AbstractCarFollowingModel.java

  1. package org.opentrafficsim.road.gtu.lane.tactical.following;

  2. import org.djunits.unit.AccelerationUnit;
  3. import org.djunits.value.vdouble.scalar.Acceleration;
  4. import org.djunits.value.vdouble.scalar.Length;
  5. import org.djunits.value.vdouble.scalar.Speed;
  6. import org.djutils.exceptions.Throw;
  7. import org.opentrafficsim.base.parameters.ParameterException;
  8. import org.opentrafficsim.base.parameters.Parameters;
  9. import org.opentrafficsim.road.gtu.lane.LaneBasedGTU;
  10. import org.opentrafficsim.road.gtu.lane.perception.PerceptionIterable;
  11. import org.opentrafficsim.road.gtu.lane.perception.headway.Headway;
  12. import org.opentrafficsim.road.network.speed.SpeedLimitInfo;

  13. /**
  14.  * Default implementation where desired speed and headway are pre-calculated for car-following.
  15.  * <p>
  16.  * Copyright (c) 2013-2020 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
  17.  * BSD-style license. See <a href="http://opentrafficsim.org/docs/current/license.html">OpenTrafficSim License</a>.
  18.  * <p>
  19.  * @version $Revision$, $LastChangedDate$, by $Author$, initial version Apr 2016 <br>
  20.  * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
  21.  */
  22. public abstract class AbstractCarFollowingModel implements CarFollowingModel
  23. {

  24.     /** Desired headway model. */
  25.     private DesiredHeadwayModel desiredHeadwayModel;

  26.     /** Desired speed model. */
  27.     private DesiredSpeedModel desiredSpeedModel;

  28.     /**
  29.      * @param desiredHeadwayModel DesiredHeadwayModel; desired headway model
  30.      * @param desiredSpeedModel DesiredSpeedModel; desired speed model
  31.      */
  32.     public AbstractCarFollowingModel(final DesiredHeadwayModel desiredHeadwayModel, final DesiredSpeedModel desiredSpeedModel)
  33.     {
  34.         this.desiredHeadwayModel = desiredHeadwayModel;
  35.         this.desiredSpeedModel = desiredSpeedModel;
  36.     }

  37.     /** {@inheritDoc} */
  38.     @Override
  39.     public final Length desiredHeadway(final Parameters parameters, final Speed speed) throws ParameterException
  40.     {
  41.         Throw.whenNull(parameters, "Parameters may not be null.");
  42.         Throw.whenNull(speed, "Speed may not be null.");
  43.         return this.desiredHeadwayModel.desiredHeadway(parameters, speed);
  44.     }

  45.     /** {@inheritDoc} */
  46.     @Override
  47.     public final Speed desiredSpeed(final Parameters parameters, final SpeedLimitInfo speedInfo) throws ParameterException
  48.     {
  49.         Throw.whenNull(parameters, "Parameters may not be null.");
  50.         Throw.whenNull(speedInfo, "Speed limit info may not be null.");
  51.         return this.desiredSpeedModel.desiredSpeed(parameters, speedInfo);
  52.     }

  53.     /** {@inheritDoc} */
  54.     @Override
  55.     public final Acceleration followingAcceleration(final Parameters parameters, final Speed speed,
  56.             final SpeedLimitInfo speedLimitInfo, final PerceptionIterable<? extends Headway> leaders) throws ParameterException
  57.     {
  58.         Throw.whenNull(parameters, "Parameters may not be null.");
  59.         Throw.whenNull(speed, "Speed may not be null.");
  60.         Throw.whenNull(speedLimitInfo, "Speed limit info may not be null.");
  61.         Throw.whenNull(leaders, "Leaders may not be null.");
  62.         // Catch negative headway
  63.         if (!leaders.isEmpty() && leaders.first().getDistance().si <= 0)
  64.         {
  65.             return new Acceleration(Double.NEGATIVE_INFINITY, AccelerationUnit.SI);
  66.         }
  67.         // Forward to method with desired speed and headway predetermined by this car-following model.
  68.         Acceleration acc = followingAcceleration(parameters, speed, desiredSpeed(parameters, speedLimitInfo),
  69.                 desiredHeadway(parameters, speed), leaders);
  70.         return acc;
  71.     }

  72.     /**
  73.      * Determination of car-following acceleration, possibly based on multiple leaders.
  74.      * @param parameters Parameters; parameters
  75.      * @param speed Speed; current speed
  76.      * @param desiredSpeed Speed; desired speed
  77.      * @param desiredHeadway Length; desired headway
  78.      * @param leaders PerceptionIterable&lt;? extends Headway&gt;; set of leader headways (guaranteed positive) and speeds,
  79.      *            ordered by headway (closest first)
  80.      * @return car-following acceleration
  81.      * @throws ParameterException if parameter exception occurs
  82.      */
  83.     protected abstract Acceleration followingAcceleration(Parameters parameters, Speed speed, Speed desiredSpeed,
  84.             Length desiredHeadway, PerceptionIterable<? extends Headway> leaders) throws ParameterException;

  85.     /** {@inheritDoc} */
  86.     @SuppressWarnings("checkstyle:designforextension")
  87.     @Override
  88.     public String toString()
  89.     {
  90.         return getLongName();
  91.     }

  92.     /** {@inheritDoc} */
  93.     @Override
  94.     public final void init(final LaneBasedGTU gtu)
  95.     {
  96.         if (this.desiredHeadwayModel instanceof Initialisable)
  97.         {
  98.             ((Initialisable) this.desiredHeadwayModel).init(gtu);
  99.         }
  100.         if (this.desiredSpeedModel instanceof Initialisable)
  101.         {
  102.             ((Initialisable) this.desiredSpeedModel).init(gtu);
  103.         }
  104.     }

  105. }