Robotic navigation and mapping

• US 9,908,702 B2
• Filed: 02/05/2016
• Issued: 03/06/2018
• Est. Priority Date: 02/05/2016
• Status: Active Grant

• Current Assignee: InVia Robotics Inc.
• Original Assignee: InVia Robotics Inc.
• Inventors: Elazary, Lior, Voorhies, Randolph Charles, Parks, II, Daniel Frank
• Primary Examiner(s): CUMBESS, YOLANDA RENEE
• Application Number:
  US15/017,223
• Publication Number:
  US 20170225891A1
• Time in Patent Office: 760 Days
• Field of Search: None
• CPC Class Codes: B65G 1/1375 the orders being assembled on a commissioning stacker-crane or truck
• CPC Class Codes: B65G 2203/041 Camera
• CPC Class Codes: G05D 1/0234 using optical markers or beacons optical beacons per se G01S1/70
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

Some embodiments efficiently locate and map item locations in a distribution site using robots and a set of markers that the robots can scan without cessation of movement. Some embodiments optimally position a robot for item retrieval or placement. The optimal position is determined by affine transform computation or feature mapping. The robot first aligns itself according to the expected item position as indicated by one or more of the markers. The alignment is determined based on size and orientation of the markers in images obtained using the robot'"'"'s camera. The robot then aligns itself according to the actual item position. Here, the repositioning is determined based on size and orientation of the actual item in images obtained using the robot'"'"'s camera. Using the robot cameras and feature mapping, robots can traverse the shelves to identify and map item location therein.

Claims

1. A method for item retrieval within a distribution site using a robot, the method comprising:

moving said robot within the distribution site across a face of a structure without pause;

scanning by said robot, a plurality of markers positioned about said face of said structure as the robot moves without pause across said face of said structure;

stopping said robot at a first position before a particular marker of the plurality of markers in response to said scanning, the particular marker indicating a position of an item to be retrieved from said structure by said robot;

obtaining an image of an item at said first position using a camera of said robot;

repositioning the robot in front of the structure from the first position to a different second position based on orientation or size of the item in said image deviating from an expected orientation or size of the item, wherein said repositioning to the second position corrects the orientation or size of the item in a subsequent image from deviating from the expected orientation or size;

retrieving at the robot second position, the item from the structure to the robot using a retrieval mechanism of the robot.

2. The method of claim 1 further comprising computing distance and orientation of the robot to the item at the first position based on the orientation and the size of the item in said image, and wherein said repositioning to the second position aligns the robot a specified distance from the item and further centers orientation of the robot relative to the item.

3. The method of claim 1, wherein stopping said robot at the first position comprises obtaining an image of the particular marker using the robot camera and granularly adjusting the robot position to cause the particular marker to appear at a predefined size and orientation in the robot camera.

4. The method of claim 3, wherein stopping said robot further comprises computing a perspective transform of the particular marker image and determining adjustments to position the robot at the first position.

5. The method of claim 3, wherein repositioning the robot to the second position comprises granularly adjusting the robot position from the first position to the second position to cause the item to appear at the expected size or orientation in the robot camera.

6. The method of claim 5, wherein granularly adjusting the robot position comprises moving the robot in three dimensions in order for the size or orientation of the item in the subsequent image to match the expected size or orientation from a prior reference image.

7. The method of claim 1 further comprising extracting a set of item features from the item image.

8. The method of claim 7 further comprising comparing size and orientation of the set of item features against features of a reference image of said item.

9. The method of claim 8, wherein said repositioning comprises determining from the robot first position, a set of movements aligning the size and orientation of the set of item features against the features of the reference image.

10. The method of claim 1 wherein said repositioning comprises adjusting the robot lateral position relative to the structure, the robot distance from the structure, and the robot height.

11. A method for mapping item locations in a distribution site with a robot, the robot comprising a motorized base, at least one camera, and a processor, the method comprising:

positioning the robot at a predefined position relative to a faç

ade of an item containing structure in the distributed site;

scanning without pause, a plurality of identifiers positioned about the faç

ade of the item containing structure as the robot traverses across the item containing structure;

obtaining a plurality of images with said camera during said traversal, the plurality of images capturing different items that are stored on the item containing structure and different identifiers of the plurality of identifiers presented adjacent to the different items;

identifying a specific product from a particular image of the plurality of images based on at least one feature of an item in the particular image matching a cataloged feature of the specific product; and

mapping a location of the specific product to at least one identifier captured in the particular image, wherein the particular image captures the item identified as the specific product adjacent to the at least one identifier.

12. The method of claim 11 further comprising sending said mapping of the specific product location to a plurality of other robots operating within the distribution site.

13. The method of claim 11 further comprising sending said mapping of the specific product location to a database, said database storing locations of a plurality of different products in the distribution site.

14. The method of claim 11, wherein positioning the robot comprises obtaining an image of an identifier of the plurality of identifiers before the robot and computing a distance and orientation of the robot based on the identifier image.

15. The method of claim 14, wherein positioning the robot further comprises adjusting the distance and orientation of the robot to match a predefined distance and orientation of the predefined position.

16. The method of claim 11, wherein the at least one feature of the item is one or more of a barcode, coloring, lettering, size, and shape of the item.

17. The method of claim 11, wherein said mapping comprises mapping the location of the specific product according to a first identifier of the plurality of identifiers designating one end of the item and a different second identifier of the plurality of identifiers designating an opposite end of the item.

18. An item retrieval system comprising:

a first set of low resolution markers;

a second set of high resolution markers; and

a robot comprising a motorized base, a camera, and a processor, the robot navigating at a first speed and at a first distance from the first set of low resolution markers until arriving at a particular low resolution marker, and navigating at a second speed that is slower than the first speed and at a second distance that is closer than the first distance until arriving at a particular high resolution marker.

19. An item retrieval system comprising:

a plurality of item containing structures arranged to a plurality of aisles;

a set of first identifiers positioned about a common plane along an outward face of the plurality of item containing structures;

a set of second identifiers positioned about a side of each item containing structure at an end of each aisle of the plurality of aisles; and

a robot comprising a motorized base, a camera, and a processor, the robot navigating to a particular item located in a particular item containing structure of the plurality of item containing structures, wherein said navigating comprises;

(i) traversing the robot across the plurality of aisles, (ii) continuously scanning by the robot, the set of second identifiers with the camera as the robot traverses across the plurality of aisles, (iii) traversing down a particular aisle of the plurality of aisle in response to detecting a particular second identifier from the set of second identifiers during said scanning, the particular second identifier identifying a subset of the set of first identifiers, and (iv) continuously scanning by the robot, the subset of first identifiers with the camera while the robot traverses the particular aisle until arriving at the particular item location designated by a first identifier of the subset of first identifiers.