Machine learning device and robot system provided with same

A machine learning device that learns an action of a robot including a hand unit to pick out a targeted workpiece from a container containing a plurality of randomly stacked workpieces, the machine learning device comprising:

• a behavior observing unit configured to observe a behavior pattern of the robot performing a pick-out action to pick out the targeted workpiece by the hand unit from the container;
• a displaced amount observing unit configured to observe, based on pieces of image data captured before and after the pick-out action by the robot and output from an image capturing device that captures an image of an inside of the container, a workpiece displaced amount indicating a displaced amount of an untargeted workpiece, not the targeted workpiece, in the container, caused by the hand unit picking out the targeted workpiece from the container;
• and
• a learning unit configured to learn, based on supervised data in which the behavior pattern and the workpiece displaced amount are associated with each other, an influence rate on the untargeted workpiece with the behavior pattern for picking out the targeted workpiece by the hand unit from the container, the influence rate depending on the workpiece displaced amount.