Numerical controller

• US 7,034,491 B2
• Filed: 07/25/2005
• Issued: 04/25/2006
• Est. Priority Date: 07/26/2004
• Status: Expired due to Fees

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Endo, Takahiko, Genma, Eiji, Kozai, Haruhiko
• Primary Examiner(s): Ip, Paul
• Application Number:
  US11/187,872
• Publication Number:
  US 20060017415A1
• Time in Patent Office: 274 Days
• Field of Search: 318/568.1, 318/568.22, 318/567, 318/569, 318630-638, 318570-575, 318560-566
• US Class Current: 318/570
• 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 2219/41041 Compensation pulses as function of direction movement
• CPC Class Codes: G05B 2219/41045 For several modes and feed speeds, a table, registers for several backlash
• CPC Class Codes: G05B 2219/41085 Compensation pulses on inversion of direction of rotation, movement

Abstract

For outputting an amount of backlash compensation according to the direction of reversal in the reversal motion of the moving axis, three output modes are prepared: (a) a mode in which a preset backlash compensation is outputted all at once, (b) a mode in which backlash compensation is outputted according to distance traveled, and (c) a mode in which backlash compensation is outputted according to time elapsed. It is determined whether the motion of the moving axis has been changed from positive to negative directions or from negative to positive directions, and with this determination result, any one of the above three output modes (a) to (c) is selected.

Claims

1. A numerical controller having a backlash compensation function that outputs backlash compensation to a position control section to compensate for backlash that occurs when the direction of motion for a moving axis is reversed, the numerical controller comprising:

setting means for setting output modes for outputting backlash compensation to the position control section, which correspond to directions of reversal in the reversal motion of the moving axis;

determining means for determining a direction of reversal in the reversal motion of the moving axis; and

backlash compensation output means for outputting the backlash compensation to the position control section by using the output mode corresponding to the direction of reversal determined by said determining means.

2. The numerical controller according to claim 1, wherein said output mode includes a mode in which the backlash compensation is outputted all at once when the direction of motion is reversed, a mode in which the backlash compensation is outputted according to distance traveled from the position where the direction of motion is reversed, or a mode in which the backlash compensation is outputted according to a time elapsed from the time when the direction of motion is reversed.

3. The numerical controller according to claim 1, wherein said output mode is a mode in which the backlash compensation is outputted according to distance traveled from the position where the direction of motion is reversed, and the amounts of backlash compensation to be outputted every distribution cycle are set individually depending on the direction of reversal.

4. The numerical controller according to claim 1, wherein said output mode is a mode in which the backlash compensation is outputted according to time elapsed from the time when the direction of motion is reversed, and the amounts of backlash compensation to be outputted every distribution cycle are set individually depending on the direction of reversal.

5. The numerical controller according to any one of claims 1 to 4, wherein the output mode is specified by a parameter setting.