Monitoring device of robot system

A monitoring device of a robot system, the robot system including:

• a robot including at least one joint shaft and a servo motor configured to drive the joint shaft;
• and a control device configured to preset a predetermined area in an operating range of the robot and control an operation of the robot,
• the monitoring device comprising:
• an external force detecting portion configured to detect external force acting on the robot;
• an area determining portion configured to determine whether or not a predetermined portion of the robot is located within the predetermined area;
• a force monitoring portion configured to
• when the area determining portion determines that the predetermined portion of the robot is located within the predetermined area, detect collision of the robot based on a first monitoring criterion including at least monitoring of the external force acting on the robot, and
• when the area determining portion determines that the predetermined portion of the robot is not located within the predetermined area, detect the collision based on a second monitoring criterion not including the monitoring of the external force;
• and
• a stop signal generating portion configured to, when the force monitoring portion detects the collision, generate a stop signal of the robot and supply the stop signal to the control device.