Numerical controller for multi-axis machine

• US 8,350,514 B2
• Filed: 04/29/2011
• Issued: 01/08/2013
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: Otsuki, Toshiaki, Ide, Soichiro, Hanaoka, Osamu, Sasaki, Takafumi
• Primary Examiner(s): Ip, Paul
• Application Number:
  US13/097,795
• Publication Number:
  US 20120001583A1
• Time in Patent Office: 620 Days
• Field of Search: 318/569, 318/807, 318/568.15, 318/568.22, 318/573, 700/180, 700/260
• US Class Current: 318/573
• 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 2219/49198 Using lookup table, map, position and corresponding quasi static error
• CPC Class Codes: G05B 2219/50297 Compensation of positioning error due to a-axis, b-axis tool rotation

Abstract

A numerical controller for controlling a multi-axis machine calculates an axis-dependent translation error amount and an axis-dependent rotation error amount based on a command axis position. Translation and rotation compensation amounts are calculated based on the axis dependent translation and rotation error amounts, respectively. The translation and rotation compensation amounts are added to command linear and rotary axis positions, respectively. Three linear axes and three rotary axes are driven to the added positions, individually. Thus, there is provided a numerical controller that enables even machining with a side face of a tool or boring to be in commanded tool position and posture (orientation) in the multi-axis machine.

Claims

1. A numerical controller for controlling a multi-axis machine which uses at least three linear axes and three rotary axes to machine a workpiece mounted on a table, the numerical controller comprising:

axis-dependent error amount calculation means for calculating an axis-dependent translation error amount and an axis-dependent rotation error amount based on a command axis position;

translation compensation amount calculation means for calculating a translation compensation amount based on the axis-dependent translation error amount;

rotation compensation amount calculation means for calculating a rotation compensation amount based on the axis-dependent rotation error amount;

compensation amount adding means for adding the translation compensation amount to a command linear axis position and adding the rotation compensation amount to a command rotary axis position; and

means for driving the three linear axes and the three rotary axes to a position calculated by the compensation amount adding means.

2. The numerical controller according to claim 1, wherein the axis-dependent error amount calculation means calculates a rotary-axis-dependent translation error amount and a rotary-axis-dependent rotation error amount as the axis-dependent translation error amount and the axis-dependent rotation error amount, respectively, based on the command rotary axis position,

the translation compensation amount calculation means calculates the translation compensation amount based on the rotary-axis-dependent translation error amount, and

the rotation compensation amount calculation means calculates the rotation compensation amount based on the rotary-axis-dependent rotation error amount.

3. The numerical controller according to claim 1, wherein the axis-dependent error amount calculation means calculates a linear-axis-dependent translation error amount and a linear-axis-dependent rotation error amount as the axis-dependent translation error amount and the axis-dependent rotation error amount, respectively, based on the command linear axis position,

the translation compensation amount calculation means calculates the translation compensation amount based on the linear-axis-dependent translation error amount, and

the rotation compensation amount calculation means calculates the rotation compensation amount based on the linear-axis-dependent rotation error amount.

4. The numerical controller according to claim 1, wherein the axis-dependent error amount calculation means calculates a linear-axis-dependent translation error amount and a linear-axis-dependent rotation error amount, based on the command linear axis position, and calculates a rotary-axis-dependent translation error amount and a rotary-axis-dependent rotation error amount, based on the command rotary axis position, as the axis-dependent translation error amount and the axis-dependent rotation error amount, respectively,

the translation compensation amount calculation means calculates the translation compensation amount based on the linear-axis-dependent translation error amount and the rotary-axis-dependent translation error amount, and

the rotation compensation amount calculation means calculates the rotation compensation amount based on the linear-axis-dependent rotation error amount and the rotary-axis-dependent rotation error amount.

5. The numerical controller according to claim 1, wherein the rotation compensation amount is obtained as a rotary axis compensation amount for rotation compensation of an actual tool length compensation vector having a rotation error with respect to a tool length compensation vector.

6. The numerical controller according to claim 1, wherein the translation compensation amount is obtained as a translation compensation amount with respect to a tool reference point vector representing a tool reference point on a table coordinate system.

7. The numerical controller according to claim 2, wherein the multi-axis machine uses at least three linear axes and three rotary axes for tool head rotation to machine the workpiece mounted on the table, and

the rotary-axis-dependent translation and rotation error amounts are translation and rotation error amounts for the three rotary axes for tool head rotation.

8. The numerical controller according to claim 1, wherein the multi-axis machine uses a L least three linear axes, one rotary axis for tool head rotation, and two rotary axes for table rotation to machine the workpiece mounted on the table, and

the rotary-axis-dependent translation and rotation error amounts are translation and rotation error amounts for the one rotary axis for tool head rotation and translation and rotation error amounts for the two rotary axes for table rotation.

9. The numerical controller according to claim 1, wherein the multi-axis machine uses at least three linear axes, two rotary axes for tool head rotation, and one rotary axis for table rotation to machine the workpiece mounted on the table, and

the rotary-axis-dependent translation and rotation error amounts are translation and rotation error amounts for the two rotary axes for tool head rotation and translation and rotation error amounts for the one rotary axis for table rotation.

10. The numerical controller according to claim 1, wherein the multi-axis machine uses at least three linear axes and three rotary axes for table rotation to machine the workpiece mounted on the table, and

the rotary-axis-dependent translation and rotation error amounts are translation and rotation error amounts for the three rotary axes for table rotation.