SYSTEMS AND METHODS FOR OBJECT PROCESSING WITH PROGRAMMABLE MOTION DEVICES USING YAWING GRIPPERS
20230234216 · 2023-07-27
Inventors
- Bretton ANDERSON (Westford, MA, US)
- Jason YAP (Newton, MA, US)
- William Chu-Hyon McMahan (Cambridge, MA, US)
- Calvin TOOTHAKER (Medford, MA, US)
- William FARMER (Bolton, MA, US)
Cpc classification
B25J15/04
PERFORMING OPERATIONS; TRANSPORTING
B25J9/0009
PERFORMING OPERATIONS; TRANSPORTING
B25J9/0093
PERFORMING OPERATIONS; TRANSPORTING
B25J17/0225
PERFORMING OPERATIONS; TRANSPORTING
International classification
B25J9/00
PERFORMING OPERATIONS; TRANSPORTING
B25J9/10
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An end-effector system is disclosed for use with a programmable motion device. The end-effector system includes an arm attachment portion for attachment to an arm of the programmable motion device, an end-effector attachment portion for attachment to an end-effector for grasping objects, a rotational shaft portion for rotational attachment to the arm attachment portion, said rotational shaft portion being coupled to the end-effector attachment portion at a distal end thereof, and a motor system providing rotation of the rotational shaft portion as well as the end-effector attachment portion with respect to the arm attachment portion.
Claims
1. An end-effector system for use with a programmable motion device, said end-effector system comprising: an arm attachment portion for attachment to an arm of the programmable motion device; an end-effector attachment portion for attachment to an end-effector for grasping objects; a rotational shaft portion for rotational attachment to the arm attachment portion, said rotational shaft portion being coupled to the end-effector attachment portion at a distal end thereof; and a motor system providing rotation of the rotational shaft portion as well as the end-effector attachment portion with respect to the arm attachment portion.
2. The end-effector system as claimed in claim 1, wherein the motor system includes a worm screw for engagement with a spline gear attached to the rotational shaft portion.
3. The end-effector system as claimed in claim 2, wherein the rotational shaft portion is a spline shaft that includes a plurality of shaft splines, and wherein the motor system includes drive splines on an inner annular surface thereof that engages the shaft splines of the spline shaft.
4. The end-effector system as claimed in claim 3, wherein the spline gear includes teeth on an outer annular surface thereof for engaging the worm screw of the motor system.
5. The end-effector system as claimed in claim 1, wherein the end-effector attachment portion extends along an axial direction and is permitted to move along the axial direction with respect to the arm attachment portion.
6. The end-effector system as claimed in claim 5, wherein the axial movement of the end-effector attachment portion with respect to the arm attachment portion is spring biased.
7. The end-effector system as claimed in claim 1, wherein the rotational shaft portion includes a vacuum hose connector at a proximal end of the rotational shaft portion that is opposite the distal end, the vacuum hose connector being adapted to engage a vacuum hose terminus at a distal end of a vacuum hose.
8. The end-effector system as claimed in claim 7, wherein the vacuum hose connector includes an annular shaft coupling that engages a rounded annular hose coupling within the vacuum hose connector, forming an open ball joint structure.
9. The end-effector system as claimed in claim 8, wherein the engagement of the annular shaft coupling and the rounded annular hose coupling permits movement of the rotational shaft portion with respect to the vacuum hose terminus in two degrees of freedom.
10. The end-effector system as claimed in claim 1, wherein the motor system includes an exposed portion of a motor shaft for manual rotation of the motor shaft.
11. The end-effector system as claimed in claim 1, wherein the end-effector system includes a cup detection sensor system that includes a helical wiring portion that accommodates movement of the rotational shaft portion with respect to the arm attachment portion.
12. An end-effector system for use with a programmable motion device, said end-effector system comprising: an arm attachment portion for attachment to an arm of the programmable motion device, said arm attachment portion extending in an axial direction and including a spline gear with inwardly facing drive splines; an end-effector attachment portion for attachment to an end-effector for grasping objects; and a spline shaft portion received by the arm attachment portion, said spline shaft portion being coupled to the end-effector attachment portion at a distal end thereof, and including shaft splines that engage the drive splines of the spline gear to permit movement of the spline shaft with respect to the arm attachment portion in the axial direction.
13. The end-effector system as claimed in claim 12, wherein the movement of the spline shaft with respect to the arm attachment portion in the axial direction is spring biased.
14. The end-effector system as claimed in claim 12, wherein the arm attachment portion further includes a motor and a worm screw that engages the spline gear to cause the spline shaft to rotate with respect to the arm attachment portion.
15. The end-effector system as claimed in claim 12, wherein the spline shaft portion includes a vacuum hose connector at a proximal end of the spline shaft portion that is opposite the distal end, the vacuum hose connector being adapted to engage a vacuum hose terminus at a distal end of a vacuum hose.
16. The end-effector system as claimed in claim 15, wherein the vacuum hose connector includes an annular shaft coupling that engages a rounded annular hose coupling with the vacuum hose connector.
17. The end-effector system as claimed in claim 15, wherein the annular shaft coupling and the rounded annular hose coupling permits movement of the spline shaft portion with respect to the vacuum hose terminus in at least two degrees of freedom.
18. The end-effector system as claimed in claim 12, wherein the motor system includes an exposed portion of a motor shaft that is adapted for manual rotation of the motor shaft.
19. The end-effector system as claimed in claim 12, wherein the end-effector system includes a cup detection sensor system that includes a helical wiring portion that accommodates movement of the rotational shaft portion with respect to the arm attachment portion.
20. An end-effector system for use with a programmable motion device, said end-effector system comprising: an arm attachment portion for attachment to an arm of the programmable motion device; an end-effector attachment portion for attachment to an end-effector for grasping objects; and a rotational shaft portion for attachment to the arm attachment portion and the end-effector portion at a distal end thereof, said rotational shaft portion being rotatable with respect to the arm attachment portion and being axially movable with respect to the arm attachment portion.
21. The end-effector system as claimed in claim 20, wherein the end-effector system further includes a motor system providing rotation of the rotational shaft portion as well as the end-effector attachment portion with respect to the arm attachment portion.
22. The end-effector system as claimed in claim 21, wherein the motor system includes a worm screw for engagement with a spline gear that is slidably attached to the rotational shaft portion.
23. The end-effector system as claimed in claim 20, wherein the rotational shaft portion is a spline shaft that includes a plurality of shaft splines, and wherein the spline gear includes drive splines that engage the shaft splines of the spline shaft.
24. The end-effector system as claimed in claim 23, wherein the spline gear includes teeth on an outer annular surface thereof for engaging a worm screw of the motor system.
25. The end-effector system as claimed in claim 20, wherein the end-effector attachment portion extends along an axial direction and is permitted to move along the axial direction with respect to the arm attachment portion.
26. The end-effector system as claimed in claim 25, wherein the axial movement of the end-effector attachment portion with respect to the arm attachment portion is spring biased.
27. The end-effector system as claimed in claim 20, wherein the motor system includes an exposed portion of a motor shaft that is adapted for manual rotation of the motor shaft.
28. The end-effector system as claimed in claim 27, wherein the exposed portion includes a surface that facilitates gripping.
29. The end-effector system as claimed in claim 20, wherein the end-effector system includes a cup detection sensor system that includes a helical wiring portion that accommodates movement of the rotational shaft portion with respect to the arm attachment portion.
30. The end-effector system as claimed in claim 29, wherein the helical wiring portion includes a first helical portion that accommodates axial movement of the rotational shaft portion with respect to the arm attachment portion.
31. The end-effector system as claimed in claim 29, wherein the helical wiring portion includes a second helical portion within the rotational shaft portion that accommodates rotational movement of the rotational shaft portion with respect to the arm attachment portion.
32. The end-effector system as claimed in claim 29, wherein the cup detection sensor system includes an elastomeric band that facilitates passage of sensor wiring into the rotational shaft portion while maintaining sufficient vacuum at the end-effector.
33. A method of operating a programmable motion device including an end-effector, said method comprising: approaching an object to be grasped along a first direction with a distal end of the end-effector; grasping the object with the distal end of the end-effector; and rotating the distal end of the end-effector with the object about a first axis that is substantially parallel with the first direction.
34. The method of claim 33, wherein the first axis is coincident with the first direction.
35. The method of claim 33, wherein the method further includes permitting movement of the distal end of the end-effector with respect to the programmable motion device along the first axis.
36. The method of claim 33, wherein the movement of the distal end of the end-effector with respect to the programmable motion device is spring biased.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The following description may be further understood with reference to the accompanying drawings in which:
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[0040] The drawings are shown for illustrative purposes only.
DETAILED DESCRIPTION
[0041] In accordance with various aspects, the invention provides an end-effector system for programmable motion devices (e.g., robotic systems) that provides high flow vacuum to grasp objects. The high flow vacuum is provided at a vacuum cup as the end-effector of the end-effector system that is coupled to a high flow vacuum system. The vacuum cup is attached to a cup attachment portion, which is in turn attached to an arm attachment portion that is attached to an articulated arm of the robotic system.
[0042] Manipulating the position and orientation of the end-effector requires movement of different joints (sometimes many of the joints) of the articulated arm. While a rigid object has six degrees of freedom (X, Y, Z, yaw, pitch, roll), each joint of an articulated arm generally has one degree of freedom. Through a combination of changing multiple joints, robotic systems may change the position and orientation of an end-effector. To move an end-effector from one position or even orientation to another, typically involves a more complex set of movements of a plurality of joints rather than simply moving one joint. Each joint however, typically has a limited range (and single dimension) of movement (such as for example, an elbow joint). In view of this, sometimes during use, a desired position/orientation of an end-effector and a current position/orientation of the end-effector are not connected by any viable path. In other words, all paths in, for example, 6 degrees of freedom are blocked. Also, sometimes a viable path may involve significant movement of a very heavy portion of the articulated arm, slowing throughput with time loss and energy consumption.
[0043] Path blockages may result from portions of the articulated arm itself, from structure(s) in the environment (such as support structure), and may result from the use of high flow vacuum sources, which require large diameter hoses that may not closely follow the sections and joints of the articulated arm. The high flow vacuum source may, for example, provide at the vacuum cup of an air-flow of at least about 100 cubic feet per minute, and a vacuum pressure at the vacuum cup of no more than about 100,000 Pascals below atmospheric, or no more than about 85,000 Pascals below atmospheric or no more than about 65,000 Pascals below atmospheric. The use of the large diameter hose generally requires that the vacuum cup be mounted in an offset position with respect to an end of the articulated arm to minimize binding of the hose. This unfortunately also has a significant impact on limiting movements of the end effector. For yawing motions, for example, where it may be desired to rotate an object about a z-axis (while grasping an object from above), a gripper may not hold an object in a way that rotation of the last joint would yaw the gripper. Additionally, in certain applications it is further desired to be able to determine a pose of a grasped object, requiring the presence of any of sensors and scanners to view the object and communicate with a processing system, where software may prescribe a desired re-orientation and path for the object.
[0044] In accordance with various aspects, the invention provides an end-effector system with a mechanical apparatus that rotates (e.g., about 60 degrees/second to about 100 degrees/second, such as about 70 degrees/second or about 90 degrees/second) a vacuum cup gripper without impeding the seal of the vacuum chamber, has enough torque to rotate a mass (e.g., less than 10 lbs - 3 lbs, such as less than 7 lbs or less than 5 lbs) of a held object, and may rotate +/- 90 degrees from a home position. In accordance with different aspects as discussed below, the end-effector system may include a worm gear drive system or a belt-driven rotation system to rotate a shaft in the end-effector system. The rotation system is not required to be synchronized with the movement of the other joints of the robotic system, is robust in design, and includes a precise rotational zero position that is easily found.
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[0047] In particular,
[0048] A cup detection sensor system may include a first helical section 110 that attaches to the vacuum hose connector 54 at coupling 112 and accommodates axial movement of the vacuum hose connector 54 with respect to the arm attachment section 34. The cup detection sensor system may also include a second helical section 111 and a cup detection connector 113 that attaches to an inductive cup detection sensor 120 as further shown in
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[0050] A fixed stop 65 limits the rotation of the spline gear (to about 355 degrees) by blocking a stop post 49 on the spline gear 46. The stop post 49 may be positioned slightly in-set into a core shaft of the spline gear 46 for additional support when contacting the fixed stop 65. As further shown in
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[0052] As noted above, the cup detection sensor system includes first helical section 110 that sits outside of the rotational spline shaft portion 50 and accommodates axial movement of the rotational spline shaft portion 50 with respect to the arm attachment section 34, as well as the second helical section 111 that accommodates the limited range of rotational movement of the rotational spline shaft portion 50 with respect to the arm attachment second 34. An elastomeric band 122 provides a sealed passage of the wiring from the cup detection connector 113 outside the rotational spline shaft portion 50 to the second helical section 111 within the rotational spline shaft portion 50. The sensor coupling 112 provides a sealed passage of the wiring from within the rotational spline shaft portion 50 to the first helical section 110 outside of the rotational spline shaft portion 50. The cup detection system thereby provides for communication of cup detection signal information through a portion of the rotational spline shaft portion 50 (avoiding becoming ensnared in the environment), yet also permits rotational and axial movement of the portion 50 with respect to the arm attachment section 34 while maintaining a high vacuum within the rotational spline shaft portion 50.
[0053] The drive splines 63 of the spline gear 46 of the arm attachment section 34 may travel relative the shaft splines 62 of the rotational spline shaft portion 50, permitting the relative axial movement of the rotational spline shaft portion 50 with respect to the arm attachment section 34. This movement may be biased by a spring 70 that is fixed at a distal end on a shoulder 68 of the rotational spline shaft portion, and is urged at a proximal end to the underside 47 of roller bearing set 45 as shown in
[0054] An annular magnet 68 is also provided on the rotational spline shaft portion 50, and a magnetic sensor 76 (shown in
[0055] The distal end of the rotational spline shaft portion 50 is coupled to the cup attachment portion 56 to which is attached the vacuum cup 58. When the rotational spline shaft portion 50 rotates within the arm attachment portion 34, the cup attachment portion 56 and vacuum cup 58 rotate with the rotational spline shaft portion 50. Rotation of the spline gear 46 therefore directly causes rotation of the vacuum cup 58 as well as any object grasped by the vacuum cup 58. The cup detection system detects the presence of a vacuum cup 58 on the cup attachment portion 56, e.g., using the inductive sensor 120. The system 30 may also determine which specific sized cup is attached to the cup attachment portion 56 using for example, specific known arrangements of magnets for each vacuum cup or specific known lengths of push pins for each vacuum cup.
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[0057] The ability of the end-effector system 30 to permit the arm attachment portion 34 to move along the axial direction of the rotational spline shaft portion 50, facilitates placement of objects without imparting contact forces on the articulated arm of the programmable motion device 12. Rotation, therefore of the rotational spline shaft portion 50 with respect to the arm attachment portion 34 is also not negatively impacted by the axial movement of the arm attachment portion 34 with respect to the rotational spline shaft portion 50. In fact, the rotation system 40 may cause rotation of the rotational spline shaft portion 50 during axial movement of the arm attachment portion 34 with respect to the rotational spline shaft portion 50. The rotation system and the spring biased axial movement response system are therefore independent of one another.
[0058] Through this use of the spring 70, the force acting against axial movement of the arm attachment portion 34 with respect to the rotational spline shaft portion 50 increases with distance of axial movement, and the arm attachment portion 34 returns to its original axial position with respect to the rotational spline shaft portion 50 when the end-effector system 30 is moved away from the object 72. When the force acting on the spring 70 is released, the relative position of the rotational spine shaft portion 50 and the arm attachment section 34 will return to a home position governed by the stop assembly 64 as shown in
[0059] Because the rotational spline shaft portion 50 rotates, the coupling between the proximal end 52 of the rotational spline shaft portion 50 and the vacuum hose 22 must permit at least some rotation of the rotational spline shaft portion 50 with respect to the distal end of the vacuum hose 22. With reference to
[0060] In accordance with various further aspects, the end-effector system may include a rotation system that uses a belt drive system.
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[0065] A centering feature (such as radial rotation alignment feature) may be positioned at a center of the limited rotational range. In other applications, one of the hard-stop shoulders (e.g., 294) may be used as a rotational home position. If the motor 240 (and 40 above) is a servo motor, a closed loop control system may be used to provide robust torque control allowing hard-stop contact at full speed and/or power. If the motor 240 (and 40 above) is an integrated stepper motor, the motor may similarly be robust, also allowing hard-stop contact at full speed and/or power, for example, by monitoring forward and backward stepper increments.
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[0069] Those skilled in the art will appreciate that numerous modifications and variations may be made to the above disclosed embodiments without departing from the spirit and scope of the present invention.