Package org.opentrafficsim.road.gtu.tactical.util.lmrs

Interface Synchronization

All Superinterfaces:

LmrsParameters, NamedConstants

public interface Synchronization
extends NamedConstants, LmrsParameters

Different forms of synchronization.

Copyright (c) 2013-2026 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
BSD-style license. See OpenTrafficSim License.

Author:

Alexander Verbraeck, Peter Knoppers, Wouter Schakel

Field Summary

Fields

Modifier and Type	Field	Description
static final Synchronization	ACTIVE	Synchronization where a suitable leader is actively targeted, in relation to infrastructure.
static final Synchronization	ALIGN_GAP	Synchronization by following the adjacent leader or aligning with the middle of the gap, whichever allows the largest acceleration.
static final Synchronization	PASSIVE	Synchronization where current leaders are taken.
static final Synchronization	PASSIVE_MOVING	Synchronization where current leaders are taken.

Fields inherited from interface org.opentrafficsim.road.gtu.tactical.util.lmrs.LmrsParameters

DCOOP, DFREE, DLC, DLEFT, DRIGHT, DSYNC, LAMBDA_V, SOCIO, VGAIN

Method Summary

Modifier and Type	Method	Description
static boolean	canBeAhead(TacticalContextEgo context, PerceivedGtu adjacentVehicle, org.djunits.value.vdouble.scalar.Length xCur, int nCur, org.djunits.value.vdouble.scalar.Speed tagSpeed, double dCoop, org.djunits.value.vdouble.scalar.Acceleration b, org.djunits.value.vdouble.scalar.Duration tMin, org.djunits.value.vdouble.scalar.Duration tMax, org.djunits.value.vdouble.scalar.Length x0, org.djunits.value.vdouble.scalar.Duration t0, org.djunits.value.vdouble.scalar.Duration lc, double desire)	Returns whether a driver estimates it can be ahead of an adjacent vehicle for merging.
static org.djunits.value.vdouble.scalar.Acceleration	gentleUrgency(org.djunits.value.vdouble.scalar.Acceleration a, double desire, Parameters params)	Return limited deceleration.
static PerceivedGtu	getFollower(PerceivedGtu gtu, PerceptionCollectable<PerceivedGtu,LaneBasedGtu> leaders, PerceivedGtu follower, org.djunits.value.vdouble.scalar.Length ownLength)	Returns the upstream gtu of the given gtu.
static org.djunits.value.vdouble.scalar.Length	getMergeDistance(LanePerception perception, LateralDirectionality lat)	Returns the distance to the next merge, stopping within this distance is futile for a lane change.
static PerceivedGtu	getTargetLeader(PerceivedGtu gtu, SortedSet<PerceivedGtu> leaders)	Returns the leader of one gtu from a set.
static org.djunits.value.vdouble.scalar.Length	requiredBufferSpace(org.djunits.value.vdouble.scalar.Speed speed, int nCur, org.djunits.value.vdouble.scalar.Length x0, org.djunits.value.vdouble.scalar.Duration t0, org.djunits.value.vdouble.scalar.Duration lc, double dCoop)	Returns the required buffer space to perform a lane change and further lane changes.
static org.djunits.value.vdouble.scalar.Acceleration	stopForEnd(TacticalContextEgo context, org.djunits.value.vdouble.scalar.Length xCur, org.djunits.value.vdouble.scalar.Length xMerge)	Calculates acceleration to stop for a split or dead-end, accounting for infrastructure.
org.djunits.value.vdouble.scalar.Acceleration	synchronize(TacticalContextEgo context, double desire, LateralDirectionality lat, LmrsData lmrsData, LateralDirectionality initiatedLaneChange)	Determine acceleration for synchronization.
static org.djunits.value.vdouble.scalar.Acceleration	tagAlongAcceleration(TacticalContextEgo context, PerceivedGtu leader, org.djunits.value.vdouble.scalar.Speed tagSpeed, double desire)	Calculates acceleration by following an adjacent vehicle, with tagging along if desire is not very high and speed is low.

Methods inherited from interface org.opentrafficsim.base.NamedConstants

name

Field Details

PASSIVE

static final Synchronization PASSIVE

Synchronization where current leaders are taken.

ALIGN_GAP

static final Synchronization ALIGN_GAP

Synchronization by following the adjacent leader or aligning with the middle of the gap, whichever allows the largest acceleration. Note that aligning with the middle of the gap then means the gap is too small, as following would cause lower acceleration. Aligning with the middle of the gap will however provide a better starting point for the rest of the process. Mainly, the adjacent follower can decelerate less, allowing more smooth merging.

PASSIVE_MOVING

static final Synchronization PASSIVE_MOVING

Synchronization where current leaders are taken. Synchronization is disabled for d_sync<d<d_coop at low speeds.

ACTIVE

static final Synchronization ACTIVE

Synchronization where a suitable leader is actively targeted, in relation to infrastructure.

Method Details

getMergeDistance

static org.djunits.value.vdouble.scalar.Length getMergeDistance(LanePerception perception,
 LateralDirectionality lat)
                                                         throws OperationalPlanException

Returns the distance to the next merge, stopping within this distance is futile for a lane change.

Parameters:

perception - perception

lat - lateral direction

Returns:

distance to the next merge

Throws:

OperationalPlanException - if there is no infrastructure perception

synchronize

org.djunits.value.vdouble.scalar.Acceleration synchronize(TacticalContextEgo context,
 double desire,
 LateralDirectionality lat,
 LmrsData lmrsData,
 LateralDirectionality initiatedLaneChange)
                                                   throws ParameterException,
OperationalPlanException

Determine acceleration for synchronization.

Parameters:

context - tactical information such as parameters and car-following model

desire - level of lane change desire

lat - lateral direction for synchronization

lmrsData - LMRS data

initiatedLaneChange - lateral direction of initiated lane change

Returns:

acceleration for synchronization

Throws:

ParameterException - if a parameter is not defined

OperationalPlanException - perception exception

gentleUrgency

static org.djunits.value.vdouble.scalar.Acceleration gentleUrgency(org.djunits.value.vdouble.scalar.Acceleration a,
 double desire,
 Parameters params)
                                                            throws ParameterException

Return limited deceleration. Deceleration is limited to b for d < dCoop. Beyond dCoop the limit is a linear interpolation between b and bCrit.

Parameters:

a - acceleration to limit

desire - lane change desire

params - parameters

Returns:

limited deceleration

Throws:

ParameterException - when parameter is no available or value out of range

getFollower

static PerceivedGtu getFollower(PerceivedGtu gtu,
 PerceptionCollectable<PerceivedGtu,LaneBasedGtu> leaders,
 PerceivedGtu follower,
 org.djunits.value.vdouble.scalar.Length ownLength)

Returns the upstream gtu of the given gtu.

Parameters:

gtu - gtu

leaders - leaders of own vehicle

follower - following vehicle of own vehicle

ownLength - own vehicle length

Returns:

upstream gtu of the given gtu

tagAlongAcceleration

static org.djunits.value.vdouble.scalar.Acceleration tagAlongAcceleration(TacticalContextEgo context,
 PerceivedGtu leader,
 org.djunits.value.vdouble.scalar.Speed tagSpeed,
 double desire)
                                                                   throws ParameterException

Calculates acceleration by following an adjacent vehicle, with tagging along if desire is not very high and speed is low.

Parameters:

context - tactical information such as parameters and car-following model

leader - leader

tagSpeed - maximum tag along speed

desire - lane change desire

Returns:

acceleration by following an adjacent vehicle including tagging along

Throws:

ParameterException - if a parameter is not present

canBeAhead

static boolean canBeAhead(TacticalContextEgo context,
 PerceivedGtu adjacentVehicle,
 org.djunits.value.vdouble.scalar.Length xCur,
 int nCur,
 org.djunits.value.vdouble.scalar.Speed tagSpeed,
 double dCoop,
 org.djunits.value.vdouble.scalar.Acceleration b,
 org.djunits.value.vdouble.scalar.Duration tMin,
 org.djunits.value.vdouble.scalar.Duration tMax,
 org.djunits.value.vdouble.scalar.Length x0,
 org.djunits.value.vdouble.scalar.Duration t0,
 org.djunits.value.vdouble.scalar.Duration lc,
 double desire)
                   throws ParameterException

Returns whether a driver estimates it can be ahead of an adjacent vehicle for merging.

Parameters:

context - tactical information such as parameters and car-following model

adjacentVehicle - adjacent vehicle

xCur - remaining distance

nCur - number of lane changes to perform

tagSpeed - maximum tag along speed

dCoop - cooperation threshold

b - critical deceleration

tMin - minimum headway

tMax - normal headway

x0 - anticipation distance

t0 - anticipation time

lc - lane change duration

desire - lane change desire

Returns:

whether a driver estimates it can be ahead of an adjacent vehicle for merging

Throws:

ParameterException - if parameter is not defined

requiredBufferSpace

static org.djunits.value.vdouble.scalar.Length requiredBufferSpace(org.djunits.value.vdouble.scalar.Speed speed,
 int nCur,
 org.djunits.value.vdouble.scalar.Length x0,
 org.djunits.value.vdouble.scalar.Duration t0,
 org.djunits.value.vdouble.scalar.Duration lc,
 double dCoop)

Returns the required buffer space to perform a lane change and further lane changes.

Parameters:

speed - representative speed

nCur - number of required lane changes

x0 - anticipation distance

t0 - anticipation time

lc - lane change duration

dCoop - cooperation threshold

Returns:

required buffer space to perform a lane change and further lane changes

stopForEnd

static org.djunits.value.vdouble.scalar.Acceleration stopForEnd(TacticalContextEgo context,
 org.djunits.value.vdouble.scalar.Length xCur,
 org.djunits.value.vdouble.scalar.Length xMerge)
                                                         throws ParameterException

Calculates acceleration to stop for a split or dead-end, accounting for infrastructure.

Parameters:

context - tactical information such as parameters and car-following model

xCur - remaining distance to end

xMerge - distance until merge point

Returns:

acceleration to stop for a split or dead-end, accounting for infrastructure

Throws:

ParameterException - if parameter is not defined

getTargetLeader

static PerceivedGtu getTargetLeader(PerceivedGtu gtu,
 SortedSet<PerceivedGtu> leaders)

Returns the leader of one gtu from a set.

Parameters:

gtu - gtu

leaders - leaders

Returns:

leader of one gtu from a set