Motor control device and image forming apparatus including the same

Patent metadata

Field	Value
Publication number	US-9893675-B2
Application number	US-201615009021-A
Country	US
Kind code	B2
Filing date	Jan 28, 2016
Priority date	Jan 30, 2015
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

In a device for controlling a motor mounted on a system with different operation modes, a controller unit calculates an input value for the motor based on an output value of the motor and a target value depending on operation modes of the system, and instructs a driver circuit of the motor to apply the input value to the motor. An estimation unit estimates an amount of rise in temperature of the motor by applying the input value for the motor to a thermal model of the motor. A notification unit compares a value estimated by the estimation unit with a threshold value. When the estimated value exceeds the threshold value, the notification unit sends a request for change of operation mode to the system.

First claim

What is claimed is:

1. A device for controlling a motor mounted on a system with different operation modes, comprising:
a controller unit configured to calculate an input value for the motor based on an output value of the motor and a target value depending on operation modes of the system, and to instruct a driver circuit of the motor to apply the input value to the motor;
an estimation unit configured to estimate an amount of rise in temperature of the motor by applying the input value for the motor to a thermal model of the motor;
a notification unit configured to compare a value estimated by the estimation unit with a threshold value, and when the estimated value exceeds the threshold value, to send a request for change of operation mode to the system,
a detector unit configured to detect a rotation rate of the motor to be used as the output value of the motor, and
a rate control unit configured to calculate the width of a pulse from the difference in rotation rate of the motor between a value detected by the detector unit and the target value depending on operation modes of the system, and to assign the width of the pulse as the input value for the motor, the pulse being to be applied to the motor by the driver circuit of the motor.

2. The device according to claim 1 , wherein
the estimation unit includes:
a measuring unit configured to measure a power loss of the motor from a pulse width calculated by the rate control unit; and
a low pass filter configured to integrate power losses of the motor measured by the measuring unit by using the thermal model of the motor to estimate the amount of rise in temperature of the motor.

3. The device according to claim 1 , wherein
the estimation unit includes a low pass filter configured to integrate pulse widths calculated by the rate control unit by using the thermal model of the motor to estimate the amount of rise in temperature of the motor.

4. The device according to claim 1 , wherein
the estimation unit updates estimation values at longer time intervals than the controller unit updates input values for the motor.

5. The device according to claim 1 , wherein
the estimation unit is equipped with two types of the thermal model of the motor, a heating model and a cooling model, and uses the heating model when the input value of the motor or the output value of the motor indicates driving of the motor, and uses the cooling model when the input value of the motor or the output value of the motor indicates stop of the motor.

6. The device according to claim 1 , wherein
the operation modes of the system include two or more modes differing in average power loss of the motor; and
the notification unit arranges an order in which the system should change operation modes to reduce the average power loss of the motor stepwise, and instructs the system to change operation modes in the order by sending requests for change of operation mode to the system.

7. An image forming apparatus comprising:
a main controller unit configured to assign an operation mode depending on a job received from a user;
two or more motors configured to be used in transferring a sheet and forming the image on the sheet;
two or more driver circuits configured to supply power to their respective motors of the two or more motors; and
a motor control unit including:
a controller unit configured to calculate input values for the two or more motors based on output values of the two or more motors and target values depending on operation modes of the image forming apparatus, and to instruct the two or more driver circuits to apply the input values to their respective motors;
an estimation unit configured to estimate amounts of rise in temperature of the two or more motors by applying the input values for the two or more motors to a thermal model of the two or more motors; and
a notification unit configured to compare a value estimated by the estimation unit with a threshold value, and when the estimated value exceeds the threshold value, to send a request for change of operation mode to the main controller unit.

8. The image forming apparatus according to claim 7 , wherein
the main controller unit, in response to the request for change of operation mode from the notification unit, selects an operation mode to be changed depending on the length of time before a job currently processed will be finished.

9. The image forming apparatus according to claim 7 , wherein
the main controller unit, in response to the request for change of operation mode from the notification unit, changes operation modes to enlarge the intervals of feeding sheets.

10. The image forming apparatus according to claim 7 , wherein
the main controller unit, in response to the request for change of operation mode from the notification unit, changes operation modes to reduce the rate of feeding a sheet.

11. The image forming apparatus according to claim 7 , wherein
the main controller unit, in response to the request for change of operation mode from the notification unit, changes operation modes to keep one motor of the two or more motors waiting or reduce the average driving time of the one motor when, for the one motor, the value estimated by the estimation unit exceeds the threshold value.

12. The image forming apparatus according to claim 7 , further comprising
a fan configured to cool at least one portion of the image forming apparatus, wherein
the main controller unit, in response to the request for change of operation mode from the notification unit, changes operation modes to change a rotation rate of the fan.

Assignees

• Konica Minolta Inc

Inventors

• Tachibana Yuta
• Sakai Katsuhide
• Koide Yasuhiro
• Tatsumoto Yuhei

Classifications

• H02P29/032

  Preventing damage to the motor, e.g. setting individual current limits for different drive conditions · CPC title

• G03G15/80

  Details relating to power supplies, circuits boards, electrical connections · CPC title

• H02P29/60 Primary

  Controlling or determining the temperature of the motor or of the drive (H02P29/02 takes precedence) · CPC title

• G03G15/5004

  Power supply control, e.g. power-saving mode, automatic power turn-off · CPC title