In China there’s an old saying: Time spent sharpening the axe will not delay chopping the firewood (磨刀不误砍柴功). In other words, when you take time to prepare your tools the work will be easier and faster. The NavVis M6 indoor mobile
mapping system (IMMS) is no exception to this rule, and you should invest some time to get it ready before each and every project. Here at NavVis we map a lot with our M6s for internal purposes and demos, and these are the top five things we always
do before we start.
1. UPDATE, UPDATE, UPDATE!
The M6 is famous for the speed and accuracy of its SLAM (simultaneous localization and mapping) and point clouds, and we have a dedicated team of developers working constantly to improve them. Make it a habit to update the software on your M6 and you’ll
always have the most up-to-date features and performance. You might not notice the difference, but behind the curtains there are bug fixes and improvements that will optimize your mapping experience. The same rule applies to the NavVis software on your
Ubuntu processing machine. Every update includes improvements that make mapping easier for you and produce higher quality results.
Every time a new version of the mapping software is released you will get an email from us. To update the software on both your processing machine and NavVis M6 connect to the internet and run Ubuntu’s Software Updater application. By default, the username
and password on your NavVis M6 are both “mapper”. If you don’t receive release emails from us, you can sign up here.
2. CLEAN YOUR SENSORS
Clean your camera lenses and lasers before mapping. Especially if you are mapping somewhere dirty or dusty, such as a construction site. Dust, oil, or water on a sensor can create noisy point clouds or blurry images. If one of your lasers is dirty you
may even get near-constant collision warnings or errors that interrupt the mapping.
Cleaning the sensors is simple. Inside the box for the head there is a microfiber cloth. Rub each of the six camera lenses and the optical surface of the four lasers gently with the dry microfiber cloth. Make sure you keep the cloth clean, and don’t forget
the sensors that are less obvious, such as the camera lens on top of the head and the laser lower on the body.
3. TIDY YOUR SSD
You probably don’t know this, but every time you finish a dataset the mapping software sorts the images on the SSD into folders. If something goes wrong in the process, the unsorted images are stored at this location: /srv/data/Pictures/Pictures_unassociated.
Normally, when the NavVis M6 restarts, they will be sorted correctly. But if something has gone wrong and your SSD has pictures in this folder it will try to sort them every time you finish a dataset. This can increase the amount of time it takes to
finish your datasets, and other more unpredictable problems. The solution is simple: regularly delete any unwanted images from the unassociated pictures folder.
Additionally, your SSD performs best if it has plenty of free space, and so after transferring a dataset to a PC and backing it up, you should delete it from the SSD.
4. INFLATE YOUR TIRES
This tip is simple but important: you should always make sure your tires are pumped up to 22 psi. Over time the butyl rubber tubes will slowly deflate, and this is especially true if the M6 has been transported by air. There is a tire pump included in
the wheel box of every M6, and it has a digital display that makes it easy for you to inflate all four tires exactly right.
5. DO A TEST MAPPING
When you are on-site take some time to collect a test dataset before you really begin. Start mapping and take some panoramas, making sure you map for at least 30 seconds before you finish the dataset. It is best if you start mapping within 15 meters of
a wall or column, to give the SLAM algorithm a reference point. After finishing the dataset you should check the images to double check that all the lens caps are off and the lenses are clean. If you notice any problems during the test mapping you can
fix them straight away and have confidence about your real project. If you find an issue you can’t fix, you still have enough time to contact us here at NavVis support.
Happy mapping!
