Servomotor control device

A servomotor control device, comprising:

• a servomotor;
• a driven body that is driven by the servomotor;
• a connection mechanism that connects the servomotor and the driven body to transmit power of the servomotor to the driven body;
• a first position detection section that detects a position of the servomotor;
• a second position detection section that detects a position of the driven body;
• and
• a motor control unit that controls the servomotor,
• wherein the motor control unit includes:
• a dual position control section that performs semi-closed feedback control based on a high-frequency component of a first deviation between a position command value for driving control of the servomotor and the position of the servomotor detected by the first position detection section, and full-closed feedback control based on a low-frequency component of a second deviation between the position command value and the position of the driven body detected by the second position detection section;
• an acquisition section that acquires a magnitude of rigidity of the connection mechanism, or a magnitude of resonance frequency of the servomotor control device;
• and
• a varying section that causes a proportion of the semi-closed feedback control to the full-closed feedback control in the dual position control section to vary in response to the magnitude of or variation in rigidity of the connection mechanism acquired by the acquisition section, or the magnitude of or variation in resonance frequency of the servomotor control device acquired by the acquisition section.