FGGroundReactions.cpp

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 Module:       FGGroundReactions.cpp
 Author:       Jon S. Berndt
 Date started: 09/13/00
 Purpose:      Encapsulates the ground reaction forces (gear and collision)
 
 ------------- Copyright (C) 2000  Jon S. Berndt (jon@jsbsim.org) -------------
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU Lesser General Public License as published by the Free
 Software Foundation; either version 2 of the License, or (at your option) any
 later version.
 
 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 details.
 
 You should have received a copy of the GNU Lesser General Public License along
 with this program; if not, write to the Free Software Foundation, Inc., 59
 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 Further information about the GNU Lesser General Public License can also be
 found on the world wide web at http://www.gnu.org.
 
FUNCTIONAL DESCRIPTION
--------------------------------------------------------------------------------
 
HISTORY
--------------------------------------------------------------------------------
09/13/00   JSB   Created
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
#include <iomanip>
 
#include "FGGroundReactions.h"
#include "FGAccelerations.h"
#include "input_output/FGXMLElement.h"
 
using namespace std;
 
namespace JSBSim {
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
FGGroundReactions::FGGroundReactions(FGFDMExec* fgex) :
   FGModel(fgex),
   FGSurface(fgex),
   DsCmd(0.0)
{
  Name = "FGGroundReactions";
 
  bind();
 
  Debug(0);
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
FGGroundReactions::~FGGroundReactions(void)
{
  for (unsigned int i=0; i<lGear.size();i++) delete lGear[i];
  lGear.clear();
 
  Debug(1);
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
bool FGGroundReactions::InitModel(void)
{
  if (!FGModel::InitModel()) return false;
 
  vForces.InitMatrix();
  vMoments.InitMatrix();
  DsCmd = 0.0;
 
  multipliers.clear();
 
  for (unsigned int i=0; i<lGear.size(); i++)
    lGear[i]->ResetToIC();
 
  return true;
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
bool FGGroundReactions::Run(bool Holding)
{
  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(this);
    vMoments += lGear[i]->GetMoments();
  }
 
  RunPostFunctions();
 
  return false;
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
bool FGGroundReactions::GetWOW(void) const
{
  bool result = false;
  for (unsigned int i=0; i<lGear.size(); i++) {
    if (lGear[i]->IsBogey() && lGear[i]->GetWOW()) {
      result = true;
      break;
    }
  }
  return result;
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
void FGGroundReactions::SetDsCmd(double cmd)
{
  DsCmd = cmd;
  for (unsigned int i=0; i<lGear.size(); ++i)
    lGear[i]->SetSteerCmd(cmd);
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
bool FGGroundReactions::Load(Element* document)
{
  int num=0;
 
  Name = "Ground Reactions Model: " + document->GetAttributeValue("name");
 
  Debug(2);
 
  // Perform base class Pre-Load
  if (!FGModel::Upload(document, true))
    return false;
 
  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");
  }
 
  for (unsigned int i=0; i<lGear.size();i++) lGear[i]->bind();
 
  PostLoad(document, FDMExec);
 
  return true;
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
string FGGroundReactions::GetGroundReactionStrings(string delimeter) const
{
  std::ostringstream buf;
 
  for (unsigned int i=0;i<lGear.size();i++) {
    if (lGear[i]->IsBogey()) {
      string name = lGear[i]->GetName();
      buf << name << " WOW" << delimeter
          << name << " stroke (ft)" << delimeter
          << name << " stroke velocity (ft/sec)" << delimeter
          << name << " compress force (lbs)" << delimeter
          << name << " wheel side force (lbs)" << delimeter
          << name << " wheel roll force (lbs)" << delimeter
          << name << " body X force (lbs)" << delimeter
          << name << " body Y force (lbs)" << delimeter
          << name << " wheel velocity vec X (ft/sec)" << delimeter
          << name << " wheel velocity vec Y (ft/sec)" << delimeter
          << name << " wheel rolling velocity (ft/sec)" << delimeter
          << name << " wheel side velocity (ft/sec)" << delimeter
          << name << " wheel slip (deg)" << delimeter;
    } else {
      string name = lGear[i]->GetName();
      buf << name << " WOW" << delimeter
          << name << " stroke (ft)" << delimeter
          << name << " stroke velocity (ft/sec)" << delimeter
          << name << " compress force (lbs)" << delimeter;
    }
  }
 
  buf << " Total Gear Force_X (lbs)" << delimeter
      << " Total Gear Force_Y (lbs)" << delimeter
      << " Total Gear Force_Z (lbs)" << delimeter
      << " Total Gear Moment_L (ft-lbs)" << delimeter
      << " Total Gear Moment_M (ft-lbs)" << delimeter
      << " Total Gear Moment_N (ft-lbs)";
 
  return buf.str();
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
string FGGroundReactions::GetGroundReactionValues(string delimeter) const
{
  std::ostringstream buf;
 
  for (unsigned int i=0;i<lGear.size();i++) {
    if (lGear[i]->IsBogey()) {
      FGLGear *gear = lGear[i];
      buf << (gear->GetWOW() ? "1" : "0") << delimeter
          << setprecision(5) << gear->GetCompLen() << delimeter
          << setprecision(6) << gear->GetCompVel() << delimeter
          << setprecision(10) << gear->GetCompForce() << delimeter
          << gear->GetWheelSideForce() << delimeter
          << gear->GetWheelRollForce() << delimeter
          << gear->GetBodyXForce() << delimeter
          << gear->GetBodyYForce() << delimeter
          << setprecision(6) << gear->GetWheelVel(eX) << delimeter
          << gear->GetWheelVel(eY) << delimeter
          << gear->GetWheelRollVel() << delimeter
          << gear->GetWheelSideVel() << delimeter
          << gear->GetWheelSlipAngle() << delimeter;
    } else {
      FGLGear *gear = lGear[i];
      buf << (gear->GetWOW() ? "1" : "0") << delimeter
          << setprecision(5) << gear->GetCompLen() << delimeter
          << setprecision(6) << gear->GetCompVel() << delimeter
          << setprecision(10) << gear->GetCompForce() << delimeter;
    }
  }
 
  FGAccelerations* Accelerations = FDMExec->GetAccelerations();
 
  buf << Accelerations->GetGroundForces(eX) << delimeter
      << Accelerations->GetGroundForces(eY) << delimeter
      << Accelerations->GetGroundForces(eZ) << delimeter
      << Accelerations->GetGroundMoments(eX) << delimeter
      << Accelerations->GetGroundMoments(eY) << delimeter
      << Accelerations->GetGroundMoments(eZ);
 
  return buf.str();
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
void FGGroundReactions::bind(void)
{
  eSurfaceType = ctGROUND;
  FGSurface::bind();
 
  PropertyManager->Tie("gear/num-units", this, &FGGroundReactions::GetNumGearUnits);
  PropertyManager->Tie("gear/wow", this, &FGGroundReactions::GetWOW);
  PropertyManager->Tie("fcs/steer-cmd-norm", this, &FGGroundReactions::GetDsCmd,
                       &FGGroundReactions::SetDsCmd);
}
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//    The bitmasked value choices are as follows:
//    unset: In this case (the default) JSBSim would only print
//       out the normally expected messages, essentially echoing
//       the config files as they are read. If the environment
//       variable is not set, debug_lvl is set to 1 internally
//    0: This requests JSBSim not to output any messages
//       whatsoever.
//    1: This value explicity requests the normal JSBSim
//       startup messages
//    2: This value asks for a message to be printed out when
//       a class is instantiated
//    4: When this value is set, a message is displayed when a
//       FGModel object executes its Run() method
//    8: When this value is set, various runtime state variables
//       are printed out periodically
//    16: When set various parameters are sanity checked and
//       a message is printed out when they go out of bounds
 
void FGGroundReactions::Debug(int from)
{
  if (debug_lvl <= 0) return;
 
  if (debug_lvl & 1) { // Standard console startup message output
    if (from == 2) { // Loading
      cout << endl << "  Ground Reactions: " << endl;
    }
  }
  if (debug_lvl & 2 ) { // Instantiation/Destruction notification
    if (from == 0) cout << "Instantiated: FGGroundReactions" << endl;
    if (from == 1) cout << "Destroyed:    FGGroundReactions" << endl;
  }
  if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
  }
  if (debug_lvl & 8 ) { // Runtime state variables
  }
  if (debug_lvl & 16) { // Sanity checking
  }
  if (debug_lvl & 64) {
    if (from == 0) { // Constructor
    }
  }
}
}