JSBSim Flight Dynamics Model 1.0 (23 February 2013)
An Open Source Flight Dynamics and Control Software Library in C++
Public Member Functions | Public Attributes

FGGroundReactions Class Reference

Manages ground reactions modeling. More...

#include <FGGroundReactions.h>

Inheritance diagram for FGGroundReactions:
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List of all members.

Public Member Functions

 FGGroundReactions (FGFDMExec *)
const FGColumnVector3 & GetForces (void) const
double GetForces (int idx) const
FGLGear * GetGearUnit (int gear) const
 Gets a gear instance.
string GetGroundReactionStrings (string delimeter) const
string GetGroundReactionValues (string delimeter) const
const FGColumnVector3 & GetMoments (void) const
double GetMoments (int idx) const
vector< LagrangeMultiplier * > * GetMultipliersList (void)
int GetNumGearUnits (void) const
bool GetWOW (void) const
bool InitModel (void)
bool Load (Element *el)
 Loads this model.
void RegisterLagrangeMultiplier (LagrangeMultiplier *lmult)
bool Run (bool Holding)
 Runs the Ground Reactions model; called by the Executive Can pass in a value indicating if the executive is directing the simulation to Hold.

Public Attributes

FGLGear::Inputs in

Detailed Description

Maintains a list of landing gear and ground contact points, all instances of FGLGear. Sums their forces and moments so that these may be provided to FGPropagate. Parses the <ground_reactions> section of the aircraft configuration file.

Configuration File Format of <ground_reactions> Section:

    <ground_reactions>
        <contact>
           ... {see FGLGear for specifics of this format}
        </contact>
        ... {more contacts}
    </ground_reactions>

Definition at line 82 of file FGGroundReactions.h.

Member Function Documentation

FGLGear* GetGearUnit ( int  gear) const [inline]
Parameters:
gearindex of gear instance
Returns:
a pointer to the FGLGear instance of the gear unit requested

Definition at line 111 of file FGGroundReactions.h.

Referenced by FGTrimAnalysisControl::initTheta(), FGFCS::Run(), FGTrimAnalysisControl::SetPhiOnGround(), and FGTrimAnalysisControl::SetThetaOnGround().

{ return lGear[gear]; }

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bool Load ( Element *  el) [virtual]
Parameters:
ela pointer to the element
Returns:
true if model is successfully loaded

Reimplemented from FGModel.

Definition at line 128 of file FGGroundReactions.cpp.

References Element::FindElement(), Element::FindNextElement(), Element::GetAttributeValue(), FGFDMExec::GetFullAircraftPath(), and Element::GetNumElements().

{
  int num=0;
  string fname="", file="";
  string separator = "/";

  fname = elem->GetAttributeValue("file");
  if (!fname.empty()) {
    file = FDMExec->GetFullAircraftPath() + separator + fname;
    document = LoadXMLDocument(file);
    if (document == 0L) return false;
  } else {
    document = elem;
  }

  Debug(2);

  unsigned int numContacts = document->GetNumElements("contact");
  lGear.resize(numContacts);
  Element* contact_element = document->FindElement("contact");
  for (unsigned int idx=0; idx<numContacts; idx++) {
    lGear[idx] = new FGLGear(contact_element, FDMExec, num++, in);
    contact_element = document->FindNextElement("contact");
  }

  FGModel::Load(document); // Perform base class Load

  for (unsigned int i=0; i<lGear.size();i++) lGear[i]->bind();

  PostLoad(document, PropertyManager);

  return true;
}

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bool Run ( bool  Holding) [virtual]
Parameters:
Holdingif true, the executive has been directed to hold the sim from advancing time. Some models may ignore this flag, such as the Input model, which may need to be active to listen on a socket for the "Resume" command to be given.
Returns:
false if no error

Reimplemented from FGModel.

Definition at line 85 of file FGGroundReactions.cpp.

References FGModel::Run().

{
  if (FGModel::Run(Holding)) return true;
  if (Holding) return false;

  RunPreFunctions();

  vForces.InitMatrix();
  vMoments.InitMatrix();

  multipliers.clear();

  // Sum forces and moments for all gear, here.
  // Some optimizations may be made here - or rather in the gear code itself.
  // The gear ::Run() method is called several times - once for each gear.
  // Perhaps there is some commonality for things which only need to be
  // calculated once.
  for (unsigned int i=0; i<lGear.size(); i++) {
    vForces  += lGear[i]->GetBodyForces();
    vMoments += lGear[i]->GetMoments();
  }

  RunPostFunctions();

  return false;
}

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The documentation for this class was generated from the following files: