Position control device, measuring device and machining device

• US 7,319,909 B2
• Filed: 01/17/2006
• Issued: 01/15/2008
• Est. Priority Date: 01/17/2005
• Status: Active Grant

• Current Assignee: Mitutoyo Corporation
• Original Assignee: Mitutoyo Corporation
• Inventors: Ishikawa, Nobuhiro
• Primary Examiner(s): Pham; Thomas K.
• Application Number:
  US11/333,409
• Publication Number:
  US 20060161274A1
• Time in Patent Office: 728 Days
• Field of Search: 700/28
• US Class Current: 700/28
• 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: G05B 2219/42091 Loop combinations, add a second loop, cascade control

Abstract

In a quadruple loop position control device (1) including: a drive controller (5) having a current control loop that controls motor current (I) and a motor speed control loop that controls a motor speed (Vm); a speed control loop (3) that controls a speed (Vd) of a driven body (2); and a position control loop (4) that controls a position (Pd) of the driven body (2), an adder (6) that adds an output value from the position control loop (4) and an output value from the speed control loop (3) and inputs an addition result to the motor speed control loop is provided. By providing the adder (6), the position control device (1) functions as a control device of a first-order system, so that occurrence of an overshoot may securely be avoided even when respective transfer functions of the position control device (1) are set for purpose of suppressing a vibrating behavior of the driven body (2).

Claims

1. A position control device that controls a position of a driven body driven by a driver according to a predetermined position command, comprising:

a position control loop including a position comparator that compares a current position of the driven body with the position command, and a position characteristic compensator that performs position characteristic compensation of the driven body based on a comparison result of the position comparator;

a speed control loop including a speed comparator that compares a current speed of the driven body with an output value from the position characteristic compensator as a speed command, and a speed characteristic compensator that performs speed characteristic compensation of the driven body based on a comparison result of the speed comparator;

an adder that adds the output value from the position characteristic compensator and an output value from the speed characteristic compensator; and

a drive controller that operates the driver to drive the driven body based on an addition result of the adder.

2. The position control device according to claim 1, wherein

the driver includes a movable part provided movably, and the driven body is connected to the movable part to be driven,

the drive controller has a driving speed control loop that controls a driving speed of the movable part of the driver, and

the driving speed control loop includes a driving speed comparator that compares a current driving speed of the movable part with the addition result of the adder as a driving speed command, and a driving speed characteristic compensator that performs driving speed characteristic compensation of the movable part based on a comparison result of the driving speed comparator.

3. The position control device according to claim 1, wherein the driven body is a low rigid load that degrades control characteristic of the position control device.

4. The position control device according to claim 1, wherein the speed characteristic compensator has a PI (proportional plus integral) compensator.

5. The position control device according to claim 1, wherein the speed characteristic compensator has a P (proportional) compensator.

6. A measuring device, comprising:

a position control device that controls a position of a driven body driven by a driver according to a predetermined position command, wherein

the position control device includes;

a position control loop including a position comparator that compares a current position of the driven body with the position command, and a position characteristic compensator that performs position characteristic compensation of the driven body based on a comparison result of the position comparator;

a speed control loop including a speed comparator that compares a current speed of the driven body with an output value from the position characteristic compensator as a speed command, and a speed characteristic compensator that performs speed characteristic compensation of the driven body based on a comparison result of the speed comparator;

an adder that adds the output value from the position characteristic compensator and an output value from the speed characteristic compensator; and

a drive controller that operates the driver to drive the driven body based on an addition result of the adder, and

the driven body is a probe relating to measurement of a workpiece.

7. The measuring device according to claim 6, wherein

the driver includes a movable part provided movably, and the driven body is connected to the movable part to be driven,

the drive controller has a driving speed control loop that controls a driving speed of the movable part of the driver, and

the driving speed control loop includes a driving speed comparator that compares a current driving speed of the movable part with the addition result of the adder as a driving speed command, and a driving speed characteristic compensator that performs driving speed characteristic compensation of the movable part based on a comparison result of the driving speed comparator.

8. The measuring device according to claim 6, wherein the driven body is a low rigid load that degrades control characteristic of the position control device.

9. The measuring device according to claim 6, wherein the speed characteristic compensator has a PI (proportional plus integral) compensator.

10. The measuring device according to claim 6, wherein the speed characteristic compensator has a P (proportional) compensator.

11. A machining device, comprising:

a position control device that controls a position of a driven body driven by a driver according to a predetermined position command, wherein

the position control device includes;

a position control loop including a position comparator that compares a current position of the driven body with the position command, and a position characteristic compensator that performs position characteristic compensation of the driven body based on a comparison result of the position comparator;

a speed control loop including a speed comparator that compares a current speed of the driven body with an output value from the position characteristic compensator as a speed command, and a speed characteristic compensator that performs speed characteristic compensation of the driven body based on a comparison result of the speed comparator;

an adder that adds the output value from the position characteristic compensator and an output value from the speed characteristic compensator; and

a drive controller that operates the driver to drive the driven body based on an addition result of the adder, and

the driven body is a tool relating to machining of a workpiece.

12. The machining device according to claim 11, wherein

the driver includes a movable part provided movably, and the driven body is connected to the movable part to be driven,

the drive controller has a driving speed control loop that controls a driving speed of the movable part of the driver, and

the driving speed control loop includes a driving speed comparator that compares a current driving speed of the movable part with the addition result of the adder as a driving speed command, and a driving speed characteristic compensator that performs driving speed characteristic compensation of the movable part based on a comparison result of the driving speed comparator.

13. The machining device according to claim 11, wherein the driven body is a low rigid load that degrades control characteristic of the position control device.

14. The machining device according to claim 11, wherein the speed characteristic compensator has a PI (proportional plus integral) compensator.

15. The machining device according to claim 11, wherein the speed characteristic compensator has a P (proportional) compensator.