Patent ID: 8180488

Claim:
A robot system comprising: a robot and a robot controller that controls the robot, the robot controller including a drive unit that moves the robot, a memory that stores an arm-occupied region and a movement-forbidden region, the arm-occupied region being defined on the basis of an arm of the robot, a tool attached to a wrist of the robot, or a workpiece that is held, the movement-forbidden region being a region that the arm-occupied region is not permitted to enter, a target position calculation unit that calculates a movement target position of the tool or the workpiece for each calculation period and generates a movement command for each axis of the robot, a movement-forbidden region entry monitoring unit that checks whether the arm-occupied region enters the movement-forbidden region, the arm-occupied region being based on the movement target position of the tool or the workpiece that has been calculated by the target position calculation unit, and outputs a stop request to stop movement of the robot if it is checked that the arm-occupied region enters the movement-forbidden region, and a predicted-coasting-position calculating unit that calculates a predicted coasting position of each axis of the robot and a coasting position of the tool or the workpiece when each axis is at the predicted coasting position by estimating a coasting angle of each axis of the robot in a case that the robot is urgently stopped when the robot is moving to the movement target position of the tool or the workpiece and by adding the estimated coasting angle of each axis to the movement command for each axis, wherein the movement-forbidden region entry monitoring unit checks whether the arm-occupied region at the coasting position enters the movement-forbidden region, and, if it is checked that the arm-occupied region at the coasting position enters the movement-forbidden region, outputs another stop request to stop movement of the robot and performs stop control to stop movement of the robot on the stop request.