Method, system and apparatus for detecting support structure obstructions

Patent metadata

Field	Value
Publication number	US-11341663-B2
Application number	US-201916429516-A
Country	US
Kind code	B2
Filing date	Jun 3, 2019
Priority date	Jun 3, 2019
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

A method in an imaging controller of detecting obstructions on a front of a support structure includes: obtaining (i) a point cloud of the support structure and an obstruction, and (ii) a support structure plane corresponding to the front of the support structure; for each of a plurality of selection depths: selecting a subset of points from the point cloud based on the selection depth; detecting obstruction candidates from the subset of points and, for each obstruction candidate: responsive to a dimensional criterion being met, determining whether the obstruction candidate meets a confirmation criterion; when the obstruction candidate meets the confirmation criterion, identifying the obstruction candidate as a confirmed obstruction; and presenting obstruction detection output data including the confirmed obstructions.

First claim

The invention claimed is:

1. A method in an imaging controller of detecting data capture obstructions on a front of a support structure, the method comprising:
obtaining (i) a point cloud of the support structure and a data capture obstruction disposed on the front of the support structure, and (ii) a support structure plane corresponding to the front of the support structure;
for each of a plurality of selection depths:
selecting a subset of points from the point cloud based on a selection depth;
detecting obstruction candidates associated with the data capture obstruction from the subset of points and, for each obstruction candidate:
responsive to determining that a dimension of the obstruction candidate meets a dimensional criterion, determining whether the obstruction candidate meets a confirmation criterion;
when the obstruction candidate meets the confirmation criterion, identifying the obstruction candidate as the data capture obstruction; and

presenting obstruction detection output data including the data capture obstruction.

2. The method of claim 1 , wherein determining whether the obstruction candidate meets the confirmation criterion includes at least one of:
determining whether the obstruction candidate exceeds a minimum obstruction dimension;
determining whether the obstruction candidate has a predetermined obstruction shape; and
determining whether the obstruction candidate has a predetermined obstruction orientation.

3. The method of claim 1 , wherein determining whether the obstruction candidate meets the confirmation criterion includes determining whether the obstruction candidate has been detected at a threshold number of previous selection depths.

4. The method of claim 3 , further comprising:
when the obstruction candidate has not been detected at the threshold number of previous selection depths, discarding the obstruction candidate.

5. The method of claim 1 , further comprising:
responsive to the dimensional criterion not being met, storing the obstruction candidate in the memory for evaluation at a subsequent selection depth.

6. The method of claim 1 , further comprising:
selecting a set of points from the point cloud corresponding to an obstruction region;
wherein the subset of points is selected from the obstruction region.

7. The method of claim 1 , further comprising setting the selection depths by:
decrementing a depth of the support structure plane by a coarse interval to set a first selection depth; and
incrementing the first selection depth by a fine interval to set a second selection depth.

8. The method of claim 1 , wherein selecting the subset of points includes selecting the points having depths smaller than the selection depth.

9. The method of claim 1 , wherein detecting obstruction candidates comprises:
generating a two-dimensional projection of the selected subset of points;
detecting contiguous sets of points in the projection; and
generating a bounding box corresponding to each contiguous set.

10. The method of claim 9 , wherein detecting obstruction candidates further comprises:
determining whether the bounding box overlaps with a previously detected obstruction candidate; and
when the bounding box overlaps with a previously detected obstruction candidate, storing an indication of the previously detected obstruction candidate with the bounding box.

11. The method of claim 1 , wherein the dimensional criterion is a threshold width.

12. A computing device, comprising:
a memory;
an imaging controller connected with the memory, the imaging controller configured to:
obtain (i) a point cloud of the support structure and a data capture obstruction disposed on a front of the support structure, and (ii) a support structure plane corresponding to the front of the support structure;
for each of a plurality of selection depths:
select a subset of points from the point cloud based on a selection depth;
detect obstruction candidates associated with the data capture obstruction from the subset of points and, for each obstruction candidate:
responsive to determining that a dimension of the obstruction candidate meets a dimensional criterion, determine whether the obstruction candidate meets a confirmation criterion;
when the obstruction candidate meets the confirmation criterion, identify the obstruction candidate as the data capture obstruction; and

present obstruction detection output data including the data capture obstruction.

13. The computing device of claim 12 , wherein the imaging controller is configured, in order to determine whether the obstruction candidate meets the confirmation criterion, to at least one of:
determine whether the obstruction candidate exceeds a minimum obstruction dimension;
determine whether the obstruction candidate has a predetermined obstruction shape; and
determine whether the obstruction candidate has a predetermined obstruction orientation.

14. The computing device of claim 12 , wherein the imaging controller is configured, in order to determine whether the obstruction candidate meets the confirmation criterion, to determine whether the obstruction candidate has been detected at a threshold number of previous selection depths.

15. The computing device of claim 12 , wherein the imaging controller is further configured to:
when the obstruction candidate has not been detected at the threshold number of previous selection depths, discard the obstruction candidate.

16. The computing device of claim 12 , wherein the imaging controller is further configured to:
responsive to the dimensional criterion not being met, store the obstruction candidate in the memory for evaluation at a subsequent selection depth.

17. The computing device of claim 12 , wherein the imaging controller is further configured to:
select a set of points from the point cloud corresponding to an obstruction region;
wherein the subset of points is selected from the obstruction region.

18. The computing device of claim 12 , wherein the imaging controller is further configured, in order to set the selection depths, to:
decrement a depth of the support structure plane by a coarse interval to set a first selection depth; and
increment the first selection depth by a fine interval to set a second selection depth.

19. The computing device of claim 12 , wherein the imaging controller is further configured, in order to select the subset of points, to select the points having depths smaller than the selection depth.

20. The computing device of claim 12 , wherein the imaging controller is further configured, in order to detect obstruction candidates, to:
generate a two-dimensional projection of the selected subset of points;
detect contiguous sets of points in the projection; and
generate a bounding box corresponding to each contiguous set.

21. The computing device of claim 20 , wherein the imaging controller is further configured, in order to detect obstruction candidates, to:
determine whether the bounding box overlaps with a previously detected obstruction candidate; and
when the bounding box overlaps with a previously detected obstruction candidate, store an indication of the previously detected obstruction candidate with the bounding box.

22. The computing device of claim 12 , wherein the dimensional criterion is a threshold width.

23. A method in an imaging controller of detecting data capture obstructions disposed on a front of a support structure, the met

Assignees

• Zebra Tech Corp

Inventors

• Gorodetsky Vlad
• Lam Joseph
• Rzeszutek Richard Jeffrey

Classifications

• G06V20/64 Primary

  Three-dimensional [3D] objects · CPC title

• G06T7/50 Primary

  Depth or shape recovery · CPC title

• G06V10/7553

  based on shape, e.g. active shape models [ASM] · CPC title

• G06V20/20

  in augmented reality scenes · CPC title

• G06T7/75

  involving models · CPC title