Hello,
I am making a VTOL tricopter to plane drone for a college capstone course and am having some issues with control. We need to throttle up the motors pretty fast to achieve takeoff without the plane tipping over and once its in the air it will rise stably for about a second but then it seems to freakout and flip out of the air. We are using a Pixhawk with a PS4 controller connected to our computer in order to control it. It seems to me that if it can takeoff stably then the issue would be controls and not a structural issue. I don’t seem to be able to attach videos so Ill include pictures from our recent flight test (The drone looks a little rough, this body is just a throw away prototype we are using for testing before we go to our final prototype).
Does anyone have experience fixing this type of problem?
Thank you,
(these frames are all within a second of each other)
The best way to get useful help is to post the .bin log file from the flight. That can be downloaded off the flight controller using mission planner, or by copying the file off the SD card. You’ll need to use a file share like dropbox or google drive since the log files are too big to post on the forum directly. Just give us one file, preferably the one from the pictures you’ve posted.
Okay, thank you for your help. I’m sharing a .bin log file from an earlier test flight, it’s a different flight then in the picture but essentially the same thing happened. I put the file in google drive and attached the link below:
Would you recommend making a new post?
Thanks
I think the drone might be under powered. All of the motors are at near full power before the machine even moves. At that point there is no control authority left to balance or stabilize the flight. So, different motors/props might be the answer, or reduce the overall weight of the drone. Smaller battery if this is just a test-bed for a bigger unit.
Tools such as ecalc.ch will help you decide on combinations. Yes, you’ll need to pay for an account, but the price is less than you’ll spend on a couple of props to do the old fashion trail and error method. (Read: it’s cheaper to pay for ecalc.ch than buy parts)
Regarding the battery, if that’s a 6S lipo battery it was not charged. The flight started at 3.5v/cell (minimum voltage for a LiPo) and dropped to 3.25v/cell (damage range for a LiPo).
Okay, thank you, we will try different props and see if that makes a difference, we were using smaller props then we were planning because we were worried about breaking our more expensive ones. This was very helpful