Abnormality diagnosing device and abnormality diagnosing method

Patent metadata

Field	Value
Publication number	US-10444288-B2
Application number	US-201815968004-A
Country	US
Kind code	B2
Filing date	May 1, 2018
Priority date	May 2, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

An abnormality diagnosing device diagnoses a driving abnormality of a single motor driven by a plurality of motor driving devices. The plurality of motor driving devices calculate a plurality of voltage command values based on a speed command, and voltages are applied to a plurality of windings possessed by the motor based on the plurality of calculated voltage command values, thereby driving the motor. The abnormality diagnosing device is equipped with a command value difference calculating unit for calculating a difference between the plurality of voltage command values calculated by the plurality of motor driving devices, and a determination unit for determining the presence of an abnormality, when an absolute value of the difference calculated exceeds a first threshold value continuously for a predetermined time period.

First claim

What is claimed is:

1. An abnormality diagnosing device adapted to diagnose a driving abnormality of a single motor that is driven by a plurality of motor driving devices;
wherein the plurality of motor driving devices calculate a plurality of voltage command values on a basis of a position command or a speed command commanded from a numerical controller, and based on the plurality of calculated voltage command values, voltages are applied to a plurality of windings possessed by the motor, thereby driving the motor;
the abnormality diagnosing device comprising:
a command value difference calculating unit adapted to calculate a difference between the plurality of voltage command values calculated by the plurality of motor driving devices; and
a determination unit adapted to determine a presence of an abnormality, in an event that an absolute value of the difference calculated by the command value difference calculating unit exceeds a first threshold value continuously for a predetermined time period.

2. The abnormality diagnosing device according to claim 1 , further comprising:
a rotational speed acquisition unit adapted to acquire a rotational speed value of the motor;
wherein the determination unit determines that there is an abnormality, if an absolute value of the rotational speed value exceeds a predetermined value, and the absolute value of the difference exceeds the first threshold value continuously for the predetermined time period.

3. The abnormality diagnosing device according to claim 1 , wherein the determination unit determines that there is an abnormality, if an absolute value of at least one from among the plurality of voltage command values exceeds a second threshold value, and the absolute value of the difference exceeds the first threshold value continuously for the predetermined time period.

4. The abnormality diagnosing device according to claim 1 , further comprising a notification unit adapted to issue a notifying alarm if the presence of an abnormality is determined by the determination unit.

5. The abnormality diagnosing device according to claim 1 , further comprising a driving stop unit adapted to stop driving of the motor by the plurality of motor driving devices if the presence of an abnormality is determined by the determination unit.

6. The abnormality diagnosing device according to claim 1 , wherein the abnormality diagnosing device is provided in the motor driving device.

7. An abnormality diagnosing method for diagnosing a driving abnormality of a single motor that is driven by a plurality of motor driving devices;
wherein the plurality of motor driving devices calculate a plurality of voltage command values on a basis of a position command or a speed command commanded from a numerical controller, and based on the plurality of calculated voltage command values, voltages are applied to a plurality of windings possessed by the motor, thereby driving the motor;
the abnormality diagnosing method comprising:
a command value difference calculating step of calculating a difference between the plurality of voltage command values calculated by the plurality of motor driving devices; and
a determining step of determining a presence of an abnormality, in an event that an absolute value of the difference calculated by the command value difference calculating step exceeds a first threshold value continuously for a predetermined time period.

8. The abnormality diagnosing method according to claim 7 , further comprising:
a rotational speed acquiring step of acquiring a rotational speed value of the motor;
wherein the determining step determines that there is an abnormality, if an absolute value of the rotational speed value exceeds a predetermined value, and the absolute value of the difference exceeds the first threshold value continuously for the predetermined time period.

9. The abnormality diagnosing method according to claim 7 , wherein the determining step determines that there is an abnormality, if an absolute value of at least one from among the plurality of voltage command values exceeds a second threshold value, and the absolute value of the difference exceeds the first threshold value continuously for the predetermined time period.

10. The abnormality diagnosing method according to claim 7 , further comprising a notifying step of issuing a notifying alarm if the presence of an abnormality is determined by the determining step.

11. The abnormality diagnosing method according to claim 7 , further comprising a driving stop step of stopping driving of the motor by the plurality of motor driving devices if the presence of an abnormality is determined by the determining step.

Assignees

• Fanuc Corp

Inventors

• Morita Yuuki
• Takahashi Kenji
• Okita Tadashi

Classifications

• H02H1/00

  Details of emergency protective circuit arrangements · CPC title

• H02P29/0241

  the fault being an overvoltage · CPC title

• H02P29/10

  for preventing overspeed or under speed · CPC title

• H02P3/18

  for stopping or slowing an AC motor · CPC title

• H02H7/0844

  Fail safe control, e.g. by comparing control signal and controlled current, isolating motor on commutation error · CPC title