//---------------------------------------------------------------------------------
// Time Slice all wheels
//---------------------------------------------------------------------------------
void CGroundSuspension::Timeslice (float dT)
{ nWonG = 0; // No wheels on ground
SumGearForces.x = SumGearMoments.x = 0.0;
SumGearForces.y = SumGearMoments.y = 0.0;
SumGearForces.z = SumGearMoments.z = 0.0;
if (type == TRICYCLE) {;}
else {;} // \todo different kind of train
std::vector<CSuspension *>::const_iterator it_whel;
for (it_whel = whl_susp.begin (); it_whel != whl_susp.end (); it_whel++) {
// is it a steering wheel ?
CSuspension *ssp = (CSuspension*)(*it_whel);
SGearData *gdt = ssp->GetGearData();
if (ssp->IsSteerWheel ()) mveh->GetGearChannel(gdt);
// is it a braking wheel ?
/// \todo .../...
// ... and finally timeslice
ssp->Timeslice (dT);
// sum all gear forces
const SVector gf = (*it_whel)->GetBodyForce_ISU ();
SumGearForces.x += gf.x;
SumGearForces.y += gf.y;
SumGearForces.z += gf.z;
// sum all gear moments
const SVector gm = (*it_whel)->GetBodyMoment_ISU ();
SumGearMoments.x += gm.x;
SumGearMoments.y += gm.y;
SumGearMoments.z += gm.z;
//--- update wheels on ground --------------------
if (ssp->IsOnGround()) nWonG++;
}
}
//---------------------------------------------------------------------------------
// Compute main gear axe barycenter
// Compute steering gear axe center in Legacy coordinate (Z is up)
//---------------------------------------------------------------------------------
void CGroundSuspension::ReadFinished (void)
{
#ifdef _DEBUG
DEBUGLOG ("CGroundSuspension::ReadFinished");
#endif
wheels_num = whl_susp.size ();
//---Compute wheel parameters --(Z is forward direction)---------
CSuspension *str = 0; // Steering wheel
max_gear = 0.0, min_gear = 0.0, mWPos = 0.0;
double wheel_min_h = -1000.0;
int nbw = 0;
std::vector<CSuspension *>::const_iterator it_whel;
for (it_whel = whl_susp.begin (); it_whel != whl_susp.end (); it_whel++) {
CSuspension *s = (CSuspension *) *it_whel;
max_gear = max (s->GetGearPosZ (), max_gear); // max forward
min_gear = min (s->GetGearPosZ (), min_gear); // min forward
mWPos = min (s->GetGearPosY (), mWPos); // lower point
wheel_min_h = max (s->GetGearPosY (), wheel_min_h ); // LH
//---Compute main gear barycenter ---------------------
if (s->IsSteerWheel()) {str = s; continue; }
nbw++;
mainW.x += s->GetGearPosX();
mainW.z += s->GetGearPosY();
mainW.y += s->GetGearPosZ();
mainR += s->GetGearRadius();
}
//--------------------------------------------------------
// The barycenter is the center of all main gear axis
// -mainW is the average contact point of all main
// gears in feet coordinates. To get the average axis
// point , we just add the average radius. (as the
// contact point is a negative position, we must add
// the wheel radius
//--------------------------------------------------------
double fac = (nbw)?(double(1) / nbw):(0);
mainW.Times(fac);
mainR *= fac;
mainW.z += mainR;
//--------------------------------------------------------
sterR = str->GetGearRadius();
//--------------------------------------------------------
// We also compute the bAGL (body above ground level)
// bAGL is used to set the aircraft level above a given terrain
// bAGL is what that must be added to ground to set
// the aircraft correctly on ground
// One foot is added for rounding up
// (relative to aircraft visual model)
// For physical model, the Cog offset must be accounted
//--------------------------------------------------------
// Wheel_base is the longitudinal amplitude of the gear
// (all wheels accounted). It is used to compute mass
// repartition over the gear
//--------------------------------------------------------
bAGL = mainR - mainW.z + 1;
//--- Compute Wheel base ---------------------------------
wheel_base = max_gear - min_gear;
//--------------------------------------------------------
if (TRICYCLE == type)
max_wheel_height = - mWPos;
else
if (TAIL_DRAGGER == type)
max_wheel_height = - (mWPos - wheel_min_h);
else
max_wheel_height = - mWPos;
}
//------------------------------------------------------------------------
// JS to LC: Removed brake force from wheel definition as it is
// only used in Suspension TimeSlice.
//-------------------------------------------------------------------------
void COpalGroundSuspension::Timeslice (float dT)
{
/// very important ! be sure to compute only during
/// engine & aerodynamics cycle
if (!globals->simulation) return;
nWonG = 0; // No wheels on ground
SumGearMoments.x = 0.0;
SumGearMoments.y = 0.0;
SumGearMoments.z = 0.0;
//--- Compute velocity in Miles per Hours ---------
double vt = (mveh->GetBodyVelocityVector ())->z;
double velocity = NMILE_PER_METRE_SEC(vt);
float fstbl = mstbl->Lookup (velocity); // 1.0f;
float fbtbl = mbtbl->Lookup (velocity); // 1.0f;
std::vector<CSuspension *>::const_iterator it_whel;
//-- Check for gear position ----------------------
if (mveh->lod->AreGearRetracted())
{ max_wheel_height_backup = max_wheel_height;
max_wheel_height = 0.0;
}
if (mveh->lod->AreGearDown())
{ max_wheel_height = max_wheel_height_backup;
}
//
for (it_whel = whl_susp.begin (); it_whel != whl_susp.end (); it_whel++) {
// is it a steering wheel ?
CSuspension *ssp = (CSuspension*)(*it_whel);
SGearData *gdt = ssp->GetGearData();
gdt->stbl = fstbl;
gdt->btbl = fbtbl;
if (mveh->lod->AreGearDown()) { /// this is the completely extended gear position
if (ssp->IsSteerWheel ()) mveh->GetGearChannel(gdt);
// ... and finally timeslice
ssp->Timeslice (dT);
if (ssp->IsOnGround()) nWonG++;
}
}
/// All the computation below is LH
// verify if this test is useful
//
// add mass moment related to main gear
// JS NOTE: The main_pos is in fact the distance between the Cg and the steering
// wheel.
// On a tricyle, the steering is in positive direction while on a Tail Dragger
// the steering is in negative direction.
// So I made the following modifications
// The steering distance (in meters) is computed in the
// CGroundSuspension::InitJoint() when wheels positions are computed
// This vector is stored into mainVM and the massCF is the coeeficent
// that modulate the mass supported by the wheel.
// Also, the mass_force is modified so that the force applied is in the
// vertical direction (Z) and is negative.
//
{
CVector mass_moment;
CVector mass_force (0, 0, -mveh->GetMassInKgs() * GRAVITY_MTS * massCF); //, 0.0);
CVector mass_pos, main_gear;
// main_gear.Set (0.0, FeetToMetres (-max_wheel_height), FeetToMetres (max_gear));
// mass_pos = *mveh->svh->GetNewCG_ISU () - main_gear;
// VectorCrossProduct (mass_moment, mass_pos, mass_force);
VectorCrossProduct (mass_moment, mainVM, mass_force);
/// add gear moment to the CG moment
SumGearMoments = VectorSum (SumGearMoments, mass_moment);
#ifdef _DEBUG_suspension
{ FILE *fp_debug;
if((fp_debug = fopen("__DDEBUG_suspension.txt", "a")) != NULL)
{
fprintf(fp_debug, "---------------------------------------------------------\n");
fprintf(fp_debug, "COpalGroundSuspension::Timeslice nWOW=%d SumF(%f %f %f) SumM(%f %f %f)\n",
nWOW,
SumGearForces.x, SumGearForces.y, SumGearForces.z,
SumGearMoments.x, SumGearMoments.y, SumGearMoments.z
);
fprintf(fp_debug, " cg(%f %f %f) mg(%f %f %f) mp(%f %f %f)\n mf(%f %f %f) mm(%f %f %f) (mwh%f Mg%f mg%f)\n",
globals->sit->user->svh->GetNewCG_ISU ()->x, globals->sit->user->svh->GetNewCG_ISU ()->y, globals->sit->user->svh->GetNewCG_ISU ()->z,
main_gear.x, main_gear.y, main_gear.z,
mass_pos.x, mass_pos.y, mass_pos.z,
mass_force.x, mass_force.y, mass_force.z,
mass_moment.x, mass_moment.y, mass_moment.z,
max_wheel_height, max_gear, min_gear
);
fprintf(fp_debug, "---------------------------------------------------------\n");
fclose(fp_debug);
} }
#endif
}
}