Combined Rotation Angle Query in ENU & Azimuth Tilt Swing

[watertreader]

Hi,

Have a query on rotation.

No matter what rotation steps we take when we rotate from a common starting coordinate axes to an end coordinate axes, two different rotation sequences would have the same combined rotation angles if the end coordinate axes are aligned for all axes. Is that right?

I have a starting coordinates axes in ENU.

When I rotate them by using Azimuth Tilt Swing coordinate rotation step, (basically a XZX rotation by the angles- angles formed by Euler roll, pitch yaw. Azimuth = roll, Tilt= 90 + roll Swing = 180- pitch) ,


would I get the same angles if I rotate them in this manner
1) Transform ENU to NED coordinate system
2) Do a RPY rotation in the manner of Z->Y->X axis.
3) Then transform the axes from the body back to the body axes defined by X- Right Wing, Y - Nose, Z = Vertical upwards from Body

Would this yield me the same axes?

Another question I have is how do we convert an Azimuth Tilt Swing Rotation System to a ROll Pitch Yaw rotation system...(the azimuth tilt swing system do not look too intuitive to me)

Regards

 

[pat_connell]

No, two different rotation sequences would not have the same combined rotation angles if the end coordinate axes are not aligned for all axes. To convert an Azimuth Tilt Swing rotation system to a Roll Pitch Yaw rotation system, you would need to use the equations provided in many standard textbooks on aircraft dynamics. For example: Azimuth = Roll, Tilt = 90 - Roll, and Swing = 180 - Pitch.