My Kwad acts weird occillations or vibrations

injanlee · Aug 5, 2017

Hello comuniti, i am new to all this and finally built my very first kwad or racing drone, but when i went to test it, was acting wery strange, callit occillations or vibrations, o dont know the term for this behaviour, note that this hapens when airmode is on, if i turn of airmode on one of the switch on my taranis the problem does not ocure, all the components are flashed and up to date, min trhodle is 1050, accelerometer on, ESCs protocol is MULTISHOT configured with betafligt 3.2.1
Note: I tried to do a test flight with the props on, but it wasent posible do to the wierd behaviour.

Here is a video of the problem, thankyou in adwance for all the help.

My set up:
7232 Lumenier RB2206C-9 2450KV SKITZO Ceramic Bearing Motor 4
6135 QAV-X CHARPU FPV Racing Quadcopter (4mm)
6424 Matek HUBOSD Eco X-Type W/XT60
6597 Lumenier LUX V2 Flight Controller
4392 Lumenier TX5GPro Mini 200mW 5.8GHz FPV Transmitter with Power Switch
6230 Lumenier CM-650 Mini, 2.1mm Lens, Top Connector - 650TVL Camera
6576 Lumenier AXII 5.8GHz Antenna (RHCP)
7023 Lumenier 5x5x3 - Butter Cutter Propeller
4379 FrSky Taranis X9D Plus 2.4GHz ACCST Radio (Mode 2)
2069 FrSky X4R-SB - 3/16 Channel Receiver w/ SBUS
6298 Lumenier 35A BLHeli_S ESC OPTO (2-6s) DSHOT 6

theGreenOrange · Aug 5, 2017

It is normal for oscillations to occur with airmode on while taking off or landing. It is not normal during regular flight. Some people put airmode on a switch and turn it off while taking off or landing, especially landing.

injanlee · Aug 5, 2017

theGreenOrange said:
It is normal for oscillations to occur with airmode on while taking off or landing. It is not normal during regular flight. Some people put airmode on a switch and turn it off while taking off or landing, especially landing.

Thank you so much for the help, i have seen people taking of in airmode and these occillations dont ocure, Why is this?

theGreenOrange · Aug 5, 2017

If you quickly pop it up in the air at least a couple feet to get out of the prop wash it shouldn't act weird.

I don't fully know all the details of airmode but I will give you my guess based off what I do know. For airmode to achieve full pitch and roll authority at low throttle, part of the algorithm deactivates 2 of the 3 PID terms. Normally the three PID terms work together to achieve a particular tune. So two quads that fly similarly could have vastly different P terms, with a similar overall effect using different I and D terms. So when you turn off I and D, they can react quite differently, since their P terms are different..