Robot system

摘要

A process includes defining, in a memory, arm-occupied regions including robot arms and a workpiece and tool attached to a robot wrist, a virtual safety protection barrier with which the arms are not allowed to come into contact, and movable ranges of robot axes; estimating the coasting angle of each robot axis for which the axis will coast when the robot is stopped due to an emergency stop while moving 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 estimated coasting angles 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 stop the robot immediately upon detection of abnormality.

主权项

1. A robot system comprising:
a robot, the robot having an arm, the arm having an axis; and a virtual safety protection barrier with which an arm-occupied region is not allowed to come into contact, the arm-occupied region including the arm of the robot, wherein, when a target position of a tip of the robot is calculated for each calculation period and a movement command for moving the axis of the arm of the robot is generated, it is checked whether or not the arm-occupied region at a target position of the tip of the robot in a subsequent calculation period will come into contact with the virtual safety protection barrier, wherein, if it is determined that the arm-occupied region will come into contact with the virtual safety protection barrier at the target position of the tip of the robot in the subsequent calculation period, then control is performed to cause the robot to stop moving before the robot begins movement from an initial position of the tip of the robot in the subsequent calculation period toward the target position of the tip of the robot in the subsequent calculation period, and wherein, if it is determined that the arm-occupied region will not come into contact with the virtual safety protection barrier at the target position of the tip of the robot in the subsequent calculation period, then a coasting angle of the axis of the arm of the robot is estimated from an actual coasting angle measured in advance and from a mechanical delay time, the coasting angle being an angle for which the axis of the arm of the robot will coast when the robot is commanded to stop while at the target position of the tip of the robot in the subsequent calculation period due to an emergency stop during movement of the robot in accordance with a movement command for moving the tip of the robot to the target position in the subsequent calculation period, and a post-coasting predicted position of the axis of the arm of the robot is determined by adding a coasting angle of the axis to the movement command for moving the axis in the subsequent calculation period, the post-coasting predicted position of the axis being a position at which the axis of the arm of the robot is predicted to stop after coasting.