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Simuv4.1 tire model updates: add lateral, longitudinal force heat multipliers. Not backwards compatible with current SC and MPA cars 

git-svn-id: https://svn.code.sf.net/p/speed-dreams/code/trunk@9118 30fe4595-0a0c-4342-8851-515496e4dcbd
This commit is contained in:
harunasan 2023-08-02 06:01:36 +00:00
parent d925d0d3a8
commit 2e67259be6
4 changed files with 90 additions and 4 deletions
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4
src/interfaces/car.h
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@ -758,6 +758,10 @@ typedef struct CarElt
#define PRM_TREADTHICKNESS "tread thickness"
#define PRM_RIMMASS "rim mass"
#define PRM_HYSTERESIS "hysteresis"
#define PRM_TIRECOOLING "tire cooling factor"
#define PRM_LATMUHEATING "lateral mu heat factor"
#define PRM_LONGMUHEATING "longitudinal mu heat factor"
#define PRM_TIRESPDCOOLING "tire speed cooling factor"
#define PRM_ALIGNTQFACTOR "aligning torque factor"
#define PRM_OPTTEMP "optimal temperature"
#define PRM_INITTEMP "initial temperature"

4
src/modules/simu/simuv4.1/simu.cpp
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@ -294,6 +294,10 @@ SimReConfig(tCarElt *carElt)
car->wheel[i].mu = car->wheel[i].muC[car->wheel[i].tireSet];
car->wheel[i].Topt = car->wheel[i].ToptC[car->wheel[i].tireSet];
car->wheel[i].hysteresisFactor = car->wheel[i].hysteresisFactorC[car->wheel[i].tireSet];
car->wheel[i].coolingFactor = car->wheel[i].coolingFactorC[car->wheel[i].tireSet];
car->wheel[i].latHeatFactor = car->wheel[i].latHeatFactorC[car->wheel[i].tireSet];
car->wheel[i].longHeatFactor = car->wheel[i].longHeatFactorC[car->wheel[i].tireSet];
car->wheel[i].tireSpeedCoolFactor = car->wheel[i].tireSpeedCoolFactorC[car->wheel[i].tireSet];
car->wheel[i].wearFactor = car->wheel[i].wearFactorC[car->wheel[i].tireSet];
car->carElt->_tyreT_opt(i) = car->wheel[i].Topt;
GfLogInfo("# SimuV4 tire compound changed mu = %.3f - hysteresis = %.2f - wear factor = %.7f\n", car->wheel[i].mu,

78
src/modules/simu/simuv4.1/wheel.cpp
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@ -70,28 +70,52 @@ void SimWheelConfig(tCar *car, int index)
wheel->treadThinkness = GfParmGetNum(hdle, WheelSect[index], PRM_TREADTHICKNESS, (char*)NULL, 0.005f); // default 5 [mm]
tdble rimmass = GfParmGetNum(hdle, WheelSect[index], PRM_RIMMASS, (char*)NULL, 7.0f); // default 7 [kg]
wheel->hysteresisFactor = GfParmGetNum(hdle, WheelSect[index], PRM_HYSTERESIS, (char*)NULL, 1.0f); // default 1.0 [-]
wheel->coolingFactor = GfParmGetNum(hdle, WheelSect[index], PRM_TIRECOOLING, (char*)NULL, 0.0f); // default 0.0 [-] maintain compatibility with older cars
wheel->latHeatFactor = GfParmGetNum(hdle, WheelSect[index], PRM_LATMUHEATING, (char*)NULL, 0.0f); // default 0.0 [-]
wheel->longHeatFactor = GfParmGetNum(hdle, WheelSect[index], PRM_LONGMUHEATING, (char*)NULL, 0.0f); // default 0.0 [-]
wheel->tireSpeedCoolFactor = GfParmGetNum(hdle, WheelSect[index], PRM_TIRESPDCOOLING, (char*)NULL, 0.0f); // default 0.0 [-] but recommend 0.5-1.25 for most cars
wheel->wearFactor = GfParmGetNum(hdle, WheelSect[index], PRM_WEAR, (char*)NULL, 1.0f);
if (car->features & FEAT_COMPOUNDS)
{
sprintf(path, "%s/%s/%s", WheelSect[index], SECT_COMPOUNDS, SECT_SOFT);
wheel->hysteresisFactorC[1] = GfParmGetNum(hdle, path, PRM_HYSTERESIS, (char*)NULL, wheel->hysteresisFactor);
wheel->coolingFactorC[1] = GfParmGetNum(hdle, path, PRM_TIRECOOLING, (char*)NULL, wheel->coolingFactor);
wheel->latHeatFactorC[1] = GfParmGetNum(hdle, path, PRM_LATMUHEATING, (char*)NULL, wheel->latHeatFactor);
wheel->longHeatFactorC[1] = GfParmGetNum(hdle, path, PRM_LONGMUHEATING, (char*)NULL, wheel->longHeatFactor);
wheel->tireSpeedCoolFactorC[1] = GfParmGetNum(hdle, path, PRM_TIRESPDCOOLING, (char*)NULL, wheel->tireSpeedCoolFactor);
wheel->wearFactorC[1] = GfParmGetNum(hdle, path, PRM_WEAR, (char*)NULL, wheel->wearFactor);
sprintf(path, "%s/%s/%s", WheelSect[index], SECT_COMPOUNDS, SECT_MEDIUM);
wheel->hysteresisFactorC[2] = GfParmGetNum(hdle, path, PRM_HYSTERESIS, (char*)NULL, wheel->hysteresisFactor);
wheel->coolingFactorC[2] = GfParmGetNum(hdle, path, PRM_TIRECOOLING, (char*)NULL, wheel->coolingFactor);
wheel->latHeatFactorC[2] = GfParmGetNum(hdle, path, PRM_LATMUHEATING, (char*)NULL, wheel->latHeatFactor);
wheel->longHeatFactorC[2] = GfParmGetNum(hdle, path, PRM_LONGMUHEATING, (char*)NULL, wheel->longHeatFactor);
wheel->tireSpeedCoolFactorC[2] = GfParmGetNum(hdle, path, PRM_TIRESPDCOOLING, (char*)NULL, wheel->tireSpeedCoolFactor);
wheel->wearFactorC[2] = GfParmGetNum(hdle, path, PRM_WEAR, (char*)NULL, wheel->wearFactor);
sprintf(path, "%s/%s/%s", WheelSect[index], SECT_COMPOUNDS, SECT_HARD);
wheel->hysteresisFactorC[3] = GfParmGetNum(hdle, path, PRM_HYSTERESIS, (char*)NULL, wheel->hysteresisFactor);
wheel->coolingFactorC[3] = GfParmGetNum(hdle, path, PRM_TIRECOOLING, (char*)NULL, wheel->coolingFactor);
wheel->latHeatFactorC[3] = GfParmGetNum(hdle, path, PRM_LATMUHEATING, (char*)NULL, wheel->latHeatFactor);
wheel->longHeatFactorC[3] = GfParmGetNum(hdle, path, PRM_LONGMUHEATING, (char*)NULL, wheel->longHeatFactor);
wheel->tireSpeedCoolFactorC[3] = GfParmGetNum(hdle, path, PRM_TIRESPDCOOLING, (char*)NULL, wheel->tireSpeedCoolFactor);
wheel->wearFactorC[3] = GfParmGetNum(hdle, path, PRM_WEAR, (char*)NULL, wheel->wearFactor);
sprintf(path, "%s/%s/%s", WheelSect[index], SECT_COMPOUNDS, SECT_WET);
wheel->hysteresisFactorC[4] = GfParmGetNum(hdle, path, PRM_HYSTERESIS, (char*)NULL, wheel->hysteresisFactor);
wheel->coolingFactorC[4] = GfParmGetNum(hdle, path, PRM_TIRECOOLING, (char*)NULL, wheel->coolingFactor);
wheel->latHeatFactorC[4] = GfParmGetNum(hdle, path, PRM_LATMUHEATING, (char*)NULL, wheel->latHeatFactor);
wheel->longHeatFactorC[4] = GfParmGetNum(hdle, path, PRM_LONGMUHEATING, (char*)NULL, wheel->longHeatFactor);
wheel->tireSpeedCoolFactorC[4] = GfParmGetNum(hdle, path, PRM_TIRESPDCOOLING, (char*)NULL, wheel->tireSpeedCoolFactor);
wheel->wearFactorC[4] = GfParmGetNum(hdle, path, PRM_WEAR, (char*)NULL, wheel->wearFactor);
sprintf(path, "%s/%s/%s", WheelSect[index], SECT_COMPOUNDS, SECT_EXTREM_WET);
wheel->hysteresisFactorC[5] = GfParmGetNum(hdle, path, PRM_HYSTERESIS, (char*)NULL, wheel->hysteresisFactor);
wheel->coolingFactorC[5] = GfParmGetNum(hdle, path, PRM_TIRECOOLING, (char*)NULL, wheel->coolingFactor);
wheel->latHeatFactorC[5] = GfParmGetNum(hdle, path, PRM_LATMUHEATING, (char*)NULL, wheel->latHeatFactor);
wheel->longHeatFactorC[5] = GfParmGetNum(hdle, path, PRM_LONGMUHEATING, (char*)NULL, wheel->longHeatFactor);
wheel->tireSpeedCoolFactorC[5] = GfParmGetNum(hdle, path, PRM_TIRESPDCOOLING, (char*)NULL, wheel->tireSpeedCoolFactor);
wheel->wearFactorC[5] = GfParmGetNum(hdle, path, PRM_WEAR, (char*)NULL, wheel->wearFactor);
if (SimRain < 1)
@ -168,6 +192,10 @@ void SimWheelConfig(tCar *car, int index)
wheel->tireSet = MIN(setupCompound->max, MAX(setupCompound->min, setupCompound->desired_value));
wheel->mu = wheel->muC[wheel->tireSet];
wheel->hysteresisFactor = wheel->hysteresisFactorC[wheel->tireSet];
wheel->coolingFactor = wheel->coolingFactorC[wheel->tireSet];
wheel->latHeatFactor = wheel->latHeatFactorC[wheel->tireSet];
wheel->longHeatFactor = wheel->longHeatFactorC[wheel->tireSet];
wheel->tireSpeedCoolFactor = wheel->tireSpeedCoolFactorC[wheel->tireSet];
wheel->wearFactor = wheel->wearFactorC[wheel->tireSet];
}
@ -392,6 +420,10 @@ void SimWheelReConfig(tCar *car, int index)
wheel->Tinit = wheel->TinitC[wheel->tireSet];
wheel->Topt = wheel->ToptC[wheel->tireSet];
wheel->hysteresisFactor = wheel->hysteresisFactorC[wheel->tireSet];
wheel->coolingFactor = wheel->coolingFactorC[wheel->tireSet];
wheel->latHeatFactor = wheel->latHeatFactorC[wheel->tireSet];
wheel->longHeatFactor = wheel->longHeatFactorC[wheel->tireSet];
wheel->tireSpeedCoolFactor = wheel->tireSpeedCoolFactorC[wheel->tireSet];
wheel->wearFactor = wheel->wearFactorC[wheel->tireSet];
GfLogInfo("# SimuV4 tire compound changed mu = %.3f - hysteresis = %.2f - wear factor = %.7f\n", wheel->mu, wheel->hysteresisFactor,
wheel->wearFactor);
@ -852,6 +884,12 @@ void SimWheelUpdateTire(tCar *car, int index)
tdble normalForce = wheel->forces.z;
tdble slip = wheel->tireSlip;
tdble lateralForce = fabs(wheel->forces.y);
tdble longForce = fabs(wheel->forces.x);
tdble absForce2 = fabs(normalForce * 0.5);
tdble slipRatio = wheel->spinVel * wheel->radius;
tdble latMod = 0;
tdble longMod = 0;
tdble wheelSpeed = fabs(wheel->spinVel * wheel->radius);
tdble deltaTemperature = wheel->Ttire - Tair;
@ -864,14 +902,26 @@ void SimWheelUpdateTire(tCar *car, int index)
tdble hysteresis = (0.05f * (sqrt(1.0f - wheel->currentWear)) * elasticity + 0.5f * slip) * wheel->hysteresisFactor;
// Calculate energy input for the tire
tdble energyGain = normalForce * wheelSpeed * SimDeltaTime * hysteresis;
tdble energyGain = normalForce * wheelSpeed * SimDeltaTime * hysteresis;
// Modifiers for energy input from lateral and longitudinal forces.
latMod = ((lateralForce - absForce2) * wheel->latHeatFactor) * SimDeltaTime * 0.0004;
longMod = ((longForce - absForce2) * wheel->longHeatFactor) * SimDeltaTime * 0.0008;
tdble energyMod = (latMod + longMod);
tdble lockMod = 0;
if (slipRatio < -0.9 && sqrt(car->airSpeed2) > 0)
{
lockMod = ((fabs(wheel->tireSlip) * wheel->longHeatFactor) * 2500) * SimDeltaTime;
}
// Calculate energy loss of the tire (convection, convection model approximation from papers,
// 5.9f + airspeed*3.7f [W/(meter*meter*Kelvin)]). Because the model is linear it is reasonable to apply
// it to the whole tire at once (no subdivision in elements).
tdble energyLoss = (5.9f + wheelSpeed * 3.7f) * deltaTemperature * wheel->tireConvectionSurface * SimDeltaTime;
tdble energyLoss = (5.9f + wheelSpeed * 3.7f) * deltaTemperature * wheel->tireConvectionSurface * SimDeltaTime * (1 + (wheel->tireSpeedCoolFactor * 1.5));
tdble deltaEnergy = energyGain - energyLoss;
tdble deltaEnergy = (lockMod + energyMod + energyGain) - energyLoss;
// Calculate heat capacity. Basically the heat capacity of the gas in the tire accounts for a "normal" TORCS tire
// around 2 percent of the whole tire heat capacity, so one could neglect this. I put it into the model because it:
@ -898,6 +948,12 @@ void SimWheelUpdateTire(tCar *car, int index)
// Energy transfer into the tire
wheel->Ttire += deltaEnergy / heatCapacity;
// Base cooling from lack of force
// static cooling, slowly cool tire down with low loads
wheel->Ttire -= ((wheel->coolingFactor) * (fabs(wheel->Ttire - Tair) * SimDeltaTime));
// Effect of temperature on live tire pressure
wheel->currentPressure = wheel->Ttire / wheel->Tinit * wheel->pressure;
// Wear
@ -926,7 +982,21 @@ void SimWheelUpdateTire(tCar *car, int index)
wheel->currentGraining = 0.0f;
}
tdble di = (wheel->Ttire - wheel->Topt)/(wheel->Topt - wheel->Tinit);
// Temperature window.
tdble di;
if (wheel->Ttire < (wheel->Topt - 20))
{
di = (wheel->Ttire - wheel->Topt - 20) / (wheel->Topt - wheel->Tinit);
}
else if (wheel->Ttire <= wheel->Topt)
{
di = 0.0;
}
else
{
di = (wheel->Ttire - wheel->Topt) / (wheel->Topt - wheel->Tinit);
}
wheel->currentGripFactor = ((1.0f-(MIN((di*di), 1.0f)))/4.0f + 3.0f/4.0f) * (1.0f - wheel->currentGraining / 10.0f);
car->carElt->_tyreCondition(index) = wheel->currentGripFactor;
car->carElt->_tyreT_in(index) = wheel->Ttire;

8
src/modules/simu/simuv4.1/wheel.h
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@ -96,6 +96,14 @@ typedef struct
tdble initialTemperature; // Initial temperature of the tire (initial pressure, p0/T0=constant)
tdble hysteresisFactor; // Factor to adjust the hysteresis (model fitting), usually close to 1.0.
tdble hysteresisFactorC[6]; // Factor to adjust the hysteresis for compounds
tdble coolingFactor; // Factor to adjust the cooling rate
tdble coolingFactorC[6]; // Factor to adjust the cooling rate for compounds
tdble latHeatFactor; // Factor to adjust lateral friction heating
tdble latHeatFactorC[6]; // Factor to adjust lateral friction heating for compounds
tdble longHeatFactor; // Factor to adjust longtudinal friction heating
tdble longHeatFactorC[6]; // Factor to adjust longtudinal friction heating for compounds
tdble tireSpeedCoolFactor; // Factor to adjust air speed cooling constant. Should be close to 1.0 for most cars.
tdble tireSpeedCoolFactorC[6]; // Factor to adjust air speed cooling constant per compound.
tdble wearFactor; // Factor to adjust the wear (model fitting), usually close to 1.0.
tdble wearFactorC[6]; // Factor to adjust the wear for compounds