The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 1998
Filed:
Jan. 29, 1996
Applicant:
Inventors:
Tetsuaki Kato, Hadano, JP;
Kokoro Hatanaka, Oshino-mura, JP;
Assignee:
Fanuc Ltd., Minamitsuru-gun, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05B / ;
U.S. Cl.
CPC ...
318630 ; 318569 ; 318632 ; 318601 ;
Abstract
A method for properly compensating for a backlash between a servomotor and a machine moving part, such as a table, driven by the servomotor in a semi-closed-loop type control. In the semi-closed-loop type servo control, the force of a motor-driven table which acts on a motor is estimated by means of a disturbance observer, the side of the groove of a ball nut directly connected to the table, with which the ridge of the ball thread directly connected to the motor is in contact, is detected by the sign of the value of the estimated force, and the direction of backlash compensation is changed in accordance with the detected result.