Servomotor driving controller

• US 7,084,596 B2
• Filed: 01/30/2004
• Issued: 08/01/2006
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Zhiwei, Tang, Iwashita, Yasusuke, Kawamura, Hiroyuki
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US10/767,058
• Publication Number:
  US 20040183495A1
• Time in Patent Office: 914 Days
• Field of Search: 318/568.13, 318/632, 318/638, 318/560, 318/609, 318/610, 318/561, 318/625, 369/44.34, 369/47.42, 369/47.44, 369/53.14, 700/29, 700/69
• US Class Current: 318/638
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/39191 Compensation for errors in mechanical components
• CPC Class Codes: G05B 2219/41084 Compensation speed axis with changing, reversing direction, quadrant circle
• CPC Class Codes: G05B 2219/42129 Teach, learn position table, model, for each reference a motor control output

Abstract

A servomotor driving controller capable of highly accurate machining, which prevents a quadrant projection upon change in the quadrant where machining is made. After the position deviation converges to zero by means of learning control, the velocity command or a difference between the velocity command and the commanded velocity which is the derivative of the position command is stored as velocity correction data. Until a predetermined time period elapses from when the sign of the position command is reversed, an amount of correction for each period of position loop processing is determined based on the correction data, and used to correct the velocity command.

Claims

1. A servomotor driving controller for drivingly controlling a servomotor, comprising:

velocity command determining means for determining and outputting a velocity command at every predetermined period based on a deviation between a position command from a host controller and a position feedback signal from a position detector; and

correction means for correcting the velocity command outputted from said velocity command determining means based on correction data for a predetermined time period,

wherein the correction data are predetermined by performing a learning control based on position deviations for predetermined periods in repeatedly driving a driven member in a predetermined region by the servomotor.

2. A servomotor driving controller according to claim 1, wherein the correction data are determined by performing the learning control based on position deviations for predetermined periods obtained in repeatedly driving a driven member in a predetermined region by the servomotor to obtain a velocity command, and by subtracting a differentiated value of the position command from the velocity command obtained by the learning control.

3. A servomotor driving controller according to claim 1, wherein the correction data are determined by analyzing correction data obtained by the learning control.

4. A servomotor driving controller according to claim 1, further comprising detecting means for detecting reversal of the position command,

wherein the correction data are predetermined for the predetermined time period from time of reversal of the position command, and said correction means corrects the velocity command based on the correction data for the predetermined time period from the reversal of the position command detected by said detecting means.

5. A servomotor driving controller according to claim 1, further comprising a computer for preparing the correction data connected therewith.

6. A servomotor driving controller for drivingly controlling a servomotor, comprising:

velocity command determining means for determining and outputting a velocity command at every predetermined period based on a deviation between a position command from a host controller and a position feedback signal from a position detector; and

correction means for correcting the velocity command outputted from said velocity command determining means based on correction data for a predetermined time period,

wherein the correction data for the predetermined time period from reversal of the position command are predetermined based on an output from an inverse function of an open-loop transfer function for generating the torque command from the velocity command when a model of friction acting on a controlled object is inputted.

7. A servomotor driving controller according to claim 6, wherein the correction data are determined by filtering the output from the inverse function.

8. A servomotor driving controller according to claim 6, wherein the correction data are advanced by a delay time of the filtering to thereby compensating for the delay time.

9. A servomotor driving controller for drivingly controlling a servomotor, comprising:

torque command determining means for determining and outputting a torque command at every predetermined period based on a deviation between a velocity command and a velocity feedback signal from a velocity detector, the velocity command being obtained based on a deviation between a position command from a host controller and a position feedback signal from a position detector; and

correction means for correcting the torque command outputted from said torque command determining means based on correction data for a predetermined time period,

wherein the correction data are predetermined using learning control based on position deviations for predetermined periods in repeatedly driving a driven member in a predetermined region by the servomotor.

10. A servomotor driving controller according to claim 9, wherein the correction data are determined by analyzing correction data obtained by the learning control.

11. A servomotor driving controller according to claim 9, further comprising a computer for preparing the correction data connected therewith.

12. A servomotor driving controller for drivingly controlling a servomotor, comprising:

torque command determining means for determining and outputting a torque command at every predetermined period based on a deviation between a velocity command and a velocity feedback signal from a velocity detector, the velocity command being obtained based on a deviation between a position command from a host controller and a position feedback signal from a position detector; and

correction means for correcting the torque command outputted from said torque command determining means based on correction data for a predetermined time period,

wherein the correction data are predetermined using learning control, the correction data being determined by performing the learning control based on position deviations for predetermined periods obtained in repeatedly driving a driven member in a predetermined region by the servomotor to obtain a torque command, and by subtracting a second-order differentiated value of the position command from the torque command obtained by the learning control.

13. A servomotor driving controller for drivingly controlling a servomotor, comprising:

torque command determining means for determining and outputting a torque command at every predetermined period based on a deviation between a velocity command and a velocity feedback signal from a velocity detector, the velocity command being obtained based on a deviation between a position command from a host controller and a position feedback signal from a position detector;

correction means for correcting the torque command outputted from said torque command determining means based on correction data for a predetermined time period; and

detecting means for detecting reversal of the position command,

wherein the correction data are predetermined for the predetermined time period from time of reversal of the position command, and said correction means corrects the torque command based on the correction data for the predetermined time period from the reversal of the position command detected by said detecting means.