Learning force limits of items for use in GCU optimization

• US 10,504,056 B1
• Filed: 12/06/2016
• Issued: 12/10/2019
• Est. Priority Date: 12/06/2016
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Stubbs, Andrew, Claretti, Ennio, Marchese, Andrew D., Barrett, Samuel Rubin
• Primary Examiner(s): Glass, Russell S
• Application Number:
  US15/371,022
• Time in Patent Office: 1,099 Days
• Field of Search: 705 28
• CPC Class Codes: B25J 9/163 learning, adaptive, model based, rule based expert control
• CPC Class Codes: G01L 5/0028 Force sensors associated with force applying means G01L5/0052, G01L5/0057, G01L5/0061 take precedence
• CPC Class Codes: G05B 19/402 characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/39322 Force and position control
• CPC Class Codes: G05B 2219/39505 Control of gripping, grasping, contacting force, force distribution
• CPC Class Codes: G06F 16/235 Update request formulation
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

Described herein are techniques for optimizing gross cubic utilization of inventory space by compressing items into closer proximity. In some embodiments, the inventory system selects an initial force limit to which an item to be stored may be subjected. The inventory system may cause a robotic arm to grasp the item and to push that item into a determined storage location. The inventory system then pushes the item into the storage location while applying a force up to the initial force limit to the item. While monitoring the position of the item, the inventory system may detect that the changes in position of the item are decreasing or stopping and determine that the item is approaching its force limit. The inventory system then updates database records with the force limit associated with the item.

Claims

1. A computer-implemented method comprising:

identifying a placement location for an item associated with force limit information;

determining a current force limit associated with the item;

causing a robotic arm to position the item proximate to the placement location;

causing the robotic arm to apply the current force limit to move the item against one or more additional items;

while applying the current force limit to the item, monitoring a rate of change in the position of the item with respect to time;

calculating, based on the rate of change in the position of the item, a new force limit for the item; and

updating the force limit information for the item with the new force limit.

2. The computer-implemented method of claim 1, wherein the current force limit is determined based on a type of the item.

3. The computer-implemented method of claim 1, wherein the current force limit is determined based on a size and mass of the item.

4. The computer-implemented method of claim 1, wherein the placement location is determined based at least in part on a size or shape of the item.

5. An inventory management system comprising:

at least one robotic arm assembly;

a processor; and

a memory including instructions that, when executed by the processor, cause the inventory management system to, at least;

remove an item from a first location;

determine a second location to receive the item, the second location determined based on an attribute of the item;

determine a level of force to be applied to the item;

move the item into the second location by applying the determined level of force;

monitor a rate of change in position of the item with respect to time; and

update the level of force based on the rate of change in the position of the item.

6. The inventory management system of claim 5, wherein the attribute of the item is a size or shape of the item.

7. The inventory management system of claim 5, wherein the second location is determined to maximize a number of items stored in an inventory space.

8. The inventory management system of claim 5, wherein the attribute of the item is a fragility of the item.

9. The inventory management system of claim 5, wherein the level of force is updated based on determining that the rate of change in the position of the item is below a threshold value.

10. The inventory management system of claim 5, wherein the instructions further cause the inventory management system to determine a compressible size of the item based on the level of force.

11. The inventory management system of claim 5, wherein the rate of change in the position of the item decreases with respect to time.

12. The inventory management system of claim 11, wherein the level of force is calculated based on a negative slope of the rate of change in the position.

13. An inventory system, comprising:

a robotic arm configured to interact with one or more inventory items;

a processor; and

a memory including instructions that, when executed by the processor, cause the inventory system to, at least;

identify a placement location for an item associated with force limit information;

determine a current force limit associated with the item;

cause the robotic arm to position the item proximate to the placement location;

cause the robotic arm to apply the current force limit to move the item against one or more additional items;

while applying the current force limit to the item, monitor a rate of change in the position of the item with respect to time;

calculate, based on the rate of change in the position of the item, a new force limit for the item; and

update force limit information for the item with the new force limit.

14. The inventory system of claim 13, wherein the instructions, when executed by the processor, further cause the inventory system to identify the item using one or more image processing techniques.

15. The inventory system of claim 13, wherein the instructions, when executed by the processor, further cause the inventory system to determine a pose appropriate for the item.

16. The inventory system of claim 15, wherein moving the item against the one or more additional items comprises manipulating the item into the determined pose.

17. The inventory system of claim 13, wherein moving the item against the one or more additional items comprises pushing the item against the one or more additional items to position the item in a storage location.

18. The inventory system of claim 17, wherein the instructions, when executed by the processor, further cause the inventory system to determine a level of compressibility for at least one item of the one or more additional items.

19. The inventory system of claim 13, wherein the new force limit is calculated upon detecting that a value for the rate of change in the position of the item is different from an expected value, wherein the expected value is determined based on a level of compressibility associated with the item.

20. The inventory system of claim 13, wherein the rate of change in position of the item is monitored using one or more machine vision techniques.