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Sync'ed JSBSim

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- Fixed the Calibrated Air Speed (CAS) computations for supersonic velocities
- Fixed the Nlf (Normal load factor) sign
- Nlf can now be specified as an initial condition via the property ic/targetNlf
- Added blocking sockets to the input features
- Added a property to piston engines to get the AFR (Air to Fuel Ratio)
- Added conversion from m/s to ft/s
- Restored the initial conditions for engines running (-1 means all engines)
This commit is contained in:
Bertrand Coconnier 2018-09-15 16:45:42 +02:00
parent ec0b515864
commit 6cc3d14032
20 changed files with 196 additions and 170 deletions
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3
src/FDM/JSBSim/FGFDMExec.cpp
View file

@ -393,11 +393,8 @@ void FGFDMExec::LoadInputs(unsigned int idx)
Auxiliary->in.SinTht = Propagate->GetSinEuler(eTht);
Auxiliary->in.CosPhi = Propagate->GetCosEuler(ePhi);
Auxiliary->in.SinPhi = Propagate->GetSinEuler(ePhi);
Auxiliary->in.Psi = Propagate->GetEuler(ePsi);
Auxiliary->in.TotalWindNED = Winds->GetTotalWindNED();
Auxiliary->in.TurbPQR = Winds->GetTurbPQR();
Auxiliary->in.WindPsi = Winds->GetWindPsi();
Auxiliary->in.Vwind = Winds->GetTotalWindNED().Magnitude();
break;
case eSystems:
// Dynamic inputs come into the components that FCS manages through properties

57
src/FDM/JSBSim/FGJSBBase.cpp
View file

@ -41,6 +41,7 @@ INCLUDES
#include <iostream>
#include <sstream>
#include <cstdlib>
#include "models/FGAtmosphere.h"
using namespace std;
@ -289,49 +290,47 @@ double FGJSBBase::PitotTotalPressure(double mach, double p)
// The denominator below is zero for Mach ~ 0.38, for which
// we'll never be here, so we're safe
return p*166.92158*pow(mach,7.0)/pow(7*mach*mach-1,2.5);
return p*166.92158009316827*pow(mach,7.0)/pow(7*mach*mach-1,2.5);
}
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
double FGJSBBase::VcalibratedFromMach(double mach, double p, double psl, double rhosl)
{
double pt = PitotTotalPressure(mach, p);
double A = pow(((pt-p)/psl+1), 1./3.5);
// Based on the formulas in the US Air Force Aircraft Performance Flight Testing
// Manual (AFFTC-TIH-99-01). In particular sections 4.6 to 4.8.
return sqrt(7*psl/rhosl*(A-1));
double FGJSBBase::MachFromImpactPressure(double qc, double p)
{
double A = qc / p + 1;
double M = sqrt(5.0*(pow(A, 1. / 3.5) - 1)); // Equation (4.12)
if (M > 1.0)
for (unsigned int i = 0; i<10; i++)
M = 0.8812848543473311*sqrt(A*pow(1 - 1.0 / (7.0*M*M), 2.5)); // Equation (4.17)
return M;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
double FGJSBBase::MachFromVcalibrated(double vcas, double p, double psl, double rhosl)
double FGJSBBase::VcalibratedFromMach(double mach, double p)
{
double pt = p + psl*(pow(1+vcas*vcas*rhosl/(7.0*psl),3.5)-1);
double asl = FGAtmosphere::StdDaySLsoundspeed;
double psl = FGAtmosphere::StdDaySLpressure;
double qc = PitotTotalPressure(mach, p) - p;
if (pt/p < 1.89293)
return sqrt(5.0*(pow(pt/p, 1./3.5) -1)); // Mach < 1
else {
// Mach >= 1
double mach = sqrt(0.77666*pt/p); // Initial guess is based on a quadratic approximation of the Rayleigh formula
double delta = 1.;
double target = pt/(166.92158*p);
int iter = 0;
return asl * MachFromImpactPressure(qc, psl);
}
// Find the root with Newton-Raphson. Since the differential is never zero,
// the function is monotonic and has only one root with a multiplicity of one.
// Convergence is certain.
while (delta > 1E-5 && iter < 10) {
double m2 = mach*mach; // Mach^2
double m6 = m2*m2*m2; // Mach^6
delta = mach*m6/pow(7.0*m2-1.0,2.5) - target;
double diff = 7.0*m6*(2.0*m2-1)/pow(7.0*m2-1.0,3.5); // Never zero when Mach >= 1
mach -= delta/diff;
iter++;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
return mach;
}
double FGJSBBase::MachFromVcalibrated(double vcas, double p)
{
double asl = FGAtmosphere::StdDaySLsoundspeed;
double psl = FGAtmosphere::StdDaySLpressure;
double qc = PitotTotalPressure(vcas / asl, psl) - psl;
return MachFromImpactPressure(qc, p);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

29
src/FDM/JSBSim/FGJSBBase.h
View file

@ -262,28 +262,31 @@ public:
* @return The total pressure in front of the Pitot tube in psf */
static double PitotTotalPressure(double mach, double p);
/** Calculate the calibrated airspeed from the Mach number. It uses the
* Rayleigh formula for supersonic speeds (See "Introduction to Aerodynamics
* of a Compressible Fluid - H.W. Liepmann, A.E. Puckett - Wiley & sons
* (1947)" §5.4 pp 75-80)
/** Compute the Mach number from the differential pressure (qc) and the
* static pressure. Based on the formulas in the US Air Force Aircraft
* Performance Flight Testing Manual (AFFTC-TIH-99-01).
* @param qc The differential/impact pressure
* @param p Pressure in psf
* @return The Mach number */
static double MachFromImpactPressure(double qc, double p);
/** Calculate the calibrated airspeed from the Mach number. Based on the
* formulas in the US Air Force Aircraft Performance Flight Testing
* Manual (AFFTC-TIH-99-01).
* @param mach The Mach number
* @param p Pressure in psf
* @param psl Pressure at sea level in psf
* @param rhosl Density at sea level in slugs/ft^3
* @return The calibrated airspeed (CAS) in ft/s
* */
static double VcalibratedFromMach(double mach, double p, double psl, double rhosl);
static double VcalibratedFromMach(double mach, double p);
/** Calculate the Mach number from the calibrated airspeed. For subsonic
* speeds, the reversed formula has a closed form. For supersonic speeds, the
* Rayleigh formula is reversed by the Newton-Raphson algorithm.
/** Calculate the Mach number from the calibrated airspeed.Based on the
* formulas in the US Air Force Aircraft Performance Flight Testing
* Manual (AFFTC-TIH-99-01).
* @param vcas The calibrated airspeed (CAS) in ft/s
* @param p Pressure in psf
* @param psl Pressure at sea level in psf
* @param rhosl Density at sea level in slugs/ft^3
* @return The Mach number
* */
static double MachFromVcalibrated(double vcas, double p, double psl, double rhosl);
static double MachFromVcalibrated(double vcas, double p);
/** Finite precision comparison.
@param a first value to compare

47
src/FDM/JSBSim/initialization/FGInitialCondition.cpp
View file

@ -53,6 +53,7 @@ INCLUDES
#include "models/FGAircraft.h"
#include "models/FGAccelerations.h"
#include "input_output/FGXMLFileRead.h"
#include "FGTrim.h"
using namespace std;
@ -148,7 +149,7 @@ void FGInitialCondition::InitializeIC(void)
lastAltitudeSet = setasl;
lastLatitudeSet = setgeoc;
enginesRunning = 0;
needTrim = 0;
trimRequested = TrimMode::tNone;
}
//******************************************************************************
@ -178,9 +179,7 @@ void FGInitialCondition::SetVcalibratedKtsIC(double vcas)
{
double altitudeASL = position.GetAltitudeASL();
double pressure = Atmosphere->GetPressure(altitudeASL);
double pressureSL = Atmosphere->GetPressureSL();
double rhoSL = Atmosphere->GetDensitySL();
double mach = MachFromVcalibrated(fabs(vcas)*ktstofps, pressure, pressureSL, rhoSL);
double mach = MachFromVcalibrated(fabs(vcas)*ktstofps, pressure);
double soundSpeed = Atmosphere->GetSoundSpeed(altitudeASL);
SetVtrueFpsIC(mach * soundSpeed);
@ -691,13 +690,12 @@ void FGInitialCondition::SetAltitudeASLFtIC(double alt)
{
double altitudeASL = position.GetAltitudeASL();
double pressure = Atmosphere->GetPressure(altitudeASL);
double pressureSL = Atmosphere->GetPressureSL();
double soundSpeed = Atmosphere->GetSoundSpeed(altitudeASL);
double rho = Atmosphere->GetDensity(altitudeASL);
double rhoSL = Atmosphere->GetDensitySL();
double mach0 = vt / soundSpeed;
double vc0 = VcalibratedFromMach(mach0, pressure, pressureSL, rhoSL);
double vc0 = VcalibratedFromMach(mach0, pressure);
double ve0 = vt * sqrt(rho/rhoSL);
double geodLatitude = position.GetGeodLatitudeRad();
@ -715,7 +713,7 @@ void FGInitialCondition::SetAltitudeASLFtIC(double alt)
switch(lastSpeedSet) {
case setvc:
mach0 = MachFromVcalibrated(vc0, pressure, pressureSL, rhoSL);
mach0 = MachFromVcalibrated(vc0, pressure);
SetVtrueFpsIC(mach0 * soundSpeed);
break;
case setmach:
@ -834,12 +832,10 @@ double FGInitialCondition::GetVcalibratedKtsIC(void) const
{
double altitudeASL = position.GetAltitudeASL();
double pressure = Atmosphere->GetPressure(altitudeASL);
double pressureSL = Atmosphere->GetPressureSL();
double rhoSL = Atmosphere->GetDensitySL();
double soundSpeed = Atmosphere->GetSoundSpeed(altitudeASL);
double mach = vt / soundSpeed;
return fpstokts * VcalibratedFromMach(mach, pressure, pressureSL, rhoSL);
return fpstokts * VcalibratedFromMach(mach, pressure);
}
//******************************************************************************
@ -916,7 +912,8 @@ bool FGInitialCondition::Load(const SGPath& rstfile, bool useStoredPath)
// Check to see if any engines are specified to be initialized in a running state
Element* running_elements = document->FindElement("running");
while (running_elements) {
enginesRunning |= 1 << int(running_elements->GetDataAsNumber());
int engineNumber = int(running_elements->GetDataAsNumber());
enginesRunning |= engineNumber == -1 ? engineNumber : 1 << engineNumber;
running_elements = document->FindNextElement("running");
}
@ -979,6 +976,27 @@ bool FGInitialCondition::LoadLatitude(Element* position_el)
//******************************************************************************
void FGInitialCondition::SetTrimRequest(std::string trim)
{
std::string& trimOption = to_lower(trim);
if (trimOption == "1")
trimRequested = TrimMode::tGround; // For backwards compatabiity
else if (trimOption == "longitudinal")
trimRequested = TrimMode::tLongitudinal;
else if (trimOption == "full")
trimRequested = TrimMode::tFull;
else if (trimOption == "ground")
trimRequested = TrimMode::tGround;
else if (trimOption == "pullup")
trimRequested = TrimMode::tPullup;
else if (trimOption == "custom")
trimRequested = TrimMode::tCustom;
else if (trimOption == "turn")
trimRequested = TrimMode::tTurn;
}
//******************************************************************************
bool FGInitialCondition::Load_v1(Element* document)
{
bool result = true;
@ -1047,7 +1065,7 @@ bool FGInitialCondition::Load_v1(Element* document)
if (document->FindElement("targetNlf"))
SetTargetNlfIC(document->FindElementValueAsNumber("targetNlf"));
if (document->FindElement("trim"))
needTrim = document->FindElementValueAsNumber("trim");
SetTrimRequest(document->FindElementValue("trim"));
// Refer to Stevens and Lewis, 1.5-14a, pg. 49.
// This is the rotation rate of the "Local" frame, expressed in the local frame.
@ -1486,6 +1504,11 @@ void FGInitialCondition::bind(FGPropertyManager* PropertyManager)
true);
PropertyManager->Tie("ic/geod-alt-ft", &position,
&FGLocation::GetGeodAltitude);
PropertyManager->Tie("ic/targetNlf", this,
&FGInitialCondition::GetTargetNlfIC,
&FGInitialCondition::SetTargetNlfIC,
true);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

11
src/FDM/JSBSim/initialization/FGInitialCondition.h
View file

@ -163,8 +163,8 @@ CLASS DOCUMENTATION
- vc (calibrated airspeed, ft/sec)
- mach (mach)
- vground (ground speed, ft/sec)
- running (-1 for all engines, 0 for no engines, 1 ... n for specific engines)
- trim (0 for no trim, 1 for ground trim)
- trim (0 for no trim, 1 for ground trim, 'Longitudinal', 'Full', 'Ground', 'Pullup', 'Custom', 'Turn')
- running (-1 for all engines, 0 ... n-1 for specific engines)
<h3>Properties</h3>
@property ic/vc-kts (read/write) Calibrated airspeed initial condition in knots
@ -679,8 +679,8 @@ public:
bool IsEngineRunning(unsigned int n) const { return (enginesRunning & (1 << n)) != 0; }
/** Does initialization file call for trim ?
@return true if initialization file (version 1) called for trim. */
bool NeedTrim(void) const { return needTrim == 0 ? false : true; }
@return Trim type, if any requested (version 1). */
int TrimRequested(void) const { return trimRequested; }
void bind(FGPropertyManager* pm);
@ -701,7 +701,7 @@ private:
altitudeset lastAltitudeSet;
latitudeset lastLatitudeSet;
unsigned int enginesRunning;
int needTrim;
int trimRequested;
FGFDMExec *fdmex;
FGAtmosphere* Atmosphere;
@ -721,6 +721,7 @@ private:
void calcThetaBeta(double alfa, const FGColumnVector3& _vt_NED);
double ComputeGeodAltitude(double geodLatitude);
bool LoadLatitude(Element* position_el);
void SetTrimRequest(std::string trim);
void Debug(int from);
};
}

2
src/FDM/JSBSim/initialization/FGTrim.cpp
View file

@ -76,7 +76,7 @@ FGTrim::FGTrim(FGFDMExec *FDMExec,TrimMode tt)
gamma_fallback=false;
mode=tt;
xlo=xhi=alo=ahi=0.0;
targetNlf=1.0;
targetNlf=fgic.GetTargetNlfIC();
debug_axis=tAll;
SetMode(tt);
if (debug_lvl & 2) cout << "Instantiated: FGTrim" << endl;

35
src/FDM/JSBSim/input_output/FGInputSocket.cpp
View file

@ -57,9 +57,8 @@ CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
FGInputSocket::FGInputSocket(FGFDMExec* fdmex) :
FGInputType(fdmex),
socket(0),
SockProtocol(FGfdmSocket::ptTCP)
FGInputType(fdmex), socket(0), SockProtocol(FGfdmSocket::ptTCP),
BlockingInput(false)
{
}
@ -84,6 +83,10 @@ bool FGInputSocket::Load(Element* el)
return false;
}
string action = el->GetAttributeValue("action");
if (to_upper(action) == "BLOCKING_INPUT")
BlockingInput = true;
return true;
}
@ -116,7 +119,9 @@ void FGInputSocket::Read(bool Holding)
if (socket == 0) return;
if (!socket->GetConnectStatus()) return;
data = socket->Receive(); // get socket transmission if present
if (BlockingInput)
socket->WaitUntilReadable(); // block until a transmission is received
data = socket->Receive(); // read data
if (data.size() > 0) {
// parse lines
@ -142,7 +147,7 @@ void FGInputSocket::Read(bool Holding)
}
}
if (command == "set") { // SET PROPERTY
if (command == "set") { // SET PROPERTY
if (argument.size() == 0) {
socket->Reply("No property argument supplied.\n");
@ -165,7 +170,7 @@ void FGInputSocket::Read(bool Holding)
value = atof(str_value.c_str());
node->setDoubleValue(value);
}
socket->Reply("");
socket->Reply("set successful\n");
} else if (command == "get") { // GET PROPERTY
@ -196,17 +201,17 @@ void FGInputSocket::Read(bool Holding)
socket->Reply(buf.str());
}
} else if (command == "hold") { // PAUSE
} else if (command == "hold") { // PAUSE
FDMExec->Hold();
socket->Reply("");
socket->Reply("Holding\n");
} else if (command == "resume") { // RESUME
FDMExec->Resume();
socket->Reply("");
socket->Reply("Resuming\n");
} else if (command == "iterate") { // ITERATE
} else if (command == "iterate") { // ITERATE
int argumentInt;
istringstream (argument) >> argumentInt;
@ -220,15 +225,15 @@ void FGInputSocket::Read(bool Holding)
}
FDMExec->EnableIncrementThenHold( argumentInt );
FDMExec->Resume();
socket->Reply("");
socket->Reply("Iterations performed\n");
} else if (command == "quit") { // QUIT
} else if (command == "quit") { // QUIT
// close the socket connection
socket->Reply("");
socket->Reply("Closing connection\n");
socket->Close();
} else if (command == "info") { // INFO
} else if (command == "info") { // INFO
// get info about the sim run and/or aircraft, etc.
ostringstream info;
@ -238,7 +243,7 @@ void FGInputSocket::Read(bool Holding)
info << "Simulation time: " << setw(8) << setprecision(3) << FDMExec->GetSimTime() << endl;
socket->Reply(info.str());
} else if (command == "help") { // HELP
} else if (command == "help") { // HELP
socket->Reply(
" JSBSim Server commands:\n\n"

1
src/FDM/JSBSim/input_output/FGInputSocket.h
View file

@ -88,6 +88,7 @@ protected:
FGfdmSocket* socket;
FGfdmSocket::ProtocolType SockProtocol;
std::string data;
bool BlockingInput;
};
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

9
src/FDM/JSBSim/input_output/FGXMLElement.cpp
View file

@ -124,6 +124,7 @@ Element::Element(const string& nm)
convert["KTS"]["FT/SEC"] = 1.68781;
convert["FT/SEC"]["KTS"] = 1.0/convert["KTS"]["FT/SEC"];
convert["M/S"]["FT/S"] = 3.2808399;
convert["M/S"]["KTS"] = convert["M/S"]["FT/S"]/convert["KTS"]["FT/SEC"];
convert["M/SEC"]["FT/SEC"] = 3.2808399;
convert["FT/S"]["M/S"] = 1.0/convert["M/S"]["FT/S"];
convert["M/SEC"]["FT/SEC"] = 3.2808399;
@ -283,7 +284,7 @@ double Element::GetAttributeValueAsNumber(const string& attr)
<< attribute << endl;
exit(-1);
}
return (number);
}
}
@ -473,8 +474,8 @@ double Element::FindElementValueAsNumberConvertTo(const string& el, const string
<< value << " DEG is outside the range [ -360 DEG ; +360 DEG ]"
<< endl;
}
if (!supplied_units.empty()) {
value *= convert[supplied_units][target_units];
}
@ -564,7 +565,7 @@ FGColumnVector3 Element::FindElementTripletConvertTo( const string& target_units
} else {
triplet(1) = 0.0;
}
item = FindElement("y");
if (!item) item = FindElement("pitch");

13
src/FDM/JSBSim/input_output/FGfdmSocket.cpp
View file

@ -357,10 +357,23 @@ void FGfdmSocket::Send(const char *data, int length)
void FGfdmSocket::WaitUntilReadable(void)
{
if (sckt_in <= 0)
return;
fd_set fds;
FD_ZERO(&fds);
FD_SET(sckt_in, &fds);
select(sckt_in+1, &fds, NULL, NULL, NULL);
/*
If you want to check select return status:
int recVal = select(sckt_in+1, &fds, NULL, NULL, NULL);
recVal: received value
0, if socket timeout
-1, if socket error
anithing else, if socket is readable
*/
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

2
src/FDM/JSBSim/math/LagrangeMultiplier.h
View file

@ -50,7 +50,7 @@ CLASS DECLARATION
struct LagrangeMultiplier {
FGColumnVector3 ForceJacobian;
FGColumnVector3 MomentJacobian;
FGColumnVector3 LeverArm;
double Min;
double Max;
double value;

52
src/FDM/JSBSim/models/FGAccelerations.cpp
View file

@ -118,7 +118,7 @@ bool FGAccelerations::Run(bool Holding)
CalculateUVWdot(); // Translational rate derivative
if (!FDMExec->GetHoldDown())
ResolveFrictionForces(in.DeltaT * rate); // Update rate derivatives with friction forces
CalculateFrictionForces(in.DeltaT * rate); // Update rate derivatives with friction forces
Debug(2);
return false;
@ -233,7 +233,7 @@ void FGAccelerations::SetHoldDown(bool hd)
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// Resolves the contact forces just before integrating the EOM.
// Computes the contact forces just before integrating the EOM.
// This routine is using Lagrange multipliers and the projected Gauss-Seidel
// (PGS) method.
// Reference: See Erin Catto, "Iterative Dynamics with Temporal Coherence",
@ -245,11 +245,8 @@ void FGAccelerations::SetHoldDown(bool hd)
// The friction forces are resolved in the body frame relative to the origin
// (Earth center).
void FGAccelerations::ResolveFrictionForces(double dt)
void FGAccelerations::CalculateFrictionForces(double dt)
{
const double invMass = 1.0 / in.Mass;
const FGMatrix33& Jinv = in.Jinv;
FGColumnVector3 vdot, wdot;
vector<LagrangeMultiplier*>& multipliers = *in.MultipliersList;
size_t n = multipliers.size();
@ -264,25 +261,30 @@ void FGAccelerations::ResolveFrictionForces(double dt)
// Assemble the linear system of equations
for (unsigned int i=0; i < n; i++) {
FGColumnVector3 v1 = invMass * multipliers[i]->ForceJacobian;
FGColumnVector3 v2 = Jinv * multipliers[i]->MomentJacobian; // Should be J^-T but J is symmetric and so is J^-1
FGColumnVector3 U = multipliers[i]->ForceJacobian;
FGColumnVector3 r = multipliers[i]->LeverArm;
FGColumnVector3 v1 = U / in.Mass;
FGColumnVector3 v2 = in.Jinv * (r*U); // Should be J^-T but J is symmetric and so is J^-1
for (unsigned int j=0; j < i; j++)
a[i*n+j] = a[j*n+i]; // Takes advantage of the symmetry of Jac^T*M^-1*Jac
for (unsigned int j=i; j < n; j++)
a[i*n+j] = DotProduct(v1, multipliers[j]->ForceJacobian)
+ DotProduct(v2, multipliers[j]->MomentJacobian);
for (unsigned int j=i; j < n; j++) {
U = multipliers[j]->ForceJacobian;
r = multipliers[j]->LeverArm;
a[i*n+j] = DotProduct(U, v1 + v2*r);
}
}
// Assemble the RHS member
// Translation
vdot = vUVWdot;
FGColumnVector3 vdot = vUVWdot;
if (dt > 0.) // Zeroes out the relative movement between the aircraft and the ground
vdot += (in.vUVW - in.Tec2b * in.TerrainVelocity) / dt;
// Rotation
wdot = vPQRdot;
FGColumnVector3 wdot = vPQRdot;
if (dt > 0.) // Zeroes out the relative movement between the aircraft and the ground
wdot += (in.vPQR - in.Tec2b * in.TerrainAngularVel) / dt;
@ -291,12 +293,14 @@ void FGAccelerations::ResolveFrictionForces(double dt)
// 2. Divide every line of 'a' and 'rhs' by a[i,i]. This is in order to save
// a division computation at each iteration of Gauss-Seidel.
for (unsigned int i=0; i < n; i++) {
double d = 1.0 / a[i*n+i];
double d = a[i*n+i];
FGColumnVector3 U = multipliers[i]->ForceJacobian;
FGColumnVector3 r = multipliers[i]->LeverArm;
rhs[i] = -DotProduct(U, vdot + wdot*r)/d;
rhs[i] = -(DotProduct(multipliers[i]->ForceJacobian, vdot)
+DotProduct(multipliers[i]->MomentJacobian, wdot))*d;
for (unsigned int j=0; j < n; j++)
a[i*n+j] *= d;
a[i*n+j] /= d;
}
// Resolve the Lagrange multipliers with the projected Gauss-Seidel method
@ -323,12 +327,16 @@ void FGAccelerations::ResolveFrictionForces(double dt)
for (unsigned int i=0; i< n; i++) {
double lambda = multipliers[i]->value;
vFrictionForces += lambda * multipliers[i]->ForceJacobian;
vFrictionMoments += lambda * multipliers[i]->MomentJacobian;
FGColumnVector3 U = multipliers[i]->ForceJacobian;
FGColumnVector3 r = multipliers[i]->LeverArm;
FGColumnVector3 F = lambda * U;
vFrictionForces += F;
vFrictionMoments += r * F;
}
FGColumnVector3 accel = invMass * vFrictionForces;
FGColumnVector3 omegadot = Jinv * vFrictionMoments;
FGColumnVector3 accel = vFrictionForces / in.Mass;
FGColumnVector3 omegadot = in.Jinv * vFrictionMoments;
vBodyAccel += accel;
vUVWdot += accel;
@ -344,7 +352,7 @@ void FGAccelerations::InitializeDerivatives(void)
// Make an initial run and set past values
CalculatePQRdot(); // Angular rate derivative
CalculateUVWdot(); // Translational rate derivative
ResolveFrictionForces(0.); // Update rate derivatives with friction forces
CalculateFrictionForces(0.); // Update rate derivatives with friction forces
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

6
src/FDM/JSBSim/models/FGAccelerations.h
View file

@ -59,8 +59,6 @@ CLASS DOCUMENTATION
- Calculate the angular accelerations
- Calculate the translational accelerations
- Calculate the angular rate
- Calculate the translational velocity
This class is collecting all the forces and the moments acting on the body
to calculate the corresponding accelerations according to Newton's second
@ -100,7 +98,7 @@ class FGAccelerations : public FGModel {
public:
/** Constructor.
@param Executive a pointer to the parent executive object */
FGAccelerations(FGFDMExec* Executive);
explicit FGAccelerations(FGFDMExec* Executive);
/// Destructor
~FGAccelerations();
@ -391,7 +389,7 @@ private:
void CalculatePQRdot(void);
void CalculateUVWdot(void);
void ResolveFrictionForces(double dt);
void CalculateFrictionForces(double dt);
void bind(void);
void Debug(int from);

10
src/FDM/JSBSim/models/FGAtmosphere.cpp
View file

@ -65,6 +65,10 @@ double FGAtmosphere::Reng = Rstar / Mair;
const double FGAtmosphere::SHRatio = 1.40;
const double FGAtmosphere::StdDaySLtemperature = 518.67;
const double FGAtmosphere::StdDaySLpressure = 2116.228;
const double FGAtmosphere::StdDaySLsoundspeed = sqrt(SHRatio*Reng*StdDaySLtemperature);
FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex) : FGModel(fdmex),
PressureAltitude(0.0), // ft
DensityAltitude(0.0), // ft
@ -91,10 +95,10 @@ bool FGAtmosphere::InitModel(void)
if (!FGModel::InitModel()) return false;
Calculate(0.0);
SLtemperature = Temperature = 518.67;
SLpressure = Pressure = 2116.228;
SLtemperature = Temperature = StdDaySLtemperature;
SLpressure = Pressure = StdDaySLpressure;
SLdensity = Density = Pressure/(Reng*Temperature);
SLsoundspeed = Soundspeed = sqrt(SHRatio*Reng*Temperature);
SLsoundspeed = Soundspeed = StdDaySLsoundspeed;
return true;
}

4
src/FDM/JSBSim/models/FGAtmosphere.h
View file

@ -211,6 +211,10 @@ public:
double altitudeASL;
} in;
static const double StdDaySLtemperature;
static const double StdDaySLpressure;
static const double StdDaySLsoundspeed;
protected:
double SLtemperature, SLdensity, SLpressure, SLsoundspeed; // Sea level conditions
double Temperature, Density, Pressure, Soundspeed; // Current actual conditions at altitude

36
src/FDM/JSBSim/models/FGAuxiliary.cpp
View file

@ -59,9 +59,9 @@ CLASS IMPLEMENTATION
FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
{
Name = "FGAuxiliary";
pt = 1.0;
tat = 1.0;
tatc = RankineToCelsius(tat);
pt = 2116.23; // ISA SL pressure
tatc = 15.0; // ISA SL temperature
tat = 518.67;
vcas = veas = 0.0;
qbar = qbarUW = qbarUV = 0.0;
@ -81,7 +81,6 @@ FGAuxiliary::FGAuxiliary(FGFDMExec* fdmex) : FGModel(fdmex)
vAeroUVW.InitMatrix();
vAeroPQR.InitMatrix();
vMachUVW.InitMatrix();
vEuler.InitMatrix();
vEulerRates.InitMatrix();
bind();
@ -117,7 +116,6 @@ bool FGAuxiliary::InitModel(void)
vAeroUVW.InitMatrix();
vAeroPQR.InitMatrix();
vMachUVW.InitMatrix();
vEuler.InitMatrix();
vEulerRates.InitMatrix();
return true;
@ -204,7 +202,7 @@ bool FGAuxiliary::Run(bool Holding)
pt = PitotTotalPressure(Mach, in.Pressure);
if (abs(Mach) > 0.0) {
vcas = VcalibratedFromMach(Mach, in.Pressure, in.PressureSL, in.DensitySL);
vcas = VcalibratedFromMach(Mach, in.Pressure);
veas = sqrt(2 * qbar / in.DensitySL);
}
else
@ -273,34 +271,12 @@ void FGAuxiliary::UpdateWindMatrices(void)
mTb2w = mTw2b.Transposed();
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// A positive headwind is blowing with you, a negative headwind is blowing against you.
// psi is the direction the wind is blowing *towards*.
// ToDo: should this simply be in the atmosphere class? Same with Get Crosswind.
double FGAuxiliary::GetHeadWind(void) const
{
return in.Vwind * cos(in.WindPsi - in.Psi);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// A positive crosswind is blowing towards the right (from teh perspective of the
// pilot). A negative crosswind is blowing towards the -Y direction (left).
// psi is the direction the wind is blowing *towards*.
double FGAuxiliary::GetCrossWind(void) const
{
return in.Vwind * sin(in.WindPsi - in.Psi);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
double FGAuxiliary::GetNlf(void) const
{
if (in.Mass != 0)
return (-in.vFw(3))/(in.Mass*slugtolb);
return (in.vFw(3))/(in.Mass*slugtolb);
else
return 0.;
}
@ -375,8 +351,6 @@ void FGAuxiliary::bind(void)
PropertyManager->Tie("accelerations/Nz", this, &FGAuxiliary::GetNz);
PropertyManager->Tie("accelerations/Ny", this, &FGAuxiliary::GetNy);
PropertyManager->Tie("forces/load-factor", this, &FGAuxiliary::GetNlf);
/* PropertyManager->Tie("atmosphere/headwind-fps", this, &FGAuxiliary::GetHeadWind, true);
PropertyManager->Tie("atmosphere/crosswind-fps", this, &FGAuxiliary::GetCrossWind, true); */
PropertyManager->Tie("aero/alpha-rad", this, (PF)&FGAuxiliary::Getalpha);
PropertyManager->Tie("aero/beta-rad", this, (PF)&FGAuxiliary::Getbeta);
PropertyManager->Tie("aero/mag-beta-rad", this, (PF)&FGAuxiliary::GetMagBeta);

7
src/FDM/JSBSim/models/FGAuxiliary.h
View file

@ -234,9 +234,6 @@ public:
else return BadUnits();
}
double GetHeadWind(void) const;
double GetCrossWind(void) const;
// Time routines, SET and GET functions, used by FGMSIS atmosphere
void SetDayOfYear (int doy) { day_of_year = doy; }
@ -282,11 +279,8 @@ public:
double SinTht;
double CosPhi;
double SinPhi;
double Psi;
FGColumnVector3 TotalWindNED;
FGColumnVector3 TurbPQR;
double WindPsi;
double Vwind;
} in;
private:
@ -302,7 +296,6 @@ private:
FGColumnVector3 vNwcg;
FGColumnVector3 vAeroPQR;
FGColumnVector3 vAeroUVW;
FGColumnVector3 vEuler;
FGColumnVector3 vEulerRates;
FGColumnVector3 vMachUVW;
FGLocation vLocationVRP;

35
src/FDM/JSBSim/models/FGLGear.cpp
View file

@ -264,7 +264,7 @@ void FGLGear::ResetToIC(void)
// Initialize Lagrange multipliers
for (int i=0; i < 3; i++) {
LMultiplier[i].ForceJacobian.InitMatrix();
LMultiplier[i].MomentJacobian.InitMatrix();
LMultiplier[i].LeverArm.InitMatrix();
LMultiplier[i].Min = 0.0;
LMultiplier[i].Max = 0.0;
LMultiplier[i].value = 0.0;
@ -675,29 +675,31 @@ void FGLGear::ComputeJacobian(const FGColumnVector3& vWhlContactVec)
velocityDirection.Normalize();
LMultiplier[ftDynamic].ForceJacobian = mT * velocityDirection;
LMultiplier[ftDynamic].MomentJacobian = vWhlContactVec * LMultiplier[ftDynamic].ForceJacobian;
LMultiplier[ftDynamic].Max = 0.;
LMultiplier[ftDynamic].Min = -fabs(staticFFactor * dynamicFCoeff * vFn(eZ));
LMultiplier[ftDynamic].LeverArm = vWhlContactVec;
// The Lagrange multiplier value obtained from the previous iteration is kept
// This is supposed to accelerate the convergence of the projected Gauss-Seidel
// algorithm. The code just below is to make sure that the initial value
// is consistent with the current friction coefficient and normal reaction.
// The Lagrange multiplier value obtained from the previous iteration is
// kept. This is supposed to accelerate the convergence of the projected
// Gauss-Seidel algorithm. The code just below is to make sure that the
// initial value is consistent with the current friction coefficient and
// normal reaction.
LMultiplier[ftDynamic].value = Constrain(LMultiplier[ftDynamic].Min, LMultiplier[ftDynamic].value, LMultiplier[ftDynamic].Max);
GroundReactions->RegisterLagrangeMultiplier(&LMultiplier[ftDynamic]);
}
else {
// Static friction is used for ctSTRUCTURE when the contact point is not moving.
// It is always used for ctBOGEY elements because the friction coefficients
// of a tyre depend on the direction of the movement (roll & side directions).
// This cannot be handled properly by the so-called "dynamic friction".
// Static friction is used for ctSTRUCTURE when the contact point is not
// moving. It is always used for ctBOGEY elements because the friction
// coefficients of a tyre depend on the direction of the movement (roll &
// side directions). This cannot be handled properly by the so-called
// "dynamic friction".
StaticFriction = true;
LMultiplier[ftRoll].ForceJacobian = mT * FGColumnVector3(1.,0.,0.);
LMultiplier[ftSide].ForceJacobian = mT * FGColumnVector3(0.,1.,0.);
LMultiplier[ftRoll].MomentJacobian = vWhlContactVec * LMultiplier[ftRoll].ForceJacobian;
LMultiplier[ftSide].MomentJacobian = vWhlContactVec * LMultiplier[ftSide].ForceJacobian;
LMultiplier[ftRoll].LeverArm = vWhlContactVec;
LMultiplier[ftSide].LeverArm = vWhlContactVec;
switch(eContactType) {
case ctBOGEY:
@ -713,10 +715,11 @@ void FGLGear::ComputeJacobian(const FGColumnVector3& vWhlContactVec)
LMultiplier[ftRoll].Min = -LMultiplier[ftRoll].Max;
LMultiplier[ftSide].Min = -LMultiplier[ftSide].Max;
// The Lagrange multiplier value obtained from the previous iteration is kept
// This is supposed to accelerate the convergence of the projected Gauss-Seidel
// algorithm. The code just below is to make sure that the initial value
// is consistent with the current friction coefficient and normal reaction.
// The Lagrange multiplier value obtained from the previous iteration is
// kept. This is supposed to accelerate the convergence of the projected
// Gauss-Seidel algorithm. The code just below is to make sure that the
// initial value is consistent with the current friction coefficient and
// normal reaction.
LMultiplier[ftRoll].value = Constrain(LMultiplier[ftRoll].Min, LMultiplier[ftRoll].value, LMultiplier[ftRoll].Max);
LMultiplier[ftSide].value = Constrain(LMultiplier[ftSide].Min, LMultiplier[ftSide].value, LMultiplier[ftSide].Max);

4
src/FDM/JSBSim/models/propulsion/FGPiston.cpp
View file

@ -388,6 +388,8 @@ FGPiston::FGPiston(FGFDMExec* exec, Element* el, int engine_number, struct Input
property_name = base_property_name + "/boostloss-hp";
PropertyManager->Tie(property_name, &BoostLossHP);
}
property_name = base_property_name + "/AFR";
PropertyManager->Tie(property_name, this, &FGPiston::getAFR);
// Set up and sanity-check the turbo/supercharging configuration based on the input values.
if (TakeoffBoost > RatedBoost[0]) bTakeoffBoost = true;
@ -749,8 +751,6 @@ void FGPiston::doFuelFlow(void)
{
double thi_sea_level = 1.3 * in.MixturePos[EngineNumber]; // Allows an AFR of infinity:1 to 11.3075:1
equivalence_ratio = thi_sea_level * 101325.0 / p_amb;
// double AFR = 10+(12*(1-in.Mixture[EngineNumber]));// mixture 10:1 to 22:1
// m_dot_fuel = m_dot_air / AFR;
m_dot_fuel = (m_dot_air * equivalence_ratio) / 14.7;
FuelFlowRate = m_dot_fuel * 2.2046; // kg to lb
if(Starved) // There is no fuel, so zero out the flows we've calculated so far

3
src/FDM/JSBSim/models/propulsion/FGPiston.h
View file

@ -46,7 +46,6 @@ INCLUDES
DEFINITIONS
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#define ID_PISTON "$Id: FGPiston.h,v 1.39 2017/04/29 11:16:46 ehofman Exp $"
#define FG_MAX_BOOST_SPEEDS 3
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@ -215,7 +214,6 @@ boostspeed they refer to:
@author David Megginson (initial porting and additional code)
@author Ron Jensen (additional engine code)
@see Taylor, Charles Fayette, "The Internal Combustion Engine in Theory and Practice"
@version $Id: FGPiston.h,v 1.39 2017/04/29 11:16:46 ehofman Exp $
*/
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@ -249,6 +247,7 @@ public:
double getOilPressure_psi(void) const {return OilPressure_psi;}
double getOilTemp_degF (void) const {return KelvinToFahrenheit(OilTemp_degK);}
double getRPM(void) const {return RPM;}
double getAFR(void) const {return m_dot_fuel > 0.0 ? m_dot_air / m_dot_fuel : INFINITY;}
protected: