Hi there,
I am a new user of the ardupilot 2.6 (ArduCopter V3.0.1, using it on a 10" quadrotor), but I have a lot of experience with my own flight controller system. I like the automatic flight capabilities of ardupilot a lot, and I had about 6 very good flights where I tested and tuned the flight modes. I tried auto-takeoff and landing too and it working very well.
On my last flight I crashed right after automatic takeoff reached the desired height. The copter went into a very steep spiral and lost height very quickly. I switched to stabilize, but there was maybe not enough time and height left to level the copter...
I attached the flight log, and I hope someone of you can help me understanding it. As the logs are pretty new to me, I have some difficulties here.
The mission consisted of about 5 waypoints, an auto-takeoff and an auto-landing. The crash happened a few seconds after take-off.
I think I made something wrong anyway: I read somewhere, that auto-takeoff uses the latest throttle position that was used during e.g. loiter. Before my crash-flight, I was flying in loiter with a relatively low battery. Then i swapped the battery and attempted the auto-takeoff. Probably auto-takeoff used a relatively high throttle value - could that be true? Is it a good idea to always do a short loiter flight before doing an auto mission?
Thanks for your help and all the best,
William
Replies
Hi William
Thought I would have a go at your logs. Also new at this, so bear with me.
observations :
1. For some reason I do not see AUTO mode in your logs. (Filter by Mode, also no NTUN messages are coming through) Did you switch on the copter while the radio was already set to Auto?
2. Your HDOP was actually very good at 1.5 all the way.
3. something clearly went wrong, because logging only started halfway through the log, at 300. I think you just plugged in and took off. more on that later.
4. Your baro readings look weird too, because it goes BELOW 0m, but I think this is related to 3 above.
5. your battery Started at 12.6, and was at 11.5 at the crash, so still ok.
Overall I think it had to so with the fact that the baro may still have been calibrating/warming up when you took off.
You are correct, it is advisable to do even a short 20 second flight in Stabilise before a mission, just to check if everything is ok.
Also
The way i understand Auto takeoff sequence is as follows:
1. Tx on, STAB mode, connect battery
2. Wait for a few minutes for satellite acquisition and equipment warmup
3. Arm, Short test hover and land. disarm.
4. Throttle at 0, ARM
5. Mode switch to AUTO
6. Advance the throttle a bit, copter will take off and mission begins.
Is this round about what you are doing, or is your method different?
I am still not sure why your copter never recorded being in AUTO mode.