Motor control device and industrial machine for suppressing vibration

A motor control device comprising:

• a position command section configured to generate a position command for a control object driven along a first of a plurality of shafts, wherein the first shaft is supported on at least one end by a supporting element;
• a position detecting section configured to detect a position of the control object along the plurality of shafts or a position of at least one motor configured to drive the control object;
• and
• a position control section configured to control a position of the at least one motor based on the generated position command and the detected position of the control object or the position of the at least one motor,
• wherein the position control section includes a vibration suppression filter configured to approximate a reverse characteristic of a vibration characteristic generated between the motor and the control object in accordance with a physical change in at least one of a position and mass of the control object, and wherein the vibration suppression filter changes an output of a vibration suppression frequency to correspond to the approximated reverse characteristic based on:
• a torsional vibration characteristic of the first shaft computed based on a first elasticity of the first shaft and the position of the control object relative to the supporting element, and an inertia of the control object on the first shaft, wherein the first elasticity is a transverse elastic modulus, and
• a spring plate vibration characteristic of a second shaft of the plurality of shafts computed based on a second elasticity of the second shaft and a position of the control object on the second shaft, and a mass of the control object, wherein the second elasticity is Young's modulus,
• wherein a spring constant k1 of the first shaft is represented by:
• k
• 1
• =
• π
• ⁢
• d
• 4
• ⁢
• G
• 32
• ⁢
• L
• ,
• and
• wherein a spring constant k2 of the second shaft is represented by:
• k
• 2
• =
• d
• 4
• ⁢
• E
• 4
• ⁢
• L
• 3
• .