model InitAngularVelocity "Internal model to initialize w_rel_b for Joints.FreeMotionScalarInit"
import SI = Modelica.SIunits;
import Modelica.Mechanics.MultiBody.Frames;
extends Modelica.Blocks.Icons.Block;
input Frames.Orientation R_a annotation (Dialog);
input Frames.Orientation R_b annotation (Dialog);
Modelica.Blocks.Interfaces.RealOutput w_rel_b[3](each final quantity = "AngularVelocity", each final unit = "rad/s") annotation (Placement(transformation(extent = {
{100, -10},
{120, 10}})));
equation
Frames.angularVelocity2(R_b) = Frames.resolve2(R_b, Frames.angularVelocity1(R_a)) + w_rel_b;
annotation (
Icon(graphics = {
Text(
extent = {
{-86, 16},
{84, -12}},
textString = "w_rel_b")}),
Documentation(info = "<html>\n<p>\nCompute relative angular velocity w_rel_b of an\n<a href=\"modelica://Modelica.Mechanics.MultiBody.Frames.Orientation\">orientation object</a> R_b\nrelative to an\n<a href=\"modelica://Modelica.Mechanics.MultiBody.Frames.Orientation\">orientation object</a> R_a,\nresolved in orientation object R_b, i.e.\n</p>\n<blockquote><pre>\nw_b_b = w_a_b + w_rel_b,\n</pre></blockquote>\n<p>\nwhere\n</p>\n<blockquote><pre>\nw_b_b ...... absolute angular velocity of frame_b resolved in frame_b,\nw_a_b ...... absolute angular velocity of frame_a resolved in frame_b,\nw_rel_b .... relative angular velocity resolved in frame_b.\n</pre></blockquote>\n</html>"));
end InitAngularVelocity;