Motor control apparatus of linear motor, motor control method of linear motor, and control program of linear motor

Patent metadata

Field	Value
Publication number	US-9360851-B2
Application number	US-201113993005-A
Country	US
Kind code	B2
Filing date	Dec 20, 2011
Priority date	Dec 28, 2010
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A motor control apparatus is provided, including: a command generation unit that generates an acceleration pattern time-sequentially indicating an acceleration command value to be used during movement of a target object to a target position using a motor, makes a change to the generated acceleration pattern to prolong a period of reducing a driving speed of the motor in accordance with response characteristics of the motor, and outputs a position command value from the changed acceleration pattern; and a control unit that drives the motor using a proportional control with respect to a position deviation between the position command value output from the command generation unit and the target position of the target object, and changes a proportional control gain in the proportional control to a value larger than a current value when the target object reaches the vicinity of the target position.

First claim

The invention claimed is:

1. A motor control apparatus, comprising:
a computer system having one or more processors;
a processor based command generation unit that generates an acceleration pattern time-sequentially indicating an acceleration command value to be used during movement of a target object to a target position using a motor, makes a change to the generated acceleration pattern to prolong a period of reducing a driving speed of the motor in accordance with response characteristics of the motor, and outputs a position command value from the changed acceleration pattern; and
a processor based control unit that drives the motor using a proportional control with respect to a position deviation between the position command value output from the command generation unit and the target position of the target object, and changes a proportional control gain in the proportional control to a value larger than a current value when the target object reaches the vicinity of the target position, wherein:
the command generation unit makes a change to the generated acceleration pattern to prolong the period of reducing the driving speed of the motor by a time longer than a response delay of the motor and has a region in which a speed calculated in the command generation unit becomes a negative value, and
the control unit includes,
a processor based position detection unit that detects a position of the target object, and
a processor based switching control unit that drives the motor when a difference between the position detected by the position detection unit and the target position is smaller than a threshold value set in advance.

2. The motor control apparatus according to claim 1 ,
wherein the control unit includes,
a processor based movement control unit that calculates a first current command value with respect to the motor using a difference between the position command value calculated by the command generation unit and the position of the target object, and a first proportional control gain, and drives the motor,
a processor based settling control unit that calculates a second current command value with respect to the motor using a difference between the target position and the position of the target object, and a second proportional control gain having a value larger than the first proportional control gain, and drives the motor, and
the switching control unit that drives the motor using the movement control unit, and drives the motor using the settling control unit.

3. The motor control apparatus according to claim 2 ,
wherein the movement control unit includes,
a processor based first position deviation calculation unit that calculates a first position deviation that is a difference between the position command value generated by the command generation unit and the position of the target object,
a processor based first speed command calculation unit that calculates a first speed command by multiplying the first position deviation by the first proportional control gain,
a processor based first speed deviation calculation unit that calculates a first speed deviation that is a difference between the first speed command calculated by the first speed command calculation unit, and a movement speed, and
a processor based first current command calculation unit that calculates a first current command using the proportional control and an integral control with respect to the first speed deviation, and
wherein the settling control unit includes,
a processor based second position deviation calculation unit that calculates a second position deviation that is a difference between the target position and the position of the target object,
a processor based second speed command calculation unit that calculates a second speed command by multiplying the second position deviation by the second proportional control gain,
a processor based second speed deviation calculation unit that calculates a second speed deviation that is a difference between the second speed command calculated by the second speed command calculation unit, and the movement speed, and
a processor based second current command calculation unit that calculates a second current command using the proportional control and the integral control with respect to the second speed deviation.

4. The motor control apparatus according to claim 1 ,
wherein the control unit includes,
a processor based speed detection unit that detects a movement speed of the target object,
a processor based movement control unit that calculates a first current command value with respect to the motor using a difference between the position command value calculated by the command generation unit and the position of the target object, and a first proportional control gain, and drives the motor,
a processor based settling control unit that calculates a second current command value with respect to the motor using a difference between the target position and the position of the target object, and a second proportional control gain having a value larger than the first proportional control gain, and drives the motor, and
the switching control unit that drives the motor using the movement control unit, and drives the motor using the settling control unit when the movement speed is lower than a threshold value set in advance in a period of reducing the movement speed.

5. The motor control apparatus according to claim 4 , further comprising:
a processor based stopping control unit that calculates a current command value with respect to the motor using a difference between a position of the target object when the driving speed of the motor is lower than the threshold value, and the position of the target object, and a third proportional control gain having a value larger than the first proportional control gain, and drives the motor,
wherein the switching control unit drives the motor using the stopping control unit when the movement speed is equal to or lower than a threshold value set in advance in a period of reducing the driving speed of the motor, and
the switching control unit drives the motor using the settling control unit after the passage of a response time according to the first proportional control gain.

6. The motor control apparatus according to claim 5 ,
wherein the movement control unit includes,
a processor based first position deviation calculation unit that calculates a first position deviation that is a difference between the position command value generated by the command generation unit and the position of the target object,
a processor based first speed command calculation unit that calculates a first speed command by multiplying the first position deviation by the first proportional control gain,
a processor based first speed deviation calculation unit that calculates a first speed deviation that is a difference between the first speed command calculated by the first speed command calculation unit, and a movement speed, and
a processor based first current command calculation unit that calculates a first current command using the proportional control and an integral control with respect to the first speed deviation,
wherein the settling control unit includes,
a processor based second position deviation calculation unit that calculates a second position deviation that is a difference between the target position and the position of the target object,
a processor based second speed command calculation unit that calculates a second speed command by multiplying the second position deviation by the second proportional control gain,
a processor based second speed deviation calculation unit that calculates a second speed deviation that is a difference between the second speed command calculated by the second speed command calcul

Assignees

• Futami Shigeru
• Thk Co Ltd

Inventors

• Futami Shigeru

Classifications

• G05B19/02 Primary

  electric · CPC title

• G05B19/18

  Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of program data in numerical form (G05B19/418 takes precedence) · CPC title

• H02P23/20

  Controlling the acceleration or deceleration · CPC title

• H02P23/22

  Controlling the speed digitally using a reference oscillator, a speed proportional pulse rate feedback and a digital comparator · CPC title

• H02P25/06 Primary

  Linear motors · CPC title