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

Class DownstreamNeighborsIterable

  • All Implemented Interfaces:
    Iterable<HeadwayGTU>, PerceptionCollectable<HeadwayGTU,​LaneBasedGTU>, PerceptionIterable<HeadwayGTU>
    public class DownstreamNeighborsIterable
extends AbstractPerceptionIterable<HeadwayGTU,​LaneBasedGTU,​Integer>
    Iterable to find downstream GTU's.

    The behavior of this search is slightly altered using boolean ignoreIfUpstream. This is to deal with the following situations in case a GTU with it's rear upstream of the considered lane is found:

    Following downstream GTUs (ignoreIfUpstream = true)
    1. From the same direction (or not a merge): the GTU can be ignored as it is also found on the upstream lane.
    2. From the other direction of a merge: the GTU can be ignored as it is followed through considering the merge conflict. Note that we cannot follow the GTU in a regular fashion. If the rear of the GTU is upstream of the conflict, the subject GTU can move up to the conflict without hitting the GTU from the other direction. Considering the GTU through the conflict deals with this, and the GTU can be ignored for regular following of downstream GTUs.

    GTUs downstream of a conflict (ignoreIfUpstream = false)
    1. From the same direction: the GTU is considered both through the conflict and as a regular downstream GTU.
    2. From the other direction of a merge: the GTU needs to be considered.

    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:
    $Revision$, $LastChangedDate$, by $Author$, initial version 19 feb. 2018
    Author:
    Alexander Verbraeck, Peter Knoppers, Wouter Schakel

    • Constructor Detail

      • DownstreamNeighborsIterable

        public DownstreamNeighborsIterable​(LaneBasedGTU perceivingGtu,
                                   LaneRecord<?> root,
                                   Length initialPosition,
                                   Length maxDistance,
                                   RelativePosition relativePosition,
                                   HeadwayGtuType headwayGtuType,
                                   RelativeLane lane,
                                   boolean ignoreIfUpstream)
        Constructor.
        Parameters:
        perceivingGtu - LaneBasedGTU; perceiving GTU
        root - LaneRecord<?>; root record
        initialPosition - Length; position on the root record
        maxDistance - Length; maximum distance to search
        relativePosition - RelativePosition; position to which distance are calculated by subclasses
        headwayGtuType - HeadwayGtuType; type of HeadwayGTU to return
        lane - RelativeLane; relative lane (used for a left/right distinction to prevent dead-locks)
        ignoreIfUpstream - boolean; whether to ignore GTU that are partially upstream of a record

    • Method Detail

      • getNext

        protected AbstractPerceptionIterable.Entry getNext​(LaneRecord<?> record,
                                                   Length position,
                                                   Integer counter)
                                            throws GTUException
        Returns the next object(s) on the lane represented by the record. This should only consider objects on the given lane. This method should not check the distance towards objects with the maximum distance. The counter will be null for the first object(s). For following object(s) it is whatever value is given with the previous output Entry. Hence, this method maintains its own counting system.
        Specified by:
        getNext in class AbstractPerceptionIterable<HeadwayGTU,​LaneBasedGTU,​Integer>
        Parameters:
        record - LaneRecord<?>; record representing the lane and direction
        position - Length; position to look beyond
        counter - C; counter
        Returns:
        next object(s) on the lane or null if none
        Throws:
        GTUException - on any exception in the process

      • getDistance

        protected Length getDistance​(LaneBasedGTU object,
                             LaneRecord<?> record,
                             Length position)
        Returns the distance to the object. The position fed in to this method is directly taken from an Entry returned by getNext. The two methods need to be consistent with each other.
        Specified by:
        getDistance in class AbstractPerceptionIterable<HeadwayGTU,​LaneBasedGTU,​Integer>
        Parameters:
        object - U; underlying object
        record - LaneRecord<?>; record representing the lane and direction
        position - Length; position of the object on the lane
        Returns:
        Length; distance to the object