Robot system

Increased security of robot operation, efficient use of the floor space in a factory or the like, and simplified facilities are achieved. A process includes defining, in a memory, arm-occupied regions (A1, A2, A3, A4, A5, A6) including robot arms (3, 4, 5) and a workpiece (9) and a tool (7) attached to a robot wrist, a virtual safety protection barrier (50) with which the arms are not allowed to come into contact, and a movable range (60) of each robot axis; estimating the coasting angle of each robot axis for which the axis will coast when the robot (1) is stopped due to an emergency stop during execution of a command for moving the robot to a next target position, from an actually measured amount of coasting and the like; determining a post-coasting predicted position of the robot by adding the coasting angles of the axes to the next target position; checking whether or not the arm-occupied regions at the post-coasting predicted position will come into contact with the virtual safety protection barrier, or whether or not the robot axes are within the movable ranges; and performing control to cause the robot to stop moving immediately upon detection of abnormality.