Motor control device

Patent metadata

Field	Value
Publication number	US-9306483-B2
Application number	US-201414284900-A
Country	US
Kind code	B2
Filing date	May 22, 2014
Priority date	May 30, 2013
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A motor control device controls a speed of a motor. The motor control device includes: a target speed generating unit that generates a target speed; a speed detecting unit that detects a current speed of the motor; a speed comparing unit that compares the target speed with the current speed to calculate a speed error; an error amplifying unit that amplifies the speed error and outputs a control value; and a motor driving unit that drives the motor in accordance with the control value. The error amplifying unit has proportional integral characteristics by which the speed error is amplified with a proportional gain and integration is performed in a lower frequency range than an integral corner frequency, increases the proportional gain as the current speed is higher, and shifts the integral corner frequency to a lower frequency as the current speed is higher.

First claim

What is claimed is:

1. A motor control device that controls a speed of a motor, the motor control device comprising:
a target speed generating unit that generates a target speed;
a speed detecting unit that detects a current speed of the motor;
a speed comparing unit that compares the target speed with the current speed to calculate a speed error;
an error amplifying unit that amplifies the speed error and outputs a control value; and
a motor driving unit that drives the motor in accordance with the control value, wherein
the error amplifying unit has proportional integral characteristics by which the speed error is amplified with a proportional gain and integration is performed in a lower frequency range than an integral corner frequency, increases the proportional gain as the current speed is higher, and shifts the integral corner frequency to a lower frequency as the current speed is higher.

2. The motor control device according to claim 1 , wherein the error amplifying unit further has proportional differential characteristics by which differentiation is performed in a higher frequency range than a differential corner frequency, increases the proportional gain as the current speed is higher, and shifts the differential corner frequency to a higher frequency as the current speed is higher.

3. The motor control device according to claim 1 , further comprising a gain variable unit that linearly increases the proportional gain with a certain inclination in accordance with the current speed, with a value when the current speed is zero as a reference.

4. The motor control device according to claim 1 , further comprising a gain variable unit that linearly increases the proportional gain with a certain inclination in accordance with the current speed, with a value when the current speed is a certain value as a reference.

5. The motor control device according to claim 3 , wherein the inclination is determined depending on a change rate of a mechanical time constant with respect to a rotation speed of the motor.

6. The motor control device according to claim 4 , wherein the inclination is determined depending on a change rate of a mechanical time constant with respect to a rotation speed of the motor.

7. A motor control device comprising:
the motor control device according to claim 3 for each of a plurality of motors, wherein
the gain variable unit uses the inclination determined for each model of the motors.

Assignees

• Suzuki Haruyuki
• Ricoh Co Ltd

Inventors

• Suzuki Haruyuki

Classifications

• H02P7/28 Primary

  using semiconductor devices · CPC title

• H02P6/16

  Circuit arrangements for detecting position · CPC title

• H02P23/0004

  Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control · CPC title

• G03G15/5008 Primary

  Driving control for rotary photosensitive medium, e.g. speed control, stop position control · CPC title