Controller

• US 20060184257A1
• Filed: 12/06/2005
• Published: 08/17/2006
• Est. Priority Date: 12/07/2004
• Status: Abandoned Application

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Okita, Tadashi, Iwashita, Yasusuke, Kawamura, Hiroyuki, Ikai, Satoshi
• Application Number:
  US11/294,461
• Publication Number:
  US 20060184257A1
• Time in Patent Office: Days
• US Class Current: 700/46
• 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 2219/37434 Measuring vibration of machine or workpiece or tool
• CPC Class Codes: G05B 2219/41117 Cancel vibration during positioning of slide
• CPC Class Codes: G05B 2219/42077 Position, speed or current, combined with vibration feedback

Abstract

In a controller, V axis and W axis for driving a driven body are tilting, not orthogonal to each other. An acceleration detector capable of detecting accelerations in a plurality of directions orthogonal to the driven body is arranged so that W-axis direction may meet Y-axis direction of an acceleration detected by the acceleration detector. An acceleration in the V-axis direction is determined by making calculations from accelerations in X-axis and Y-axis directions detected by acceleration detectors. Based on the determined accelerations in the V-axis and W-axis directions, a position command, a speed command or a current command to servo motors driving the V axis and W axis is corrected. Such correction suppresses the driven body from generation of vibrations.

Claims

1. A controller, equipped with servo motors for driving a driven body in a plurality of driving shaft directions different from each other, respectively, and detection means for detecting speed of the driven body to control the speed of the driven body, the controller comprising:

acceleration detection means which is installed on the driven body and detects accelerations in a plurality of directions;

acceleration calculating means for determining accelerations in the directions of respective driving shafts for driving the driven body based on the acceleration detection values in a plurality of directions detected by the acceleration detection means; and

command correction means for correcting speed commands and/or current commands of the servo motors for driving the driving shafts based on the accelerations in the directions of the respective driving shafts determined by the acceleration calculating means so as to suppress the driven body from vibrating.

2. The controller according to claim 1 wherein

the acceleration detection means detects accelerations in two or three directions orthogonal to each other;

and

the acceleration calculating means calculates accelerations in the directions of the driving shafts of the driven body not parallel to the directions of the accelerations detected by the acceleration detection means, from the detected accelerations in two or three directions.

3. The controller according to claim 2, further comprising:

displacement calculating means for calculating a displacement amount between the direction of the acceleration detected by the acceleration detection means and direction of the driving shaft for driving the driven body is provided;

wherein

the acceleration calculation means calculates an accelerations in the direction of the driving shaft of the driven body not parallel to the accelerations detected by the acceleration detection means from the accelerations in two or three directions detected by the acceleration detection means and a displacement amount detected by the displacement calculation means.

4. The controller according to claim 1 wherein

the driven body is installed on a base equipped with a rotation driving shaft for swinging the driven body;

the acceleration calculation means determines an acceleration in the driving direction of the driving shaft for driving the base from the acceleration detection values detected by the acceleration detection means; and

the command correction means corrects a speed command and/or a current command of the servo motor for driving the base driving shaft, based on the accelerations determined by the acceleration calculation means.

5. The controller according to claim 1 wherein

the controller controls the position of the driven body, in addition to the speed of the driven body, and

the command correction means corrects a speed command of the servo motors for driving the driving shafts based on accelerations in the directions of the respective driving shafts determined by the acceleration calculating means, in addition to, or in place of, the speed command and/or current command of the servo motors.

8. The controller according to claim 1 or claim 6 wherein

the acceleration calculation means determines an acceleration of a driving shaft affected by gravity by making such a calculation as to eliminate an influence of the gravity from a displacement amount between a direction of the driving shaft and a direction of the gravity.

6. A controller, equipped with servo motors for driving a driven body in a plurality of driving shaft directions different from each other, respectively, and detection means for detecting the position of, or the position and speed of, the driven body to control the speeds of the driven body, comprises:

acceleration detection means which is installed on the driven body and detects accelerations in two or three directions orthogonal to each other;

displacement estimation means for estimating a displacement amount between a direction of the acceleration detected by the acceleration detection means and that of the driving shaft for driving the driven body based on a command position;

acceleration calculation means for determining an acceleration of the driven body in a traveling direction from the detected accelerations in the two or three directions detected by the acceleration detection means and the displacement amount detected by the displacement estimation means; and

command correction means for correcting at least one of a position command, a speed command and a current command of the servo motor for driving the associated driving shaft, based on the acceleration calculated by the acceleration calculation means.

7. The controller according to claim 6 wherein

the driven body is installed on a base having a rotation driving shaft for swinging the driven body;

the acceleration calculation means determines an acceleration in the driving direction of the driving shaft for driving the base from the acceleration detection value detected by the acceleration detection means; and

the command correction means corrects at least one of a position command, a speed command and a current command of the servo motor for driving the base driving shaft based on the accelerations determined by the acceleration calculation means.