1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
6 Purpose: Encapsulates the inertial frame forces (coriolis and centrifugal)
8 ------------- Copyright (C) 2000 Jon S. Berndt (jon@jsbsim.org) -------------
10 This program is free software; you can redistribute it and/or modify it under
11 the terms of the GNU Lesser 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 Lesser General Public License for more
20 You should have received a copy of the GNU Lesser 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 Lesser 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 "FGFDMExec.h"
40 #include "FGPropagate.h"
42 #include "FGMassBalance.h"
49 static const char *IdSrc = "$Id$";
50 static const char *IdHdr = ID_INERTIAL;
52 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
54 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
57 FGInertial::FGInertial(FGFDMExec* fgex) : FGModel(fgex)
62 RotationRate = 0.00007292115;
63 GM = 14.07644180E15; // WGS84 value
64 RadiusReference = 20925650.00; // Equatorial radius (WGS84)
65 C2_0 = -4.84165371736E-04; // WGS84 value for the C2,0 coefficient
66 J2 = 1.0826266836E-03; // WGS84 value for J2
67 a = 20925646.3255; // WGS84 semimajor axis length in feet
68 b = 20855486.5951; // WGS84 semiminor axis length in feet
73 RotationRate = 0.0000026617;
74 GM = 1.7314079E14; // Lunar GM
75 RadiusReference = 5702559.05; // Equatorial radius
76 C2_0 = 0; // value for the C2,0 coefficient
77 J2 = 2.033542482111609E-4; // value for J2
78 a = 5702559.05; // semimajor axis length in feet
79 b = 5695439.63; // semiminor axis length in feet
83 gAccelReference = GM/(RadiusReference*RadiusReference);
84 gAccel = GM/(RadiusReference*RadiusReference);
91 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
93 FGInertial::~FGInertial(void)
98 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
100 bool FGInertial::InitModel(void)
102 if (!FGModel::InitModel()) return false;
109 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
111 bool FGInertial::Run(void)
113 // Fast return if we have nothing to do ...
114 if (FGModel::Run()) return true;
115 if (FDMExec->Holding()) return false;
120 double r = Propagate->GetRadius();
121 gAccel = GetGAccel(r);
122 earthPosAngle += State->Getdt()*RotationRate;
129 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
131 double FGInertial::GetGAccel(double r) const
136 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
138 void FGInertial::bind(void)
140 PropertyManager->Tie("position/epa-rad", this, &FGInertial::GetEarthPositionAngle);
143 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
144 // The bitmasked value choices are as follows:
145 // unset: In this case (the default) JSBSim would only print
146 // out the normally expected messages, essentially echoing
147 // the config files as they are read. If the environment
148 // variable is not set, debug_lvl is set to 1 internally
149 // 0: This requests JSBSim not to output any messages
151 // 1: This value explicity requests the normal JSBSim
153 // 2: This value asks for a message to be printed out when
154 // a class is instantiated
155 // 4: When this value is set, a message is displayed when a
156 // FGModel object executes its Run() method
157 // 8: When this value is set, various runtime state variables
158 // are printed out periodically
159 // 16: When set various parameters are sanity checked and
160 // a message is printed out when they go out of bounds
162 void FGInertial::Debug(int from)
164 if (debug_lvl <= 0) return;
166 if (debug_lvl & 1) { // Standard console startup message output
167 if (from == 0) { // Constructor
171 if (debug_lvl & 2 ) { // Instantiation/Destruction notification
172 if (from == 0) cout << "Instantiated: FGInertial" << endl;
173 if (from == 1) cout << "Destroyed: FGInertial" << endl;
175 if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
177 if (debug_lvl & 8 ) { // Runtime state variables
179 if (debug_lvl & 16) { // Sanity checking
181 if (debug_lvl & 64) {
182 if (from == 0) { // Constructor
183 cout << IdSrc << endl;
184 cout << IdHdr << endl;