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) 2013-2023 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
  17.  * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
  18.  * </p>
  19.  * @author <a href="https://dittlab.tudelft.nl">Wouter Schakel</a>
  20.  */
  21. public abstract class AbstractCarFollowingModel implements CarFollowingModel
  22. {

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

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

  27.     /**
  28.      * @param desiredHeadwayModel DesiredHeadwayModel; desired headway model
  29.      * @param desiredSpeedModel DesiredSpeedModel; desired speed model
  30.      */
  31.     public AbstractCarFollowingModel(final DesiredHeadwayModel desiredHeadwayModel, final DesiredSpeedModel desiredSpeedModel)
  32.     {
  33.         this.desiredHeadwayModel = desiredHeadwayModel;
  34.         this.desiredSpeedModel = desiredSpeedModel;
  35.     }

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

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

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

  71.     /**
  72.      * Determination of car-following acceleration, possibly based on multiple leaders.
  73.      * @param parameters Parameters; parameters
  74.      * @param speed Speed; current speed
  75.      * @param desiredSpeed Speed; desired speed
  76.      * @param desiredHeadway Length; desired headway
  77.      * @param leaders PerceptionIterable&lt;? extends Headway&gt;; set of leader headways (guaranteed positive) and speeds,
  78.      *            ordered by headway (closest first)
  79.      * @return car-following acceleration
  80.      * @throws ParameterException if parameter exception occurs
  81.      */
  82.     protected abstract Acceleration followingAcceleration(Parameters parameters, Speed speed, Speed desiredSpeed,
  83.             Length desiredHeadway, PerceptionIterable<? extends Headway> leaders) throws ParameterException;

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

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

  104. }