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Re #620: add sideways sticking when speed is < 0.1 m/s

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git-svn-id: https://svn.code.sf.net/p/speed-dreams/code/trunk@5326 30fe4595-0a0c-4342-8851-515496e4dcbd

Former-commit-id: 6c803b39112b9d784b95f94b137ee9315efaf2e5
Former-commit-id: c987681c74dc38c27f9c76aafcb5449e284133f1
This commit is contained in:
kakukri 2013-03-16 18:16:27 +00:00
parent 2ac40459cc
commit e35e4d4add
2 changed files with 28 additions and 3 deletions
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22
src/modules/simu/simuv4/car.cpp
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@ -177,6 +177,8 @@ SimCarUpdateForces(tCar *car)
tdble SinTheta;
tdble Cosz, Sinz;
tdble v, R, Rv, Rm, Rx, Ry;
tdble carspeed;
tdble desiredF, desiredTq;
Cosz = car->Cosz = cos(car->DynGCg.pos.az);
Sinz = car->Sinz = sin(car->DynGCg.pos.az);
@ -255,6 +257,24 @@ SimCarUpdateForces(tCar *car)
} else {
Rm = (tdble) (SIGN(car->DynGCg.vel.az) * R * car->wheelbase / 2.0);
}
F.M.z -= Rm;
/* simulate sticking when car almost stationary */
carspeed = car->DynGC.vel.x * car->DynGC.vel.x
+ car->DynGC.vel.y * car->DynGC.vel.y + car->DynGC.vel.z * car->DynGC.vel.z;
if ((car->features & FEAT_SLOWGRIP) && ( carspeed < 0.1 ) ) {
w = -w; //make it positive
/* desired force to stop sideway slide */
desiredF = - m * car->DynGC.vel.y / SimDeltaTime;
if ( (fabs(desiredF - F.F.y)) < w ) {F.F.y = desiredF;}
else if ( (desiredF - F.F.y) > 0.0 ) {F.F.y += w;}
else {F.F.y -= w;}
/* desired torque to stop yaw */
desiredTq = - car->DynGC.vel.az / ( SimDeltaTime * car->Iinv.z );
if ( (fabs(desiredTq - F.M.z)) < 0.5 * w * car->wheelbase) {F.M.z = desiredTq;}
else if ( (desiredTq - F.M.z) > 0.0 ) {F.M.z += 0.5 * w * car->wheelbase;}
else {F.M.z -= 0.5 * w * car->wheelbase;}
}
/* compute accelerations */
car->DynGC.acc.x = F.F.x * minv;
@ -267,7 +287,7 @@ SimCarUpdateForces(tCar *car)
car->DynGCg.acc.ax = car->DynGC.acc.ax = F.M.x * car->Iinv.x;
car->DynGCg.acc.ay = car->DynGC.acc.ay = F.M.y * car->Iinv.y;
car->DynGCg.acc.az = car->DynGC.acc.az = (F.M.z - Rm) * car->Iinv.z;
car->DynGCg.acc.az = car->DynGC.acc.az = F.M.z * car->Iinv.z;
}
static void

9
src/modules/simu/simuv4/wheel.cpp
View file

@ -210,8 +210,13 @@ void SimWheelUpdateForce(tCar *car, int index)
sx = wrl;
sy = 0.0f;
} else {
sx = (vt - wrl) / fabs(vt);
sy = sin(sa);
if (car->features & FEAT_SLOWGRIP) {
sx = (vt - wrl) / MAX(fabs(vt), 1.0); //avoid divergence
sy = sin(sa);
} else {
sx = (vt - wrl) / fabs(vt);
sy = sin(sa);
}
}
Ft = 0.0f;