US 7,479,750 B2
Controller for electric motor
Yasusuke Iwashita, Fujiyoshida (Japan); Kazuomi Maeda, Yamaga (Japan); and Yukio Toyozawa, Koshi (Japan)
Assigned to Fanuc Ltd, Minamitsuru-gun, Yamanashi (Japan)
Filed on Jan. 30, 2007, as Appl. No. 11/699,582.
Claims priority of application No. 2006-023290 (JP), filed on Jan. 31, 2006.
Prior Publication US 2007/0205738 A1, Sep. 06, 2007
Int. Cl. G05B 11/01 (2006.01)
U.S. Cl. 318—560  [318/567; 318/568.13] 10 Claims
OG exemplary drawing
 
1. A controller comprising:
a learning control unit for determining learning data based on a positional deviation between a target-position command commanding superimposed-type motion including repetitive motion and a positional fed-back variable obtained from an output portion of an electric motor, storing the learning data, and correcting the positional deviation by using the learning data; and
an operation control section for controlling an operation of the electric motor based on a corrected positional deviation obtained in said learning control unit;
said learning control unit comprising:
a first learning section for determining, based on said positional deviation, and storing first learning data in a periodic manner according to a first learning period;
a learning-data correcting section for correcting said first learning data in a manner as to eliminate an influence of a local change included in at least one of said target-position command and said positional fed-back variable, said local change arising in a periodic manner according to a period different from said first learning period; and
a positional-deviation correcting section for correcting said positional deviation by using corrected learning data obtained by correcting said first learning data in said learning-data correcting section.