A machine learning device is configured to perform machine learning with respect to a servo motor control device including a non-linear friction compensator that creates a compensation value with respect to non-linear friction on the basis of a position command, the machine learning device including: a state information acquisition unit configured to acquire state information including a servo state including position error, and combination of compensation coefficients of the non-linear friction compensation unit, by causing the servo motor control device to execute a predetermined program; an action information output unit configured to output action information including adjustment information of the combination of compensation coefficients; a reward output unit configured to output a reward value in reinforcement learning, based on the position error; and a value function updating unit configured to update an action value function on the basis of the reward value, the state information, and the action information.
Machine learning device, servo motor control device, servo motor control system, and machine learning method