Removing oldest keyframes

Posted by kgeebelen on
URL: http://official-rtab-map-forum.206.s1.nabble.com/Removing-oldest-keyframes-tp10476.html

Dear Mathieu,

I have a use case where I have a robot driving both indoor and outdoor in an industrial environment (outdoor area next to the factory). For indoor, we have a working localization system. For outdoor, the robot is equiped with both a RTK GNSS receiver and a stereo camera. However, when we go from indoor to outdoor, the GNSS receiver needs a considerable amount of time (20 seconds up to 1 minute) to get an RTK-fix. Our idea is to use the stereo camera and GNSS together with RTAB-Map to get an accurate, drift-free map of the environment, which we can then use to localize within when there is no GNSS signal, and still achieve sufficient accuracy. We could already create a proof-of-concept of this with the current functionalities of RTAB-Map.

However, the outdoor environment is changing drastically from day to day, so we need to constantly update the map with GNSS. If we keep RTAB-Map in mapping modus all the time however, the map just grows unbounded. In this application, it would be perfectly fine to just throw away the oldest keyframes from the map, and only keep the most recent ones in order to constrain the size of the map (e.g. only keep keyframes from the last 10 hours, and remove anything older than that).

Is this something that is either already possible with RTAB-Map, or could (easily) be added? If so, could you give some pointers on how to approach this?

Thanks,
Best regards,
Kurt