SERVO SYSTEM AND METHOD OF ESTIMATING SERVICE LIFE OF BATTERY

摘要

A servo system (100) is provided with: a motor drive circuit (6) which drives a servo motor (2) on the basis of a motor drive signal; a servo control unit (5) which generates the motor drive signal on the basis of a command signal transmitted from a controller (4) and an absolute position of the servo motor, detected by an encoder (1); a battery (7) which supplies electric power to the encoder if electric power is not being supplied to the encoder from an external power supply; a battery control unit (10) which measures a short-circuit current value and an open-circuit voltage value of the battery while electric power is being supplied to the encoder from the external power supply; and a storage unit (11) which retains an internal impedance of the battery, obtained by the servo control unit on the basis of the short-circuit current value and the open-circuit voltage value. An external device (12) which is connected to the servo system and which retains information relating to changes in the internal impedance of the battery over time estimates the service life of the battery on the basis of the internal impedance retained by the storage unit and the information relating to changes in the internal impedance over time.