. For this reason, the cost concerning the control system of a mechanical system can be reduced.

  In addition, it is possible to determine an increase in rotational speed synchronous vibration without performing frequency analysis or autocorrelation analysis. For this reason, it is not necessary to once record data sampled simultaneously with the rotation period signal, and it is not necessary to provide a function for performing frequency analysis or autocorrelation analysis. As a result, the cost of the abnormality monitoring device 11 can be reduced, and it can be determined from the data that can be acquired by operating the motor 2 normally whether or not the rotational speed synchronous vibration has increased. It is possible to constantly monitor the occurrence of machine abnormalities.

  Furthermore, by extracting a frequency component n times the rotational speed of the motor 2 from the torque disturbance τd sampled by the rotational speed synchronization signal sampling unit 5, the frequency component of vibration excited by an abnormality is caused by acceleration / deceleration. Even when the frequency component of the signal is buried, the frequency component of the signal due to acceleration / deceleration can be removed. For this reason, it is possible to extract a change in the frequency component of vibration excited by an abnormality without using a measuring instrument for vibration measurement, and to suppress a decrease in abnormality diagnosis accuracy.

  In the first embodiment described above, the method of providing the effective value calculation unit 7 in the rotation synchronization disturbance component extraction unit 4 has been described, but the effective value calculation unit 7 may not be provided. In the first embodiment described above, the method of providing the rotation speed synchronization vibration increase determination unit 8 in the abnormality monitoring device 11 has been described. However, the rotation speed synchronization vibration increase determination unit 8 is provided separately from the abnormality monitoring device 11. It may be.

Embodiment 2. FIG.
FIG. 2 is a block diagram showing a schematic configuration of Embodiment 2 of the abnormality monitoring apparatus according to the present invention. 2, the abnormality monitoring device 21 is provided with a rotation synchronization disturbance component extraction unit 14 instead of the rotation synchronization disturbance component extraction unit 4 of FIG. The rotation synchronization disturbance component extraction unit 14 is provided with a rotation number synchronization vibration amplitude identification unit 9 instead of the rotation number synchronization signal sampling unit 5 and the rotation number synchronization periodic bandpass filter 6 of FIG.

  Here, the rotation speed synchronization vibration amplitude identification unit 9 identifies the amplitude of vibration having a period corresponding to n times the rotation number of the motor 2 from the torque disturbance τd calculated by the disturbance component calculation unit 3. Can be output as the magnitude of the torque disturbance τd having a period synchronized with the number of rotations.

  When the position command sp is input to the position / speed control unit 1, a motor current command si corresponding to the position command sp is generated and sent to the motor 2 and the disturbance component calculation unit 3. When the motor current command si is sent to the motor 2, the motor 2 rotates based on the motor current command si. Further, the motor speed vm and the motor position pm are detected from the motor 2, the motor speed vm is sent to the disturbance component calculation unit 3, and the motor position pm is sent to the rotation speed synchronous vibration amplitude identification unit 9.

  When the motor current command si and the motor speed vm are sent to the disturbance component calculation unit 3, the torque disturbance τd included in the motor current command si is calculated from the motor current command si and the motor speed vm, and the torque disturbance τd rotates. It is output to the number synchronization vibration amplitude identification unit 9.

  Next, when the torque disturbance τd calculated by the disturbance component calculation unit 3 and the motor position pm detected from the motor 2 are input to the rotation speed synchronous vibration amplitude identification unit 9, the number of rotations of the motor 2 is n times. The amplitude of vibration having a period corresponding to is identified and output to the effective value calculation unit 7 as the magnitude of the torque disturbance τd having a period synchronized with the rotation speed of the motor 2.

Here, the amplitude of vibration having a period corresponding to n times the rotation speed of the motor 2 can be identified as follows. That is, assuming that the torque disturbance τd calculated by the disturbance component calculation unit 3 is a vibration having a period corresponding to n times the rotation speed of the motor 2, the torque disturbance τd is given by the following equation (6). Can do.
τd = vl * sin (n * Pm + φ) (6)

  However, vl is the amplitude of vibration having a period corresponding to n times the number of rotations of the motor 2.

Here, when defining para1 = vl * cosφ and para2 = vl * sinφ, the equation (6) can be given by the following equation (7).
τd = para1 * sin (n * Pm) + para2 * cos (n * Pm) (7)

Here, the value in the kth identification period is k (for example, Pm _k , Pvib _k, etc.). Further, it is assumed that the sequential estimated values of para1 and para2 are ph1 and ph2. Further, vectors yp _k , p _k , rp _k and matrix Rp _k are defined by the following equations (8) to (11), respectively.
yp _k = [sin (n * Pm _k ), cos (n * Pm _k )] (8)
p _k = [ph1 _k , ph2 _k ] (9)
Rp _k = Rp _k−1 + moit * (− σ * Rp _k−1 + yp _k ^T yp _k ) (10)
_{rp k = rp k-1 +} moit * (- σ * rp k-1 + τd k * yp k) ··· (11)

In this case, the sequential estimated values of para1 and para2 in the kth identification period can be given by the following equation (12).
_{p k = p k-1 -moit} * G (Rp k · p k-1 -rp k) ··· (12)

  However, moit is an estimation period, σ is a constant, and G is a constant matrix.

Then, the sequential estimated _{p k = [ph1 k, ph2} k], estimated value in the k-th period of the amplitude vl is given by the following equation (13).
_{vl k = sqrt (ph1 k *} ph1 k + ph2 k * ph2 k) ··· (13)

Then, the rotational speed synchronous vibration amplitude identification unit 9 may output a vl _k calculated in equation (13).

  When the amplitude of vibration having a period corresponding to n times the number of rotations of the motor 2 is input to the effective value calculation unit 7, the absolute value is calculated and further passed through a low-pass filter such as a first-order lag filter. As a result, the effective value of the amplitude of vibration with a period corresponding to n times the rotational speed of the motor 2 is calculated and output to the rotational speed synchronous vibration increase determination unit 8.

  Then, in the rotation number synchronous vibration increase discriminating unit 8, the effective value of the amplitude of vibration having a period corresponding to n times the rotation number of the motor 2 is compared with a threshold value and corresponds to n times the rotation number of the motor 2. When the effective value of the amplitude of the periodic vibration is equal to or greater than the threshold value, it is determined that the rotational speed synchronous vibration has increased.

  Thereby, the vibration excited by the abnormality can be extracted without using a dedicated measuring device for measuring the vibration excited when the abnormality occurs in the rotating system such as the motor. For this reason, the cost concerning the control system of a mechanical system can be reduced.

  In addition, it is possible to determine an increase in rotational speed synchronous vibration without performing frequency analysis or autocorrelation analysis. For this reason, it is not necessary to once record data sampled simultaneously with the rotation period signal, and it is not necessary to provide a function for performing frequency analysis or autocorrelation analysis. As a result, the cost of the abnormality monitoring device 21 can be reduced, and it can be determined from the data that can be acquired by operating the motor 2 normally whether or not the rotational speed synchronous vibration has increased. It is possible to constantly monitor the occurrence of machine abnormalities.

  Furthermore, by identifying the amplitude of vibration with a period corresponding to n times the number of rotations of the motor 2 in the rotation number synchronous vibration amplitude identification unit 9, the frequency component of vibration excited by an abnormality is the signal of acceleration / deceleration. Even when the frequency component is buried, the frequency component of the signal due to acceleration / deceleration can be removed. For this reason, it is possible to extract a change in the frequency component of vibration excited by an abnormality without using a measuring instrument for vibration measurement, and to suppress a decrease in abnormality diagnosis accuracy.

  In the second embodiment described above, the method of providing the rotation speed synchronization vibration increase determination unit 8 in the abnormality monitoring device 21 has been described. However, the rotation speed synchronization vibration increase determination unit 8 is provided separately from the abnormality monitoring device 21. It may be.

Embodiment 3 FIG.
In the second embodiment described above, the rotation speed synchronization vibration amplitude identification unit 9 calculates the vibration amplitude having a period corresponding to n times the rotation number of the motor 2 from the torque disturbance τd calculated by the disturbance component calculation unit 3. The identification method has been described. On the other hand, the rotational speed synchronous vibration amplitude identifying unit 9 has a cycle corresponding to na (na is a positive integer) times the rotational speed of the motor 2 from the torque disturbance τd calculated by the disturbance component calculating unit 3. The amplitude of the vibration corresponding to nb (nb is a positive integer different from na) times the vibration amplitude and the rotation speed of the motor 2 is identified, and the magnitude of the disturbance component of the period synchronized with the rotation speed of the motor 2 You may make it output.

  That is, the rotational speed synchronization vibration amplitude identification unit 9 regards the torque disturbance τd as the sum of the vibration having a period corresponding to na times the rotation speed of the motor 2 and the vibration having a period corresponding to nb times, and increasing the value to na times. You may make it calculate the amplitude of the vibration of the corresponding period, and the amplitude of the vibration of the period corresponding to nb times collectively.

That is, if the torque disturbance τd calculated by the disturbance component calculation unit 3 is regarded as the sum of the vibration having a period corresponding to na times the rotational speed of the motor 2 and the vibration having a period corresponding to nb times, the torque disturbance τd can be given by the following equation (14).
τd = vla * sin (na * Pm + φa) + vla * sin (na * Pm + φa)
(14)

  However, vla is the amplitude of vibration with a period corresponding to na times the rotational speed of the motor 2, and vlb is the amplitude of vibration with a period corresponding to nb times the rotational speed of the motor 2.

Here, when defining para1a = vla * cosφa, para2a = vla * sinφa, para1b = vlb * cosφb, and para2b = vlb * sinφb, equation (14) can be given by the following equation (15).
τd = para1a * sin (na * Pm) + para2a * cos (na * Pm)
+ Para1b * sin (nb * Pm) + para2b * cos (nb * Pm)
(15)

Here, it is assumed that the sequential estimated values of para1a, para2a, para1b, and para2b are ph1a, ph2a, ph1b, and ph2b. Further, vectors yp _k , p _k , rp _k and matrix Rp _k are defined by the following equations (16) to (19), respectively.
_{yp k = [sin (na *} Pm k), cos (na * Pm k), sin (nb * Pm k), cos (nb * Pm k)] ··· (16)
p _k = [ph1a _k , ph2a _k, ph1b _k , ph2b _k ] (17)
Rp _k = Rp _k−1 + moit * (− σ * Rp _k−1 + yp _k ^T yp _k ) (18)
_{rp k = rp k-1 +} moit * (- σ * rp k-1 + τd k * yp k) ··· (19)

In this case, the sequential estimated values of para1a, para2a, para1b, and para2b in the k-th identification period can be given by the following equation (20).
p _k = p _k−1 −moit * G (Rp _k · p _k−1 −rp _k ) (20)

Then, the _{p k} which sequentially estimated amplitude vla, the estimate at the k-th cycle of VLB, can be given by the following expression (21) and (22).
vla _k = sqrt (ph1a _k * ph1a _k + ph2a _k * ph2a _k ) (21)
vlb _k = sqrt (ph1b _k * ph1b _k + ph2b _k * ph2b _k ) (22)

Then, the rotational speed synchronous vibration amplitude identification unit 9 can output the _vla k, VLB _k calculated in (21) and (22).

  In the third embodiment described above, the torque disturbance τd is regarded as the sum of the vibration having a period corresponding to na times the number of revolutions of the motor 2 and the vibration having a period corresponding to nb times, and corresponds to na times. The method of collectively calculating the amplitude of the periodic vibration and the amplitude of the periodic vibration corresponding to nb times has been described. On the other hand, the torque disturbance τd is regarded as the sum of vibrations of three or more periods corresponding to an integer multiple of the rotation speed of the motor 2, and three or more periods corresponding to an integer multiple of the rotation speed of the motor 2 is considered. The amplitudes of the vibrations may be calculated collectively.

Embodiment 4 FIG.
FIG. 3 is a block diagram showing a schematic configuration of Embodiment 4 of the abnormality monitoring apparatus according to the present invention. In FIG. 3, the abnormality monitoring device 31 is provided with a rotation synchronization disturbance component extraction unit 24 instead of the rotation synchronization disturbance component extraction unit 4 of FIG. 1. The rotation synchronization disturbance component extraction unit 24 includes the rotation number synchronization vibration sampling unit 5, the rotation number synchronization periodic bandpass filter 6 and the effective value calculation unit 7 in FIG. 9 is provided.

  When the position command sp is input to the position / speed control unit 1, a motor current command si corresponding to the position command sp is generated and sent to the motor 2 and the disturbance component calculation unit 3. When the motor current command si is sent to the motor 2, the motor 2 rotates based on the motor current command si. Further, the motor speed vm and the motor position pm are detected from the motor 2, and the motor speed vm is sent to the disturbance component calculation unit 3, and the motor position pm is detected by the rotation speed synchronization signal sampling unit 5 and the rotation speed synchronization vibration amplitude identification unit 9. Sent to.

  When the motor current command si and the motor speed vm are sent to the disturbance component calculation unit 3, the torque disturbance τd included in the motor current command si is calculated from the motor current command si and the motor speed vm, and the torque disturbance τd is rotated. It is output to the number synchronization signal sampling unit 5.

  Next, when the torque disturbance τd calculated by the disturbance component calculation unit 3 and the motor position pm detected from the motor 2 are input to the rotation speed synchronization signal sampling unit 5, the motor position pm becomes the motor displacement width sd. The value of the torque disturbance τd is output to the rotational speed synchronization period band pass filter 6 every time the step position determined on the basis is exceeded.

  Next, when the value of the torque disturbance τd sampled by the rotation speed synchronization signal sampling unit 5 is input to the rotation speed synchronization period bandpass filter 6, the rotation speed n of the motor 2 is calculated from the value of the torque disturbance τd. Double frequency components are extracted and output to the rotational frequency synchronization vibration amplitude identification unit 9.

  Next, the frequency component of n times the rotation speed of the motor 2 extracted by the rotation speed synchronization period bandpass filter 6 and the motor position pm detected from the motor 2 are input to the rotation speed synchronization vibration amplitude identification unit 9. Then, the amplitude of vibration having a period corresponding to n times the rotational speed of the motor 2 is identified, and is output to the effective value calculation unit 7 as the magnitude of the torque disturbance τd having a period synchronized with the rotational speed of the motor 2.

  When the amplitude of vibration having a period corresponding to n times the number of rotations of the motor 2 is input to the effective value calculation unit 7, the absolute value is calculated and further passed through a low-pass filter such as a first-order lag filter. As a result, the effective value of the amplitude of vibration with a period corresponding to n times the rotational speed of the motor 2 is calculated and output to the rotational speed synchronous vibration increase determination unit 8.

  Then, in the rotation number synchronous vibration increase discriminating unit 8, the effective value of the amplitude of vibration having a period corresponding to n times the rotation number of the motor 2 is compared with a threshold value and corresponds to n times the rotation number of the motor 2. When the effective value of the amplitude of the periodic vibration is equal to or greater than the threshold value, it is determined that the rotational speed synchronous vibration has increased.

  Thereby, the vibration excited by the abnormality can be extracted without using a dedicated measuring device for measuring the vibration excited when the abnormality occurs in the rotating system such as the motor. For this reason, the cost concerning the control system of a mechanical system can be reduced.

  In addition, it is possible to determine an increase in rotational speed synchronous vibration without performing frequency analysis or autocorrelation analysis. For this reason, it is not necessary to once record data sampled simultaneously with the rotation period signal, and it is not necessary to provide a function for performing frequency analysis or autocorrelation analysis. As a result, the cost of the abnormality monitoring device 31 can be reduced, and it can be determined from the data that can be acquired by operating the motor 2 normally whether or not the rotation speed synchronous vibration has increased. It is possible to constantly monitor the occurrence of machine abnormalities.

  Furthermore, by identifying the amplitude of vibration with a period corresponding to n times the number of rotations of the motor 2 in the rotation number synchronous vibration amplitude identification unit 9, the frequency component of vibration excited by an abnormality is the signal of acceleration / deceleration. Even when the frequency component is buried, the frequency component of the signal due to acceleration / deceleration can be removed. For this reason, it is possible to extract a change in the frequency component of vibration excited by an abnormality without using a measuring instrument for vibration measurement, and to suppress a decrease in abnormality diagnosis accuracy.

  In the fourth embodiment described above, the method of providing the effective value calculation unit 7 in the rotation synchronization disturbance component extraction unit 24 has been described, but the effective value calculation unit 7 may not be provided. In the fourth embodiment described above, the method of providing the rotation speed synchronization vibration increase determination unit 8 in the abnormality monitoring device 31 has been described. However, the rotation speed synchronization vibration increase determination unit 8 is provided separately from the abnormality monitoring device 31. It may be.

Embodiment 5 FIG.
FIG. 4 is a block diagram showing a schematic configuration of Embodiment 5 of the abnormality monitoring apparatus according to the present invention. 4, the abnormality monitoring device 41 is provided with a rotation synchronization disturbance component extraction unit 34 instead of the rotation synchronization disturbance component extraction unit 14 of FIG. 2. The rotation synchronization disturbance component extraction unit 34 is provided with a rotation speed synchronization vibration amplitude identification unit 9.

  When the position command sp is input to the position / speed control unit 1, a motor current command si corresponding to the position command sp is generated and sent to the motor 2 and the disturbance component calculation unit 3. When the motor current command si is sent to the motor 2, the motor 2 rotates based on the motor current command si. Further, the motor speed vm and the motor position pm are detected from the motor 2, the motor speed vm is sent to the disturbance component calculation unit 3, and the motor position pm is sent to the rotation speed synchronous vibration amplitude identification unit 9.

  When the motor current command si and the motor speed vm are sent to the disturbance component calculation unit 3, the torque disturbance τd included in the motor current command si is calculated from the motor current command si and the motor speed vm, and the torque disturbance τd is rotated. It is output to the number synchronization vibration amplitude identification unit 9.

  Next, when the torque disturbance τd calculated by the disturbance component calculation unit 3 and the motor position pm detected from the motor 2 are input to the rotation speed synchronous vibration amplitude identification unit 9, the number of rotations of the motor 2 is n times. The amplitude of the vibration corresponding to the period is identified and output to the rotation-synchronized vibration increase determination unit 8.

  Then, in the rotation number synchronous vibration increase discriminating unit 8, the amplitude of vibration having a period corresponding to n times the rotation number of the motor 2 is compared with a threshold value, and vibration having a period corresponding to n times the rotation number of the motor 2. Is greater than or equal to the threshold value, it is determined that the rotational frequency synchronization vibration has increased.

  Thereby, the vibration excited by the abnormality can be extracted without using a dedicated measuring device for measuring the vibration excited when the abnormality occurs in the rotating system such as the motor. For this reason, the cost concerning the control system of a mechanical system can be reduced.

  In addition, it is possible to determine an increase in rotational speed synchronous vibration without performing frequency analysis or autocorrelation analysis. For this reason, it is not necessary to once record data sampled simultaneously with the rotation period signal, and it is not necessary to provide a function for performing frequency analysis or autocorrelation analysis. As a result, the cost of the abnormality monitoring device 41 can be reduced, and it can be determined from the data that can be acquired by operating the motor 2 normally whether or not the rotational speed synchronous vibration has increased. It is possible to constantly monitor the occurrence of machine abnormalities.

  Furthermore, by identifying the amplitude of vibration with a period corresponding to n times the number of rotations of the motor 2 in the rotation number synchronous vibration amplitude identification unit 9, the frequency component of vibration excited by an abnormality is the signal of acceleration / deceleration. Even when the frequency component is buried, the frequency component of the signal due to acceleration / deceleration can be removed. For this reason, it is possible to extract a change in the frequency component of vibration excited by an abnormality without using a measuring instrument for vibration measurement, and to suppress a decrease in abnormality diagnosis accuracy.

  In the fifth embodiment described above, the method of providing the rotation speed synchronization vibration increase determination unit 8 in the abnormality monitoring device 41 has been described. However, the rotation speed synchronization vibration increase determination unit 8 is provided separately from the abnormality monitoring device 41. It may be.

  In the above-described embodiment, the disturbance component calculation unit 3 has described the method for calculating the torque disturbance τd included in the motor current command si from the motor current command si and the motor speed vm. A disturbance component included in at least one of the current, the motor acceleration, and the motor speed may be calculated. For example, the disturbance component calculation unit 3 may calculate a torque disturbance included in the motor current from the motor current and the motor speed vm. Alternatively, the disturbance component may be calculated based on the difference between the model speed corresponding to the ideal motor speed and the motor speed. Alternatively, the disturbance component may be calculated based on the difference between the model acceleration corresponding to the ideal motor acceleration and the motor acceleration.

Embodiment 6 FIG.
FIG. 5 is a block diagram showing a schematic configuration of Embodiment 6 of the abnormality monitoring apparatus according to the present invention. 5, the abnormality monitoring device 51 is provided with a disturbance component calculation unit 13 instead of the disturbance component calculation unit 3 of FIG. In addition, in addition to the position / speed control unit 1 and the motor 2, a model speed calculation unit 10 is provided in the rotation system in which the abnormality monitoring device 11 performs abnormality monitoring. Here, the model speed calculation unit 10 can calculate the model speed mv based on the position command sp. The disturbance component calculation unit 13 can calculate the disturbance component d based on the difference between the model speed mv and the motor speed vm.

  When the position command sp is input to the position / speed control unit 1, a torque command st corresponding to the position command sp is generated and sent to the motor 2. When the torque command st is sent to the motor 2, the motor 2 rotates based on the torque command st. Further, the motor speed vm and the motor position pm are detected from the motor 2, and the motor speed vm is sent to the disturbance component calculation unit 13, and the motor position pm is sent to the rotation speed synchronization signal sampling unit 5.

  When the position command sp is input to the model speed calculation unit 10, the model speed mv is calculated based on the position command sp and sent to the disturbance component calculation unit 13.

  When the model speed mv and the motor speed vm are sent to the disturbance component calculation unit 13, the disturbance component d is calculated from the difference between the model speed mv and the motor speed vm, and the disturbance component d is sent to the rotation speed synchronization signal sampling unit 5. Is output.

  Next, when the disturbance component d calculated by the disturbance component calculation unit 13 and the motor position pm detected from the motor 2 are input to the rotation speed synchronization signal sampling unit 5, the motor position pm becomes the motor displacement width sd. The value of the disturbance component d is output to the rotational speed synchronization period bandpass filter 6 every time the step position determined on the basis is exceeded.

  Next, when the value of the disturbance component d sampled by the rotation speed synchronization signal sampling unit 5 is input to the rotation speed synchronization period bandpass filter 6, n of the rotation speed of the motor 2 is calculated from the value of the disturbance component d. Double frequency components are extracted and output to the effective value calculation unit 7.

  When a frequency component that is n times the rotation speed of the motor 2 is input to the effective value calculation unit 7, the absolute value thereof is calculated and further passed through a low-pass filter such as a first-order lag filter, whereby the motor 2 The effective value of the frequency component n times the number of rotations is calculated and output to the rotation number synchronous vibration increase determination unit 8.

  Then, in the rotational speed synchronous vibration increase discriminating unit 8, the effective value of the frequency component n times the rotational speed of the motor 2 is compared with the threshold value, and the effective value of the frequency component n times the rotational speed of the motor 2 is obtained. When the threshold value is exceeded, it is determined that the rotational speed synchronization vibration has increased.

  Thereby, the vibration excited by the abnormality can be extracted without using a dedicated measuring device for measuring the vibration excited when the abnormality occurs in the rotating system such as the motor. For this reason, the cost concerning the control system of a mechanical system can be reduced.

  In addition, it is possible to determine an increase in rotational speed synchronous vibration without performing frequency analysis or autocorrelation analysis. For this reason, it is not necessary to once record data sampled simultaneously with the rotation period signal, and it is not necessary to provide a function for performing frequency analysis or autocorrelation analysis. As a result, the cost of the abnormality monitoring device 51 can be reduced, and it can be determined from the data that can be acquired by operating the motor 2 normally whether or not the rotational speed synchronous vibration has increased. It is possible to constantly monitor the occurrence of machine abnormalities.

  Further, by extracting a frequency component of n times the rotational speed of the motor 2 from the disturbance component d sampled by the rotational speed synchronization signal sampling unit 5, the frequency component of the vibration excited by the abnormality is caused by acceleration / deceleration. Even when the frequency component of the signal is buried, the frequency component of the signal due to acceleration / deceleration can be removed. For this reason, it is possible to extract a change in the frequency component of vibration excited by an abnormality without using a measuring instrument for vibration measurement, and to suppress a decrease in abnormality diagnosis accuracy.

  In the sixth embodiment described above, the method of providing the effective value calculation unit 7 in the rotation synchronization disturbance component extraction unit 4 has been described, but the effective value calculation unit 7 may not be provided. In the sixth embodiment described above, the method of providing the rotation speed synchronization vibration increase determination unit 8 in the abnormality monitoring device 51 has been described. However, the rotation speed synchronization vibration increase determination unit 8 is provided separately from the abnormality monitoring device 51. It may be. In the sixth embodiment described above, the method of providing the model speed calculation unit 10 separately from the abnormality monitoring device 51 has been described. However, the model speed calculation unit 10 may be provided in the abnormality monitoring device 51.

  In the abnormality monitoring device 51 described above, the method of inputting the disturbance component d calculated by the disturbance component calculation unit 13 of FIG. 5 to the rotation synchronization disturbance component extraction unit 4 has been described. However, the disturbance component calculation unit of FIG. The disturbance component d calculated at 13 may be input to the rotation-synchronized disturbance component extraction unit 14 of FIG. 2, or the disturbance component d calculated by the disturbance component calculation unit 13 of FIG. The disturbance component d calculated by the disturbance component calculation unit 13 in FIG. 5 may be input to the rotation synchronization disturbance component extraction unit 34 in FIG. 4. Also good.

  FIG. 6 is a block diagram illustrating a schematic configuration example of the model speed calculation unit 10 of FIG. In FIG. 6, the model speed calculation unit 10 includes subtractors 61 and 63, proportional controllers 62 and 64, and integral controllers 65 and 66. Here, a proportional controller 62 is connected to the subsequent stage of the subtractor 61. A subtracter 63 is connected to the subsequent stage of the proportional controller 62. A proportional controller 64 is connected to the subsequent stage of the subtracter 63. An integral controller 65 is connected to the subsequent stage of the proportional controller 64. An integration controller 66 is connected to the subsequent stage of the integration controller 65. The output of the integration controller 65 is returned to the subtracter 63, and the output of the integration controller 66 is returned to the subtractor 61.

  When the position command sp is input to the subtractor 61, it is subtracted from the model position mp output from the integration controller 66 and output to the proportional controller 62. Then, the output of the subtractor 61 is amplified by the proportional controller 62 and then input to the subtracter 63. Then, the subtracter 63 subtracts the output of the proportional controller 62 from the model speed mv output from the integral controller 65 and outputs the result to the proportional controller 64. Then, the output of the subtracter 63 is amplified by the proportional controller 64, so that the model acceleration ma is generated and input to the integral controller 65. Then, the model acceleration ma is integrated by the integration controller 65 to generate a model speed mv, which is input to the integration controller 66 and input to the disturbance component calculation unit 13 in FIG. Further, the model speed mv is integrated by the integration controller 66, whereby the model position mp is generated.

  In the above-described embodiment, the speed control of the rotating system based on the speed command has been described by taking as an example the case where the abnormality monitoring device is applied to the control device that performs the position control of the rotating system based on the position command sp. The abnormality monitoring device may be applied to the control device that performs the control, or may be applied to the control device that performs torque control (or force control) of the rotating system based on the torque command (or force command). .

  As described above, the abnormality monitoring apparatus according to the present invention is a vibration excited by an abnormality without using a dedicated measuring instrument for measuring the vibration excited when an abnormality occurs in a rotating system such as a motor. To the method of diagnosing abnormalities in rotating systems such as industrial robots, mounting machines, injection molding machines, machine tools, printing machines, semiconductor manufacturing equipment, packaging machines, elevators, air conditioners, and in-vehicle devices Is suitable.

DESCRIPTION OF SYMBOLS 1 Position / speed control part 2 Motor 3, 13 Disturbance component calculation part 4, 14, 24, 34 Rotation synchronous disturbance component extraction part 5 Rotation speed synchronous signal sampling part 6 Rotation speed synchronous period bandpass filter 7 Effective value calculation part 8 Rotation Number-synchronous vibration increase determination unit 9 Rotation-synchronous vibration amplitude identification unit 10 Model speed calculation unit 11, 21, 31, 41, 51 Abnormality monitoring device 61, 63 Subtractor 62, 64 Proportional controller 65, 66 Integration controller

Claims (10)

A disturbance component calculation unit that calculates a disturbance component included in at least one of the motor current command, the motor current, the motor acceleration, and the motor speed;
An abnormality monitoring apparatus comprising: a rotation synchronization disturbance component extraction unit that extracts a disturbance component having a period synchronized with a rotation speed of a motor from the disturbance component calculated by the disturbance component calculation unit.   The abnormality monitoring device according to claim 1, wherein the disturbance component calculation unit calculates a torque disturbance as the disturbance component from the motor current command and the motor speed.   The abnormality monitoring apparatus according to claim 1, wherein the disturbance component calculation unit calculates a torque disturbance as the disturbance component from the motor current and the motor speed.   The abnormality monitoring device according to claim 1, wherein the disturbance component calculation unit calculates the disturbance component based on a difference between a model speed and the motor speed.   The abnormality monitoring device according to claim 1, wherein the disturbance component calculation unit calculates the disturbance component based on a difference between a model acceleration and the motor acceleration. The rotation synchronization disturbance component extraction unit
A rotational speed synchronization signal sampling unit that samples the disturbance component calculated by the disturbance component calculation unit according to a predetermined motor displacement width;
A rotation speed synchronization period band-pass filter that extracts a frequency component that is n (n is a positive integer) times the rotation speed of the motor from the disturbance component sampled by the rotation speed synchronization signal sampling unit. The abnormality monitoring apparatus according to any one of claims 1 to 5. The rotation synchronization disturbance component extraction unit
From the disturbance component calculated by the disturbance component calculation unit, the amplitude of vibration having a period corresponding to n (n is a positive integer) times the rotation speed of the motor is identified, and the period synchronized with the rotation speed of the motor The abnormality monitoring apparatus according to any one of claims 1 to 6, further comprising: a rotation speed synchronization vibration amplitude identification unit that outputs the magnitude of a disturbance component of the rotation number. The rotation synchronization disturbance component extraction unit
From the disturbance component calculated by the disturbance component calculation unit, the amplitude of vibration having a period corresponding to na (na is a positive integer) times the rotation speed of the motor and nb (nb is na) of the rotation speed of the motor. A rotation speed synchronization vibration amplitude identification unit is provided that identifies the amplitude of vibration having a period corresponding to a different positive integer) and outputs the amplitude as a disturbance component having a period synchronized with the rotation speed of the motor. The abnormality monitoring device according to any one of claims 1 to 6. The rotation synchronization disturbance component extraction unit
9. The abnormality monitoring device according to claim 6, further comprising an effective value calculation unit that calculates an effective value of a magnitude of a disturbance component having a period synchronized with the rotation speed of the motor.   2. The rotation-synchronized vibration increase determining unit that determines that the rotation-synchronized vibration has increased when an output value from the rotation-synchronized disturbance component extracting unit exceeds a threshold value. 10. The abnormality monitoring apparatus according to any one of 9 above.

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