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Omega
2D/3D

Omega[bnum] returns the angular velocity (2D) or angular velocity vector (3D) of body bnum.

• In Modeler2D, Omega returns a scalar Omega.
• In Modeler3D, Omega returns the angular velocity is a vector of the form: {Omegax, Omegay, Omegaz}.
• If the
Euler solution method is specified with SetSymbols, Omega returns the angular velocity in terms of Euler parameters and their derivatives. With the Angular solution method Omega simply returns CapitalThetabnumd (2D) or {CapitalOmegaxbnum, CapitalOmegaybnum, CapitalOmegazbnum} (3D).
• In Modeler3D, Omega accepts the Coordinates option to specify whether the angular velocity should be returned in Global or body Local coordinates. The default setting is Coordinates->Global.
• See also: Alpha, Rotation, Velocity.

Further Examples

Load the Modeler3D package and define a simple model.

Here is the angular velocity of the link body, expressed in terms of Euler parameters.

If we rebuild the model in terms of local angular coordinates, the symbolic results differ but the numeric results are unchanged.

Compare the results from the same inputs. The symbolic expression for the angular velocity is complex because the modeling coordinate system used is local angular coordinates but Omega gives results in global coordinates by default.

The angular velocity expressed in the local coordinate system of the link body is trivial, and almost numerically identical because the link body is almost aligned with the global coordinate system.

See HelpModel3D.