Bitcraze Forums

Hi,
I mentionned somewhere, and I read other posts considering the freezing of the crazyflie python client after a crash. I discover a reason of this freezing: the controller output shows hard oscillations of roll rate: Thus the commands of the joypad are absolutely inactive.
I manually changed the position and the controller went back to a normal behaviour: What part of the firmware do I have to investigate?
Regards
Jean-Claude

How do you get this behavior? Is there a way to reproduce it?

All that has to do with the stabilization happens in the stabilization loop in stabilizer.c. So I would start to look there and then dive in the modules that outputs questionable values.

I don't like to reproduce this behaviour because it appears after hard crashes... I will investigate stabilizer.c

New: something like the discontinuities of the roll rate appears when cf2 is on the back after a crash. But it differs from my graph because it stops as soon as cf2 is put back on its feet...

Hi,
I confirm the test made on roll rate. This graph shows the beginning of the freeze. I also confirm that a move by hand of the cf stops the phenomenon.
This instability does not appear on pitch control, until now.
Where does this behaviour comes from?
Regards
Jean-Claude

Hi
I confirm the phenomenon on my cf. For some reason, mainly a crash, but not only, the controller output instability on roll rate, as in preceding figures. I did not succeed trying to enter the instability by rapid turns around roll axis. Even rough and 180°.
Once the desequilibrium is attained, it do not stops, the only way to get stabilized is being give a large move to the cf.
During desequilibrium time, there is no active command from the client.
Gyro and acc measures are OK during this period. The commands from client are obtained by firmware (they are visible on the plotter tab).
Regards
Jean-Claude

A quick question. Is the kalman filter or the complementary filter running?

Hi
In the starting log I can see "estimator 2". I suppose this means Kalmann filter. The cf is eqipped with the flowdeck for a perfect stability, except fast horizontal run, or the unstabilities we are talking about here.
Regards
Jean-Claude

Hi!
For two weeks, I fly crazyflie without vertical assistance: flowdeck or z-ranger. I neither had the freeze problem nor roll rate instability. I verified that estimator is the estimator 1 on connection console message. So the problem would be linked to estimator 2?
I will make new test adding the vertical assistance deck.
BR
Jean-Claude

And, this morning, I installed the flow deck... At first run, the freeze of the crazyflie occured... Estimator 2 is used. Sure it is responsible for this behaviour. Do I have to write an issue for this which looks like a bug?
BR
Jean-Claude