Modelica.Mechanics.MultiBody.Forces.Internal

Internal package, should not be used by user

Information

Extends from Modelica.Icons.Package (Icon for standard packages).

Package Content

Name Description

BasicForce Force acting between two frames, defined by 3 input signals

BasicTorque Torque acting between two frames, defined by 3 input signals

BasicWorldForce External force acting at frame_b, defined by 3 input signals

BasicWorldTorque External torque acting at frame_b, defined by 3 input signals

standardGravityAcceleration Standard gravity fields (no/parallel/point field)

Name	Description
BasicForce	Force acting between two frames, defined by 3 input signals
BasicTorque	Torque acting between two frames, defined by 3 input signals
BasicWorldForce	External force acting at frame_b, defined by 3 input signals
BasicWorldTorque	External torque acting at frame_b, defined by 3 input signals
standardGravityAcceleration	Standard gravity fields (no/parallel/point field)

Modelica.Mechanics.MultiBody.Forces.Internal.BasicForce

Force acting between two frames, defined by 3 input signals

Modelica.Mechanics.MultiBody.Forces.Internal.BasicForce

Information

The 3 signals of the force connector are interpreted as the x-, y- and z-coordinates of a force acting at the frame connector to which frame_b of this component is attached. Via parameter resolveInFrame it is defined, in which frame these coordinates shall be resolved:

Types.ResolveInFrameAB.	Meaning
world	Resolve input force in world frame
frame_a	Resolve input force in frame_a
frame_b	Resolve input force in frame_b (= default)
frame_resolve	Resolve input force in frame_resolve (frame_resolve must be connected)

If resolveInFrame = ResolveInFrameAB.frame_resolve, the force coordinates are with respect to the frame, that is connected to frame_resolve.

If resolveInFrame is not ResolveInFrameAB.frame_resolve, then the position vector and the orientation object of frame_resolve must be set to constant values from the outside in order that the model remains balanced (these constant values are ignored).

Extends from Modelica.Mechanics.MultiBody.Interfaces.PartialTwoFrames (Base model for components providing two frame connectors + outer world + assert to guarantee that the component is connected).

Parameters

Type Name Default Description

ResolveInFrameAB resolveInFrame Modelica.Mechanics.MultiBody... Frame in which force is resolved (1: world, 2: frame_a, 3: frame_b, 4: frame_resolve)

Type	Name	Default	Description
ResolveInFrameAB	resolveInFrame	Modelica.Mechanics.MultiBody...	Frame in which force is resolved (1: world, 2: frame_a, 3: frame_b, 4: frame_resolve)

Connectors

Type Name Description

Frame_a frame_a Coordinate system fixed to the component with one cut-force and cut-torque

Frame_b frame_b Coordinate system fixed to the component with one cut-force and cut-torque

Frame_resolve frame_resolve The input signals are optionally resolved in this frame

input RealInput force[3] x-, y-, z-coordinates of force resolved in frame defined by resolveInFrame [N]

Type	Name	Description
Frame_a	frame_a	Coordinate system fixed to the component with one cut-force and cut-torque
Frame_b	frame_b	Coordinate system fixed to the component with one cut-force and cut-torque
Frame_resolve	frame_resolve	The input signals are optionally resolved in this frame
input RealInput	force[3]	x-, y-, z-coordinates of force resolved in frame defined by resolveInFrame [N]

Modelica definition

model BasicForce 
  "Force acting between two frames, defined by 3 input signals"

  import Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB;
  extends Modelica.Mechanics.MultiBody.Interfaces.PartialTwoFrames;
  Interfaces.Frame_resolve frame_resolve 
    "The input signals are optionally resolved in this frame";
  Modelica.Blocks.Interfaces.RealInput force[3](each final quantity="Force", each final unit=
                 "N") 
    "x-, y-, z-coordinates of force resolved in frame defined by resolveInFrame";
  parameter Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB
    resolveInFrame=
    Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB.frame_b 
    "Frame in which force is resolved (1: world, 2: frame_a, 3: frame_b, 4: frame_resolve)";

  Modelica.SIunits.Position r_0[3] 
    "Position vector from origin of frame_a to origin of frame_b resolved in world frame";
  Modelica.SIunits.Force f_b_0[3] "frame_b.f resoved in world frame";

equation 
  assert(cardinality(frame_resolve) > 0, "Connector frame_resolve must be connected at least once and frame_resolve.r_0/.R must be set");
  frame_resolve.f = zeros(3);
  frame_resolve.t = zeros(3);

   if resolveInFrame == ResolveInFrameAB.frame_a then
      f_b_0     = -Frames.resolve1(frame_a.R, force);
      frame_b.f =  Frames.resolve2(frame_b.R, f_b_0);
   elseif resolveInFrame == ResolveInFrameAB.frame_b then
      f_b_0     = -Frames.resolve1(frame_b.R, force);
      frame_b.f = -force;
   elseif resolveInFrame == ResolveInFrameAB.world then
      f_b_0     = -force;
      frame_b.f =  Frames.resolve2(frame_b.R, f_b_0);
   elseif resolveInFrame == ResolveInFrameAB.frame_resolve then
      f_b_0     = -Frames.resolve1(frame_resolve.R, force);
      frame_b.f = Frames.resolve2(frame_b.R, f_b_0);
   else
      assert(false, "Wrong value for parameter resolveInFrame");
      f_b_0     = zeros(3);
      frame_b.f = zeros(3);
   end if;
   frame_b.t = zeros(3);

   // Force and torque balance
   r_0 = frame_b.r_0 - frame_a.r_0;
   zeros(3) = frame_a.f + Frames.resolve2(frame_a.R, f_b_0);
   zeros(3) = frame_a.t + Frames.resolve2(frame_a.R, cross(r_0, f_b_0));
end BasicForce;

Modelica.Mechanics.MultiBody.Forces.Internal.BasicTorque

Torque acting between two frames, defined by 3 input signals

Modelica.Mechanics.MultiBody.Forces.Internal.BasicTorque

Information

The 3 signals of the torque connector are interpreted as the x-, y- and z-coordinates of a torque acting at the frame connector to which frame_b of this component is attached. Via parameter resolveInFrame it is defined, in which frame these coordinates shall be resolved:

Types.ResolveInFrameAB.	Meaning
world	Resolve input torque in world frame
frame_a	Resolve input torque in frame_a
frame_b	Resolve input torque in frame_b (= default)
frame_resolve	Resolve input torque in frame_resolve (frame_resolve must be connected)

If resolveInFrame = ResolveInFrameAB.frame_resolve, the torque coordinates are with respect to the frame, that is connected to frame_resolve.

Extends from Modelica.Mechanics.MultiBody.Interfaces.PartialTwoFrames (Base model for components providing two frame connectors + outer world + assert to guarantee that the component is connected).

Parameters

Type Name Default Description

ResolveInFrameAB resolveInFrame Modelica.Mechanics.MultiBody... Frame in which torque is resolved (1: world, 2: frame_a, 3: frame_b, 4: frame_resolve)

Type	Name	Default	Description
ResolveInFrameAB	resolveInFrame	Modelica.Mechanics.MultiBody...	Frame in which torque is resolved (1: world, 2: frame_a, 3: frame_b, 4: frame_resolve)

Connectors

Type Name Description

Frame_a frame_a Coordinate system fixed to the component with one cut-force and cut-torque

Frame_b frame_b Coordinate system fixed to the component with one cut-force and cut-torque

Frame_resolve frame_resolve The input signals are optionally resolved in this frame

input RealInput torque[3] x-, y-, z-coordiantes of torque resolved in frame defined by resolveInFrame [N.m]

Type	Name	Description
Frame_a	frame_a	Coordinate system fixed to the component with one cut-force and cut-torque
Frame_b	frame_b	Coordinate system fixed to the component with one cut-force and cut-torque
Frame_resolve	frame_resolve	The input signals are optionally resolved in this frame
input RealInput	torque[3]	x-, y-, z-coordiantes of torque resolved in frame defined by resolveInFrame [N.m]

Modelica definition

model BasicTorque 
  "Torque acting between two frames, defined by 3 input signals"

  import SI = Modelica.SIunits;
  import Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB;
  extends Modelica.Mechanics.MultiBody.Interfaces.PartialTwoFrames;
  Interfaces.Frame_resolve frame_resolve 
    "The input signals are optionally resolved in this frame";

  Modelica.Blocks.Interfaces.RealInput torque[3](each final quantity="Torque", each final unit=
                 "N.m") 
    "x-, y-, z-coordiantes of torque resolved in frame defined by resolveInFrame";
  parameter Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB
    resolveInFrame=
    Modelica.Mechanics.MultiBody.Types.ResolveInFrameAB.frame_b 
    "Frame in which torque is resolved (1: world, 2: frame_a, 3: frame_b, 4: frame_resolve)";

  SI.Position r_0[3] 
    "Position vector from origin of frame_a to origin of frame_b resolved in world frame";
  SI.Torque t_b_0[3] "frame_b.t resoved in world frame";

equation 
  assert(cardinality(frame_resolve) > 0, "Connector frame_resolve must be connected at least once and frame_resolve.r_0/.R must be set");
  frame_resolve.f = zeros(3);
  frame_resolve.t = zeros(3);

  r_0 = frame_b.r_0 - frame_a.r_0;
  frame_a.f = zeros(3);
  frame_b.f = zeros(3);

   if resolveInFrame == ResolveInFrameAB.frame_a then
      t_b_0     = -Frames.resolve1(frame_a.R, torque);
      frame_b.t =  Frames.resolve2(frame_b.R, t_b_0);
   elseif resolveInFrame == ResolveInFrameAB.frame_b then
      t_b_0     = -Frames.resolve1(frame_b.R, torque);
      frame_b.t = -torque;
   elseif resolveInFrame == ResolveInFrameAB.world then
      t_b_0     = -torque;
      frame_b.t =  Frames.resolve2(frame_b.R, t_b_0);
   elseif resolveInFrame == ResolveInFrameAB.frame_resolve then
      t_b_0     = -Frames.resolve1(frame_resolve.R, torque);
      frame_b.t =  Frames.resolve2(frame_b.R, t_b_0);
   else
      assert(false, "Wrong value for parameter resolveInFrame");
      t_b_0     = zeros(3);
      frame_b.t = zeros(3);
   end if;

   // torque balance
   zeros(3) = frame_a.t + Frames.resolve2(frame_a.R, t_b_0);
end BasicTorque;

Modelica.Mechanics.MultiBody.Forces.Internal.BasicWorldForce

External force acting at frame_b, defined by 3 input signals

Modelica.Mechanics.MultiBody.Forces.Internal.BasicWorldForce

Information

The 3 signals of the force connector are interpreted as the x-, y- and z-coordinates of a force acting at the frame connector to which this component is attached. Via parameter resolveInFrame it is defined, in which frame these coordinates shall be resolved:

Types.ResolveInFrameB.	Meaning
world	Resolve input force in world frame (= default)
frame_b	Resolve input force in frame_b
frame_resolve	Resolve input force in frame_resolve (frame_resolve must be connected)

If resolveInFrame = Types.ResolveInFrameB.frame_resolve, the force coordinates are with respect to the frame, that is connected to frame_resolve.

If resolveInFrame is not Types.ResolveInFrameB.frame_resolve, then the position vector and the orientation object of frame_resolve must be set to constant values from the outside in order that the model remains balanced (these constant values are ignored).

Extends from Interfaces.PartialOneFrame_b (Base model for components providing one frame_b connector + outer world + assert to guarantee that the component is connected).

Parameters

Type Name Default Description

ResolveInFrameB resolveInFrame Modelica.Mechanics.MultiBody... Frame in which force is resolved (1: world, 2: frame_b, 3: frame_resolve)

Type	Name	Default	Description
ResolveInFrameB	resolveInFrame	Modelica.Mechanics.MultiBody...	Frame in which force is resolved (1: world, 2: frame_b, 3: frame_resolve)

Connectors

Type Name Description

Frame_b frame_b Coordinate system fixed to the component with one cut-force and cut-torque

Frame_resolve frame_resolve The input signals are optionally resolved in this frame

input RealInput force[3] x-, y-, z-coordinates of force resolved in frame defined by resolveInFrame [N]

Type	Name	Description
Frame_b	frame_b	Coordinate system fixed to the component with one cut-force and cut-torque
Frame_resolve	frame_resolve	The input signals are optionally resolved in this frame
input RealInput	force[3]	x-, y-, z-coordinates of force resolved in frame defined by resolveInFrame [N]

Modelica definition

model BasicWorldForce 
  "External force acting at frame_b, defined by 3 input signals"

  import SI = Modelica.SIunits;
  import Modelica.Mechanics.MultiBody.Types.ResolveInFrameB;
  extends Interfaces.PartialOneFrame_b;
  Interfaces.Frame_resolve frame_resolve 
    "The input signals are optionally resolved in this frame";

  Modelica.Blocks.Interfaces.RealInput force[3](each final quantity="Force", each final unit=
                 "N") 
    "x-, y-, z-coordinates of force resolved in frame defined by resolveInFrame";
  parameter Modelica.Mechanics.MultiBody.Types.ResolveInFrameB
    resolveInFrame=
    Modelica.Mechanics.MultiBody.Types.ResolveInFrameB.world 
    "Frame in which force is resolved (1: world, 2: frame_b, 3: frame_resolve)";

equation 
   assert(cardinality(frame_resolve) > 0, "Connector frame_resolve must be connected at least once and frame_resolve.r_0/.R must be set");
   frame_resolve.f = zeros(3);
   frame_resolve.t = zeros(3);

   if resolveInFrame == ResolveInFrameB.world then
      frame_b.f = -Frames.resolve2(frame_b.R, force);
   elseif resolveInFrame == ResolveInFrameB.frame_b then
      frame_b.f = -force;
   elseif resolveInFrame == ResolveInFrameB.frame_resolve then
      frame_b.f = -Frames.resolveRelative(force, frame_resolve.R, frame_b.R);
   else
      assert(false, "Wrong value for parameter resolveInFrame");
      frame_b.f = zeros(3);
   end if;
   frame_b.t = zeros(3);
end BasicWorldForce;

Modelica.Mechanics.MultiBody.Forces.Internal.BasicWorldTorque

External torque acting at frame_b, defined by 3 input signals

Modelica.Mechanics.MultiBody.Forces.Internal.BasicWorldTorque

Information

The 3 signals of the torque connector are interpreted as the x-, y- and z-coordinates of a torque acting at the frame connector to which this component is attached. Via parameter resolveInFrame it is defined, in which frame these coordinates shall be resolved:

Types.ResolveInFrameB.	Meaning
world	Resolve input torque in world frame (= default)
frame_b	Resolve input torque in frame_b
frame_resolve	Resolve input torque in frame_resolve (frame_resolve must be connected)

If resolveInFrame = Types.ResolveInFrameB.frame_resolve, the torque coordinates are with respect to the frame, that is connected to frame_resolve.

Extends from Interfaces.PartialOneFrame_b (Base model for components providing one frame_b connector + outer world + assert to guarantee that the component is connected).

Parameters

Type Name Default Description

ResolveInFrameB resolveInFrame Modelica.Mechanics.MultiBody... Frame in which torque is resolved (1: world, 2: frame_b, 3: frame_resolve)

Type	Name	Default	Description
ResolveInFrameB	resolveInFrame	Modelica.Mechanics.MultiBody...	Frame in which torque is resolved (1: world, 2: frame_b, 3: frame_resolve)

Connectors

Type Name Description

Frame_b frame_b Coordinate system fixed to the component with one cut-force and cut-torque

Frame_resolve frame_resolve The input signals are optionally resolved in this frame

input RealInput torque[3] x-, y-, z-coordinates of torque resolved in frame defined by resolveInFrame [N.m]

Type	Name	Description
Frame_b	frame_b	Coordinate system fixed to the component with one cut-force and cut-torque
Frame_resolve	frame_resolve	The input signals are optionally resolved in this frame
input RealInput	torque[3]	x-, y-, z-coordinates of torque resolved in frame defined by resolveInFrame [N.m]

Modelica definition

model BasicWorldTorque 
  "External torque acting at frame_b, defined by 3 input signals"

  import SI = Modelica.SIunits;
  import Modelica.Mechanics.MultiBody.Types.ResolveInFrameB;
  extends Interfaces.PartialOneFrame_b;
  Interfaces.Frame_resolve frame_resolve 
    "The input signals are optionally resolved in this frame";

  Modelica.Blocks.Interfaces.RealInput torque[3](each final quantity="Torque", each final unit=
                 "N.m") 
    "x-, y-, z-coordinates of torque resolved in frame defined by resolveInFrame";
  parameter Modelica.Mechanics.MultiBody.Types.ResolveInFrameB
    resolveInFrame=
    Modelica.Mechanics.MultiBody.Types.ResolveInFrameB.world 
    "Frame in which torque is resolved (1: world, 2: frame_b, 3: frame_resolve)";

equation 
   assert(cardinality(frame_resolve) > 0, "Connector frame_resolve must be connected at least once and frame_resolve.r_0/.R must be set");
   frame_resolve.f = zeros(3);
   frame_resolve.t = zeros(3);

   if resolveInFrame == ResolveInFrameB.world then
      frame_b.t = -Frames.resolve2(frame_b.R, torque);
   elseif resolveInFrame == ResolveInFrameB.frame_b then
      frame_b.t = -torque;
   elseif resolveInFrame == ResolveInFrameB.frame_resolve then
      frame_b.t = -Frames.resolveRelative(torque, frame_resolve.R, frame_b.R);
   else
      assert(false, "Wrong value for parameter resolveInFrame");
      frame_b.t = zeros(3);
   end if;
   frame_b.f = zeros(3);
end BasicWorldTorque;

Modelica.Mechanics.MultiBody.Forces.Internal.standardGravityAcceleration

Standard gravity fields (no/parallel/point field)

Information

This function defines the standard gravity fields for the World object.

*gravityType*	*gravity [m/s2]*	*description*
Types.GravityType.NoGravity	= {0,0,0}	No gravity
Types.GravityType.UniformGravity	= g	Constant parallel gravity field
Types.GravityType.PointGravity	= -(mue/(rr))r/\|r\|	Point gravity field with spherical mass

Extends from Modelica.Mechanics.MultiBody.Interfaces.partialGravityAcceleration.

Inputs

Type Name Default Description

Position r[3] Position vector from world frame to actual point, resolved in world frame [m]

GravityTypes gravityType Type of gravity field

Acceleration g[3] Constant gravity acceleration, resolved in world frame, if gravityType=UniformGravity [m/s2]

Real mue Field constant of point gravity field, if gravityType=PointGravity [m3/s2]

Type	Name	Description
Position	r[3]	Position vector from world frame to actual point, resolved in world frame [m]
GravityTypes	gravityType	Type of gravity field
Acceleration	g[3]	Constant gravity acceleration, resolved in world frame, if gravityType=UniformGravity [m/s2]
Real	mue	Field constant of point gravity field, if gravityType=PointGravity [m3/s2]

Outputs

Type Name Description

Acceleration gravity[3] Gravity acceleration at position r, resolved in world frame [m/s2]

Type	Name	Description
Acceleration	gravity[3]	Gravity acceleration at position r, resolved in world frame [m/s2]

Modelica definition

function standardGravityAcceleration 
  "Standard gravity fields (no/parallel/point field)"
  extends Modelica.Mechanics.MultiBody.Interfaces.partialGravityAcceleration;
  import Modelica.Mechanics.MultiBody.Types.GravityTypes;
  input GravityTypes gravityType "Type of gravity field";
  input Modelica.SIunits.Acceleration g[3] 
    "Constant gravity acceleration, resolved in world frame, if gravityType=UniformGravity";
  input Real mue(unit="m3/s2") 
    "Field constant of point gravity field, if gravityType=PointGravity";
algorithm 
gravity := if gravityType == GravityTypes.UniformGravity then g else 
           if gravityType == GravityTypes.PointGravity then 
              -(mue/(r*r))*(r/Modelica.Math.Vectors.length(r)) else zeros(3);
end standardGravityAcceleration;

Automatically generated Fri Nov 12 16:30:27 2010.