TapFly mode - obstacle avoidance... didn't.

dmurphynj · Mar 26, 2017

Hi folks!

Unfortunately my P4P (a/k/a "Pegasus") took a hard crash yesterday. I was trying out TapFly mode, and it flew straight into a tree. I'm really not sure why obstacle avoidance couldn't/didn't/wouldn't avoid said tree. Shame on me for not reacting quicker; that's 100% my fault... but I'm still trying to figure out why the P4P didn't see/avoid the tree.

Can someone with more brains than me take a look and see what I did wrong?

Log file here: Phantom Log Viewer - PhantomHelp.com
Video here:
Thanks so much for your help. Trying to learn all I can and be able to trust some of the newer flight modes... first time out with TapFly, and not impressed, clearly...

edit: Adding - I realize the log says I'm in a Class D warning zone; I checked with AirMap before I flew (which I trust more than DJI's database) - and ...

Bayne Park - Outside KMMU

dmurphynj
Mar 26, 2017

...

(ps - for those asking, I do have DJI Care on the P4P so it will go in for repair/replacement.)

alokbhargava · Mar 26, 2017

Log points to following:

1. You tapped far away the range of OA
2. Cache of tablet was full so your display may not be correct and thus the direction of its movement
3. There are no signs that you used sticks to deflect from collision which was possible even if the tablet was not ok

Sorry for the mishap

dmurphynj · Mar 26, 2017

alokbhargava said:
Log points to following:

1. You tapped far away the range of OA
2. Cache of tablet was full so your display may not be correct and thus the direction of its movement
3. There are no signs that you used sticks to deflect from collision which was possible even if the tablet was not ok

Sorry for the mishap

Thanks much for the quick reply! To address your points in order ....

#1 - it would not "arm" TapFly mode when I tapped too far away. I tapped again in a different spot, which did allow it to proceed. So the "Cannot enter TapFly" message was for the previous attempt, not the one that actually flew.

#2 - The cache should only be for video saving, yes? That's not urgent to me - the video was saved on the SD card of course.

#3 - Correct. That was definitely my mistake; I was trying to figure out what was going on and did not react in time. 100% on me.

It's not so much the cause of the crash I'm looking for (smashing a tree is fairly obvious) - but why the obstacle avoidance didn't kick in. I realize I could've done a manual save but when it was clear the OA wasn't going to work, my reflexes were just too slow.

alokbhargava · Mar 27, 2017

OA is not effective if the light is too dark or too bright or object is too small. Don't know if this makes sense.

I'm really not sure what would happen to video processing and display if cache gets full.

dmurphynj · Mar 27, 2017

alokbhargava said:
OA is not effective if the light is too dark or too bright or object is too small. Don't know if this makes sense.

I'm really not sure what would happen to video processing and display if cache gets full.

I do understand about OA - but this was mid-day on a partially overcast day. That should be nearly ideal conditions for the OA - you can see from the video that it's really great conditions; should be plenty of contrast. Just trying to figure out what happened. If.a large, mature tree is too small, then what would the right size be?

jmy7213 · Mar 28, 2017

I notice that the tree didnt have much foliage on it. Its been proven, the p4p with all its glory, usually wont avoid thin things like bare branches, wires, or tripods.

dmurphynj · Mar 28, 2017

jmy7213 said:
I notice that the tree didnt have much foliage on it. Its been proven, the p4p with all its glory, usually wont avoid thin things like bare branches, wires, or tripods.

... looks like I learned that the hard way. Now, having said that... bare or not, the tree has plenty of branches and large trunks so I was surprised it didn't even make an attempt to avoid. A single branch or wire or whatever, I'd completely understand... but the tree kinda loomed large in the image.

Ah well, nascent technology -- thankfully this is what DJI Care is for!