MSCFModel_IDM Class Reference

#include <MSCFModel_IDM.h>

Inheritance diagram for MSCFModel_IDM:

Detailed Description

The Intellignet Driver Model (IDM) car-following model.

See also:: MSCFModel

Definition at line 45 of file MSCFModel_IDM.h.


Public Member Functions
	MSCFModel_IDM (const MSVehicleType *vtype, SUMOReal accel, SUMOReal decel, SUMOReal timeHeadWay, SUMOReal mingap, SUMOReal tau) throw ()
	Constructor.
	~MSCFModel_IDM () throw ()
	Destructor.
Currently fixed methods
SUMOReal	brakeGap (SUMOReal speed) const throw ()
	Returns the distance the vehicle needs to halt including driver's reaction time.
SUMOReal	getMaxDecel () const throw ()
	Get the vehicle's maximum deceleration [m/s^2].
SUMOReal	getSecureGap (const SUMOReal speed, const SUMOReal leaderSpeedAfterDecel) const throw ()
	Returns the minimum gap to reserve if the leader is braking at maximum.
SUMOReal	getSpeedAfterMaxDecel (SUMOReal v) const throw ()
	Returns the velocity after maximum deceleration.
void	leftVehicleVsafe (const MSVehicle const ego, const MSVehicle const neigh, SUMOReal &vSafe) const throw ()
	Incorporates the influence of the vehicle on the left lane.
SUMOReal	maxNextSpeed (SUMOReal speed) const throw ()
	Returns the maximum speed given the current speed.
Implementations of the MSCFModel interface
SUMOReal	ffeS (const MSVehicle *const veh, SUMOReal gap2pred) const throw ()
	Computes the vehicle's safe speed for approaching a non-moving obstacle (no dawdling).
SUMOReal	ffeV (const MSVehicle const veh, const MSVehicle const pred) const throw ()
	Computes the vehicle's safe speed (no dawdling).
SUMOReal	ffeV (const MSVehicle *const veh, SUMOReal gap2pred, SUMOReal predSpeed) const throw ()
	Computes the vehicle's safe speed (no dawdling).
SUMOReal	ffeV (const MSVehicle *const veh, SUMOReal speed, SUMOReal gap2pred, SUMOReal predSpeed) const throw ()
	Computes the vehicle's safe speed (no dawdling).
SUMOReal	getMaxAccel (SUMOReal v) const throw ()
	Get the vehicle's maximum acceleration [m/s^2].
int	getModelID () const throw ()
	Returns the model's name.
SUMOReal	getTau () const throw ()
	Get the driver's reaction time [s].
bool	hasSafeGap (SUMOReal speed, SUMOReal gap, SUMOReal predSpeed, SUMOReal laneMaxSpeed) const throw ()
	Returns whether the given gap is safe.
SUMOReal	interactionGap (const MSVehicle *const , SUMOReal vL) const throw ()
	Returns the maximum gap at which an interaction between both vehicles occurs.
SUMOReal	moveHelper (MSVehicle const veh, const MSLane const lane, SUMOReal vPos) const throw ()
	Applies interaction with stops and lane changing model influences.
Methods to override by model implementation
virtual void	saveState (std::ostream &os)
	Saves the model's definition into the state.
Protected Attributes
SUMOReal	myDecel
	The vehicle's maximum deceleration [m/s^2].
SUMOReal	myInverseTwoDecel
	The precomputed value for 1/(2*d).
const MSVehicleType *	myType
	The type to which this model definition belongs to.
Private Member Functions
SUMOReal	_updateSpeed (SUMOReal gap2pred, SUMOReal mySpeed, SUMOReal predSpeed, SUMOReal desSpeed) const throw ()
SUMOReal	desiredSpeed (const MSVehicle *const veh) const throw ()
Private Attributes
model parameter
SUMOReal	myAccel
	The vehicle's maximum acceleration [m/s^2].
SUMOReal	myMinSpace
	The desired minimum Gap to the leading vehicle (no matter the speed).
SUMOReal	myTau
	The driver's reaction time [s].
SUMOReal	myTimeHeadWay
	The driver's desired time headway [s].

Constructor & Destructor Documentation

MSCFModel_IDM::MSCFModel_IDM	(	const MSVehicleType *	vtype,
		SUMOReal	accel,
		SUMOReal	decel,
		SUMOReal	timeHeadWay,
		SUMOReal	mingap,
		SUMOReal	tau
	)			throw ()

Constructor.

Parameters:

`[in]`	accel	The maximum acceleration
`[in]`	decel	The maximum deceleration
`[in]`	timeHeadWay
`[in]`	mingap

Definition at line 46 of file MSCFModel_IDM.cpp.

00049         : MSCFModel(vtype, decel),
00050         myAccel(accel), myTimeHeadWay(timeHeadWay), myMinSpace(mingap), myTau(tau) {
00051 
00052 }

MSCFModel_IDM::~MSCFModel_IDM ( ) throw ()

Destructor.

Definition at line 55 of file MSCFModel_IDM.cpp.

00055 {}

Member Function Documentation

SUMOReal MSCFModel_IDM::_updateSpeed	(	SUMOReal	gap2pred,
		SUMOReal	mySpeed,
		SUMOReal	predSpeed,
		SUMOReal	desSpeed
	)			const throw () `[private]`

Definition at line 133 of file MSCFModel_IDM.cpp.

References ACCEL2SPEED, DELTA_IDM, MAX2(), myAccel, MSCFModel::myDecel, myMinSpace, myTimeHeadWay, and SUMOReal.

Referenced by ffeS(), ffeV(), and hasSafeGap().

00133                                                                                                                     {
00134     SUMOReal delta_v = mySpeed - predSpeed;
00135     SUMOReal s_star_raw = myMinSpace + mySpeed*myTimeHeadWay + (mySpeed*delta_v)/(2*sqrt(myAccel*myDecel));
00136     SUMOReal s_star = MAX2(s_star_raw, myMinSpace);
00137     SUMOReal acc = myAccel * (1. - pow((double)(mySpeed/desSpeed), (double) DELTA_IDM) - (s_star*s_star)/(gap2pred*gap2pred));
00138     SUMOReal vNext = mySpeed + ACCEL2SPEED(acc);
00139     return vNext;
00140 }

SUMOReal MSCFModel::brakeGap ( SUMOReal speed ) const throw () [inherited]

Returns the distance the vehicle needs to halt including driver's reaction time.

Parameters:

[in] speed The vehicle's current speed

Returns:: The distance needed to halt

Definition at line 66 of file MSCFModel.cpp.

References MSCFModel::getTau(), and MSCFModel::myInverseTwoDecel.

Referenced by MSVehicle::checkRewindLinkLanes(), MSLane::getLeaderOnConsecutive(), getMaxSpeedRegardingNextLanes(), MSLaneChanger::getRealLeader(), MSLane::isEmissionSuccess(), and MSVehicle::vsafeCriticalCont().

00066                                                 {
00067     return speed * speed * myInverseTwoDecel + speed * getTau();
00068 }

SUMOReal MSCFModel_IDM::desiredSpeed ( const MSVehicle *const veh ) const throw () [inline, private]

Definition at line 177 of file MSCFModel_IDM.h.

References MSVehicle::getLane(), MSLane::getMaxSpeed(), MSVehicleType::getMaxSpeed(), MIN2(), and MSCFModel::myType.

Referenced by ffeS(), ffeV(), and interactionGap().

00177                                                                      {
00178         return MIN2(myType->getMaxSpeed(), veh->getLane().getMaxSpeed());
00179     }

SUMOReal MSCFModel_IDM::ffeS	(	const MSVehicle *const	veh,
		SUMOReal	gap2pred
	)			const throw () `[virtual]`

Computes the vehicle's safe speed for approaching a non-moving obstacle (no dawdling).

Parameters:

`[in]`	veh	The vehicle (EGO)
`[in]`	gap2pred	The (netto) distance to the the obstacle

Returns:: EGO's safe speed for approaching a non-moving obstacle

See also:: MSCFModel::ffeS

Todo:: generic Interface, models can call for the values they need

Implements MSCFModel.

Definition at line 97 of file MSCFModel_IDM.cpp.

References _updateSpeed(), desiredSpeed(), and SUMOReal.

00097                                                                                 {
00098     SUMOReal desSpeed = desiredSpeed(veh);
00099     return _updateSpeed(gap2pred, veh->getSpeed(), desSpeed, desSpeed);
00100 }

SUMOReal MSCFModel_IDM::ffeV	(	const MSVehicle *const	veh,
		const MSVehicle *const	pred
	)			const throw () `[virtual]`

Computes the vehicle's safe speed (no dawdling).

Parameters:

`[in]`	veh	The vehicle (EGO)
`[in]`	pred	The LEADER

Returns:: EGO's safe speed

See also:: MSCFModel::ffeV

Todo:: generic Interface, models can call for the values they need

Implements MSCFModel.

Definition at line 91 of file MSCFModel_IDM.cpp.

References _updateSpeed(), and desiredSpeed().

00091                                                                                            {
00092     return _updateSpeed(veh->gap2pred(*pred), veh->getSpeed(), pred->getSpeed(), desiredSpeed(veh));
00093 }

SUMOReal MSCFModel_IDM::ffeV	(	const MSVehicle *const	veh,
		SUMOReal	gap2pred,
		SUMOReal	predSpeed
	)			const throw () `[virtual]`

Computes the vehicle's safe speed (no dawdling).

Parameters:

`[in]`	veh	The vehicle (EGO)
`[in]`	gap2pred	The (netto) distance to the LEADER
`[in]`	predSpeed	The speed of LEADER

Returns:: EGO's safe speed

See also:: MSCFModel::ffeV

Todo:: used by MSLCM_DK2004, allows hypothetic values of gap2pred and predSpeed

Implements MSCFModel.

Definition at line 85 of file MSCFModel_IDM.cpp.

References _updateSpeed(), and desiredSpeed().

00085                                                                                                     {
00086     return _updateSpeed(gap2pred, veh->getSpeed(), predSpeed, desiredSpeed(veh));
00087 }

SUMOReal MSCFModel_IDM::ffeV	(	const MSVehicle *const	veh,
		SUMOReal	speed,
		SUMOReal	gap2pred,
		SUMOReal	predSpeed
	)			const throw () `[virtual]`

Computes the vehicle's safe speed (no dawdling).

Parameters:

`[in]`	veh	The vehicle (EGO)
`[in]`	speed	The vehicle's speed
`[in]`	gap2pred	The (netto) distance to the LEADER
`[in]`	predSpeed	The speed of LEADER

Returns:: EGO's safe speed

See also:: MSCFModel::ffeV

Implements MSCFModel.

Definition at line 79 of file MSCFModel_IDM.cpp.

References _updateSpeed(), and desiredSpeed().

00079                                                                                                                     {
00080     return _updateSpeed(gap2pred, speed, predSpeed, desiredSpeed(veh));
00081 }

SUMOReal MSCFModel_IDM::getMaxAccel ( SUMOReal v ) const throw () [inline, virtual]

Get the vehicle's maximum acceleration [m/s^2].

As some models describe that a vehicle is accelerating slower the higher its speed is, the velocity is given.

Parameters:

[in] v The vehicle's velocity

Returns:: The maximum acceleration

Implements MSCFModel.

Definition at line 149 of file MSCFModel_IDM.h.

References myAccel.

00149                                                    {
00150         return myAccel;
00151     }

SUMOReal MSCFModel::getMaxDecel ( ) const throw () [inline, inherited]

Get the vehicle's maximum deceleration [m/s^2].

Returns:: The maximum deceleration (in m/s^2) of vehicles of this class

Definition at line 218 of file MSCFModel.h.

References MSCFModel::myDecel.

Referenced by MSCFModel::getSecureGap(), MSLCM_DK2004::informBlocker(), TraCIServerAPI_VehicleType::processGet(), MSVehicle::vsafeCriticalCont(), MSLCM_DK2004::wantsChangeToLeft(), and MSLCM_DK2004::wantsChangeToRight().

00218                                          {
00219         return myDecel;
00220     }

int MSCFModel_IDM::getModelID ( ) const throw () [inline, virtual]

Returns the model's name.

Returns:: The model's name

See also:: MSCFModel::getModelName

Implements MSCFModel.

Definition at line 158 of file MSCFModel_IDM.h.

References SUMO_TAG_CF_IDM.

00158                                    {
00159         return SUMO_TAG_CF_IDM;
00160     }

SUMOReal MSCFModel::getSecureGap	(	const SUMOReal	speed,
		const SUMOReal	leaderSpeedAfterDecel
	)			const throw () `[inline, inherited]`

Returns the minimum gap to reserve if the leader is braking at maximum.

Parameters:

`[in]`	speed	EGO's speed
`[in]`	leaderSpeedAfterDecel	LEADER's speed after he has decelerated with max. deceleration rate

Definition at line 234 of file MSCFModel.h.

References MSCFModel::getMaxDecel(), MSCFModel::getTau(), and SUMOReal.

Referenced by MSLane::freeEmit(), and MSLane::isEmissionSuccess().

00234                                                                                                     {
00235         const SUMOReal speedDiff = speed - leaderSpeedAfterDecel;
00236         return speedDiff * speedDiff / getMaxDecel() + speed * getTau();
00237     }

SUMOReal MSCFModel::getSpeedAfterMaxDecel ( SUMOReal v ) const throw () [inline, inherited]

Returns the velocity after maximum deceleration.

Parameters:

[in] v The velocity

Returns:: The velocity after maximum deceleration

Definition at line 244 of file MSCFModel.h.

References ACCEL2SPEED, MAX2(), MSCFModel::myDecel, and SUMOReal.

Referenced by MSLane::freeEmit(), MSCFModel_PWag2009::hasSafeGap(), MSCFModel_KraussOrig1::hasSafeGap(), MSCFModel_Krauss::hasSafeGap(), MSCFModel_Kerner::hasSafeGap(), hasSafeGap(), and MSLane::isEmissionSuccess().

00244                                                              {
00245         return MAX2((SUMOReal) 0, v - (SUMOReal) ACCEL2SPEED(myDecel));
00246     }

SUMOReal MSCFModel_IDM::getTau ( ) const throw () [inline, virtual]

Get the driver's reaction time [s].

Returns:: The reaction time of this class' drivers in s

Reimplemented from MSCFModel.

Definition at line 166 of file MSCFModel_IDM.h.

References myTau.

00166                                     {
00167         return myTau;
00168     }

bool MSCFModel_IDM::hasSafeGap	(	SUMOReal	speed,
		SUMOReal	gap,
		SUMOReal	predSpeed,
		SUMOReal	laneMaxSpeed
	)			const throw () `[virtual]`

Returns whether the given gap is safe.

"safe" means that no collision occur when using the gap, given other values.

Parameters:

`[in]`	speed	EGO's speed
`[in]`	gap	The (netto) gap between LEADER and EGO
`[in]`	predSpeed	LEADER's speed
`[in]`	laneMaxSpeed	The maximum velocity allowed on the lane

Returns:: Whether the given gap is safe

Todo:: evaluate signature

See also:: MSCFModel::hasSafeGap

Todo:: update logic to IDM

Implements MSCFModel.

Definition at line 122 of file MSCFModel_IDM.cpp.

References _updateSpeed(), MSCFModel::getSpeedAfterMaxDecel(), MSCFModel::maxNextSpeed(), MIN3(), SPEED2DIST, and SUMOReal.

00122                                                                                                                {
00123     if (gap<0) {
00124         return false;
00125     }
00126     SUMOReal vSafe = _updateSpeed(speed, gap, predSpeed, laneMaxSpeed);
00127     SUMOReal vNext = MIN3(maxNextSpeed(speed), laneMaxSpeed, vSafe);
00128     return (vNext>=getSpeedAfterMaxDecel(speed) && gap >= SPEED2DIST(speed));
00129 }

SUMOReal MSCFModel_IDM::interactionGap	(	const MSVehicle * const	veh,
		SUMOReal	vL
	)			const throw () `[virtual]`

Returns the maximum gap at which an interaction between both vehicles occurs.

"interaction" means that the LEADER influences EGO's speed.

Parameters:

`[in]`	veh	The EGO vehicle
`[in]`	vL	LEADER's speed

Returns:: The interaction gap

Todo:: evaluate signature

See also:: MSCFModel::interactionGap

Todo:: update logic to IDM

Implements MSCFModel.

Definition at line 105 of file MSCFModel_IDM.cpp.

References DELTA_IDM, desiredSpeed(), MAX2(), myAccel, MSCFModel::myInverseTwoDecel, SPEED2DIST, and SUMOReal.

00105                                                                                     {
00106     // Resolve the IDM equation to gap. Assume predecessor has
00107     // speed != 0 and that vsafe will be the current speed plus acceleration,
00108     // i.e that with this gap there will be no interaction.
00109     SUMOReal acc = myAccel * (1. - pow((double)(veh->getSpeed()/desiredSpeed(veh)), (double) DELTA_IDM));
00110     SUMOReal vNext = veh->getSpeed() + acc;
00111     SUMOReal gap = (vNext - vL) *
00112                    ((veh->getSpeed() + vL) * myInverseTwoDecel) +
00113                    vL * 1;
00114 
00115     // Don't allow timeHeadWay < deltaT situations.
00116     return MAX2(gap, SPEED2DIST(vNext));
00117 }

void MSCFModel::leftVehicleVsafe	(	const MSVehicle *const	ego,
		const MSVehicle *const	neigh,
		SUMOReal &	vSafe
	)			const throw () `[inherited]`

Incorporates the influence of the vehicle on the left lane.

In Germany, vehicles on the right lane must not pass a vehicle on the lane left to the if the allowed velocity>60km/h

Parameters:

`[in]`	ego	The ego vehicle
`[in]`	neigh	The neighbor vehicle on the left lane
`[in,out]`	vSafe	Current vSafe; may be adapted due to the left neighbor

Definition at line 48 of file MSCFModel.cpp.

References MSCFModel::ffeV(), MAX2(), MIN2(), and SUMOReal.

Referenced by MSVehicle::moveRegardingCritical().

00048                                                                                                                      {
00049     if (neigh!=0&&neigh->getSpeed()>60./3.6) {
00050         SUMOReal mgap = MAX2((SUMOReal) 0, neigh->getPositionOnLane()-neigh->getVehicleType().getLength()-ego->getPositionOnLane());
00051         SUMOReal nVSafe = ffeV(ego, mgap, neigh->getSpeed());
00052         if (mgap-neigh->getSpeed()>=0) {
00053             vSafe = MIN2(vSafe, nVSafe);
00054         }
00055     }
00056 }

SUMOReal MSCFModel::maxNextSpeed ( SUMOReal speed ) const throw () [inherited]

Returns the maximum speed given the current speed.

The implementation of this method must take into account the time step duration.

Justification: Due to air brake or other influences, the vehicle's next maximum speed may depend on the vehicle's current speed (given).

Parameters:

[in] speed The vehicle's current speed

Returns:: The maximum possible speed for the next step

Definition at line 60 of file MSCFModel.cpp.

References ACCEL2SPEED, MSCFModel::getMaxAccel(), MSVehicleType::getMaxSpeed(), MIN2(), MSCFModel::myType, and SUMOReal.

Referenced by MSCFModel_PWag2009::ffeS(), MSCFModel_KraussOrig1::ffeS(), MSCFModel_Krauss::ffeS(), MSCFModel_Kerner::ffeS(), MSCFModel_PWag2009::ffeV(), MSCFModel_KraussOrig1::ffeV(), MSCFModel_Krauss::ffeV(), MSCFModel_Kerner::ffeV(), MSLane::getFollowerOnConsecutive(), MSCFModel_PWag2009::hasSafeGap(), MSCFModel_KraussOrig1::hasSafeGap(), MSCFModel_Krauss::hasSafeGap(), MSCFModel_Kerner::hasSafeGap(), hasSafeGap(), MSCFModel_PWag2009::interactionGap(), MSCFModel_KraussOrig1::interactionGap(), MSCFModel_Krauss::interactionGap(), MSCFModel_Kerner::interactionGap(), MSCFModel_PWag2009::moveHelper(), MSCFModel_KraussOrig1::moveHelper(), MSCFModel_Krauss::moveHelper(), MSCFModel_Kerner::moveHelper(), moveHelper(), MSVehicle::moveRegardingCritical(), MSLCM_DK2004::patchSpeed(), and MSVehicle::vsafeCriticalCont().

00060                                                     {
00061     return MIN2(speed + (SUMOReal) ACCEL2SPEED(getMaxAccel(speed)), myType->getMaxSpeed());
00062 }

SUMOReal MSCFModel_IDM::moveHelper	(	MSVehicle *const	veh,
		const MSLane *const	lane,
		SUMOReal	vPos
	)			const throw () `[virtual]`

Applies interaction with stops and lane changing model influences.

Parameters:

`[in]`	veh	The ego vehicle
`[in]`	lane	The lane ego is at
`[in]`	vPos	The possible velocity

Returns:: The velocity after applying interactions with stops and lane change model influences

!! reverify

Implements MSCFModel.

Definition at line 59 of file MSCFModel_IDM.cpp.

References ACCEL2SPEED, MAX2(), MSCFModel::maxNextSpeed(), MIN2(), MIN3(), MSCFModel::myDecel, SPEED2ACCEL, and SUMOReal.

00059                                                                                                        {
00060     SUMOReal oldV = veh->getSpeed(); // save old v for optional acceleration computation
00061     vPos = MIN2(vPos, veh->processNextStop(vPos)); // process stops
00062     // we need the acceleration for emission computation;
00063     //  in this case, we neglect dawdling, nonetheless, using
00064     //  vSafe does not incorporate speed reduction due to interaction
00065     //  on lane changing
00066     veh->setPreDawdleAcceleration(SPEED2ACCEL(vPos-oldV));
00067     //
00068     SUMOReal vNext = vPos;
00069     return
00070         veh->getLaneChangeModel().patchSpeed(
00071             MAX2((SUMOReal) 0, veh->getSpeed()-(SUMOReal)ACCEL2SPEED(myDecel)), 
00072             vNext,
00073             MIN3(vNext, lane->getMaxSpeed(), maxNextSpeed(oldV)),//vaccel(myState.mySpeed, myLane->maxSpeed())),
00074             vNext);
00075 }

void MSCFModel::saveState ( std::ostream & os ) [virtual, inherited]

Saves the model's definition into the state.

Parameters:

[in] os The output to write the definition into

Definition at line 71 of file MSCFModel.cpp.

00071 {}

Field Documentation

SUMOReal MSCFModel_IDM::myAccel [private]

The vehicle's maximum acceleration [m/s^2].

Definition at line 187 of file MSCFModel_IDM.h.

Referenced by _updateSpeed(), getMaxAccel(), and interactionGap().

SUMOReal MSCFModel::myDecel [protected, inherited]

The vehicle's maximum deceleration [m/s^2].

Definition at line 255 of file MSCFModel.h.

Referenced by _updateSpeed(), MSCFModel_PWag2009::_v(), MSCFModel_Kerner::_v(), MSCFModel_KraussOrig1::_vsafe(), MSCFModel_Krauss::_vsafe(), MSCFModel::getMaxDecel(), MSCFModel::getSpeedAfterMaxDecel(), MSCFModel_PWag2009::moveHelper(), MSCFModel_KraussOrig1::moveHelper(), MSCFModel_Krauss::moveHelper(), MSCFModel_Kerner::moveHelper(), and moveHelper().

SUMOReal MSCFModel::myInverseTwoDecel [protected, inherited]

The precomputed value for 1/(2*d).

Definition at line 258 of file MSCFModel.h.

Referenced by MSCFModel::brakeGap(), MSCFModel_PWag2009::interactionGap(), MSCFModel_KraussOrig1::interactionGap(), MSCFModel_Krauss::interactionGap(), MSCFModel_Kerner::interactionGap(), and interactionGap().

SUMOReal MSCFModel_IDM::myMinSpace [private]

The desired minimum Gap to the leading vehicle (no matter the speed).

Definition at line 193 of file MSCFModel_IDM.h.

Referenced by _updateSpeed().

SUMOReal MSCFModel_IDM::myTau [private]

The driver's reaction time [s].

Definition at line 196 of file MSCFModel_IDM.h.

Referenced by getTau().

SUMOReal MSCFModel_IDM::myTimeHeadWay [private]

The driver's desired time headway [s].

Definition at line 190 of file MSCFModel_IDM.h.

Referenced by _updateSpeed().

const MSVehicleType* MSCFModel::myType [protected, inherited]

The type to which this model definition belongs to.

Definition at line 252 of file MSCFModel.h.

Referenced by desiredSpeed(), MSCFModel_Krauss::getMaxAccel(), and MSCFModel::maxNextSpeed().

The documentation for this class was generated from the following files:

MSCFModel_IDM Class Reference

Detailed Description

Public Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation