Hello,

I am trying to calculate a position in a 3D space from the following data:

I have an origin which corresponds to the end of a segment with a known length. The segment's opposite end should be calculated according to the segment's orientation, provided as a quaternion. This first segment is tied to a second one, with a known length too. This second segment can freely rotate around the joint. Its orientation is also given as a quaternion.

The seeked position (possibly in a cartesian space) corresponds to the second segment's opposite end.

I don't understand how I can use the quaternions to position the segments. My software can easily convert quaternions to Euler angles and axis-angle but I have no idea which representation is best for my purpose.

Here's a picture showing the position of the sensors and their orientation.

Thank you in advance for helping.