Package org.opentrafficsim.road.gtu.lane.perception.headway

Interface Headway

All Superinterfaces:

Comparable<Headway>, Identifiable, PerceivedObject, Serializable

All Known Subinterfaces:

HeadwayGTU, HeadwayLaneBasedObject

All Known Implementing Classes:

AbstractHeadway, AbstractHeadwayCopy, AbstractHeadwayGTU, AbstractHeadwayLaneBasedObject, CarFollowingUtil.CarFollowingHeadway, HeadwayBusStop, HeadwayConflict, HeadwayDistance, HeadwayGTUPerceived, HeadwayGTUReal, HeadwayGTURealCopy, HeadwayGTUSimple, HeadwayGTUType, HeadwayObject, HeadwayStopLine, HeadwayTrafficLight

public interface Headway
extends PerceivedObject, Comparable<Headway>

Interface for a reference to information about a (lane based) GTU and a headway. The Headway can store information about GTUs or objects ahead of the reference GTU, behind the reference GTU, or (partially) parallel to the reference GTU. In addition to the (perceived) headway, several other pieces of information can be stored, such as (perceived) speed, (perceived) acceleration, (perceived) turn indicators, and (perceived) braking lights.
Special care must be taken in curves when perceiving headway of a GTU or object on an adjacent lane.The question is whether we perceive the parallel or ahead/behind based on a line perpendicular to the front/back of the GTU (rectangular), or perpendicular to the center line of the lane (wedge-shaped in case of a curve). The difficulty of a wedge-shaped situation is that reciprocity might be violated: in case of a clothoid, for instance, it is not sure that the point on the center line when projected from lane 1 to lane 2 is the same as the projection from lane 2 to lane 1. The same holds for shapes with sharp bends. Therefore, algorithms implementing headway should only project the reference point of the reference GTU on the center line of the adjacent lane, and then calculate the forward position and backward position on the adjacent lane based on the reference point. Still, our human perception of what is parallel and what not, is not reflected by fractional positions. See examples in http://simulation.tudelft.nl:8085/browse/OTS-113.

Copyright (c) 2013-2020 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
BSD-style license. See OpenTrafficSim License.

Version:

$Revision: 1368 $, $LastChangedDate: 2015-09-02 00:20:20 +0200 (Wed, 02 Sep 2015) $, by $Author: averbraeck $, initial version 11 feb. 2015

Author:

Alexander Verbraeck, Peter Knoppers

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Headway.ObjectType	the object types that can be distinguished for headway.

Method Summary

Modifier and Type	Method	Description
default int	compareTo(Headway headway)
Acceleration	getAcceleration()
Length	getDistance()	Retrieve the strongly typed distance to the other object.
String	getId()
Length	getLength()
Headway.ObjectType	getObjectType()
Length	getOverlap()	Return the (perceived) overlap with the other object.
Length	getOverlapFront()	Return the (perceived) front overlap to the other object.
Length	getOverlapRear()	Return the (perceived) rear overlap to the other object.
Speed	getSpeed()
boolean	isAhead()
boolean	isBehind()
boolean	isParallel()

Method Detail

getId

String getId()

Specified by:

getId in interface Identifiable

Returns:

String; the id of the other object for comparison purposes, cannot be null.

getLength

Length getLength()

Returns:

Length; the length of the other object; can be null if unknown.

getSpeed

Speed getSpeed()

Returns:

Speed; the (perceived) speed of the other object; can be null if unknown.

getDistance

Length getDistance()

Retrieve the strongly typed distance to the other object.

Returns:

Length; the distance to the object, return value null indicates that the other object is parallel to the reference object

getObjectType

Headway.ObjectType getObjectType()

Returns:

Length; the (perceived) object Type, can be null if no object type unknown.

getAcceleration

Acceleration getAcceleration()

Returns:

Acceleration; acceleration the (perceived) acceleration of the other object; can be null if unknown.

getOverlapFront

Length getOverlapFront()

Return the (perceived) front overlap to the other object. This value should be null if there is no overlap. In the figure for two GTUs below, it is distance c, positive for GTU1, negative for GTU2.

 ----------
 |  GTU 1 |          ----->
 ----------
      ---------------
      |    GTU 2    |          ----->
      ---------------
 | a  | b |     c   |
 

Returns:

Length; the (perceived) front overlap to the other object or null if there is no overlap.

getOverlapRear

Length getOverlapRear()

Return the (perceived) rear overlap to the other object. This value should be null if there is no overlap.In the figure below for two GTUs, it is distance a, positive for GTU1, negative for GTU2.

 ----------
 |  GTU 1 |          ----->
 ----------
      ---------------
      |    GTU 2    |          ----->
      ---------------
 | a  | b |     c   |
 

Returns:

Length; the (perceived) rear overlap to the other object or null if there is no overlap.

getOverlap

Length getOverlap()

Return the (perceived) overlap with the other object. This value should be null if there is no overlap. In the figure below for two GTUs, it is distance b, positive for GTU1 and GTU2.

 ----------
 |  GTU 1 |          ----->
 ----------
      ---------------
      |    GTU 2    |          ----->
      ---------------
 | a  | b |     c   |
 

Returns:

Length, the (perceived) overlap with the other object or null if there is no overlap.

isAhead

boolean isAhead()

Returns:

whether the other object is in front of the reference object.

isBehind

boolean isBehind()

Returns:

whether the other object is behind the reference object.

isParallel

boolean isParallel()

Returns:

whether the other object is parallel the reference object.

compareTo

default int compareTo(Headway headway)

Specified by:

compareTo in interface Comparable<Headway>