US Patent No. 9,285,785

MOTOR CONTROL DEVICE FOR SUPPRESSING NATURAL VIBRATIONS


Patent No. 9,285,785
Issue Date March 15, 2016
Title Motor Control Device For Suppressing Natural Vibrations
Inventorship Naoto Sonoda, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 9,285,785

1. A motor control device configured to output a control signal for controlling a motor, while suppressing natural vibrations
of a target object constituted of the motor and a driven member to be driven by the motor, the motor control device comprising:
a frequency component extracting unit configured to extract a frequency component included in the control signal at a first
frequency step size;

a frequency detection unit configured to detect a frequency corresponding to a natural frequency of the target object constituted
of the motor and the driven member to be driven by the motor from the frequency component extracted by the frequency component
extracting unit;

a frequency step size setting unit configured to set a second frequency step size smaller than the first frequency step size;
a center frequency changing unit configured to change a center frequency in such a manner that the second frequency step size
is successively added or subtracted to or from the center frequency, when the natural frequency is changed by an integral
multiple of 1 or more of the first frequency step size in detecting a frequency corresponding to the natural frequency by
the frequency detection unit;

a variable bandstop filter configured to input the control signal, and configured such that the center frequency is variable
by the center frequency changing unit in order to output the control signal after a frequency component corresponding to the
natural frequency after the change is removed from the control signal; and

an extraction range setting unit configured to set a frequency component range of the control signal to be extracted by the
frequency component extracting unit.