Maths - Rotations - Correspondance 2

From: Wessam Bahnass
To: Martin Baker
Sent: Sunday, December 30, 2001 11:33 AM
Subject: Quaternion To Euler Conversion

Hi,

I've read your web-page about Quat-Euler conversion..
However, I'm lost with it a little.. I'm used to express Euler Angle
Rotations with rotations around X,Y then Z, not "heading, bank and
attitude"..
Can you help me with the code that does the conversion from Quat-To-EulerXYZ
in Radians?

Thanks a lot.

Wessam Bahnassi

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From: Martin Baker
To: Wessam Bahnass
Sent: Sunday, December 30, 2001 11:33 AM
Subject: Quaternion To Euler Conversion

Hi Wessam Bahnassi

There are lots of possible ways to define rotations. I think it is very
important to define what conventions are being used because finite rotations
do not commute, and therefore the order that the rotations are applied is
important, and so it is not enough to just define the axis, we need to
define the order that the rotations are applied. Also I think we need to
decide if the frame of reference moves with the object, or is it a fixed
frame of reference.

I have come across some NASA standards referred to in books, but I can not
find these standards on the web.

If you know of any standards that are available on the web and define all
these things, I would be very interested to hear about it as I would like to
make sure all the examples on my web pages are to the same standard.

Thanks,

Martin