Robotic Navigation and Mapping

• US 20170225891A1
• Filed: 02/05/2016
• Published: 08/10/2017
• Est. Priority Date: 02/05/2016
• Status: Active Grant

• Current Assignee: InVia Robotics Inc.
• Original Assignee: InVia Robotics, LLC
• Inventors: Elazary, Lior, Voorhies, Randolph Charles, Parks, II, Daniel Frank
• Granted Patent: US 9,908,702 B2
• Time in Patent Office: Days
• 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 using a robot, the method comprising:

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

stopping said robot at a first position before a particular marker of the plurality of markers indicating position of an item to be retrieved by said robot;

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

repositioning the robot from the first position to a different second position based on appearance of the item in said image, wherein the second position corrects the robot'"'"'s position to account for deviations in the item position from an expected position identified by the particular marker;

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 the robot distance and orientation to the item at the first position based on appearance of the item in said image, and wherein said repositioning optimally aligns the distance and orientation of the robot relative to the item for on-center and on-balanced retrieval of said 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 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 a predefined size and orientation in the robot camera.

5. The method of claim 4, wherein granularly adjusting the robot position comprises moving the robot in three dimensions in order for the size and orientation of item in the robot camera to match a size an orientation of the item from a prior image.

6. 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.

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:

scanning without pause, a plurality of identifiers positioned about an item containing structure of the distribution site as the robot traverses across said structure;

obtaining a plurality of images of said structure with said camera during said traversal;

associating each image of the plurality of images to at least one identifier of the plurality of identifiers closest to the robot when obtaining the image;

identifying an item from a particular image of the plurality of images based on an item feature in the particular image matching a cataloged feature of the item; and

mapping a location of the item to the at least one identifier associated with the particular image.

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

13. The method of claim 11 further comprising sending said location to item mapping to a database storing locations of a plurality of items of the distribution site.

14. The method of claim 11 further comprising positioning the robot at a predefined position relative to the structure before said scanning and obtaining.

15. The method of claim 14, 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.

16. The method of claim 15, 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.

17. The method of claim 11, wherein the feature of the item is one of a barcode, coloring, lettering, size, and shape of the item.

18. The method of claim 11, wherein said mapping comprises mapping the item location 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.

19. 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.

20. 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 by continuously scanning the set of second identifiers with the camera as the robot traverses across the plurality of aisles until arriving at an aisle identified by a particular second identifier of the set of second identifiers identifying a subset of the set of first identifiers and by continuously scanning the set of first identifiers with the camera as the robot traverses the aisle until arriving at the particular item location designated by a first identifier of the subset of first identifiers.