Controller

• US 7,657,356 B2
• Filed: 11/30/2005
• Issued: 02/02/2010
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Okita, Tadashi, Iwashita, Yasusuke, Kawamura, Hiroyuki, Ikai, Satoshi
• Primary Examiner(s): Camby; Richard M.
• Application Number:
  US11/289,319
• Publication Number:
  US 20060116786A1
• Time in Patent Office: 1,525 Days
• Field of Search: 701/1, 701/29, 701/36, 701/50, 483 16- 19, 483/30, 483/38, 483/901, 83 57- 67, 700/188
• US Class Current: 701/50
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/37388 Acceleration or deceleration, inertial measurement
• CPC Class Codes: G05B 2219/43058 Limitation of acceleration, permissible, tolerable acceleration
• CPC Class Codes: Y10T 483/1702 Rotating work machine tool [e.g., screw machine, lathe, etc.]
• CPC Class Codes: Y10T 483/1733 Rotary spindle machine tool [e.g., milling machine, boring, machine, grinding machine, etc.]

Abstract

An acceleration detection unit for detecting acceleration is mounted on a driven body. When a previous block is a positioning command, the system waits till the detected value of acceleration detected by the acceleration detection unit becomes equal to or less than a set value αs after the distribution of the movement command of the positioning command is ended. If the detected value of acceleration becomes equal to or less than the set value αs, the distribution of the movement command of the next block is started. Because the cutting feed, etc., is started after the detected value of acceleration has become equal to or less than the set value αs and the vibrations stopped, machining can be conducted with high accuracy.

Claims

1. A controller of a machining tool for controlling the position and/or speed of a driven body, comprising:

detection means for detecting the position and/or speed of the driven body;

acceleration detection means for detecting the acceleration of the driven body; and

a stoppage determination processing unit for determining the stoppage of the driven body based on a detected value of acceleration detected by the acceleration detection means after completion of a positioning command to the driven body, wherein

operation processing of the next command is carried out after the stoppage has been determined in the stoppage determination processing unit,

wherein the positioning command to the driven body is taken as a positioning command based on a fast feed command, and the stoppage determination processing unit determines the stoppage of the driven body based on the detected value of acceleration detected by the acceleration detection means only after the fast feed command completion.

2. The controller according to claim 1, wherein the stoppage determination processing unit determines the stoppage when the absolute value of the detected value of acceleration becomes equal to or less than a preset value.

3. The controller according to claim 1, wherein the operation processing of the next command is an operation for cutting.

4. The controller according to claim 1, wherein the operation processing of the next command is an operation for cutting tool replacement.

5. A controller of a machining tool which has detection means for detecting the position and/or speed of a driven body and controls the position and/or speed of the driven body, comprising:

acceleration detection means for detecting the acceleration of the driven body;

an evaluation processing unit for conducting prescribed calculations for evaluating the vibration state of the driven body during acceleration or deceleration and within the preset time interval after the end of the acceleration or deceleration on the basis of the acceleration detected by the acceleration detection means; and

change means for decreasing the variation ratio of a speed command to the driven body based on the evaluation value calculated by the evaluation processing unit.

12. The controller according to claim 5, wherein the evaluation value to be calculated by said evaluation processing unit is an average value of the acceleration detection values for each axis.

6. A controller of a machining tool for controlling the position and/or speed of a driven body, comprising:

detection means for detecting the position and/or speed of the driven body;

acceleration detection means for detecting the acceleration of the driven body;

an evaluation processing unit for conducting prescribed calculations for evaluating the vibration state of the driven body during a prescribed time interval that is set in advance from an acceleration or deceleration start; and

change for decreasing the variation ratio of a speed command to the driven body based on the evaluation value calculated by the evaluation processing unit.

7. The controller according to claim 6, where the change means, when changing a time constant of the acceleration or deceleration, increases the prescribed time interval that is set from the start of the acceleration or deceleration in conjunction with increase in the time constant.

8. A controller of a machining tool for controlling the position and/or speed of a driven body, comprising:

position/speed detection means for detecting the position and/or speed of the driven body;

acceleration detection means for detecting the acceleration of the driven body; and

acceleration estimation means for obtaining an acceleration estimation value based on the detection value from the position/speed detection means, wherein

acceleration value estimated by the acceleration estimation means and the detected value of acceleration obtained from the acceleration detection means are compared with each other and, when the absolute value of the difference therebetween is equal to or larger than a preset threshold, the speed command or variation ratio of the speed command to the driven body is decreased.

9. The controller according to claim 8, wherein the acceleration estimation means obtains an acceleration estimation value based on a speed command value, instead of the detection value from the means for detecting the position or speed of the driven body.

10. A controller of a machining tool for controlling the position and/or speed of a driven body, comprising:

detection means for detecting the position and/or speed of the driven body;

acceleration detection means for detecting the acceleration of the driven body; and

change means for decreasing the variation ratio of a speed command to the driven body when the detected value of acceleration detected by the acceleration detection means becomes equal to or greater than a preset threshold during a prescribed time interval that is set in advance from an acceleration or deceleration start.

11. A controller of a machining tool for controlling the position and/or speed of a driven body, comprising:

detection means for detecting the position and/or speed of the driven body;

acceleration detection means for detecting the acceleration of the driven body;

an evaluation processing unit for conducting prescribed calculations for evaluating the vibration state of the driven body during acceleration or deceleration and within the preset time interval after the end of the acceleration or deceleration; and

change means for decreasing a speed command to the driven body.