src/FDM/JSBSim/models/FGMassBalance.h

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Header:       FGMassBalance.h
   4  Author:       Jon S. Berndt
   5  Date started: 09/12/2000
   6
   7  ------------- Copyright (C) 2000  Jon S. Berndt (jsb@hal-pc.org) --------------
   8
   9  This program is free software; you can redistribute it and/or modify it under
  10  the terms of the GNU Lesser General Public License as published by the Free Software
  11  Foundation; either version 2 of the License, or (at your option) any later
  12  version.
  13
  14  This program is distributed in the hope that it will be useful, but WITHOUT
  15  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  16  FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
  17  details.
  18
  19  You should have received a copy of the GNU Lesser General Public License along with
  20  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  21  Place - Suite 330, Boston, MA  02111-1307, USA.
  22
  23  Further information about the GNU Lesser General Public License can also be found on
  24  the world wide web at http://www.gnu.org.
  25
  26 HISTORY
  27 --------------------------------------------------------------------------------
  28 09/12/2000  JSB  Created
  29
  30 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  31 SENTRY
  32 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  33
  34 #ifndef FGMASSBALANCE_H
  35 #define FGMASSBALANCE_H
  36
  37 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  38 INCLUDES
  39 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  40
  41 #include "FGModel.h"
  42 #include <math/FGColumnVector3.h>
  43 #include <math/FGMatrix33.h>
  44 #include <input_output/FGXMLElement.h>
  45 #include <vector>
  46
  47 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  48 DEFINITIONS
  49 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  50
  51 #define ID_MASSBALANCE "$Id$"
  52
  53 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  54 FORWARD DECLARATIONSS
  55 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  56
  57 namespace JSBSim {
  58
  59 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  60 CLASS DOCUMENTATION
  61 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  62
  63 /** Models weight, balance and moment of inertia information.  Maintains a vector
  64     of point masses. Sums the contribution of all, and provides this to FGPropagate.
  65     Loads the \<mass_balance> section of the aircraft configuration file.
  66
  67     <h3>Configuration File Format:</h3>
  68 @code
  69     <mass_balance>
  70         <ixx unit="{SLUG*FT2 | KG*M2}"> {number} </ixx>
  71         <iyy unit="{SLUG*FT2 | KG*M2}"> {number} </iyy>
  72         <izz unit="{SLUG*FT2 | KG*M2}"> {number} </izz>
  73         <ixy unit="{SLUG*FT2 | KG*M2}"> {number} </ixy>
  74         <ixz unit="{SLUG*FT2 | KG*M2}"> {number} </ixz>
  75         <iyz unit="{SLUG*FT2 | KG*M2}"> {number} </iyz>
  76         <emptywt unit="{LBS | KG"> {number} </emptywt>
  77         <location name="CG" unit="{IN | M}">
  78             <x> {number} </x>
  79             <y> {number} </y>
  80             <z> {number} </z>
  81         </location>
  82         <pointmass name="{string}">
  83             <weight unit="{LBS | KG}"> {number} </weight>
  84             <location name="POINTMASS" unit="{IN | M}">
  85                 <x> {number} </x>
  86                 <y> {number} </y>
  87                 <z> {number} </z>
  88             </location>
  89         </pointmass>
  90         ... other point masses ...
  91     </mass_balance>
  92 @endcode
  93   */
  94
  95 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  96 CLASS DECLARATION
  97 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  98
  99 class FGMassBalance : public FGModel
 100 {
 101
 102 public:
 103   FGMassBalance(FGFDMExec*);
 104   ~FGMassBalance();
 105
 106   bool Load(Element* el);
 107   bool InitModel(void);
 108   bool Run(void);
 109
 110   inline double GetMass(void) const {return Mass;}
 111   inline double GetWeight(void) const {return Weight;}
 112   inline FGColumnVector3& GetXYZcg(void) {return vXYZcg;}
 113   inline double GetXYZcg(int axis) const  {return vXYZcg(axis);}
 114
 115   /** Computes the inertia contribution of a pointmass.
 116       Computes and returns the inertia matrix of a pointmass of mass
 117       slugs at the given vector r in the structural frame. The units
 118       should be for the mass in slug and the vector in the structural
 119       frame as usual in inches.
 120       @param slugs the mass of this single pointmass given in slugs
 121       @param r the location of this single pointmass in the structural frame
 122    */
 123   FGMatrix33 GetPointmassInertia(double slugs, const FGColumnVector3& r) const
 124   {
 125     FGColumnVector3 v = StructuralToBody( r );
 126     FGColumnVector3 sv = slugs*v;
 127     double xx = sv(1)*v(1);
 128     double yy = sv(2)*v(2);
 129     double zz = sv(3)*v(3);
 130     double xy = -sv(1)*v(2);
 131     double xz = -sv(1)*v(3);
 132     double yz = -sv(2)*v(3);
 133     return FGMatrix33( yy+zz, xy, xz,
 134                        xy, xx+zz, yz,
 135                        xz, yz, xx+yy );
 136   }
 137
 138   /** Conversion from the structural frame to the body frame.
 139       Converts the location given in the structural frame
 140       coordinate system to the body frame. The units of the structural
 141       frame are assumed to be in inches. The unit of the result is in
 142       ft.
 143       @param r vector coordinate in the structural reference frame (X positive
 144                aft, measurements in inches).
 145       @return vector coordinate in the body frame, in feet.
 146    */
 147   FGColumnVector3 StructuralToBody(const FGColumnVector3& r) const;
 148
 149   inline void SetEmptyWeight(double EW) { EmptyWeight = EW;}
 150   inline void SetBaseCG(const FGColumnVector3& CG) {vbaseXYZcg = vXYZcg = CG;}
 151
 152   void AddPointMass(Element* el);
 153   double GetPointMassWeight(void);
 154   double GetPointMassWeight(int idx) const {
 155     if (idx < (int)PointMasses.size()) return(PointMasses[idx]->Weight);
 156     else return 0.0;
 157   }
 158
 159   void SetPointMassWeight(int idx, double pmw) {
 160     if (idx < (int)PointMasses.size()) {
 161       PointMasses[idx]->Weight = pmw;
 162     }
 163   }
 164
 165   FGColumnVector3& GetPointMassMoment(void);
 166   FGMatrix33& GetJ(void) {return mJ;}
 167   FGMatrix33& GetJinv(void) {return mJinv;}
 168   void SetAircraftBaseInertias(FGMatrix33 BaseJ) {baseJ = BaseJ;}
 169
 170 private:
 171   double Weight;
 172   double EmptyWeight;
 173   double Mass;
 174   FGMatrix33 mJ;
 175   FGMatrix33 mJinv;
 176   FGMatrix33 pmJ;
 177   FGMatrix33 baseJ;
 178   FGColumnVector3 vXYZcg;
 179   FGColumnVector3 vXYZtank;
 180   FGColumnVector3 vbaseXYZcg;
 181   FGColumnVector3 vPMxyz;
 182   FGColumnVector3 PointMassCG;
 183   FGMatrix33& CalculatePMInertias(void);
 184
 185   struct PointMass {
 186     PointMass(double w, FGColumnVector3& vXYZ) {
 187       Weight = w;
 188       Location = vXYZ;
 189     }
 190     FGColumnVector3 Location;
 191     double Weight;
 192   };
 193
 194   vector <struct PointMass*> PointMasses;
 195
 196   void bind(void);
 197   void Debug(int from);
 198 };
 199 }
 200 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 201 #endif