Title:
METHODS OF DETECTING OSCILLATION IN THE SERVO SYSTEM AND AUTOMATICALLY ADJUSTING THE SPEED LOOP GAIN
Document Type and Number:
WIPO Patent Application WO/1990/007735
Kind Code:
A1
Abstract:
The invention relates to methods of automatically detecting oscillation in the servo system and quickly, properly and automatically adjusting the speed loop gain in the servo system. The motor is rotated forward and reverse in a vibrating manner by actuating the servo system under the condition where a positional loop gain is set to a large value, and various frequency components of a speed signal (Vt) are calculated by Fourier transform while increasing the speed loop gains (k1, k2) in the oscillation detection process, and a main vibration component (fmax) having a maximum amplitude is discriminated repetitively (201, 202) out of these frequency components. When the main vibration component abruptly increases, a judgement that oscillation took place in the servo system due to resonance in the machine system is given and alarm is displayed (204, 209). In the gain adjustment, the speed loop gain is changed and the motor is vibrated under the integration-proportional control or the proportional-integration control mode. During this period, when the main vibration component assumes a value near a reference frequency (fa), the loop gain and the control mode (P) are fixed at this moment (303). When the main vibration component does not reach the reference frequency during the proportional integration control, the loop gain that is calculated based on an upper-limit cut-off frequency (flim) is fixed (311).
Inventors:
IWASHITA YASUSUKE (JP)
Application Number:
PCT/JP1989/001296
Publication Date:
July 12, 1990
Filing Date:
December 25, 1989
Export Citation:
Assignee:
FANUC LTD (JP)
International Classes:
C07C275/26; G05B5/01; G05B13/02; (IPC1-7): G05B13/02
Foreign References:
| JPH05549706A |
Other References:
See also references of EP 0401383A4
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