Hi,
3 days ago I had a bad crash. Copter Crash (the crash happens at about 5:20).
One can hear a beeping sound at 4:42 and I only can imagine it being at least 2 ESCs.
My Setup is:
Well its a complete selfmade copter. Weight about 2.4 kg and a flighttime of about 13 mins (aggressive style)... so really a good one.
- LiPo 5000 mAh Hacker 4S 20 C
- Motors: Torxpower 4 x
http://www.quadcopters.co.uk/mt2814-11-torxpower-3536-pro-heavy-lift-motor-710kv-124-p.asp
- Board: APM 2.6 with GPS and Powermodule
- Frame: Very Vibrationfree Aluminium- Carbon frame. Very Solid!!
- ESCs: 4x Turnigy plush 30 Amp
- Servo stabilized Gimbal with Nikon AW110
Now how it happened. I started with a full throttle up for 25 seconds and turned on GPS hold. Maybe not the best idea(25 secs full throttle)... Then I made some turns and started to descend in GPS hold. At a lower altitude I switched in Stabilize and flew some aggressive turns with switching flightmodes at one point I think but went back to stabilize. And then the desaster happened! After a fast turn the copter started to do saltos with no warnings before (I couldnt see anything weird). I tried to switch it in GPS hold and gave more throttle, because I thought that if i lowered it I would crash definitely. Well I crashed either way. I guess that my front Motors cut off power and my rear throttled up pretty much so I got the fast saltos.
I do really need help and suggestions, please!!! I just wanted to open a one man company (in Germany) to sell pictures and had everything set (insurance for the copter, flight permission etc. etc.) and I definitely want to presume this plan but really dont want to happen this again!
Thanks a lot! And I might need help with the logs (once I tried to get them but I failed, so after the crash I didnt power up the APM in order to not loose the logs). Can someone guide me through getting the logs and then go through them with me? That would be really great!
It was such a great copter!!!!! 13 mins aggressive flight time with 2.4 Kg!
Replies
Ok I will declare this post as solved. Solution is: Don´t use the power module!^^
Thanks for your help! All of you :)
Wow, there is just so much going on in this log. I'll hit the items as I see them.
- First, you are correct about low vibration. You BarAlt tracks your RelAlt almost perfectly. That's really nice.
- Your log is showing nonsensical sonar values that are nowhere near the actual altitudes. Do you have sonar enabled?
- Your logging ceases while the quad is still 23.66 meters in the air. This suggests a power failure to the APM, either a bad connection or a bad Power Module.
- There are serious issues with your ThrIn data. From around 3 minutes to 4 minutes your throttle essentially went to zero. It didn't see your radio. Your quad should have gone into Failsafe (it was enabled) but didn't. I don't know why.
- Your Roll tracked very well with your RollIn right up until the end. Your Pitch wasn't quite as good. For the last 25 recorded seconds it looks like you were requesting a down pitch of about 20 degrees but your quad was only giving you about half of what you were requesting.
- Your Vcc looks looks OK.
In summary the quad was doing what you asked it to do, until it just lost power 23 meters up. I'd look at the power connections between the battery and APM, including the Power Module. Could be something as simple as a bad connection. You mentioned the quad was doing "saltos" (I assume that's somersaults!). The log doesn't show any record of that. It could be that if your APM lost power while your motors and ESCs were still powered, very weird crap could ensue. That would be my guess.
But have a look at the sonar issue and check your RC radio. Something's not right there.
Hm and when I listen carefully I can hear that the motors stop spinning BEFORE hitting the ground, which means that a powerloss seems the best explanation or? A radio fail should have ended in a fail safe and ESC failure some motors should have gone mad and spinning up. The only thing I cant remember is if I lowered throttle while falling. but I dont think so. I guess I tried to save it with throttle power up until the bitter end. What is somersaults? When you mean "backflips" then no, because it flipped really fast in flying direction ( forward ). Can it flip so fast in forward direction, when i was flying fast and motors stopped at the same time?
Hmmm I dont use sonar... and Im a bit confused about that. A thing I noticed that my powermodule displays the wrong voltage (an other voltage than my LiPosaver). And my radio never did something like this and as you mentioned the failsafe was set up and tested in missionplanner. Did you watch the video I posted? Why did he flip when the apm lost power? SOrry I am new to logs ;)
Your log shows you have sonar enabled, so if you don't actually have it you should disable in in Mission Planner.
In your video you can still hear the motors running after the quad starts tumbling. And I assume the beeping is from the ESCs after the image goes dark. This would be consistent with the power failing to the APM. Again, either a bad connection or bad Power Module. You could have a loose wire in the DF connectors in either the Power Module or APM. The logging clearly stops before the tumbling begins.
I don't know what's up with your radio, but it doesn't look good. Here's a plot showing your throttle in, throttle out and baro altitude. Two things to note here, the first being that logging stops while the quad is still in the air. And second is the throttle in going to zero between minutes 3 and 4.
The throttle 0 is due to decending in loiter. There I can put my throttle to 0 and have the fastest decending possible in loiter--- so no worries about that. I fly a plane with the same radio and have no problems at all.
The last thing I cant get is why the motors still run while APM being off. What is a DF connector?
THANKS FOR THE HELP!!!!!! Alone I wouldnt have get any valuable clues! THANKS!
You are absolutely right about the throttle in Loiter. Not sure why I didn't notice that. I suppose it's because I almost never put my throttle in AltHold or Loiter to zero. I did that once and without thinking switched it back to Stabilize. That was, ahem.....a learning experience.
And yes, Andre is right, I was referring to the DF13 connector. I have had instances of the wire actually coming out of the connector housing after repeated pulling on them (Lesson: Don't pull on them!). I also had a case where a spring female pin in a DF13 somehow got expanded and didn't grip the pin securely. As a result my compass kept going in and out. It took quite some time to track down that problem. I fixed it by releasing that female pin form the connector and squeezing it back to shape.
ok, so you had a failsafe commanding throttle all way down too (loiter alone would not descend.)
DF must be "short" for DF13 , just google it, you'll recognize it :)
so thats the connection but whats "short"?^^ but why can i take the control back after it is in failsafe?
When I mentioned "short" - I meant that when you read "DF" its somebody's idea if shorting down "DF13" - which is a bad idea, becuase DF3, DF11, DF80 exists too, and that's just the types I remember right now.
What exactly do you mean by "can't take control after failsafe" ? - the exact events would be helpful.
An example, ; if a ThrottleFS is trigged, and RTL started, getting in range would not automatically make you in control, as your sticks may be in random position (thr=0) and make it fly off with the wind. So it remain in RTL, not reading your input - ntil you change mode (to/from anything) to indicate that you are in control.
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