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How to fly with quaternion more than 90 deg Pitch?

PostPosted: Sun May 01, 2011 9:06 pm
by jbsimon
Hello Together,

very nice project. I just take a look, I plan use one of my planes
for gluonpilot. (with planes I am a beginner :))

At the moment, I am a little bit confused, about quaternion (IMU/AHRS)
inside a plane.

Normal IMU has a dynamic range of
Pitch +-90deg
Roll/Heading +-180deg

You compare the IMU position with stick position (desired pitch etc.)
What will happen if you fly more than 90deg Pitch. (not a Looping, just more than 90deg)
Roll and Heading will change to ~180deg immediately.

Plane will make a roll and full turn?
Is it possible to fly more then 90deg Pitch with IMU?

Thank you & Best Regards
Julian

Re: How to fly with quaternion more than 90 deg Pitch?

PostPosted: Mon May 02, 2011 3:06 pm
by Tom
Hi Julian,

I don't know if you are refering to something specific, but I suppose there are 2 options:
- If you want to do "loops", you would need another stabilization mode called "acro mode". This one will keep a constant angular rate. For example, a loop would require a constant angular rate along the pitch axis
- I'm sure there is a way to overcome the +-90° weird change if you write your code smart enough

Tom

Re: How to fly with quaternion more than 90 deg Pitch?

PostPosted: Mon May 02, 2011 10:10 pm
by jbsimon
Hello Tom,

thank you for you feedback.

I think I understand Acro-Mode, but I am interesting about
a stabilized Mode with Nick larger than 90 deg.
maybee 120 deg. Finds back to horizontal, but
no Looping, Rolls etc, but you can fly nosedive
with sporty setting :)

I know Mikrokopter can do this. And I have
seen Euler will make here trouble (because changes
in presentation... when Nick larger than 90deg)

Maybee there is a solution... but I do not
know mutch about Quaternionen.
Do you know if Quaternionen has also inside
this change (when Nick > 90deg) or if it
caused only by transformation to Euler?

(I have only worked with euler in the past)

Thank you & Best Regard
Julian