org.opentrafficsim.road.gtu.lane.tactical.following

Class AbstractIDM

java.lang.Object

org.opentrafficsim.road.gtu.lane.tactical.following.AbstractCarFollowingModel

org.opentrafficsim.road.gtu.lane.tactical.following.AbstractIDM

All Implemented Interfaces:

CarFollowingModel, DesiredHeadwayModel, DesiredSpeedModel, Initialisable

Direct Known Subclasses:

IDM, IDMPlus, IDMPlusMulti

public abstract class AbstractIDM
extends AbstractCarFollowingModel

Implementation of the IDM. See https://en.wikipedia.org/wiki/Intelligent_driver_model

Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
BSD-style license. See OpenTrafficSim License.

Version:

$Revision$, $LastChangedDate$, by $Author$, initial version Apr 22, 2016

Author:

Alexander Verbraeck, Peter Knoppers, Wouter Schakel

Field Summary

Fields

Modifier and Type	Field and Description
protected static ParameterTypeAcceleration	A Acceleration parameter type.
protected static ParameterTypeAcceleration	B Comfortable deceleration parameter type.
protected static ParameterTypeAcceleration	B0 Adjustment deceleration parameter type.
static ParameterTypeDouble	DELTA Acceleration flattening.
static DesiredSpeedModel	DESIRED_SPEED Default IDM desired speed model.
protected static ParameterTypeDouble	FSPEED Speed limit adherence factor parameter type.
static DesiredHeadwayModel	HEADWAY Default IDM desired headway model.
protected static ParameterTypeLength	S0 Stopping distance parameter type.
protected static ParameterTypeDuration	T Desired headway parameter type.

Fields inherited from interface org.opentrafficsim.road.gtu.lane.tactical.following.CarFollowingModel

CAR_FOLLOWING_MODEL

Constructor Summary

Constructors

Constructor and Description
AbstractIDM(DesiredHeadwayModel desiredHeadwayModel, DesiredSpeedModel desiredSpeedModel) Constructor with modular models for desired headway and desired speed.

Method Summary

Modifier and Type	Method and Description
protected abstract Acceleration	combineInteractionTerm(Acceleration aFree, Parameters parameters, Speed speed, Speed desiredSpeed, Length desiredHeadway, PerceptionIterable<? extends Headway> leaders) Combines an interaction term with the free term.
protected Length	dynamicDesiredHeadway(Parameters parameters, Speed speed, Length desiredHeadway, Speed leaderSpeed) Determines the dynamic desired headway, which is non-negative.
protected Length	dynamicHeadwayTerm(Parameters parameters, Speed speed, Speed leaderSpeed) Determines the dynamic headway term.
protected Acceleration	followingAcceleration(Parameters parameters, Speed speed, Speed desiredSpeed, Length desiredHeadway, PerceptionIterable<? extends Headway> leaders) Determination of car-following acceleration, possibly based on multiple leaders.

Methods inherited from class org.opentrafficsim.road.gtu.lane.tactical.following.AbstractCarFollowingModel

desiredHeadway, desiredSpeed, followingAcceleration, init, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.opentrafficsim.road.gtu.lane.tactical.following.CarFollowingModel

getLongName, getName

Field Detail

A

protected static final ParameterTypeAcceleration A

Acceleration parameter type.

B

protected static final ParameterTypeAcceleration B

Comfortable deceleration parameter type.

T

protected static final ParameterTypeDuration T

Desired headway parameter type.

S0

protected static final ParameterTypeLength S0

Stopping distance parameter type.

B0

protected static final ParameterTypeAcceleration B0

Adjustment deceleration parameter type.

FSPEED

protected static final ParameterTypeDouble FSPEED

Speed limit adherence factor parameter type.

DELTA

public static final ParameterTypeDouble DELTA

Acceleration flattening.

HEADWAY

public static final DesiredHeadwayModel HEADWAY

Default IDM desired headway model.

DESIRED_SPEED

public static final DesiredSpeedModel DESIRED_SPEED

Default IDM desired speed model.

Constructor Detail

AbstractIDM

public AbstractIDM(DesiredHeadwayModel desiredHeadwayModel,
                   DesiredSpeedModel desiredSpeedModel)

Constructor with modular models for desired headway and desired speed.

Parameters:

desiredHeadwayModel - DesiredHeadwayModel; desired headway model

desiredSpeedModel - DesiredSpeedModel; desired speed model

Method Detail

followingAcceleration

protected Acceleration followingAcceleration(Parameters parameters,
                                             Speed speed,
                                             Speed desiredSpeed,
                                             Length desiredHeadway,
                                             PerceptionIterable<? extends Headway> leaders)
                                      throws ParameterException

Determination of car-following acceleration, possibly based on multiple leaders. This implementation calculates the IDM free term, which is returned if there are no leaders. If there are leaders combineInteractionTerm() is invoked to combine the free term with some implementation specific interaction term. The IDM free term is limited by a deceleration of B0 for cases where the current speed is above the desired speed. This method can be overridden if the free term needs to be redefined.

Specified by:

followingAcceleration in class AbstractCarFollowingModel

Parameters:

parameters - Parameters; Parameters.

speed - Speed; Current speed.

desiredSpeed - Speed; Desired speed.

desiredHeadway - Length; Desired headway.

leaders - PerceptionIterable<? extends Headway>; Set of leader headways (guaranteed positive) and speeds, ordered by headway (closest first).

Returns:

Car-following acceleration.

Throws:

ParameterException - If parameter exception occurs.

combineInteractionTerm

protected abstract Acceleration combineInteractionTerm(Acceleration aFree,
                                                       Parameters parameters,
                                                       Speed speed,
                                                       Speed desiredSpeed,
                                                       Length desiredHeadway,
                                                       PerceptionIterable<? extends Headway> leaders)
                                                throws ParameterException

Combines an interaction term with the free term. There should be at least 1 leader for this method.

Parameters:

aFree - Acceleration; Free term of acceleration.

parameters - Parameters; Parameters.

speed - Speed; Current speed.

desiredSpeed - Speed; Desired speed.

desiredHeadway - Length; Desired headway.

leaders - PerceptionIterable<? extends Headway>; Set of leader headways (guaranteed positive) and speeds, ordered by headway (closest first).

Returns:

Combination of terms into a single acceleration.

Throws:

ParameterException - In case of parameter exception.

dynamicDesiredHeadway

protected final Length dynamicDesiredHeadway(Parameters parameters,
                                             Speed speed,
                                             Length desiredHeadway,
                                             Speed leaderSpeed)
                                      throws ParameterException

Determines the dynamic desired headway, which is non-negative.

Parameters:

parameters - Parameters; Parameters.

speed - Speed; Current speed.

desiredHeadway - Length; Desired headway.

leaderSpeed - Speed; Speed of the leading vehicle.

Returns:

Dynamic desired headway.

Throws:

ParameterException - In case of parameter exception.

dynamicHeadwayTerm

protected final Length dynamicHeadwayTerm(Parameters parameters,
                                          Speed speed,
                                          Speed leaderSpeed)
                                   throws ParameterException

Determines the dynamic headway term. May be used on individual leaders for multi-anticipative following.

Parameters:

parameters - Parameters; Parameters.

speed - Speed; Current speed.

leaderSpeed - Speed; Speed of the leading vehicle.

Returns:

Dynamic headway term.

Throws:

ParameterException - In case of parameter exception.