Systems and methods for optical target based indoor vehicle navigation

Patent metadata

Field	Value
Publication number	US-12140963-B2
Application number	US-202318481571-A
Country	US
Kind code	B2
Filing date	Oct 5, 2023
Priority date	Feb 23, 2018
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

Vehicles, systems, and methods for navigating or tracking the navigation of a materials handling vehicle along a surface that may include a camera and vehicle functions to match two-dimensional image information from camera data associated with the input image of overhead features with a plurality of global target locations of a warehouse map to generate a plurality of candidate optical targets, an optical target associated with each global target location and a code; filter the targets to determine a candidate optical target; decode the target to identify the associated code; identify an optical target associated with the identified code; determine a camera metric relative to the identified optical target and the position and orientation of the identified optical target in the warehouse map; calculate a vehicle pose based on the camera metric; and navigate the materials handling vehicle utilizing the vehicle pose.

First claim

What is claimed is:

1. A materials handling vehicle comprising a camera communicatively coupled to a vehicular processor of the materials handling vehicle for capturing an input image of overhead features, wherein the vehicular processor executes vehicle functions comprising:
generating a plurality of feature candidates from the overhead features in the input image;
extracting one or more active target candidates from the feature candidates;
verifying the active target candidates in the input image to generate a detected active target;
decoding a pattern of the detected active target to generate an identified code;
identifying an optical target associated with the identified code to determine an identified optical target representative of the overhead features in the input image;
determining a camera metric comprising representations of a distance and an angle of the camera relative to the identified optical target and a position and orientation of the identified optical target in a warehouse map in response to the determination of the identified optical target;
calculating a vehicle pose based on the camera metric;
determining whether the materials handling vehicle is localized or lost;
updating a current estimated pose based on the vehicle pose in response to a determination that the materials handling vehicle is localized;
resetting the current estimated pose to the vehicle pose in response to a determination that the materials handling vehicle is lost; and
navigating the materials handling vehicle utilizing the updated or reset estimated pose.

2. The materials handling vehicle of claim 1 , wherein the extraction of the active target candidates comprises:
filtering points of the feature candidates to generate feature candidate points;
extracting candidate target fragments from the feature candidate points;
aggregating the candidate target fragments into lines; and
generating the active target candidates from the lines.

3. The materials handling vehicle of claim 2 , wherein the validation of the active target candidates comprises removing the active target candidates that have sizes beyond a predetermined size range or lack associations with a code.

4. The materials handling vehicle of claim 1 , wherein the validation of the active target candidates comprises removing the active target candidates that have sizes beyond a predetermined size range or lack associations with a code.

5. The materials handling vehicle of claim 1 , wherein the determination of the materials handling vehicle being lost or localized comprises:
determining whether the materials handling vehicle left an area indicated in the warehouse map or whether the materials handling vehicle lacked a capability of determining the current estimated pose based on the overhead features in the past;
determining that the materials handling vehicle is lost in response to a determination that the materials handling vehicle left the area or lacked the capability of determining the current estimated pose; and
determining that the materials handling vehicle is localized in response to a determination that the materials handling vehicle remained in the area indicated in the warehouse map or was capable of determining the current estimated pose.

6. The materials handling vehicle of claim 2 , wherein the determination of the materials handling vehicle being lost or localized comprises:
determining whether the materials handling vehicle left an area indicated in the warehouse map or whether the materials handling vehicle lacked a capability of determining the current estimated pose based on the overhead features in the past;
determining that the materials handling vehicle is lost in response to a determination that the materials handling vehicle left the area or lacked the capability of determining the current estimated pose; and
determining that the materials handling vehicle is localized in response to a determination that the materials handling vehicle remained in the area indicated in the warehouse map or was capable of determining the current estimated pose.

7. The materials handling vehicle of claim 3 , wherein the determination of the materials handling vehicle being lost or localized comprises:
determining whether the materials handling vehicle left an area indicated in the warehouse map or whether the materials handling vehicle lacked a capability of determining the current estimated pose based on the overhead features in the past;
determining that the materials handling vehicle is lost in response to a determination that the materials handling vehicle left the area or lacked the capability of determining the current estimated pose; and
determining that the materials handling vehicle is localized in response to a determination that the materials handling vehicle remained in the area indicated in the warehouse map or was capable of determining the current estimated pose.

8. The materials handling vehicle of claim 4 , wherein the determination of the materials handling vehicle being lost or localized comprises:
determining whether the materials handling vehicle left an area indicated in the warehouse map or whether the materials handling vehicle lacked a capability of determining the current estimated pose based on the overhead features in the past;
determining that the materials handling vehicle is lost in response to a determination that the materials handling vehicle left the area or lacked the capability of determining the current estimated pose; and
determining that the materials handling vehicle is localized in response to a determination that the materials handling vehicle remained in the area indicated in the warehouse map or was capable of determining the current estimated pose.

9. The materials handling vehicle of claim 1 , wherein each optical target comprises a plurality of light emitting diodes (LEDs).

10. The materials handling vehicle of claim 1 , wherein each optical target comprises a plurality of light emitting diodes (LEDs) covered by respective angular diffusion lenses configured to attenuate a forward brightness and increase an associated angular sideways brightness such that each LED has an angular emission characteristic comprising a higher energy emission toward angular side directions compared to a forward facing direction of each LED.

11. The materials handling vehicle of claim 1 , wherein each active target is a unique active target and comprises a plurality of point light sources arranged in a pattern defining a code for each respective unique active target as a respective unique code.

12. The materials handling vehicle of claim 1 , wherein:
each active target comprises a plurality of point light sources mounted on a bar that is configured for attachment to a ceiling as an overhead feature of the overhead features; and
the plurality of point light sources comprises a light pattern as a code for each respective active target.

13. The materials handling vehicle of claim 1 , wherein each optical target comprises a series of magnetic mounts disposed on a back surface opposite a front surface on which a plurality of point light sources are mounted, the series of magnetic mounts configured to mount each optical target against a ceiling to comprise an overhead feature of the overhead features.

14. The materials handling vehicle of claim 1 , wherein each optical target comprises a center marker.

15. The materials handling vehicle of claim 1 , wherein each optical target comprises an end marker.

16. A method of navigating a materials handling vehicle along an inventory transit surface, wh

Assignees

• Crown Equip Corp

Inventors

• Haeusler Ralf
• Park Stuart
• Bell Mark

Classifications

• G05D2111/54

  for measuring the travel distances, e.g. by counting the revolutions of wheels · CPC title

• G05D2111/10

  Optical signals · CPC title

• G06V20/56

  exterior to a vehicle by using sensors mounted on the vehicle · CPC title

• G05D1/646

  Following a predefined trajectory, e.g. a line marked on the floor or a flight path · CPC title

• G05D1/644

  Optimisation of travel parameters, e.g. of energy consumption, journey time or distance · CPC title