Main Challenges and Areas of Complication
Challenge: Open/Outdoor Spaces
When scanning outside, the range of the scanner is automatically reduced to 10m.
This is due to additional error sources such as natural light / sunlight interference with the scanner and the assumption that there may be less features when working outside.
- Keep the scanner faced towards the nearest significant feature
- Keep distance between the nearest significant feature of the scan to a maximum of 10m
- Significant features should not be smaller than 1x1x1m
This will significantly improve the result when capturing data outdoors.
Challenge: Narrow and Less Accessible Spaces
Some areas may not be accessible by foot or it may not be possible to create a loop because of how the area is structured.
The REVO system is versatile and can be mounted on remote robots, telescopic poles and similar supports.
By default, when processing the data, the bounding box around the scan head is created in order to avoid error of person scanning.
When narrow spaces are surveyed, in the processing stage the bounding box settings should be adjusted. This helps the SLAM algorithm to find features which are closer to the scanner.
Challenge: Tall Facades
Similarly to long corridors and tunnels, the laser signal will not bounce back to the scanner and the measurement will not be taken due to the angle of incidence.
As mentioned above, the REVO system can be mounted on telescopic pole to help overcome this.
Using stairs or other convenient ways gain height close to the façade will also enable the scanning of taller features.
Challenge: Moving Objects
It is highly recommended to scan static empty spaces as movement within the area being scanned may result in a noisy point cloud and could also cause problems with scan registration.
Moving objects will impact on the amount of correct scan points. If the structure is occluded it is less likely to get a good amount of quality data. If possible, schedule the survey when there is the least amount of people expected survey area.
Slow-moving traffic can cause alignment issues in SLAM and will occlude the object of capture. It is highly recommended to avoid any non-stable object movements whilst scanning.
Challenge: Shiny, Reflective Surfaces and Glass
Objects such as mirrors, water, bottles, glass etc. can cause unnecessary noise in the final point cloud.
Eliminate these features from the scan by:
- Cover the features/objects
- Adjust the lighting conditions by closing the blinds and using diffused light sources
- Schedule scan for day/time with minimal intrusive sunlight