Machine learning device, control system, control device, and machine learning method

A machine learning device that performs machine learning with respect to a control device of a machine tool, the control device controlling synchronous operation of a spindle motor and a feed axis motor,

• the machine learning device comprising:
• a first memory configured to store a first program;
• and
• a first processor configured to execute the first program and control the machine learning device to:
• cause the control device to execute a tapping program to acquire from the control device, state information including at least a torque command value with respect to the spindle motor, a drive state including deceleration of the spindle motor, and a ratio of a movement distance in acceleration and a movement distance in deceleration of the spindle motor;
• output action information, including adjustment information of the ratio of the movement distance in acceleration and the movement distance in deceleration of the spindle motor included in the state information, to the control device;
• output a reward value in reinforcement learning based on a torque command value in deceleration and a target torque command value in deceleration;
• and
• update an action value function based on the reward value, the state information, and the action information.