Motor control apparatus for controlling operation of mover of motor

• US 7,026,779 B2
• Filed: 09/27/2004
• Issued: 04/11/2006
• Est. Priority Date: 09/29/2003
• Status: Expired due to Fees

• Current Assignee: Okuma Corporation
• Original Assignee: Okuma Corporation
• Inventors: Eba, Koji
• Primary Examiner(s): Ip, Paul
• Application Number:
  US10/950,888
• Publication Number:
  US 20050067996A1
• Time in Patent Office: 561 Days
• Field of Search: 318560-563, 318567-569, 318607-618, 318628-632
• US Class Current: 318/609
• CPC Class Codes: G05B 19/19 characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path
• CPC Class Codes: G05B 2219/42062 Position and speed and current
• CPC Class Codes: H02P 21/05 specially adapted for damping motor oscillations, e.g. for reducing hunting

Abstract

A motor control apparatus of the present invention comprises a velocity detector for detecting a rotation velocity of a mover of a motor, a position detector for detecting a position of the mover, a differentiator for performing time differentiation with respect to the position detected by the position detector to obtain a velocity calculation value, a feedback signal generating circuit for generating a feedback signal including the velocity detection value obtained by the velocity detector as a high frequency component and the velocity calculation value obtained by the differentiator as a low frequency component, and a linear amplifier and an integrating amplifier for performing PI control, the linear amplifier and the integrating amplifier performing linear amplification and integrating amplification of a difference between the velocity instruction and the feedback signal, respectively.

Claims

1. A motor control apparatus for controlling the operation of a mover of a motor in accordance with a velocity instruction, the apparatus comprising:

a velocity detector for detecting a rotation velocity of the mover;

a position detector for detecting a position of the mover;

a differentiator for performing time differentiation with respect to the position detected by the position detector to obtain a velocity calculation value;

a feedback signal generating circuit for generating a feedback signal including the velocity detection value obtained by the velocity detector as a high frequency component and the velocity calculation value obtained by the differentiator as a low frequency

component; and

a linear amplifier and an integrating amplifier for performing PI control, the linear amplifier and the integrating amplifier performing linear amplification and integrating amplification of a difference between the velocity instruction and the feedback signal, respectively.

2. A motor control apparatus according to claim 1, comprising a velocity detection value correction section which has information concerning an offset error and corrects an offset error contained in the velocity detection value detected by the velocity detector based on the information.

3. A motor control apparatus according to claim 2, comprising a correction data generation section for generating data of the offset error or the correction table, based on a difference between the velocity detection value from the velocity detector and the velocity calculation value obtained by time differentiation of the rotation position detected by the position detector.

4. A motor control apparatus according to claim 1, comprising a velocity detection value correction section which has a correction table storing gain error information corresponding to the position information, captures the position detection value from the position detector, reads out the corresponding gain error information with reference to the correction table, and corrects a gain error contained in the velocity detection value obtained by the velocity detector based on the gain error information.

5. A motor control apparatus according to claim 1, wherein,

the velocity detector includes a magnet fixed on one of a mover and a stator and a plurality of windings fixed to the other one of the mover and the stator for generating a plurality of induced voltages having different phases depending on the change of flux linkage of the magnet,

the motor control apparatus further including correction means which has a flux linkage table storing information on the number of flux linkages corresponding to the position information, captures the position detection value from the position detector, obtains information of the number of flux linkages corresponding to the position detection value with reference to the flux linkage table, and corrects the induced voltage generated by the plurality of windings based on the information of the number of flux linkages.

6. A motor control apparatus according to claim 5, comprising a flux linkage table calibration section for calibrating data of the flux linkage table based on the induced voltage value of each of the windings.

7. A motor control apparatus for controlling the operation of a mover of a motor in accordance with a velocity instruction, the apparatus comprising:

a velocity detector for detecting a rotation velocity of the mover;

a position detector for detecting a position of the mover;

a differentiator for performing time differentiation with respect to the position detected by the position detector to obtain a velocity calculation value; and

a linear amplifier and an integrating amplifier for performing PI control, the linear amplifier performing linear amplification of a difference between the velocity instruction and the velocity detection value obtained by the velocity detector, and the integrating amplifier performing integrating amplification of a difference between the velocity instruction and the velocity calculation value obtained by the differentiator.