Spiraling Scans

Discuss all BLK2GO related products here
Post Reply
ctintp
I have made <0 posts
I have made <0 posts
Posts: 1
Joined: Tue Dec 21, 2021 8:56 pm
Full Name: Chris Tindall
Company Details: TowerPinkster
Company Position Title: Mechanical Designer
Country: United States
Linkedin Profile: No

Spiraling Scans

Post by ctintp »

I am pretty new to the BLK2GO, and I have been having issues on scans that circle buildings. I'll start a scan, walk around a building and once processed a spiraling effect can be seen in Recap. The ground where I start will be lower and sometimes offset from the ground at the end of the scan. Any insight into what I am doing wrong or how I can correct it would be appreciated.
You do not have the required permissions to view the files attached to this post.
badam
V.I.P Member
V.I.P Member
Posts: 301
Joined: Tue May 11, 2021 5:36 pm
Full Name: Adam Berta
Company Details: InnoScan 3D Hungary Kft
Company Position Title: unknown
Country: Hungary
Linkedin Profile: No
Has thanked: 9 times
Been thanked: 71 times
Contact:

Re: Spiraling Scans

Post by badam »

ctintp wrote: Wed Dec 22, 2021 12:16 pm I am pretty new to the BLK2GO, and I have been having issues on scans that circle buildings. I'll start a scan, walk around a building and once processed a spiraling effect can be seen in Recap. The ground where I start will be lower and sometimes offset from the ground at the end of the scan. Any insight into what I am doing wrong or how I can correct it would be appreciated.
short answare forget the 2go you need to have good features to work with a slam device, clear walls, etc.maybe if you put good features like big carton boxes you could have better result, but it is not worth the effort i think...

it is true for a tls scanner as well, but you will have the opportunity to correct the issues with a tls scanner like an rtc360, blk360 or P series, or other brand scanners.
User avatar
kpob46
I have made 70-80 posts
I have made 70-80 posts
Posts: 71
Joined: Sat Aug 16, 2014 5:43 pm
7
Full Name: Kyle OBrien
Company Details: Nutrien
Company Position Title: Mine Technologist
Country: Canada
Location: Saskatoon, SK
Has thanked: 8 times
Been thanked: 7 times

Re: Spiraling Scans

Post by kpob46 »

It seems that the length of traversing around the entire building has exceeded the SLAM algorithms ability to close the survey properly. I would suggest trying to complete smaller, sequential closure loops, if you can.
VXGrid
V.I.P Member
V.I.P Member
Posts: 293
Joined: Fri Feb 24, 2017 10:47 am
4
Full Name: Martin Graner
Company Details: PointCab GmbH
Company Position Title: Research and Development
Country: Germany
Linkedin Profile: No
Has thanked: 92 times
Been thanked: 83 times
Contact:

Re: Spiraling Scans

Post by VXGrid »

What the people said above:
The loop closure did not occure (the device did not recognize that your beginning and your end were the same area, so it was able to do loop closure -> distributing the error onto the complete path, so what you got was only the IMU drifted point cloud data).

What you could try:
Forcing loop closure: Stay nearer to certain recognizable features like walls (into 3 dimensions), boxes etc. at the beginning and at the end.
As well as scan this areas a little bit longer.
Make sure that your view direction is identical when starting and when finishing (so same features are visible).
If possible you could even travers a small percentage of the starting loop again when you are finishing up (so there is overlapp between your start and end).

Keep the distance your scanner can scan in mind.
In addition, keep in mind that "distance where point are measured" is not identical with "points can be used for SLAM" (don't know how the SLAM from Leica works, if they do visual SLAM or 3D SLAM or both.
Post Reply

Return to “Leica BLK2GO”