Motor output oscillations on Cube Orange+

PX4 Autopilot
1

I have a Cube Pilot Orange+ running PX4 v.1.15.1 and have experienced some issues with the motor output oscillating between a reasonable value and 0.

It is a small 250 frame and the cube is attached to small dampeners. I have tried multiple things to resolve this so my question is simply if any one ever experienced this and what could be the issue?

MotorOutputOscillations1
MotorOutputOscillations1962×417 51.1 KB

MotorOutputOscillations3
MotorOutputOscillations3983×422 99.5 KB

I have tried multiple types of settings, different firmware versions, different dampeners, different PIDs, different filters (cutoff frequencies), different props, diffrent communication methods to the ESC etc. The results are always the same even though different versions of it.

So instead of discussing the specifics of the rig and testing any new other thing I am looking for what could be the root cause of such oscillations.

  1. Can a bad ESC-communication/connection cause this? Have tried oneshot and PWM400 and different firmware and versions on the ESC and also different units of the ESC (SpeedyBee BLS 60A 4-1 ESC).
  2. Can bad electrical behaviour case this? Could connections and drops in power supply cause such an issue? Could that cause the OUTPUT to look like this?
  3. Can a too responsive PID cause this?
  4. Could this be due to the Cube Orange+ dampening?
  5. Any other interesting way that this can occur?

I have also tried several different Cube units and reflashed multiple times :slight_smile:

2

Hi,
Do you have the complete log file link to place here .
What is the size of your props .

3

I prefer not to focus on the specific log file since this is occurs with a large range of settings and I am more interested in the root cause questions. But here is the logfile.
https://logs.px4.io/plot_app?log=71e995fb-54d7-4108-be7d-2eee3c46af5d

The props are 5" or 6" and I have tried multiple types, folding and non folding. Not the props that are causing this.
Here is a log file with only one motor connected and not attached to the frame (hence no vibration from motor to frame/FC) and no propeller.
https://logs.px4.io/plot_app?log=638a7a79-6924-499d-9a99-626d7f75165e

But the question is more general, what could cause such a phenomena?

4

My opinion is that these two logs have different levels of interference, so I give them for your reference.