I tried to setup MTF-02 with Ardupilot for indoor flying without GPS. It works perfectly in FLOWHOLD with RC, but we can not make takeoff autonomously from mavproxy in GUIDED. It says “Need position estimate”. We made EKF origin in Mission planner and if we move it manually, it moves on the map. We noticed this error disappears if we lift drone manually (seems optical flow quality gets better). So how can I take off drone without position estimate at the start?
In future we plan to use Aruco for precise navigation, but the problem remains - position can be given only while drone is flying, because at the ground camera will be too close and won’t be able to recognize markers.
Welcome to the comunity.
Search the forum for “Need position estimate”, there are lots of people with the same issue.
Use their existing solution
Hello! Thanks, I tried to search, but most of the solutions is to use any of position source (camera, GPS, etc.). Some people said that it stopped working after certain Ardupilot version. But there is no clear answer.
You need to set an arbitrary initial position as the EKF origin.
EDIT: okay further reading your post it seems that you already did this and it goes away when you lift the drone.
This is because the minimum rangefinder distance being larger than what it actually is. If you’re rangefinder gives a measurement of 2cm while on the ground, you should set the minimum rangefinder distance as equal to or below this value.
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Hi! Thanks! It worked, we have reduced RNGFND1_MIN_CM and it finally can takeoff without any external position source.
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