Can I use range finder for vision based precision landing? Due to altitude variance landing is not happening properly

Hi all,

Using RPI 4 8GB Ram and v2.1 cam for vision based precision landing.
In mission planner the alltitude is keep changing place to place.
Because of that precision landing is not triggering properly.

How to solve this issue.

Kindly provide the solution.


Get a better sensor?

My question is
Can I use range find sensor to detect the altitude so that I can trigger landing command to the particular altitude that I want.

usually you trigger the landing at high altitude and then use the precision landing state machine to do all the decisions. did you tried that?

Yes, Its happening like what you said.
But I am triggering LAND command 60 cm above from the aruco marker. So what is happening here is sometime land command is triggering and landing, sometime it’s not happening and drone going away from the aruco.

So what I thought was, If I use range finder exactly I can trigger the landing command at 60 cm above from aruco marker.



60cm is pretty close to marker, unless you have fisheye lens (rectified), chances that you miss the target are high. As @amilcarlucas wrote, the sequence is generally initiated higher above target so the detection can kick-in and take command for Precision Landing.

Aruco detection is starting at 7meter itself. It is properly detecting, adjusting and coming down towards aruco.
Before landing, sometime it’s going away from aruco. I wrote a code such a way the final landing will be triggered at 60cm above from the aruco. Sometimes it is landing exactly on the aruco.
Sometime after reaching 60 cm above from the aruco the FINAL LANDING is not triggering.

For this issue, I am asking, Can I use range find sensor?
So that I can get exact value from the sensor and trigger FINAL LANDING command at 60 or 80 cm above from the aruco.

I expecting 15 to 30cm error. Most of the time it’s happening. Sometimes the error is more than 30cm.

I always use Lidar for this type of experiment but they are feeding the FC directly.
As for aruco landing, I made a double tag target with a large and smaller size aruco tag and switch to the smaller for the last meter, that is what @fnoop did as well and documented here:

GitHub - goodrobots/vision_landing: Precision landing using visual targets

I am also using double. Bigger one and smaller one.

So Cal I remove that final landing command? Will it go to ground and land automatically and precisely?

Well, I assume that you have set the Precision_Loiter command somehow ?