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 extern short debug_lvl;
47 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
49 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
52 FGInertial::FGInertial(FGFDMExec* fgex) : FGModel(fgex),
61 if (debug_lvl & 2) cout << "Instantiated: FGInertial" << endl;
64 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
66 FGInertial::~FGInertial(void)
68 if (debug_lvl & 2) cout << "Destroyed: FGInertial" << endl;
71 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
73 bool FGInertial::Run(void)
75 float stht, ctht, sphi, cphi;
77 if (!FGModel::Run()) {
79 stht = sin(Rotation->GetEuler(eTht));
80 ctht = cos(Rotation->GetEuler(eTht));
81 sphi = sin(Rotation->GetEuler(ePhi));
82 cphi = cos(Rotation->GetEuler(ePhi));
84 vForces(eX) = -GRAVITY*stht;
85 vForces(eY) = GRAVITY*sphi*ctht;
86 vForces(eZ) = GRAVITY*cphi*ctht;
88 // The following equation for vOmegaLocal terms shows the angular velocity
89 // calculation _for_the_local_frame_ given the earth's rotation (first set)
90 // at the current latitude, and also the component due to the aircraft
91 // motion over the curved surface of the earth (second set).
93 vOmegaLocal(eX) = OMEGA_EARTH * cos(Position->GetLatitude());
94 vOmegaLocal(eY) = 0.0;
95 vOmegaLocal(eZ) = OMEGA_EARTH * -sin(Position->GetLatitude());
97 vOmegaLocal(eX) += Position->GetVe() / Position->GetRadius();
98 vOmegaLocal(eY) += -Position->GetVn() / Position->GetRadius();
99 vOmegaLocal(eZ) += 0.00;
101 // vForces = State->GetTl2b()*(-2.0*vOmegaLocal * Position->GetVel());
103 vRadius(3) = Position->GetRadius();
104 vForces += State->GetTl2b()*(vOmegaLocal * (vOmegaLocal * vRadius));
106 vForces *= MassBalance->GetMass(); // IMPORTANT !!!!!!!!!!!!!!!!!!!!!!!!!!!!
114 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
116 bool FGInertial::LoadInertial(FGConfigFile* AC_cfg)
121 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
123 void FGInertial::Debug(void)
125 //TODO: Add your source code here