universal.world File Reference

Example of how to set a universal joint. More...

Detailed Description

Example of how to set a universal joint including range limitations.

A universal joint is consituted by two coincident revolute joints that form an angle of 90 degrees. The way to encode this joints is defining and implicit reference frame in between the two involved links (named ground and link in the example). The X unitary vector of this implicit reference frame is aligned with the axis $Q_i \rightarrow P_i$ and the Y unitary vector with the $Q_{i+1} \rightarrow P_{i+1}$ . The Z axis of this implicit link is the cross product of the X and Y unitary vectors.

The ranges of the universal joint are defined with two vectors,

one in the first link: when the first rotation angle is 0 this vector is aligned with the Y axis of the implicit link defined above.
one in the second link: when the second rotation angle is 0 this vector is aligned with the Z axis of the implicit link defined above.

Definition in file universal.world.