Hi experts,
I need some advice.
I mounted 4 TF-Lunas on my drone for obstacle avoidance.
Front-right-left - bottom.
I made my first test flight but the response to objects seem to brutal.Even so brutal that the drone had a crash.
Can it be that the ground is seen as object to avoid ?.
Settings where detection range 4 mtr. and mode was slide FC mode was Loiter.
Can i change the sensitivity of the (re) action on the different sensors ?.
How many meters can the TF-Lunas see? I think the problem is the that the look ahead distance is too short. For example. If your look ahead distance is 5m, your minimal distance to object is 2m, the multirotor has only 3meters to react. This leads to a very aggressive stop maneuver which could cause a crash.
I got a similar behavior with the Lightware LW20 as a proximity sensor. It seems that single spot laser are maybe not the best choice for this application (at least in my case). I mounted my LW20 on a gimbal to probe all objects in flight direction. Without that the sensor probes the ground in low altitude flights and the multirotor starts to dance very strangely 
Hi!
We need more information to get to the cause of the crash. Mostly a log should tell us what went wrong… so please post that here.
Secondly, which version of ArduCopter are you using?
Anything except current “Master” does not have the ability to actually backaway from obstacle, or well, do anything except limit(reduce) the velocity towards the obstacle that the user commands. So at the most ArduCopter’s avoidance will do is stop you from going in a particular direction if it sees an obstacle there. (Note: I am strictly talking about ArduCopter 4.0.4 and below, running “Simple Avoidance”). Therefore it seems a little unlikely that avoidance system made the drone crash.
Anyhow, please share a log. Anything without a log is just a wild guess.
See my video looks familiar ?. According to the log it sees object until about 9 mtrs. I was however not pushing (towards objects ) in any way in sense of speed…The braking (avoidance) (re) actions seem to be extreme high. If it sees objects on 3 sides in my opinion it goes wild …like it did ?.
Here is the log , https://drive.google.com/file/d/1agOhQ6Vmnfhl4MlLtQ_M8YbFCZa8Dthb/view?usp=sharing
I had “slide” behavior not “stop” in my settings. That’s exactly what it tried to do seeing objects in front right and left, until it hit a fence. ( nowhere to go ? )
I’m using Copter 4.04
PS - now i have stop in the settings , makes more sense to me .
Ah …now i know what you mean !!! …this could really be my "problem "