Spiraling Scans
-
- I have made <0 posts
- Posts: 1
- Joined: Tue Dec 21, 2021 8:56 pm
- 2
- Full Name: Chris T
- Company Details: TPTA
- Company Position Title: Mechanical Designer
- Country: United States
- Linkedin Profile: No
- Has thanked: 1 time
Spiraling Scans
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.
-
- V.I.P Member
- Posts: 916
- Joined: Tue May 11, 2021 5:36 pm
- 2
- Full Name: Adam Berta
- Company Details: InnoScan 3D Hungary Kft
- Company Position Title: unknown
- Country: Hungary
- Linkedin Profile: No
- Has thanked: 52 times
- Been thanked: 297 times
- Contact:
Re: Spiraling Scans
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...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.
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.
- kpob46
- I have made 100> posts
- Posts: 102
- Joined: Sat Aug 16, 2014 5:43 pm
- 9
- Full Name: Kyle OBrien
- Company Details: Nutrien
- Company Position Title: Mine Technologist
- Country: Canada
- Location: Saskatoon, SK
- Has thanked: 18 times
- Been thanked: 23 times
Re: Spiraling Scans
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.
-
- V.I.P Member
- Posts: 544
- Joined: Fri Feb 24, 2017 10:47 am
- 7
- Full Name: Martin Graner
- Company Details: PointCab GmbH
- Company Position Title: Research and Development
- Country: Germany
- Linkedin Profile: No
- Has thanked: 160 times
- Been thanked: 175 times
- Contact:
Re: Spiraling Scans
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.
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.