985 lines
25 KiB
C++
985 lines
25 KiB
C++
#include "Atmosphere.hpp"
|
|
#include "ControlMap.hpp"
|
|
#include "Gear.hpp"
|
|
#include "Math.hpp"
|
|
#include "Glue.hpp"
|
|
#include "RigidBody.hpp"
|
|
#include "Surface.hpp"
|
|
#include "Thruster.hpp"
|
|
|
|
#include "Airplane.hpp"
|
|
|
|
namespace yasim {
|
|
|
|
// gadgets
|
|
inline float norm(float f) { return f<1 ? 1/f : f; }
|
|
inline float abs(float f) { return f<0 ? -f : f; }
|
|
|
|
Airplane::Airplane()
|
|
{
|
|
_emptyWeight = 0;
|
|
_pilotPos[0] = _pilotPos[1] = _pilotPos[2] = 0;
|
|
_wing = 0;
|
|
_tail = 0;
|
|
_ballast = 0;
|
|
_cruiseP = 0;
|
|
_cruiseT = 0;
|
|
_cruiseSpeed = 0;
|
|
_cruiseWeight = 0;
|
|
_approachP = 0;
|
|
_approachT = 0;
|
|
_approachSpeed = 0;
|
|
_approachAoA = 0;
|
|
_approachWeight = 0;
|
|
|
|
_dragFactor = 1;
|
|
_liftRatio = 1;
|
|
_cruiseAoA = 0;
|
|
_tailIncidence = 0;
|
|
}
|
|
|
|
Airplane::~Airplane()
|
|
{
|
|
int i;
|
|
for(i=0; i<_fuselages.size(); i++)
|
|
delete (Fuselage*)_fuselages.get(i);
|
|
for(i=0; i<_tanks.size(); i++)
|
|
delete (Tank*)_tanks.get(i);
|
|
for(i=0; i<_thrusters.size(); i++)
|
|
delete (ThrustRec*)_thrusters.get(i);
|
|
for(i=0; i<_gears.size(); i++)
|
|
delete (GearRec*)_gears.get(i);
|
|
for(i=0; i<_surfs.size(); i++)
|
|
delete (Surface*)_surfs.get(i);
|
|
for(i=0; i<_contacts.size(); i++)
|
|
delete[] (float*)_contacts.get(i);
|
|
}
|
|
|
|
void Airplane::iterate(float dt)
|
|
{
|
|
// The gear might have moved. Change their aerodynamics.
|
|
updateGearState();
|
|
|
|
_model.iterate();
|
|
}
|
|
|
|
void Airplane::consumeFuel(float dt)
|
|
{
|
|
// This is a really simple implementation that assumes all engines
|
|
// draw equally from all tanks in proportion to the amount of fuel
|
|
// stored there. Needs to be fixed, but that has to wait for a
|
|
// decision as to what the property interface will look like.
|
|
int i, outOfFuel = 0;
|
|
float fuelFlow = 0, totalFuel = 0.00001; // <-- overflow protection
|
|
for(i=0; i<_thrusters.size(); i++)
|
|
fuelFlow += ((ThrustRec*)_thrusters.get(i))->thruster->getFuelFlow();
|
|
for(i=0; i<_tanks.size(); i++)
|
|
totalFuel += ((Tank*)_tanks.get(i))->fill;
|
|
for(i=0; i<_tanks.size(); i++) {
|
|
Tank* t = (Tank*)_tanks.get(i);
|
|
t->fill -= dt * fuelFlow * (t->fill/totalFuel);
|
|
if(t->fill <= 0) {
|
|
t->fill = 0;
|
|
outOfFuel = 1;
|
|
}
|
|
}
|
|
if(outOfFuel)
|
|
for(int i=0; i<_thrusters.size(); i++)
|
|
((ThrustRec*)_thrusters.get(i))->thruster->setFuelState(false);
|
|
|
|
// Set the tank masses on the RigidBody
|
|
for(i=0; i<_tanks.size(); i++) {
|
|
Tank* t = (Tank*)_tanks.get(i);
|
|
_model.getBody()->setMass(t->handle, t->fill);
|
|
}
|
|
}
|
|
|
|
ControlMap* Airplane::getControlMap()
|
|
{
|
|
return &_controls;
|
|
}
|
|
|
|
Model* Airplane::getModel()
|
|
{
|
|
return &_model;
|
|
}
|
|
|
|
void Airplane::getPilotAccel(float* out)
|
|
{
|
|
State* s = _model.getState();
|
|
|
|
// Gravity
|
|
Glue::geodUp(s->pos, out);
|
|
Math::mul3(-9.8f, out, out);
|
|
|
|
// The regular acceleration
|
|
float tmp[3];
|
|
Math::mul3(-1, s->acc, tmp);
|
|
Math::add3(tmp, out, out);
|
|
|
|
// Convert to aircraft coordinates
|
|
Math::vmul33(s->orient, out, out);
|
|
|
|
// FIXME: rotational & centripetal acceleration needed
|
|
}
|
|
|
|
void Airplane::setPilotPos(float* pos)
|
|
{
|
|
int i;
|
|
for(i=0; i<3; i++) _pilotPos[i] = pos[i];
|
|
}
|
|
|
|
void Airplane::getPilotPos(float* out)
|
|
{
|
|
int i;
|
|
for(i=0; i<3; i++) out[i] = _pilotPos[i];
|
|
}
|
|
|
|
int Airplane::numGear()
|
|
{
|
|
return _gears.size();
|
|
}
|
|
|
|
Gear* Airplane::getGear(int g)
|
|
{
|
|
return ((GearRec*)_gears.get(g))->gear;
|
|
}
|
|
|
|
void Airplane::updateGearState()
|
|
{
|
|
for(int i=0; i<_gears.size(); i++) {
|
|
GearRec* gr = (GearRec*)_gears.get(i);
|
|
float ext = gr->gear->getExtension();
|
|
|
|
gr->surf->setXDrag(ext);
|
|
gr->surf->setYDrag(ext);
|
|
gr->surf->setZDrag(ext);
|
|
}
|
|
}
|
|
|
|
void Airplane::setApproach(float speed, float altitude)
|
|
{
|
|
// The zero AoA will become a calculated stall AoA in compile()
|
|
setApproach(speed, altitude, 0);
|
|
}
|
|
|
|
void Airplane::setApproach(float speed, float altitude, float aoa)
|
|
{
|
|
_approachSpeed = speed;
|
|
_approachP = Atmosphere::getStdPressure(altitude);
|
|
_approachT = Atmosphere::getStdTemperature(altitude);
|
|
_approachAoA = aoa;
|
|
}
|
|
|
|
void Airplane::setCruise(float speed, float altitude)
|
|
{
|
|
_cruiseSpeed = speed;
|
|
_cruiseP = Atmosphere::getStdPressure(altitude);
|
|
_cruiseT = Atmosphere::getStdTemperature(altitude);
|
|
_cruiseAoA = 0;
|
|
_tailIncidence = 0;
|
|
}
|
|
|
|
void Airplane::setElevatorControl(int control)
|
|
{
|
|
_approachElevator.control = control;
|
|
_approachElevator.val = 0;
|
|
_approachControls.add(&_approachElevator);
|
|
}
|
|
|
|
void Airplane::addApproachControl(int control, float val)
|
|
{
|
|
Control* c = new Control();
|
|
c->control = control;
|
|
c->val = val;
|
|
_approachControls.add(c);
|
|
}
|
|
|
|
void Airplane::addCruiseControl(int control, float val)
|
|
{
|
|
Control* c = new Control();
|
|
c->control = control;
|
|
c->val = val;
|
|
_cruiseControls.add(c);
|
|
}
|
|
|
|
int Airplane::numTanks()
|
|
{
|
|
return _tanks.size();
|
|
}
|
|
|
|
float Airplane::getFuel(int tank)
|
|
{
|
|
return ((Tank*)_tanks.get(tank))->fill;
|
|
}
|
|
|
|
float Airplane::getFuelDensity(int tank)
|
|
{
|
|
return ((Tank*)_tanks.get(tank))->density;
|
|
}
|
|
|
|
float Airplane::getTankCapacity(int tank)
|
|
{
|
|
return ((Tank*)_tanks.get(tank))->cap;
|
|
}
|
|
|
|
void Airplane::setWeight(float weight)
|
|
{
|
|
_emptyWeight = weight;
|
|
}
|
|
|
|
void Airplane::setWing(Wing* wing)
|
|
{
|
|
_wing = wing;
|
|
}
|
|
|
|
void Airplane::setTail(Wing* tail)
|
|
{
|
|
_tail = tail;
|
|
}
|
|
|
|
void Airplane::addVStab(Wing* vstab)
|
|
{
|
|
_vstabs.add(vstab);
|
|
}
|
|
|
|
void Airplane::addFuselage(float* front, float* back, float width,
|
|
float taper, float mid)
|
|
{
|
|
Fuselage* f = new Fuselage();
|
|
int i;
|
|
for(i=0; i<3; i++) {
|
|
f->front[i] = front[i];
|
|
f->back[i] = back[i];
|
|
}
|
|
f->width = width;
|
|
f->taper = taper;
|
|
f->mid = mid;
|
|
_fuselages.add(f);
|
|
}
|
|
|
|
int Airplane::addTank(float* pos, float cap, float density)
|
|
{
|
|
Tank* t = new Tank();
|
|
int i;
|
|
for(i=0; i<3; i++) t->pos[i] = pos[i];
|
|
t->cap = cap;
|
|
t->fill = cap;
|
|
t->density = density;
|
|
t->handle = 0xffffffff;
|
|
return _tanks.add(t);
|
|
}
|
|
|
|
void Airplane::addGear(Gear* gear)
|
|
{
|
|
GearRec* g = new GearRec();
|
|
g->gear = gear;
|
|
g->surf = 0;
|
|
_gears.add(g);
|
|
}
|
|
|
|
void Airplane::addThruster(Thruster* thruster, float mass, float* cg)
|
|
{
|
|
ThrustRec* t = new ThrustRec();
|
|
t->thruster = thruster;
|
|
t->mass = mass;
|
|
int i;
|
|
for(i=0; i<3; i++) t->cg[i] = cg[i];
|
|
_thrusters.add(t);
|
|
}
|
|
|
|
void Airplane::addBallast(float* pos, float mass)
|
|
{
|
|
_model.getBody()->addMass(mass, pos);
|
|
_ballast += mass;
|
|
}
|
|
|
|
int Airplane::addWeight(float* pos, float size)
|
|
{
|
|
WeightRec* wr = new WeightRec();
|
|
wr->handle = _model.getBody()->addMass(0, pos);
|
|
|
|
wr->surf = new Surface();
|
|
wr->surf->setPosition(pos);
|
|
wr->surf->setTotalDrag(size*size);
|
|
_model.addSurface(wr->surf);
|
|
_surfs.add(wr->surf);
|
|
|
|
return _weights.add(wr);
|
|
}
|
|
|
|
void Airplane::setWeight(int handle, float mass)
|
|
{
|
|
WeightRec* wr = (WeightRec*)_weights.get(handle);
|
|
|
|
_model.getBody()->setMass(wr->handle, mass);
|
|
|
|
// Kill the aerodynamic drag if the mass is exactly zero. This is
|
|
// how we simulate droppable stores.
|
|
if(mass == 0) {
|
|
wr->surf->setXDrag(0);
|
|
wr->surf->setYDrag(0);
|
|
wr->surf->setZDrag(0);
|
|
} else {
|
|
wr->surf->setXDrag(1);
|
|
wr->surf->setYDrag(1);
|
|
wr->surf->setZDrag(1);
|
|
}
|
|
}
|
|
|
|
void Airplane::setFuelFraction(float frac)
|
|
{
|
|
int i;
|
|
for(i=0; i<_tanks.size(); i++) {
|
|
Tank* t = (Tank*)_tanks.get(i);
|
|
t->fill = frac * t->cap;
|
|
_model.getBody()->setMass(t->handle, t->cap * frac);
|
|
}
|
|
}
|
|
|
|
float Airplane::getDragCoefficient()
|
|
{
|
|
return _dragFactor;
|
|
}
|
|
|
|
float Airplane::getLiftRatio()
|
|
{
|
|
return _liftRatio;
|
|
}
|
|
|
|
float Airplane::getCruiseAoA()
|
|
{
|
|
return _cruiseAoA;
|
|
}
|
|
|
|
float Airplane::getTailIncidence()
|
|
{
|
|
return _tailIncidence;
|
|
}
|
|
|
|
char* Airplane::getFailureMsg()
|
|
{
|
|
return _failureMsg;
|
|
}
|
|
|
|
int Airplane::getSolutionIterations()
|
|
{
|
|
return _solutionIterations;
|
|
}
|
|
|
|
void Airplane::setupState(float aoa, float speed, State* s)
|
|
{
|
|
float cosAoA = Math::cos(aoa);
|
|
float sinAoA = Math::sin(aoa);
|
|
s->orient[0] = cosAoA; s->orient[1] = 0; s->orient[2] = sinAoA;
|
|
s->orient[3] = 0; s->orient[4] = 1; s->orient[5] = 0;
|
|
s->orient[6] = -sinAoA; s->orient[7] = 0; s->orient[8] = cosAoA;
|
|
|
|
s->v[0] = speed; s->v[1] = 0; s->v[2] = 0;
|
|
|
|
int i;
|
|
for(i=0; i<3; i++)
|
|
s->pos[i] = s->rot[i] = s->acc[i] = s->racc[i] = 0;
|
|
|
|
// Put us 1m above the origin, or else the gravity computation in
|
|
// Model goes nuts
|
|
s->pos[2] = 1;
|
|
}
|
|
|
|
void Airplane::addContactPoint(float* pos)
|
|
{
|
|
float* cp = new float[3];
|
|
cp[0] = pos[0];
|
|
cp[1] = pos[1];
|
|
cp[2] = pos[2];
|
|
_contacts.add(cp);
|
|
}
|
|
|
|
float Airplane::compileWing(Wing* w)
|
|
{
|
|
// The tip of the wing is a contact point
|
|
float tip[3];
|
|
w->getTip(tip);
|
|
addContactPoint(tip);
|
|
if(w->isMirrored()) {
|
|
tip[1] *= -1;
|
|
addContactPoint(tip);
|
|
}
|
|
|
|
// Make sure it's initialized. The surfaces will pop out with
|
|
// total drag coefficients equal to their areas, which is what we
|
|
// want.
|
|
w->compile();
|
|
|
|
float wgt = 0;
|
|
int i;
|
|
for(i=0; i<w->numSurfaces(); i++) {
|
|
Surface* s = (Surface*)w->getSurface(i);
|
|
|
|
float td = s->getTotalDrag();
|
|
s->setTotalDrag(td);
|
|
|
|
_model.addSurface(s);
|
|
|
|
float mass = w->getSurfaceWeight(i);
|
|
mass = mass * Math::sqrt(mass);
|
|
float pos[3];
|
|
s->getPosition(pos);
|
|
_model.getBody()->addMass(mass, pos);
|
|
wgt += mass;
|
|
}
|
|
return wgt;
|
|
}
|
|
|
|
float Airplane::compileFuselage(Fuselage* f)
|
|
{
|
|
// The front and back are contact points
|
|
addContactPoint(f->front);
|
|
addContactPoint(f->back);
|
|
|
|
float wgt = 0;
|
|
float fwd[3];
|
|
Math::sub3(f->front, f->back, fwd);
|
|
float len = Math::mag3(fwd);
|
|
float wid = f->width;
|
|
int segs = (int)Math::ceil(len/wid);
|
|
float segWgt = len*wid/segs;
|
|
int j;
|
|
for(j=0; j<segs; j++) {
|
|
float frac = (j+0.5f) / segs;
|
|
|
|
float scale = 1;
|
|
if(frac < f->mid)
|
|
scale = f->taper+(1-f->taper) * (frac / f->mid);
|
|
else
|
|
scale = f->taper+(1-f->taper) * (frac - f->mid) / (1 - f->mid);
|
|
|
|
// Where are we?
|
|
float pos[3];
|
|
Math::mul3(frac, fwd, pos);
|
|
Math::add3(f->back, pos, pos);
|
|
|
|
// _Mass_ weighting goes as surface area^(3/2)
|
|
float mass = scale*segWgt * Math::sqrt(scale*segWgt);
|
|
_model.getBody()->addMass(mass, pos);
|
|
wgt += mass;
|
|
|
|
// Make a Surface too
|
|
Surface* s = new Surface();
|
|
s->setPosition(pos);
|
|
float sideDrag = len/wid;
|
|
s->setYDrag(sideDrag);
|
|
s->setZDrag(sideDrag);
|
|
s->setTotalDrag(scale*segWgt);
|
|
|
|
// FIXME: fails for fuselages aligned along the Y axis
|
|
float o[9];
|
|
float *x=o, *y=o+3, *z=o+6; // nicknames for the axes
|
|
Math::unit3(fwd, x);
|
|
y[0] = 0; y[1] = 1; y[2] = 0;
|
|
Math::cross3(x, y, z);
|
|
Math::unit3(z, z);
|
|
Math::cross3(z, x, y);
|
|
s->setOrientation(o);
|
|
|
|
_model.addSurface(s);
|
|
_surfs.add(s);
|
|
}
|
|
return wgt;
|
|
}
|
|
|
|
// FIXME: should probably add a mass for the gear, too
|
|
void Airplane::compileGear(GearRec* gr)
|
|
{
|
|
Gear* g = gr->gear;
|
|
|
|
// Make a Surface object for the aerodynamic behavior
|
|
Surface* s = new Surface();
|
|
gr->surf = s;
|
|
|
|
// Put the surface at the half-way point on the gear strut, give
|
|
// it a drag coefficient equal to a square of the same dimension
|
|
// (gear are really draggy) and make it symmetric. Assume that
|
|
// the "length" of the gear is 3x the compression distance
|
|
float pos[3], cmp[3];
|
|
g->getCompression(cmp);
|
|
float length = 3 * Math::mag3(cmp);
|
|
g->getPosition(pos);
|
|
Math::mul3(0.5, cmp, cmp);
|
|
Math::add3(pos, cmp, pos);
|
|
|
|
s->setPosition(pos);
|
|
s->setTotalDrag(length*length);
|
|
|
|
_model.addGear(g);
|
|
_model.addSurface(s);
|
|
_surfs.add(s);
|
|
}
|
|
|
|
void Airplane::compileContactPoints()
|
|
{
|
|
// Figure it will compress by 20cm
|
|
float comp[3];
|
|
float DIST = 0.2f;
|
|
comp[0] = 0; comp[1] = 0; comp[2] = DIST;
|
|
|
|
// Give it a spring constant such that at full compression it will
|
|
// hold up 10 times the planes mass. That's about right. Yeah.
|
|
float mass = _model.getBody()->getTotalMass();
|
|
float spring = (1/DIST) * 9.8f * 10.0f * mass;
|
|
float damp = 2 * Math::sqrt(spring * mass);
|
|
|
|
int i;
|
|
for(i=0; i<_contacts.size(); i++) {
|
|
float *cp = (float*)_contacts.get(i);
|
|
|
|
Gear* g = new Gear();
|
|
g->setPosition(cp);
|
|
|
|
g->setCompression(comp);
|
|
g->setSpring(spring);
|
|
g->setDamping(damp);
|
|
g->setBrake(1);
|
|
|
|
// I made these up
|
|
g->setStaticFriction(0.6f);
|
|
g->setDynamicFriction(0.5f);
|
|
|
|
_model.addGear(g);
|
|
}
|
|
}
|
|
|
|
void Airplane::compile()
|
|
{
|
|
double ground[3];
|
|
ground[0] = 0; ground[1] = 0; ground[2] = 1;
|
|
_model.setGroundPlane(ground, -100000);
|
|
|
|
RigidBody* body = _model.getBody();
|
|
int firstMass = body->numMasses();
|
|
|
|
// Generate the point masses for the plane. Just use unitless
|
|
// numbers for a first pass, then go back through and rescale to
|
|
// make the weight right.
|
|
float aeroWgt = 0;
|
|
|
|
// The Wing objects
|
|
aeroWgt += compileWing(_wing);
|
|
aeroWgt += compileWing(_tail);
|
|
int i;
|
|
for(i=0; i<_vstabs.size(); i++) {
|
|
aeroWgt += compileWing((Wing*)_vstabs.get(i));
|
|
}
|
|
|
|
// The fuselage(s)
|
|
for(i=0; i<_fuselages.size(); i++) {
|
|
aeroWgt += compileFuselage((Fuselage*)_fuselages.get(i));
|
|
}
|
|
|
|
// Count up the absolute weight we have
|
|
float nonAeroWgt = _ballast;
|
|
for(i=0; i<_thrusters.size(); i++)
|
|
nonAeroWgt += ((ThrustRec*)_thrusters.get(i))->mass;
|
|
|
|
// Rescale to the specified empty weight
|
|
float wscale = (_emptyWeight-nonAeroWgt)/aeroWgt;
|
|
for(i=firstMass; i<body->numMasses(); i++)
|
|
body->setMass(i, body->getMass(i)*wscale);
|
|
|
|
// Add the thruster masses
|
|
for(i=0; i<_thrusters.size(); i++) {
|
|
ThrustRec* t = (ThrustRec*)_thrusters.get(i);
|
|
body->addMass(t->mass, t->cg);
|
|
}
|
|
|
|
// Add the tanks, empty for now.
|
|
float totalFuel = 0;
|
|
for(i=0; i<_tanks.size(); i++) {
|
|
Tank* t = (Tank*)_tanks.get(i);
|
|
t->handle = body->addMass(0, t->pos);
|
|
totalFuel += t->cap;
|
|
}
|
|
_cruiseWeight = _emptyWeight + totalFuel*0.5f;
|
|
_approachWeight = _emptyWeight + totalFuel*0.2f;
|
|
|
|
body->recalc();
|
|
|
|
// Add surfaces for the landing gear.
|
|
for(i=0; i<_gears.size(); i++)
|
|
compileGear((GearRec*)_gears.get(i));
|
|
|
|
// The Thruster objects
|
|
for(i=0; i<_thrusters.size(); i++) {
|
|
ThrustRec* tr = (ThrustRec*)_thrusters.get(i);
|
|
tr->handle = _model.addThruster(tr->thruster);
|
|
}
|
|
|
|
// Ground effect
|
|
float gepos[3];
|
|
float gespan = _wing->getGroundEffect(gepos);
|
|
_model.setGroundEffect(gepos, gespan, 0.15f);
|
|
|
|
solveGear();
|
|
solve();
|
|
|
|
// Do this after solveGear, because it creates "gear" objects that
|
|
// we don't want to affect.
|
|
compileContactPoints();
|
|
}
|
|
|
|
void Airplane::solveGear()
|
|
{
|
|
float cg[3], pos[3];
|
|
_model.getBody()->getCG(cg);
|
|
|
|
// Calculate spring constant weightings for the gear. Weight by
|
|
// the inverse of the distance to the c.g. in the XY plane, which
|
|
// should be correct for most gear arrangements. Add 50cm of
|
|
// "buffer" to keep things from blowing up with aircraft with a
|
|
// single gear very near the c.g. (AV-8, for example).
|
|
float total = 0;
|
|
int i;
|
|
for(i=0; i<_gears.size(); i++) {
|
|
GearRec* gr = (GearRec*)_gears.get(i);
|
|
Gear* g = gr->gear;
|
|
g->getPosition(pos);
|
|
Math::sub3(cg, pos, pos);
|
|
gr->wgt = 1.0f/(0.5f+Math::sqrt(pos[0]*pos[0] + pos[1]*pos[1]));
|
|
total += gr->wgt;
|
|
}
|
|
|
|
// Renormalize so they sum to 1
|
|
for(i=0; i<_gears.size(); i++)
|
|
((GearRec*)_gears.get(i))->wgt /= total;
|
|
|
|
// The force at max compression should be sufficient to stop a
|
|
// plane moving downwards at 2x the approach descent rate. Assume
|
|
// a 3 degree approach.
|
|
float descentRate = 2.0f*_approachSpeed/19.1f;
|
|
|
|
// Spread the kinetic energy according to the gear weights. This
|
|
// will results in an equal compression fraction (not distance) of
|
|
// each gear.
|
|
float energy = 0.5f*_approachWeight*descentRate*descentRate;
|
|
|
|
for(i=0; i<_gears.size(); i++) {
|
|
GearRec* gr = (GearRec*)_gears.get(i);
|
|
float e = energy * gr->wgt;
|
|
float comp[3];
|
|
gr->gear->getCompression(comp);
|
|
float len = Math::mag3(comp);
|
|
|
|
// Energy in a spring: e = 0.5 * k * len^2
|
|
float k = 2 * e / (len*len);
|
|
|
|
gr->gear->setSpring(k * gr->gear->getSpring());
|
|
|
|
// Critically damped (too damped, too!)
|
|
gr->gear->setDamping(2*Math::sqrt(k*_approachWeight*gr->wgt)
|
|
* gr->gear->getDamping());
|
|
|
|
// These are pretty generic
|
|
gr->gear->setStaticFriction(0.8f);
|
|
gr->gear->setDynamicFriction(0.7f);
|
|
}
|
|
}
|
|
|
|
void Airplane::initEngines()
|
|
{
|
|
for(int i=0; i<_thrusters.size(); i++) {
|
|
ThrustRec* tr = (ThrustRec*)_thrusters.get(i);
|
|
tr->thruster->init();
|
|
}
|
|
}
|
|
|
|
void Airplane::stabilizeThrust()
|
|
{
|
|
int i;
|
|
for(i=0; i<_thrusters.size(); i++)
|
|
_model.getThruster(i)->stabilize();
|
|
}
|
|
|
|
void Airplane::runCruise()
|
|
{
|
|
setupState(_cruiseAoA, _cruiseSpeed, &_cruiseState);
|
|
_model.setState(&_cruiseState);
|
|
_model.setAir(_cruiseP, _cruiseT,
|
|
Atmosphere::calcStdDensity(_cruiseP, _cruiseT));
|
|
|
|
// The control configuration
|
|
_controls.reset();
|
|
int i;
|
|
for(i=0; i<_cruiseControls.size(); i++) {
|
|
Control* c = (Control*)_cruiseControls.get(i);
|
|
_controls.setInput(c->control, c->val);
|
|
}
|
|
_controls.applyControls(1000000); // Huge dt value
|
|
|
|
// The local wind
|
|
float wind[3];
|
|
Math::mul3(-1, _cruiseState.v, wind);
|
|
Math::vmul33(_cruiseState.orient, wind, wind);
|
|
|
|
// Cruise is by convention at 50% tank capacity
|
|
setFuelFraction(0.5);
|
|
|
|
// Set up the thruster parameters and iterate until the thrust
|
|
// stabilizes.
|
|
for(i=0; i<_thrusters.size(); i++) {
|
|
Thruster* t = ((ThrustRec*)_thrusters.get(i))->thruster;
|
|
t->setWind(wind);
|
|
t->setAir(_cruiseP, _cruiseT,
|
|
Atmosphere::calcStdDensity(_cruiseP, _cruiseT));
|
|
}
|
|
stabilizeThrust();
|
|
|
|
updateGearState();
|
|
|
|
// Precompute thrust in the model, and calculate aerodynamic forces
|
|
_model.getBody()->recalc();
|
|
_model.getBody()->reset();
|
|
_model.initIteration();
|
|
_model.calcForces(&_cruiseState);
|
|
}
|
|
|
|
void Airplane::runApproach()
|
|
{
|
|
setupState(_approachAoA, _approachSpeed, &_approachState);
|
|
_model.setState(&_approachState);
|
|
_model.setAir(_approachP, _approachT,
|
|
Atmosphere::calcStdDensity(_approachP, _approachT));
|
|
|
|
// The control configuration
|
|
_controls.reset();
|
|
int i;
|
|
for(i=0; i<_approachControls.size(); i++) {
|
|
Control* c = (Control*)_approachControls.get(i);
|
|
_controls.setInput(c->control, c->val);
|
|
}
|
|
_controls.applyControls(1000000);
|
|
|
|
// The local wind
|
|
float wind[3];
|
|
Math::mul3(-1, _approachState.v, wind);
|
|
Math::vmul33(_approachState.orient, wind, wind);
|
|
|
|
// Approach is by convention at 20% tank capacity
|
|
setFuelFraction(0.2f);
|
|
|
|
// Run the thrusters until they get to a stable setting. FIXME:
|
|
// this is lots of wasted work.
|
|
for(i=0; i<_thrusters.size(); i++) {
|
|
Thruster* t = ((ThrustRec*)_thrusters.get(i))->thruster;
|
|
t->setWind(wind);
|
|
t->setAir(_approachP, _approachT,
|
|
Atmosphere::calcStdDensity(_approachP, _approachT));
|
|
}
|
|
stabilizeThrust();
|
|
|
|
updateGearState();
|
|
|
|
// Precompute thrust in the model, and calculate aerodynamic forces
|
|
_model.getBody()->recalc();
|
|
_model.getBody()->reset();
|
|
_model.initIteration();
|
|
_model.calcForces(&_approachState);
|
|
}
|
|
|
|
void Airplane::applyDragFactor(float factor)
|
|
{
|
|
float applied = Math::sqrt(factor);
|
|
_dragFactor *= applied;
|
|
_wing->setDragScale(_wing->getDragScale() * applied);
|
|
_tail->setDragScale(_tail->getDragScale() * applied);
|
|
int i;
|
|
for(i=0; i<_vstabs.size(); i++) {
|
|
Wing* w = (Wing*)_vstabs.get(i);
|
|
w->setDragScale(w->getDragScale() * applied);
|
|
}
|
|
for(i=0; i<_surfs.size(); i++) {
|
|
Surface* s = (Surface*)_surfs.get(i);
|
|
s->setTotalDrag(s->getTotalDrag() * applied);
|
|
}
|
|
}
|
|
|
|
void Airplane::applyLiftRatio(float factor)
|
|
{
|
|
float applied = Math::sqrt(factor);
|
|
_liftRatio *= applied;
|
|
_wing->setLiftRatio(_wing->getLiftRatio() * applied);
|
|
_tail->setLiftRatio(_tail->getLiftRatio() * applied);
|
|
int i;
|
|
for(i=0; i<_vstabs.size(); i++) {
|
|
Wing* w = (Wing*)_vstabs.get(i);
|
|
w->setLiftRatio(w->getLiftRatio() * applied);
|
|
}
|
|
}
|
|
|
|
float Airplane::clamp(float val, float min, float max)
|
|
{
|
|
if(val < min) return min;
|
|
if(val > max) return max;
|
|
return val;
|
|
}
|
|
|
|
float Airplane::normFactor(float f)
|
|
{
|
|
if(f < 0) f = -f;
|
|
if(f < 1) f = 1/f;
|
|
return f;
|
|
}
|
|
|
|
void Airplane::solve()
|
|
{
|
|
static const float ARCMIN = 0.0002909f;
|
|
|
|
float tmp[3];
|
|
_solutionIterations = 0;
|
|
_failureMsg = 0;
|
|
while(1) {
|
|
#if 0
|
|
printf("%d %f %f %f %f %f\n", //DEBUG
|
|
_solutionIterations,
|
|
1000*_dragFactor,
|
|
_liftRatio,
|
|
_cruiseAoA,
|
|
_tailIncidence,
|
|
_approachElevator.val);
|
|
#endif
|
|
|
|
if(_solutionIterations++ > 10000) {
|
|
_failureMsg = "Solution failed to converge after 10000 iterations";
|
|
return;
|
|
}
|
|
|
|
// Run an iteration at cruise, and extract the needed numbers:
|
|
runCruise();
|
|
|
|
_model.getThrust(tmp);
|
|
float thrust = tmp[0];
|
|
|
|
_model.getBody()->getAccel(tmp);
|
|
Math::tmul33(_cruiseState.orient, tmp, tmp);
|
|
float xforce = _cruiseWeight * tmp[0];
|
|
float clift0 = _cruiseWeight * tmp[2];
|
|
|
|
_model.getBody()->getAngularAccel(tmp);
|
|
Math::tmul33(_cruiseState.orient, tmp, tmp);
|
|
float pitch0 = tmp[1];
|
|
|
|
// Run an approach iteration, and do likewise
|
|
runApproach();
|
|
|
|
_model.getBody()->getAngularAccel(tmp);
|
|
Math::tmul33(_approachState.orient, tmp, tmp);
|
|
double apitch0 = tmp[1];
|
|
|
|
_model.getBody()->getAccel(tmp);
|
|
Math::tmul33(_approachState.orient, tmp, tmp);
|
|
float alift = _approachWeight * tmp[2];
|
|
|
|
// Modify the cruise AoA a bit to get a derivative
|
|
_cruiseAoA += ARCMIN;
|
|
runCruise();
|
|
_cruiseAoA -= ARCMIN;
|
|
|
|
_model.getBody()->getAccel(tmp);
|
|
Math::tmul33(_cruiseState.orient, tmp, tmp);
|
|
float clift1 = _cruiseWeight * tmp[2];
|
|
|
|
// Do the same with the tail incidence
|
|
_tail->setIncidence(_tailIncidence + ARCMIN);
|
|
runCruise();
|
|
_tail->setIncidence(_tailIncidence);
|
|
|
|
_model.getBody()->getAngularAccel(tmp);
|
|
Math::tmul33(_cruiseState.orient, tmp, tmp);
|
|
float pitch1 = tmp[1];
|
|
|
|
// Now calculate:
|
|
float awgt = 9.8f * _approachWeight;
|
|
|
|
float dragFactor = thrust / (thrust-xforce);
|
|
float liftFactor = awgt / (awgt+alift);
|
|
float aoaDelta = -clift0 * (ARCMIN/(clift1-clift0));
|
|
float tailDelta = -pitch0 * (ARCMIN/(pitch1-pitch0));
|
|
|
|
// Sanity:
|
|
if(dragFactor <= 0 || liftFactor <= 0)
|
|
break;
|
|
|
|
// And the elevator control in the approach. This works just
|
|
// like the tail incidence computation (it's solving for the
|
|
// same thing -- pitching moment -- by diddling a different
|
|
// variable).
|
|
const float ELEVDIDDLE = 0.001f;
|
|
_approachElevator.val += ELEVDIDDLE;
|
|
runApproach();
|
|
_approachElevator.val -= ELEVDIDDLE;
|
|
|
|
_model.getBody()->getAngularAccel(tmp);
|
|
Math::tmul33(_approachState.orient, tmp, tmp);
|
|
double apitch1 = tmp[1];
|
|
float elevDelta = -apitch0 * (ELEVDIDDLE/(apitch1-apitch0));
|
|
|
|
// Now apply the values we just computed. Note that the
|
|
// "minor" variables are deferred until we get the lift/drag
|
|
// numbers in the right ballpark.
|
|
|
|
applyDragFactor(dragFactor);
|
|
applyLiftRatio(liftFactor);
|
|
|
|
// Solver threshold. How close to the solution are we trying
|
|
// to get? Trying too hard can result in oscillations about
|
|
// the correct solution, which is bad. Stick this in as a
|
|
// compile time constant for now, and consider making it
|
|
// settable per-model.
|
|
float STHRESH = 1.6;
|
|
|
|
// DON'T do the following until the above are sane
|
|
if(normFactor(dragFactor) > STHRESH*1.0001
|
|
|| normFactor(liftFactor) > STHRESH*1.0001)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
// OK, now we can adjust the minor variables:
|
|
_cruiseAoA += 0.5f*aoaDelta;
|
|
_tailIncidence += 0.5f*tailDelta;
|
|
|
|
_cruiseAoA = clamp(_cruiseAoA, -0.175f, 0.175f);
|
|
_tailIncidence = clamp(_tailIncidence, -0.175f, 0.175f);
|
|
|
|
if(abs(xforce/_cruiseWeight) < STHRESH*0.0001 &&
|
|
abs(alift/_approachWeight) < STHRESH*0.0001 &&
|
|
abs(aoaDelta) < STHRESH*.000017 &&
|
|
abs(tailDelta) < STHRESH*.000017)
|
|
{
|
|
// If this finaly value is OK, then we're all done
|
|
if(abs(elevDelta) < STHRESH*0.0001)
|
|
break;
|
|
|
|
// Otherwise, adjust and do the next iteration
|
|
_approachElevator.val += 0.8 * elevDelta;
|
|
if(abs(_approachElevator.val) > 1) {
|
|
_failureMsg = "Insufficient elevator to trim for approach";
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if(_dragFactor < 1e-06 || _dragFactor > 1e6) {
|
|
_failureMsg = "Drag factor beyond reasonable bounds.";
|
|
return;
|
|
} else if(_liftRatio < 1e-04 || _liftRatio > 1e4) {
|
|
_failureMsg = "Lift ratio beyond reasonable bounds.";
|
|
return;
|
|
} else if(Math::abs(_cruiseAoA) >= .17453293) {
|
|
_failureMsg = "Cruise AoA > 10 degrees";
|
|
return;
|
|
} else if(Math::abs(_tailIncidence) >= .17453293) {
|
|
_failureMsg = "Tail incidence > 10 degrees";
|
|
return;
|
|
}
|
|
}
|
|
}; // namespace yasim
|