Motor control device and belt tension state detection device

Patent metadata

Field	Value
Publication number	US-11828665-B2
Application number	US-201917285099-A
Country	US
Kind code	B2
Filing date	Oct 9, 2019
Priority date	Oct 31, 2018
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A motor control device is capable of detecting, through use of a small-sized or simple device, a state of belt tension in a belt transmitting torque of an electric motor in a motor system. A motor control device includes a drive controller that outputs a drive command signal that drives an electric motor of a motor system, and a belt tension state value calculation unit that outputs a belt tension state value on a basis of a drive detection signal detecting an angle of rotation, an angular velocity, or an angular acceleration in the motor system. The belt tension state value indicates a state of belt tension in a belt. The motor system includes a load machine, a driven pulley mechanically connected to the load machine, the belt wound onto the driven pulley, a drive pulley that the belt is wound onto, and the electric motor mechanically connected to the drive pulley.

First claim

The invention claimed is:

1. A motor control device comprising:
a drive controller to output a drive command signal that drives an electric motor of a motor system, the motor system including a belt driver defined by a drive pulley, a driven pulley, and a belt wound on the driven pulley and the drive pulley, a load machine mechanically connected to the driven pulley, and the electric motor mechanically connected to the drive pulley; and
a belt tension state value calculator to output a belt tension state value on a basis of a ratio of frequency characteristics of a drive detection signal to frequency characteristics of any one of the drive command signal, a detection value of current in the electric motor, and a detection value of torque of the electric motor, a drive detection signal detecting one of an angle of rotation, an angular velocity, and an angular acceleration in the motor system, the belt tension state value indicating a state of belt tension in the belt.

2. The motor control device according to claim 1 , wherein the belt tension state value calculator outputs the belt tension state value on a basis of a result of detection of a state of torsional vibration of the belt driver.

3. The motor control device according to claim 1 , further comprising
an operating command generator to output an operating command signal, the operating command signal being a command for operation of an electric motor and serving as a target in generation of the drive command signal, wherein
on a basis of the operating command signal and the drive detection signal, the drive controller outputs the drive command signal that causes the electric motor to follow the operating command signal.

4. The motor control device according to claim 1 , further comprising a belt tension anomaly determiner to compare the belt tension state value and a predetermined reference value and to output, on a basis of a result of the comparison, a belt tension anomaly determination value indicating whether a state of belt tension in the belt is normal or anomalous.

5. The motor control device according to claim 4 , further comprising a machine learning device including:
a state observer to observe a state variable including the belt tension state value and the belt tension anomaly determination value; and
a learner to learn the reference value in accordance with a training data set created on a basis of the state variable.

6. The motor control device according to claim 5 , wherein
the learner includes:
a reward calculator to calculate a reward on a basis of the reference value and the state variable; and
an action-value function updater to update, on a basis of the state variable and the reward, an action-value function for calculation of the reference value.

7. The motor control device according to claim 6 , wherein
the machine learning device also includes
a decision-maker to determine the reference value on a basis of the action-value function.

8. The motor control device according to claim 1 , wherein the drive controller outputs the drive command signal on a basis of first mechanical specifications stored in and output from a first mechanical specifications storage, the first mechanical specifications being relevant to a state of torsional vibration of the belt driver.

9. The motor control device according to claim 1 , wherein the belt tension state value calculator performs first signal processing on the drive detection signal on a basis of second mechanical specifications stored in and output from a second mechanical specifications storage, the second mechanical specifications being relevant to a state of torsional vibration of the belt driver, the first signal processing including one of filtering in a frequency domain and data sampling, and the belt tension state value calculator unit outputs the belt tension state value on a basis of a signal obtained as a result of the first signal processing performed on the drive detection signal.

10. The motor control device according to claim 1 , wherein the drive controller outputs the drive command signal on a basis of a first belt tension state value memory output from a first belt tension state value storage pre-storing the belt tension state value as the first belt tension state value memory.

11. The motor control device according to claim 1 , wherein the belt tension state value calculator performs second signal processing on the drive detection signal on a basis of a second belt tension state value memory output from a second belt tension state value storage pre-storing the belt tension state value as the second belt tension state value memory, the second signal processing including one of filtering in a frequency domain and data sampling, and the belt tension state value calculator outputs the belt tension state value on a basis of a signal obtained as a result of the second signal processing performed on the drive detection signal.

12. A belt tension state detection device comprising a belt tension state value calculator to output a belt tension state value on a basis of a ratio of frequency characteristics of a drive detection signal to frequency characteristics of any one of a drive command signal, a detection value of current in an electric motor, and a detection value of torque of the electric motor, a drive detection signal detecting one of an angle of rotation, an angular velocity, and an angular acceleration in a motor system, the belt tension state value indicating a state of belt tension in a belt, the motor system including a load machine, a driven pulley mechanically connected to the load machine, the belt wound on the driven pulley, a drive pulley having the belt wound thereon, and an electric motor that is mechanically connected to the drive pulley and is driven by a drive command signal output from a drive controller.

Assignees

• Mitsubishi Electric Corp

Inventors

• Sekiguchi Hiroyuki
• Takano Naoto

Classifications

• G01L5/10 Primary

  using electrical means · CPC title

• F16H7/02 Primary

  with belts; with V-belts · CPC title

• H02P29/00

  Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors (arrangements for starting electric motors H02P1/00; arrangements for stopping or slowing electric motors H02P3/00; control of motors that can be connected to two or more different electric power supplies H02P4/00; regulating or controlling the speed or torque of two or more electric motors H02P5/00; vector control H02P21/00) · CPC title

• F16H7/00

  Gearings for conveying rotary motion by endless flexible members (specific for conveying rotary motion with variable gear ratio or for reversing rotary motion F16H9/00) · CPC title

• H02P21/13

  Observer control, e.g. using Luenberger observers or Kalman filters · CPC title