Robot system

1. A robot system comprising:

a crane unit configured to suspend a workpiece;

a crane moving mechanism that allows the crane unit to move in a horizontal direction;

a manipulator unit that holds and moves the crane unit supporting the workpiece; and

a controller configured to control the crane unit to support the workpiece at a first position and configured to control the manipulator unit to move the crane unit supporting the workpiece toward a second position and to place the supported workpiece at the second position,

wherein the manipulator unit comprises:

an arm; and

a plurality of servomotors that drive the arm, and

wherein the controller comprises a torque controller that, if a load equal to or higher than a predetermined load is exerted on the servomotors, allows rotation of the servomotors to follow the load.

2. The robot system according to claim 1 , further comprising a hand unit coupled to a distal end of the manipulator unit, the hand unit being capable of holding and releasing the workpiece, the hand unit being suspended by the crane unit.

3. The robot system according to claim 1 , wherein the manipulator unit comprises a pair of arms each having a hand unit at a distal end of each of the arms.

4. The robot system according to claim 3 , wherein when the manipulator unit moves the crane unit toward the second position, one arm among the pair of arms holds the crane unit and another arm among the pair of arms holds the workpiece supported by the crane unit.

5. The robot system according to claim 1 ,

wherein the crane moving mechanism comprises a rail member, the rail member extending in the horizontal direction, and

wherein the crane unit is supported movably along the rail member.

6. The robot system according to claim 1 , wherein the manipulator unit includes a pedestal that is fixed to a floor, and a rotary body mounted on the pedestal and being rotatable with respect to the pedestal.

7. The robot system according to claim 1 , wherein the controller includes a storage device configured to store a work procedure, and wherein the controller is configured to operate the manipulator unit, the crane unit, and the crane moving mechanism in accordance with the stored work procedure.

8. The robot system according to claim 1 , wherein the controller is further configured to control the manipulator unit to move the crane unit supporting the workpiece toward a third position and to place the supported workpiece at the third position.

9. The robot system according to claim 8 , wherein controller is further configured to control the manipulator unit to move the crane unit supporting the workpiece from the first position toward the second position and the third position alternately.

10. A robot system comprising:

a manipulator unit comprising:

a hand unit; and

a controller configured to control a motion of the manipulator unit and comprising:

a crane signal input section configured to receive an input of a position signal from a crane unit that suspends a workpiece and that drives the workpiece in a vertical direction, the controller being configured to control the motion of the manipulator unit based on the position signal from the crane unit,

wherein the manipulator unit comprises:

an arm to which the hand unit is connected; and

a plurality of servomotors that drive the arm, and

wherein the controller comprises a torque controller that, if a load equal to or higher than a predetermined load is exerted on the servomotors, allows rotation of the servomotors to follow the load.

11. The robot system according to claim 10 , wherein the manipulator unit includes a pedestal that is fixed to a floor, and a rotary body mounted on the pedestal and being rotatable with respect to the pedestal.

12. The robot system according to claim 10 , wherein the controller includes a storage device configured to store a work procedure, and wherein the controller is configured to operate the manipulator unit in conjunction with the operation of the crane unit and in accordance with the stored work procedure.

13. The robot system according to claim 10 , wherein the controller is further configured to control the manipulator unit to move the crane unit supporting the workpiece from a first position toward a second position or a third position, and to place the supported workpiece at the second position or the third position.

14. The robot system according to claim 13 , wherein controller is further configured to control the manipulator unit to move the crane unit supporting the workpiece from the first position toward the second position and the third position alternately.

15. A robot system comprising:

supporting means for suspending and supporting a workpiece;

moving means for allowing the supporting means to move in a horizontal direction;

manipulating means for holding and moving the supporting means supporting the workpiece; and

controlling means for controlling the supporting means to support the workpiece at a first position and controlling the manipulating means to move the supporting means supporting the workpiece toward a second position and to place the workpiece at the second position,

wherein the manipulating means comprises:

an arm; and

a plurality of servomotors that drive the arm, and

wherein the controlling means comprises a torque controller that, if a load equal to or higher than a predetermined load is exerted on the servomotors, allows rotation of the servomotors to follow the load.

16. The robot system according to claim 15 , wherein the manipulating means includes a pedestal that is fixed to a floor, and a rotary body mounted on the pedestal and being rotatable with respect to the pedestal.

17. The robot system according to claim 15 , wherein the controlling means includes a storage device configured to store a work procedure, and wherein the controlling means operates the manipulating means, the supporting means, and the moving means in accordance with the stored work procedure.

18. The robot system according to claim 15 , wherein the controlling means is further configured to control the manipulating means to move the supporting means supporting the workpiece from a first position toward a second position or a third position, and to place the supported workpiece at the second position or the third position.

19. The robot system according to claim 18 , wherein controlling means is further configured to control the manipulating means to move the supporting means supporting the workpiece from the first position toward the second position and the third position alternately.