speed-dreams/speed-dreams-code
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Qualitative tire temperature model

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git-svn-id: https://svn.code.sf.net/p/speed-dreams/code/trunk@5454 30fe4595-0a0c-4342-8851-515496e4dcbd

Former-commit-id: b2321cf21004e782e12525f0492d518fe7a7892b
Former-commit-id: c7c0d9717fbf9e7c93b8fecc4044d64de83489bb
This commit is contained in:
kakukri 2013-05-16 21:50:48 +00:00
parent 6a189c7db8
commit 3d208eb809
3 changed files with 50 additions and 0 deletions
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5
src/modules/simu/simuv4/car.cpp
View file

@ -57,6 +57,11 @@ SimCarConfig(tCar *car)
if (strcmp(enabling, VAL_YES) == 0) {
car->features = car->features | FEAT_REVLIMIT;
}
enabling = GfParmGetStr(hdle, SECT_FEATURES, PRM_TIRETEMPDEG, VAL_NO);
if (strcmp(enabling, VAL_YES) == 0) {
car->features = car->features | FEAT_TIRETEMPDEG;
}
/* continue with car parameters */
car->dimension.x = GfParmGetNum(hdle, SECT_CAR, PRM_LEN, (char*)NULL, 4.7f);
car->dimension.y = GfParmGetNum(hdle, SECT_CAR, PRM_WIDTH, (char*)NULL, 1.9f);

38
src/modules/simu/simuv4/wheel.cpp
View file

@ -24,6 +24,9 @@ static const char *WheelSect[4] = {SECT_FRNTRGTWHEEL, SECT_FRNTLFTWHEEL, SECT_RE
static const char *SuspSect[4] = {SECT_FRNTRGTSUSP, SECT_FRNTLFTSUSP, SECT_REARRGTSUSP, SECT_REARLFTSUSP};
static const char *BrkSect[4] = {SECT_FRNTRGTBRAKE, SECT_FRNTLFTBRAKE, SECT_REARRGTBRAKE, SECT_REARLFTBRAKE};
tdble Tair = 273; //air temperature in K
tdble Ttrack = 283; //track temperature in K
void
SimWheelConfig(tCar *car, int index)
{
@ -80,6 +83,16 @@ SimWheelConfig(tCar *car, int index)
wheel->relPos.z = wheel->radius - wheel->susp.spring.x0;
wheel->relPos.ay = wheel->relPos.az = 0.0f;
wheel->steer = 0.0f;
/* temperature and degradation */
wheel->Ttire = Tair;
wheel->Topt = GfParmGetNum(hdle, WheelSect[index], PRM_OPTTEMP, (char*)NULL, 350.0f);
tdble coldmufactor = GfParmGetNum(hdle, WheelSect[index], PRM_COLDMUFACTOR, (char*)NULL, 1.0f);
coldmufactor = MIN(MAX(coldmufactor, 0.0f), 1.0f);
wheel->muTmult = (1 - coldmufactor) / ((wheel->Topt - Tair) * (wheel->Topt - Tair));
wheel->heatingm = GfParmGetNum(hdle, WheelSect[index], PRM_HEATINGMULT, (char*)NULL, 6e-5);
wheel->aircoolm = GfParmGetNum(hdle, WheelSect[index], PRM_AIRCOOLINGMULT, (char*)NULL, 12e-4);
wheel->speedcoolm = GfParmGetNum(hdle, WheelSect[index], PRM_SPEEDCOOLINGMULT, (char*)NULL, 0.25);
/* components */
SimSuspConfig(hdle, SuspSect[index], &(wheel->susp), wheel->weight0, x0);
@ -158,6 +171,7 @@ void SimWheelUpdateForce(tCar *car, int index)
tdble s, sa, sx, sy; // slip vector
tdble stmp, F, Bx;
tdble mu;
tdble tireCond = 1.0;
tdble reaction_force = 0.0f;
wheel->state = 0;
@ -245,6 +259,12 @@ void SimWheelUpdateForce(tCar *car, int index)
// load sensitivity
mu = wheel->mu * (wheel->lfMin + (wheel->lfMax - wheel->lfMin) * exp(wheel->lfK * wheel->forces.z / wheel->opLoad));
//temperature and degradation
if (car->features & FEAT_TIRETEMPDEG) {
tireCond = 1 - wheel->muTmult * (wheel->Ttire - wheel->Topt)*(wheel->Ttire - wheel->Topt);
mu *= tireCond;
}
F *= wheel->forces.z * mu * wheel->trkPos.seg->surface->kFriction; /* coeff */
@ -280,6 +300,24 @@ void SimWheelUpdateForce(tCar *car, int index)
car->carElt->_wheelSlipSide(index) = sy*v;
car->carElt->_wheelSlipAccel(index) = sx*v;
car->carElt->_reaction[index] = reaction_force;
car->carElt->_tyreEffMu(index) = mu;
tdble Work = 0.0;
/* update tire temperature and degradation */
if (car->features & FEAT_TIRETEMPDEG) {
//heat from the work of friction
Work = (wheel->forces.x * (wrl * CosA - wheel->bodyVel.x)
+ wheel->forces.y * (wrl * SinA - wheel->bodyVel.y)) * SimDeltaTime;
wheel->Ttire += Work * wheel->heatingm;
//air cooling
wheel->Ttire -= wheel->aircoolm * (1 + wheel->speedcoolm * v) * (wheel->Ttire - Tair) * SimDeltaTime;
//filling carElt
car->carElt->_tyreT_in(index) = wheel->Ttire;
car->carElt->_tyreT_mid(index) = wheel->Ttire;
car->carElt->_tyreT_out(index) = wheel->Ttire;
car->carElt->_tyreCondition(index) = tireCond;
}
printf("T=%g, W=%g\n",wheel->Ttire,Work);
}

7
src/modules/simu/simuv4/wheel.h
View file

@ -77,6 +77,13 @@ typedef struct
tdble camber; /* camber, negative toward exterior on both sides */
tdble pressure; /* tire pressure */
tdble rel_vel; /* relative velocity - used for realstic suspension movement*/
tdble Ttire; /* tire temperature in K */
tdble Topt; /* optimal temperature in K, where mu maximal */
tdble muTmult; /* mu = mumax * (1 - muTmult*(T-Topt)^2) */
tdble heatingm; /* heating multiplier */
tdble aircoolm; /* air cooling multiplier */
tdble speedcoolm; /* how aircoolm increases with speed */
tDynAxis in;
tDynAxis feedBack;