1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
6 Purpose: Encapsulates the inertial frame forces (coriolis and centrifugal)
8 ------------- Copyright (C) 2000 Jon S. Berndt (jsb@hal-pc.org) -------------
10 This program is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free Software
12 Foundation; either version 2 of the License, or (at your option) any later
15 This program is distributed in the hope that it will be useful, but WITHOUT
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
20 You should have received a copy of the GNU General Public License along with
21 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
22 Place - Suite 330, Boston, MA 02111-1307, USA.
24 Further information about the GNU General Public License can also be found on
25 the world wide web at http://www.gnu.org.
27 FUNCTIONAL DESCRIPTION
28 --------------------------------------------------------------------------------
31 --------------------------------------------------------------------------------
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
36 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
38 #include "FGInertial.h"
39 #include "FGPosition.h"
40 #include "FGMassBalance.h"
42 static const char *IdSrc = "$Id$";
43 static const char *IdHdr = ID_INERTIAL;
45 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
47 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
50 FGInertial::FGInertial(FGFDMExec* fgex) : FGModel(fgex)
57 RotationRate = 0.00007272205217;
59 RadiusReference = 20925650.00;
60 gAccelReference = GM/(RadiusReference*RadiusReference);
61 gAccel = GM/(RadiusReference*RadiusReference);
63 if (debug_lvl & 2) cout << "Instantiated: FGInertial" << endl;
66 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
68 FGInertial::~FGInertial(void)
70 if (debug_lvl & 2) cout << "Destroyed: FGInertial" << endl;
73 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
75 bool FGInertial::Run(void)
77 double stht, ctht, sphi, cphi;
79 if (!FGModel::Run()) {
81 gAccel = GM / (Position->GetRadius()*Position->GetRadius());
83 stht = sin(Rotation->GetEuler(eTht));
84 ctht = cos(Rotation->GetEuler(eTht));
85 sphi = sin(Rotation->GetEuler(ePhi));
86 cphi = cos(Rotation->GetEuler(ePhi));
88 vGravity(eX) = vForces(eX) = -gravity()*stht;
89 vGravity(eY) = vForces(eY) = gravity()*sphi*ctht;
90 vGravity(eZ) = vForces(eZ) = gravity()*cphi*ctht;
92 // The following equation for vOmegaLocal terms shows the angular velocity
93 // calculation _for_the_local_frame_ given the earth's rotation (first set)
94 // at the current latitude, and also the component due to the aircraft
95 // motion over the curved surface of the earth (second set).
97 vOmegaLocal(eX) = omega() * cos(Position->GetLatitude());
98 vOmegaLocal(eY) = 0.0;
99 vOmegaLocal(eZ) = omega() * -sin(Position->GetLatitude());
101 vOmegaLocal(eX) += Position->GetVe() / Position->GetRadius();
102 vOmegaLocal(eY) += -Position->GetVn() / Position->GetRadius();
103 vOmegaLocal(eZ) += 0.00;
105 // vForces = State->GetTl2b()*(-2.0*vOmegaLocal * Position->GetVel());
107 vRadius(3) = Position->GetRadius();
108 vForces += State->GetTl2b()*(vOmegaLocal * (vOmegaLocal * vRadius));
110 vForces *= MassBalance->GetMass(); // IMPORTANT !!!!!!!!!!!!!!!!!!!!!!!!!!!!
118 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
120 bool FGInertial::LoadInertial(FGConfigFile* AC_cfg)
125 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
127 void FGInertial::Debug(void)
129 //TODO: Add your source code here