EP-4735214-A2 - APPARATUS AND METHOD FOR OPTIMIZING SWAP TIME

Abstract

A robotic apparatus including an arm member configured to pivot about a first axis, a first end effector, a second end effector, a drive unit, and a control unit. The first and second end effectors are pivotably connected to the arm member about a second axis, and each have a surface to receive a workpiece. The drive unit drives the arm member to pivot about the first axis, and to drive the first and second end effectors to pivot about the second axis. The control unit controls the drive unit to move the arm member and the first and second end effectors to perform a swapping operation that includes the first and second end effectors swapping arc positions at opposite ends of an arc of constant radius of curvature such that the workpieces on the first and second end effectors each travel at equal and constant velocities along the arc.

Inventors

• ROGERS, JOHN CHARLES

Assignees

• Kabushiki Kaisha Yaskawa Denki
• Yaskawa America, Inc.

Dates

Publication Date

20260506

Application Date

20240626

Claims (20)

1. 1. A robotic apparatus comprising: an arm member configured to pivot about a first axis; a first end effector pivotably connected to the arm member about a second axis, the first end effector having a first surface upon which a first workpiece can be received; a second end effector pivotably connected to the arm member about the second axis, the second end effector having a second surface upon which a second workpiece can be received; at least one drive unit configured to drive the arm member to pivot about the first axis, the at least one drive unit being configured to drive the first end effector to pivot about the second axis, the at least one drive unit being configured to drive the second end effector to pivot about the second axis; and a control unit configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector to perform a swapping operation that includes the first end effector and the second end effector swapping arc positions disposed at opposite ends of an arc having a constant radius of curvature, the control unit being configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector such that the first workpiece received on the first end effector and the second workpiece received on the second end effector each travel at equal and constant velocities along the arc.
2. 2. The robotic apparatus of claim 1, wherein the control unit is configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector such that the equal and constant velocities produce centripetal acceleration values acting upon the first workpiece and the second workpiece along the arc that do not exceed a predetermined acceleration limit.
3. 3. The robotic apparatus of claim 2, wherein the control unit is configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector during the swapping operation without exceeding the predetermined acceleration limit to retain the first workpiece and the second workpiece on the first end effector and the second end effector, respectively, solely with surface friction without use of a suction device and without use of an edge gripping device.
4. 4. The robotic apparatus of claim 1, wherein the first end effector and the second end effector each includes at least one of an edge-gripping device and a suction device.
5. 5. The robotic apparatus of claim 1, wherein the swapping operation further includes at least one of: moving the first end effector such that the first workpiece or a center of a workpiece holding position of the first end effector moves from a first start position to a first arc position of the arc positions; and moving the second end effector such that the second workpiece or a center of a workpiece holding position of the second end effector moves from a second start position to a second arc position of the arc positions.
6. 6. The robotic apparatus of claim 5, wherein the movement of the first workpiece from the first start position to the first arc position includes straight linear movement and/or curved movement.
7. 7. The robotic apparatus of claim 5, wherein the first start position is located within a processing chamber, and the second start position is located within a supply/output chamber.
8. 8. The robotic apparatus of claim 5, wherein the movement of the first workpiece from the first start position to the first arc position includes straight linear movement of a first length, and wherein the movement of the second workpiece from the second start position to the second arc position includes straight linear movement of a second length.
9. 9. The robotic apparatus of claim 8, wherein the control unit is configured to move the first end effector and the second end effector in symmetric motions during an entirety of the swapping operation when the first length is equal to the second length.
10. 10. The robotic apparatus of claim 8, wherein the control unit is configured to move the first end effector and the second end effector in nonsymmetric motions during a portion of the swapping operation when the first length is unequal to the second length.
11. 11. A method of transporting workpieces with a robotic apparatus, comprising: providing a robotic apparatus having: an arm member configured to pivot about a first axis; a first end effector pivotably connected to the arm member about a second axis, the first end effector having a first surface upon which a first workpiece can be received; a second end effector pivotably connected to the arm member about the second axis, the second end effector having a second surface upon which a second workpiece can be received; at least one drive unit configured to drive the arm member to pivot about the first axis, the at least one drive unit being configured to drive the first end effector to pivot about the second axis, the at least one drive unit being configured to drive the second end effector to pivot about the second axis; and a control unit configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector; and controlling the at least one drive unit to move the arm member, the first end effector and the second end effector to perform a swapping operation that includes the first end effector and the second end effector swapping arc positions disposed at opposite ends of an arc having a constant radius of curvature, wherein the at least one drive unit is controlled to move the arm member, the first end effector and the second end effector such that the first workpiece received on the first end effector and the second workpiece received on the second end effector each travel at equal and constant velocities along the arc.
12. 12. The method of claim 11, wherein the at least one drive unit is controlled to move the arm member, the first end effector and the second end effector such that the equal and constant velocities produce centripetal acceleration values acting upon the first workpiece and the second workpiece along the arc that do not exceed a predetermined acceleration limit.
13. 13. The method of claim 12, wherein the at least one drive unit is controlled to move the arm member, the first end effector and the second end effector during the swapping operation without exceeding the predetermined acceleration limit to retain the first workpiece and the second workpiece on the first end effector and the second end effector, respectively, solely with surface friction without use of a suction device and without use of an edge gripping device.
14. 14. The method of claim 11, wherein the first end effector and the second end effector each includes at least one of an edge-gripping device and a suction device.
15. 15. The method of claim 11, wherein the swapping operation further includes at least one of: moving the first end effector such that the first workpiece or a center of a workpiece holding position of the first end effector moves from a first start position to a first arc position of the arc positions; and moving the second end effector such that the second workpiece or a center of a workpiece holding position of the second end effector moves from a second start position to a second arc position of the arc positions.
16. 16. The method of claim 15, wherein the movement of the first workpiece from the first start position to the first arc position includes straight linear movement and/or curved movement.
17. 17. The method of claim 15, wherein the first start position is located within a processing chamber, and the second start position is located within a supply/output chamber.
18. 18. The method of claim 15, wherein the movement of the first workpiece from the first start position to the first arc position includes straight linear movement of a first length, and wherein the movement of the second workpiece from the second start position to the second arc position includes straight linear movement of a second length.
19. 19. The method of claim 18, wherein the control unit is configured to move the first end effector and the second end effector in symmetric motions during an entirety of the swapping operation when the first length is equal to the second length.
20. 20. The method of claim 18, wherein the control unit is configured to move the first end effector and the second end effector in nonsymmetric motions during a portion of the swapping operation when the first length is unequal to the second length.

Description

TITLE OF THE INVENTION APPARATUS AND METHOD FOR OPTIMIZING SWAP TIME CROSS-REFERENCE TO RELATED APPLICATION [0001] The present application claims priority to U.S. Provisional Application No. 63/523,942, filed on June 29, 2023, the entire contents of which are herein incorporated by reference. BACKGROUND OF THE INVENTION Field of the Invention [0002] The present invention relates to a robotic apparatus, robotic handling system, and method for transporting a workpiece between various positions. Discussion of the Background [0003] Automated transfer devices significantly improve the efficiency, speed, and reliability at which workpieces such as semiconductor wafers are processed. Automation is particularly useful in clean room environments. When robots are used for wafer transferring should quickly and precisely transfer a wafer between various locations to reduce manufacturing time and ensure sufficient yield. [0004] A need exists for devices that can increase the yield of a manufacturing operation, thereby reducing cost and increasing output over time. SUMMARY OF THE INVENTION [0005] The present disclosure advantageously describes a robotic apparatus comprising an arm member, a first end effector, a second end effector, at least one drive unit, and a control unit. The arm member is configured to pivot about a first axis. The first end effector is pivotably connected to the arm member about a second axis, and the first end effector has a first surface upon which a first workpiece can be received. The second end effector is pivotably connected to the arm member about the second axis, and the second end effector has a second surface upon which a second workpiece can be received. The at least one drive unit is configured to drive the arm member to pivot about the first axis. The at least one drive unit is configured to drive the first end effector to pivot about the second axis, and to drive the second end effector to pivot about the second axis. The control unit is configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector to perform a swapping operation that includes the first end effector and the second end effector swapping arc positions disposed at opposite ends of an arc having a constant radius of curvature. The control unit is configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector such that the first workpiece received on the first end effector and the second workpiece received on the second end effector each travel at equal and constant velocities along the arc. [0006] The present disclosure advantageously describes a method of transporting workpieces with a robotic apparatus, comprising: providing a robotic apparatus having: an arm member configured to pivot about a first axis; a first end effector pivotably connected to the arm member about a second axis, the first end effector having a first surface upon which a first workpiece can be received; a second end effector pivotably connected to the arm member about the second axis, the second end effector having a second surface upon which a second workpiece can be received; at least one drive unit configured to drive the arm member to pivot about the first axis, the at least one drive unit being configured to drive the first end effector to pivot about the second axis, the at least one drive unit being configured to drive the second end effector to pivot about the second axis; and a control unit configured to control the at least one drive unit to move the arm member, the first end effector and the second end effector. The method further comprises controlling the at least one drive unit to move the arm member, the first end effector and the second end effector to perform a swapping operation that includes the first end effector and the second end effector swapping arc positions disposed at opposite ends of an arc having a constant radius of curvature, wherein the at least one drive unit is controlled to move the arm member, the first end effector and the second end effector such that the first workpiece received on the first end effector and the second workpiece received on the second end effector each travel at equal and constant velocities along the arc. BRIEF DESCRIPTION OF THE DRAWINGS [0007] A more complete appreciation of the invention and many of the attendant advantages thereof will become readily apparent with reference to the following detailed description, particularly when considered in conjunction with the accompanying drawings, in which: [0008] FIGS. 1 A-1H are plan views of arms that can be employed with a robot according to exemplary embodiments of the present invention; [0009] FIG. 2 is a diagram illustrating a robot and a control unit according to an exemplary embodiment of the present invention; [0010] FIG. 3 is a block diagram illustrating a control unit and drive units according to an exemplary