org.opentrafficsim.road.gtu.following

Interface GTUFollowingModel

All Known Implementing Classes:

AbstractGTUFollowingModel, FixedAccelerationModel, IDM, IDMPlus, SequentialFixedAccelerationModel

public interface GTUFollowingModel

GTU following model interface.
GTU following models following this interface compute an acceleration.

Copyright (c) 2013-2015 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
BSD-style license. See OpenTrafficSim License.

Version:

$Revision: 1401 $, $LastChangedDate: 2015-09-14 01:33:02 +0200 (Mon, 14 Sep 2015) $, by $Author: averbraeck $, initial version Jul 2, 2014

Author:

Peter Knoppers

Method Summary

Modifier and Type	Method and Description
DualAccelerationStep	computeAcceleration(LaneBasedGTU referenceGTU, Collection<HeadwayGTU> otherGTUs, org.djunits.value.vdouble.scalar.Speed speedLimit) Compute the lowest accelerations (or most severe decelerations) that would be used if a referenceGTU is present (inserted, or not removed) in a set of other GTUs. If any GTU in the set of otherGTUs has a null headway (indicating that the other GTU is in fact parallel to the referenceGTU), prohibitive decelerations shall be returned. Two AccelerationStep values are returned in a DualAccelerationStep. TODO We should probably add a be ready to stop before argument to prevent vehicles that cannot see their leader, or should slow down for a crossing from accelerating to unsafe speeds.
AccelerationStep	computeAcceleration(LaneBasedGTU follower, org.djunits.value.vdouble.scalar.Speed leaderSpeed, org.djunits.value.vdouble.scalar.Length.Rel headway, org.djunits.value.vdouble.scalar.Speed speedLimit) Compute the acceleration that would be used to follow a leader. TODO We should probably add a be ready to stop before argument to prevent vehicles that cannot see their leader, or should slow down for a crossing from accelerating to unsafe speeds.
org.djunits.value.vdouble.scalar.Acceleration	computeAcceleration(org.djunits.value.vdouble.scalar.Speed followerSpeed, org.djunits.value.vdouble.scalar.Speed followerMaximumSpeed, org.djunits.value.vdouble.scalar.Speed leaderSpeed, org.djunits.value.vdouble.scalar.Length.Rel headway, org.djunits.value.vdouble.scalar.Speed speedLimit) Compute the acceleration that would be used to follow a leader. TODO We should probably add a be ready to stop before argument to prevent vehicles that cannot see their leader, or should slow down for a crossing from accelerating to unsafe speeds.
AccelerationStep	computeAccelerationWithNoLeader(LaneBasedGTU gtu, org.djunits.value.vdouble.scalar.Speed speedLimit) Compute the acceleration that would be used if the is not leader in sight.
String	getLongName() Return complete textual information about this instantiation of this GTU following model.
String	getName() Return the name of this GTU following model.
org.djunits.value.vdouble.scalar.Time.Rel	getStepSize() Return the step size of this GTU following model.
org.djunits.value.vdouble.scalar.Acceleration	maximumSafeDeceleration() Return the maximum safe deceleration for use in gap acceptance models.
org.djunits.value.vdouble.scalar.Length.Rel	minimumHeadway(org.djunits.value.vdouble.scalar.Speed followerSpeed, org.djunits.value.vdouble.scalar.Speed leaderSpeed, org.djunits.value.vdouble.scalar.Length.Rel precision, org.djunits.value.vdouble.scalar.Speed speedLimit, org.djunits.value.vdouble.scalar.Speed followerMaximumSpeed) Compute the minimum net headway given the speed of the follower and the leader. At the returned headway, the follower would decelerate with it's maximum comfortable deceleration.

Method Detail

computeAcceleration

AccelerationStep computeAcceleration(LaneBasedGTU follower,
                                     org.djunits.value.vdouble.scalar.Speed leaderSpeed,
                                     org.djunits.value.vdouble.scalar.Length.Rel headway,
                                     org.djunits.value.vdouble.scalar.Speed speedLimit)
                              throws org.opentrafficsim.core.network.NetworkException

Compute the acceleration that would be used to follow a leader.
TODO We should probably add a be ready to stop before argument to prevent vehicles that cannot see their leader, or should slow down for a crossing from accelerating to unsafe speeds.

Parameters:

follower - LaneBasedGTU; the GTU for which acceleration is computed

leaderSpeed - DoubleScalar.Abs<SpeedUnit>; the speed of the leader

headway - DoubleScalar.Rel<LengthUnit>; the headway of the leader

speedLimit - DoubleScalarAbs<SpeedUnit>; the local speed limit

Returns:

AccelerationStep; the result of application of the GTU following model

Throws:

org.opentrafficsim.core.network.NetworkException - on network inconsistency

computeAcceleration

org.djunits.value.vdouble.scalar.Acceleration computeAcceleration(org.djunits.value.vdouble.scalar.Speed followerSpeed,
                                                                  org.djunits.value.vdouble.scalar.Speed followerMaximumSpeed,
                                                                  org.djunits.value.vdouble.scalar.Speed leaderSpeed,
                                                                  org.djunits.value.vdouble.scalar.Length.Rel headway,
                                                                  org.djunits.value.vdouble.scalar.Speed speedLimit)

Compute the acceleration that would be used to follow a leader.
TODO We should probably add a be ready to stop before argument to prevent vehicles that cannot see their leader, or should slow down for a crossing from accelerating to unsafe speeds.

Parameters:

followerSpeed - DoubleScalar.Abs<SpeedUnit>; the speed of the follower at the current time

followerMaximumSpeed - DoubleScalar.Abs<SpeedUnit>; the maximum speed that the follower is capable of driving at

leaderSpeed - DoubleScalar.Abs<SpeedUnit>; the speed of the follower at the current time

headway - DoubleScalar.Rel<LengthUnit>; the net headway (distance between the front of the follower to the rear of the leader) at the current time

speedLimit - DoubleScalar.Abs<SpeedUnit>; the local speed limit

Returns:

DoubleScalar.Abs<AccelerationUnit>; the acceleration (or, if negative, deceleration) resulting from application of the GTU following model

computeAcceleration

DualAccelerationStep computeAcceleration(LaneBasedGTU referenceGTU,
                                         Collection<HeadwayGTU> otherGTUs,
                                         org.djunits.value.vdouble.scalar.Speed speedLimit)
                                  throws org.opentrafficsim.core.network.NetworkException

Compute the lowest accelerations (or most severe decelerations) that would be used if a referenceGTU is present (inserted, or not removed) in a set of other GTUs.
If any GTU in the set of otherGTUs has a null headway (indicating that the other GTU is in fact parallel to the referenceGTU), prohibitive decelerations shall be returned.
Two AccelerationStep values are returned in a DualAccelerationStep.
TODO We should probably add a be ready to stop before argument to prevent vehicles that cannot see their leader, or should slow down for a crossing from accelerating to unsafe speeds.

Parameters:

referenceGTU - LaneBasedGTU; the GTU for which the accelerations are computed

otherGTUs - Collection<HeadwayGTU>; the other GTUs. A negative headway value indicates that the other GTU is a follower. NB. If the referenceGTU is contained in this Collection, it is ignored.

speedLimit - DoubleScalar.Abs<SpeedUnit>; the local speed limit

Returns:

DualAccelerationStep; the result with the lowest accelerations (or most severe decelerations) of application of the GTU following model of the referenceGTU for each leader and follower

Throws:

org.opentrafficsim.core.network.NetworkException - on network inconsistency

computeAccelerationWithNoLeader

AccelerationStep computeAccelerationWithNoLeader(LaneBasedGTU gtu,
                                                 org.djunits.value.vdouble.scalar.Speed speedLimit)
                                          throws org.opentrafficsim.core.network.NetworkException

Compute the acceleration that would be used if the is not leader in sight.

Parameters:

gtu - LaneBasedGTU; the GTU for which acceleration is computed

speedLimit - DoubleScalar.Abs<SpeedUnit>; the local speed limit

Returns:

AccelerationStep; the result of application of the GTU following model

Throws:

org.opentrafficsim.core.network.NetworkException - on network inconsistency

minimumHeadway

org.djunits.value.vdouble.scalar.Length.Rel minimumHeadway(org.djunits.value.vdouble.scalar.Speed followerSpeed,
                                                           org.djunits.value.vdouble.scalar.Speed leaderSpeed,
                                                           org.djunits.value.vdouble.scalar.Length.Rel precision,
                                                           org.djunits.value.vdouble.scalar.Speed speedLimit,
                                                           org.djunits.value.vdouble.scalar.Speed followerMaximumSpeed)

Compute the minimum net headway given the speed of the follower and the leader.
At the returned headway, the follower would decelerate with it's maximum comfortable deceleration.

Parameters:

followerSpeed - DoubleScalar.Abs<SpeedUnit>; speed of the follower

leaderSpeed - DoubleScalar.Abs<SpeedUnit>; speed of the leader

precision - DoubleScalar.Rel<LengthUnit>; the required precision of the result (must be > 0)

speedLimit - DoubleScalar.Abs<SpeedUnit>; the local speed limit

followerMaximumSpeed - DoubleScalar.Abs<SpeedUnit>; the maximum speed that the follower can drive at

Returns:

DoubleScalar.Rel<LengthUnit>

maximumSafeDeceleration

org.djunits.value.vdouble.scalar.Acceleration maximumSafeDeceleration()

Return the maximum safe deceleration for use in gap acceptance models. This is the deceleration that may be enforced upon a new follower due to entering a road or changing into an adjacent lane. The result shall be a positive value. In most car following models this value is named b.

Returns:

DoubleScalar.Abs<AccelerationUnit>; must be a positive value!

getStepSize

org.djunits.value.vdouble.scalar.Time.Rel getStepSize()

Return the step size of this GTU following model.

Returns:

DoubleScalar.Rel<TimeUnit>; the step size of the GTU following model

getName

String getName()

Return the name of this GTU following model.

Returns:

String; just the name of the GTU following model

getLongName

String getLongName()

Return complete textual information about this instantiation of this GTU following model.

Returns:

String; the name and parameter values of the GTU following model