US Patent No. 9,228,509

MOTOR CONTROL APPARATUS THAT GENERATES PRELOAD TORQUE VALUE AS FUNCTION OF MOTOR ACCELERATION


Patent No. 9,228,509
Issue Date January 05, 2016 
Title Motor Control Apparatus That Generates Preload Torque Value As Function Of Motor Acceleration
Inventorship Kazuomi Maeda, Yamanashi (JP)
Assignee Fanuc Corporation, Yamanashi (JP)

Claim of US Patent No. 9,228,509

1. A motor control apparatus for tandem control of a first motor and a second motor in order to drive single driven member,
said motor control apparatus comprising:
a torque command value generating unit which generates a first torque command value for said first motor and a second torque
command value for said second motor, based on at least one set selected from among a set comprising a position command value
for said first motor, position information of said first motor, and speed information of said first motor, a set comprising
a position command value for said second motor, position information of said second motor, and speed information of said second
motor, and a set comprising a position command value for said driven member, position information of said driven member, and
speed information of said driven member;

a first preload torque value generating unit which calculates first acceleration corresponding to acceleration of said first
motor, and calculates a first preload torque value to be a value which is proportional to an absolute value of said first
acceleration and is larger than said first torque command value, said first preload torque value being a torque value that
is appended in advance to said first torque command value so that the direction of force applied to a drive shaft of said
first motor and the direction of force applied to a drive shaft of said second motor will become opposite to each other;

a second preload torque value generating unit which calculates second acceleration corresponding to acceleration of said second
motor, and calculates a second preload torque value to be a value which is proportional to an absolute value of said second
acceleration and is larger than said second torque command value, said second preload torque value being a torque value that
is appended in advance to said second torque command value so that the direction of force applied to the drive shaft of said
first motor and the direction of force applied to the drive shaft of said second motor will become opposite to each other;

a first motor driving unit which drives said first motor based on said first torque command value and said first preload torque
value; and

a second motor driving unit which drives said second motor based on said second torque command value and said second preload
torque value.