RelativePosition

model RelativePosition "Measure relative position vector between the origins of two frame connectors"
    extends Internal.PartialRelativeSensor;

    Blocks.Interfaces.RealOutput r_rel[3] "Relative position vector resolved in frame defined by resolveInFrame"
        annotation (Placement(transformation(
            extent = {
                {-10, -10}, 
                {10, 10}},
            rotation = -90,
            origin = {0, -110})));
    Modelica.Mechanics.MultiBody.Interfaces.Frame_resolve frame_resolve if resolveInFrame == Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB.frame_resolve "Coordinate system in which r_rel is optionally resolved"
        annotation (Placement(transformation(extent = {
            {84, 64}, 
            {116, 96}})));
    parameter Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB resolveInFrame = Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB.frame_a "Frame in which output vector r_rel shall be resolved (world, frame_a, frame_b, or frame_resolve)";
protected
    Internal.BasicRelativePosition relativePosition(resolveInFrame = resolveInFrame) annotation (Placement(transformation(extent = {
        {-10, -10}, 
        {10, 10}})));
    Modelica.Mechanics.MultiBody.Interfaces.ZeroPosition zeroPosition if not resolveInFrame == Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB.frame_resolve annotation (Placement(transformation(extent = {
        {52, 20}, 
        {72, 40}})));
equation
    connect(relativePosition.frame_a,frame_a) annotation (Line(
        points = {
            {-10, 0}, 
            {-100, 0}},
        color = {95, 95, 95},
        thickness = 0.5));
    connect(relativePosition.frame_b,frame_b) annotation (Line(
        points = {
            {10, 0}, 
            {100, 0}},
        color = {95, 95, 95},
        thickness = 0.5));
    connect(relativePosition.r_rel,r_rel) annotation (Line(
        points = {
            {0, -11}, 
            {0, -110}},
        color = {0, 0, 127}));
    connect(relativePosition.frame_resolve,frame_resolve) annotation (Line(
        points = {
            {10, 8}, 
            {20, 8}, 
            {20, 8}, 
            {30, 8}, 
            {30, 80}, 
            {100, 80}},
        color = {95, 95, 95},
        pattern = LinePattern.Dot));
    connect(zeroPosition.frame_resolve,relativePosition.frame_resolve) annotation (Line(
        points = {
            {52, 30}, 
            {30, 30}, 
            {30, 8}, 
            {10, 8}},
        color = {95, 95, 95},
        pattern = LinePattern.Dot));

    annotation (
        Icon(
            coordinateSystem(
                preserveAspectRatio = true,
                extent = {
                    {-100, -100}, 
                    {100, 100}}),
            graphics = {
                Line(
                    points = {
                        {0, -70}, 
                        {0, -100}},
                    color = {0, 0, 127}), 
                Text(
                    extent = {
                        {-127, 95}, 
                        {134, 143}},
                    textString = "%name",
                    lineColor = {0, 0, 255}), 
                Text(
                    extent = {
                        {18, -80}, 
                        {102, -110}},
                    textString = "r_rel")}),
        Documentation(info = "<html>\n<p>\nThe relative position vector between the origins of frame_a and frame_b are\ndetermined and provided at the output signal connector <strong>r_rel</strong>.\n</p>\n\n<p>\nVia parameter <strong>resolveInFrame</strong> it is defined, in which frame\nthe position vector is resolved:\n</p>\n\n<table border=1 cellspacing=0 cellpadding=2>\n<tr><th><strong>resolveInFrame =<br>Types.ResolveInFrameAB.</strong></th><th><strong>Meaning</strong></th></tr>\n<tr><td>world</td>\n    <td>Resolve vector in world frame</td></tr>\n\n<tr><td>frame_a</td>\n    <td>Resolve vector in frame_a</td></tr>\n\n<tr><td>frame_b</td>\n    <td>Resolve vector in frame_b</td></tr>\n\n<tr><td>frame_resolve</td>\n    <td>Resolve vector in frame_resolve</td></tr>\n</table>\n\n<p>\nIf resolveInFrame = Types.ResolveInFrameAB.frame_resolve, the conditional connector\n\"frame_resolve\" is enabled and r_rel is resolved in the frame, to\nwhich frame_resolve is connected. Note, if this connector is enabled, it must\nbe connected.\n</p>\n\n<h4>Example</h4>\n<p>\nIf resolveInFrame = Types.ResolveInFrameAB.frame_a, the output vector is\ncomputed as:\n</p>\n\n<blockquote><pre>\nr_rel = MultiBody.Frames.resolve2(frame_a.R, frame_b.r_0 - frame_a.r_0);\n</pre></blockquote>\n</html>"));
end RelativePosition;