Dear all,
I built DIY H-quad with APM 2.6 in it and tested many times in Europe (where I am based at this moment). This quad is for supporting my social-ecological research in Bornean rain forest (i.e. mapping with indigenous communities for protection). It worked well during testings with different flying mode (stabilized, Loiter, RTL, waypoints). Due to the long flights and regulation, I deconstruct the copter and re-construct it again in Indonesia now. Tried to do the whole processes again from the beginning (i.e. Tx calibration, ESC calibration (without mission planner) and radio calibration, accel calibration and compass calibration via MP 1.2.96.
I tried to make it fly today and it yaws and drifts during take off, so basically I was not able to make it hovering as it's too dangerous I think (never happened before). Tried to check the "tilt" on motors and frame etc. and make sure that everything's not tilting. I noticed that when I do compass calibration, it gives me lots of points (or let's say it keeps on giving me points) despite that I didn't move at all the H-copter (APM). So at the end, it gives me around 250 points. I thought it might be one of the problem.
I would like to know if somebody else has (ever) the same problem? and maybe some ideas of solution?
I am lucky enough that I am still with slow internet connection now, any information and clue would definitely be much appreciated. Thank you very much
warm regards,
Rai
Replies
Rai,
Please let us know how you solve the problem. Going there in 8 weeks with my Hexa.
Thanks and have fun there.
Dear HOH,
Thanks for your attention and nice to know that somebody else is in the boat as well :). I luckily had a support from a fellow who is in my opinion mastering APM so well, so here are the steps we did :
(1) We erased eeprom from the APM ( I guess it's like formatting again your harddisk).
(2) We install the firmware (in my case H-copter)
(3) Calibrate everything from MP (compass, accelerometer and radio) and I try to do it far enough from sources of any source of electromagnetic field that I can think of :).
(4) We calibrate the ESC
(5) Re-check the motors direction, thus the propeller.
Whe I tried to fly it again, it flew way much better and not yawing although with a bit of drift, but I couldn't feel too much vibration (I haven't analyze the log though). Then I try to do manual PID settings and now it flies much better (still not perfect I guess as it still tends to drift very little bit) and enough for what I need at this point.
so you are planning also to do similar mission in Borneo? where about? would be nice to catch up if possible :). I'll also fly the flying wing for larger and farther area.
I hope it helps and best wishes!
Rai
APM will collect points whether you're doing the compass dance or not. But you must complete the "dance". It doesn't matter which way you start or end the dance, just that the copter faces all directions with all 6 of it's sides. This way it learns where North is in relation to it's own orientation.
Dear Graham,
Thanks lot! It's good to know that whether we dance with the quad or not, the APM will collect points. I thought we have to "dance" to be able to collect points. Thanks lot Graham for the information.
Best,
R
Hi Rai,
Are you sure you calibrated your compass the right way? You moved from the "upper" part of the globe to the "lower" part. So are you sure that North is where you think it is? When calibrating my quad I thought North was the direction when I looked North, but it turned out that North direction was "going into the ground" because of the declination.
Ask someone anywhere on the globe to point at the magnetic North and 99% will point somewhere parallel at the surface, which is wrong 99% of the time :-)
Hope this helps.
Martin.
Dear Martin,
Thanks so much! I have never ever thought about that, thanks! I will do/think as you suggest. Thanks again!
best,
R
Dear all,
Another addition that I just noticed and I am not sure if it's normal? My MP shows that the yaw degree is above 100 (to be precise between 102 and 104). I don't have any clue if it's normal or not. However, during the tests, it never gives me such "huge" number.
Another thing is, where I do test now is close to the high voltage power plants, I have a suspicion that it might have something to do with that? where the magnetic field from the power plants might influence the calibration? Thank you so much for any input.
Thank you so much for your attention and information and any input
warm regards,
Rai
hi Rai,
We are in the same boat.. we do R&D in Canada, and our UAV/UAS kits are being using in the field in Jamaica. One big issue we found in Kingston, Jamaica is that you MUST do your compass calibration in a opened field way from any iron, and mag fields. Every home, office, and building in Kingston is filled with iron security bars. Do you calibrations away from that power plant.
The other issue we found when reassembling the kits in the field.. 'vibration is a bitch'. Make sure you mount your sensors firmly and with good anti-virbration mounts (and ensure no loose cables that can 'tap' your sensors during flight).
Hope this helps..
Chris
Dear Christopher,
thanks soooo much for the information. I will do as you told me. I will report once I am able to assembly again and when it can fly :). Thanks lot
best,
Rai