Robotic system with packing mechanism

Patent metadata

Field	Value
Publication number	US-10696493-B1
Application number	US-201916428645-A
Country	US
Kind code	B1
Filing date	May 31, 2019
Priority date	May 31, 2019
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A method for operating a robotic system includes determining package groupings for placing available packages on a platform; generating a two-dimensional (2D) placement plan based on discretized models representative of the available packages and the platform; generating a three-dimensional (3D) stacking plan based on the 2D placement plan; and implementing the 3D stacking plan for placing the available packages on the platform.

First claim

We claim:

1. A method for operating a robotic system, the method comprising:
implementing a stacking plan for placing available packages on a platform using an end effector of a robotic arm and according to a three-dimensional (3D) mapping with one or more of the available packages placed on top of one or more other packages, wherein implementing the stacking plan includes:
identifying a package set representing the available packages designated for placement on the platform;
accessing discretized object models corresponding to the package set, wherein the discretized object models each represent physical dimensions, shapes, or a combination thereof of a package type in the available packages;
accessing a discretized platform model representing the platform where the available packages are to be placed;
determining, using at least one processor of the robotic system, package groupings based on the available packages, wherein the package groupings each represent a subgrouping of the available packages;
calculating, using the at least one processor, a processing order for the package groupings;
generating, using the at least one processor, placement plans based on the package groupings according to the processing order, wherein the placement plans represent two-dimensional (2D) mappings of the available packages along a horizontal plane; and
generating, using the at least one processor, the stacking plan based on converting the placement plans into 3D states, wherein the stacking plan represents the 3D mapping of the available packages and the placement plans correspond to layers within the 3D mapping.

2. The method of claim 1 , wherein implementing the stacking plan further includes:
calculating a packing sequence based on the stacking plan, wherein the packing sequence is for identifying a placing order for the available packages; and
implementing the stacking plan according to the packing sequence for transferring and placing the available packages.

3. The method of claim 2 , wherein:
calculating the packing sequence includes:
adjusting the placement plans by reassigning one or more of the available packages from a lower-layer placement plan to a higher-layer placement plan, and
calculating the packing sequence for each placement plan; and

implementing the stacking plan further includes implementing the stacking plan for placing the available packages layer-by-layer.

4. The method of claim 2 , wherein calculating the packing sequence includes analyzing the stacking plan according to heights of the available packages, placement locations of the available packages relative to a unit location, or a combination thereof.

5. The method of claim 1 , wherein determining the package groupings includes grouping the available packages according to specified priorities, fragility ratings, package weight ranges, heights, package types, or a combination thereof for the available packages.

6. The method of claim 1 , wherein calculating the processing order includes prioritizing the package groupings according to a number of packages therein, a combined horizontal area, weight ranges, fragility ratings, or a combination thereof.

7. The method of claim 6 , wherein calculating the processing order includes calculating the processing order for an initial set of the available packages before implementing the stacking plan.

8. The method of claim 6 , wherein calculating the processing order includes calculating the processing order for a remaining set of the available packages after or while implementing the stacking plan.

9. The method of claim 1 , wherein:
generating the placement plans includes:
identifying package types within the available packages; and
iteratively deriving placement locations for each of the available packages based on:
determining an initial placement location for one of the package types, and
deriving candidate placement locations for a next package based on one or more placement conditions; and

the placement plans each represent a unique placement combination of the initial placement location and the candidate placement locations of one or more of the available packages.

10. The method of claim 9 , wherein the one or more placement conditions include package dimensions, collision probabilities, fragility ratings, package weight ranges, separation requirements, package quantity conditions, or a combination thereof.

11. The method of claim 9 , wherein iteratively deriving placement locations includes:
tracking the placement plans across iterations;
calculating placement scores for the placement plans according to the one or more placement conditions; and
sequencing the placement plans according to the placement scores.

12. The method of claim 11 , wherein tracking the combinations includes:
generating and updating a search tree including the placement plans; and
stopping the iterations based on determining an empty source status or an unchanged score status.

13. The method of claim 9 , wherein the candidate placement locations are within a threshold distance from the initial placement location along a horizontal direction.

14. The method of claim 1 , wherein generating the stacking plan includes generating the stacking plan according to stacking rules regarding an overlap between a top package and a support package, an overhang of the top package over the support package, a center-of-mass (CoM) location of the top package relative to one or more support packages, a separation distance between two or more support packages, a difference in heights of two or more support packages, or a combination thereof.

15. The method of claim 1 , wherein:
generating the placement plans and generating the stacking plan include deriving candidate stacking scenarios;
each candidate stacking scenario is recursively or iteratively derived based on:
generating a lower 2D plan for forming a lower layer,
identifying one or more planar sections of the first candidate 2D plan, wherein each planar section represents adjacent and/or continuous horizontal top surfaces,
generating an upper 2D plan based on testing placement of remaining package groupings relative to the one or more planar sections,
calculating a placement score for the candidate stacking scenario at least based on a number of placed packages, and
stopping the iterations or the recursions based on determining an empty source status, a full layer status, or an unchanged score status; and

generating the stacking plan includes generating the stacking plan based on selecting one of the candidate stacking scenarios according to the placement score.

16. A robotic system comprising:
at least one processor; and
at least one memory device communicatively connected to the at least one processor and having stored thereon instructions that, when executed by the at least one processor, cause the robotic system to implement a stacking plan for placing available packages on a platform using an end effector of a robotic arm and according to a three-dimensional (3D) mapping with one or more of the available packages placed on top of one or more other packages,
wherein, to implement the stacking plan, the robotic system is configured to:
identify a package set representing the available packages designated for placement on the platform;
access discretized object models corresponding to the package set,
access a discretized platform model representing the platform where the available packages are to be placed;
determine package groupings based on the available packages, wherein the package groupings each represent a

Assignees

• Mujin Inc

Inventors

• Diankov Rosen Nilolaev
• Kanunikov Denys

Classifications

• B65G2814/0305

  Adding to the top · CPC title

• B65G61/00 Primary

  Use of pick-up or transfer devices or of manipulators for stacking or de-stacking articles not otherwise provided for · CPC title

• B65G57/22

  in layers each of predetermined arrangement · CPC title

• B65G57/03

  from above · CPC title

• B25J9/1694

  characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion · CPC title