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);
68 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
70 FGInertial::~FGInertial(void)
76 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
78 bool FGInertial::Run(void)
80 double stht, ctht, sphi, cphi;
82 if (!FGModel::Run()) {
84 gAccel = GM / (Position->GetRadius()*Position->GetRadius());
86 stht = sin(Rotation->GetEuler(eTht));
87 ctht = cos(Rotation->GetEuler(eTht));
88 sphi = sin(Rotation->GetEuler(ePhi));
89 cphi = cos(Rotation->GetEuler(ePhi));
91 vGravity(eX) = vForces(eX) = -gravity()*stht;
92 vGravity(eY) = vForces(eY) = gravity()*sphi*ctht;
93 vGravity(eZ) = vForces(eZ) = gravity()*cphi*ctht;
95 // The following equation for vOmegaLocal terms shows the angular velocity
96 // calculation _for_the_local_frame_ given the earth's rotation (first set)
97 // at the current latitude, and also the component due to the aircraft
98 // motion over the curved surface of the earth (second set).
100 vOmegaLocal(eX) = omega() * cos(Position->GetLatitude());
101 vOmegaLocal(eY) = 0.0;
102 vOmegaLocal(eZ) = omega() * -sin(Position->GetLatitude());
104 vOmegaLocal(eX) += Position->GetVe() / Position->GetRadius();
105 vOmegaLocal(eY) += -Position->GetVn() / Position->GetRadius();
106 vOmegaLocal(eZ) += 0.00;
108 // vForces = State->GetTl2b()*(-2.0*vOmegaLocal * Position->GetVel());
110 vRadius(3) = Position->GetRadius();
111 vForces += State->GetTl2b()*(vOmegaLocal * (vOmegaLocal * vRadius));
113 vForces *= MassBalance->GetMass(); // IMPORTANT !!!!!!!!!!!!!!!!!!!!!!!!!!!!
121 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
123 bool FGInertial::LoadInertial(FGConfigFile* AC_cfg)
128 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
129 // The bitmasked value choices are as follows:
130 // unset: In this case (the default) JSBSim would only print
131 // out the normally expected messages, essentially echoing
132 // the config files as they are read. If the environment
133 // variable is not set, debug_lvl is set to 1 internally
134 // 0: This requests JSBSim not to output any messages
136 // 1: This value explicity requests the normal JSBSim
138 // 2: This value asks for a message to be printed out when
139 // a class is instantiated
140 // 4: When this value is set, a message is displayed when a
141 // FGModel object executes its Run() method
142 // 8: When this value is set, various runtime state variables
143 // are printed out periodically
144 // 16: When set various parameters are sanity checked and
145 // a message is printed out when they go out of bounds
147 void FGInertial::Debug(int from)
149 if (debug_lvl <= 0) return;
151 if (debug_lvl & 1) { // Standard console startup message output
152 if (from == 0) { // Constructor
156 if (debug_lvl & 2 ) { // Instantiation/Destruction notification
157 if (from == 0) cout << "Instantiated: FGInertial" << endl;
158 if (from == 1) cout << "Destroyed: FGInertial" << endl;
160 if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
162 if (debug_lvl & 8 ) { // Runtime state variables
164 if (debug_lvl & 16) { // Sanity checking
166 if (debug_lvl & 64) {
167 if (from == 0) { // Constructor
168 cout << IdSrc << endl;
169 cout << IdHdr << endl;
174 void FGInertial::bind(void){
175 PropertyManager->Tie("forces/fbx-inertial-lbs", this,1,
176 &FGInertial::GetForces);
177 PropertyManager->Tie("forces/fby-inertial-lbs", this,2,
178 &FGInertial::GetForces);
179 PropertyManager->Tie("forces/fbz-inertial-lbs", this,3,
180 &FGInertial::GetForces);
183 void FGInertial::unbind(void){
184 PropertyManager->Untie("forces/fbx-inertial-lbs");
185 PropertyManager->Untie("forces/fby-inertial-lbs");
186 PropertyManager->Untie("forces/fbz-inertial-lbs");