# Model is unstable at pi/2

When my UAV rotate pi/2 in the perspective of the inertial reference frame, it get unstable.

The message structure I use is from the Euler rotation. Does it have some kind of singularity? There is some way to avoid it?

best regards,

You could try using quaternions

I see that it's not singularity. It's because the angle changes. I am guessing is something like 0 to pi. thx