package org.opentrafficsim.road.gtu.lane.tactical.following;
   
   import org.djunits.unit.AccelerationUnit;
   import org.djunits.value.vdouble.scalar.Acceleration;
   import org.djunits.value.vdouble.scalar.Length;
   import org.djunits.value.vdouble.scalar.Speed;
   import org.opentrafficsim.base.parameters.ParameterException;
   import org.opentrafficsim.base.parameters.Parameters;
   import org.opentrafficsim.road.gtu.lane.perception.PerceptionIterable;
  import org.opentrafficsim.road.gtu.lane.perception.headway.Headway;
  
  /**
   * Implementation of the IDM+. See Schakel, W.J., Knoop, V.L., and Van Arem, B. (2012),
   * <a href="http://victorknoop.eu/research/papers/TRB2012_LMRS_reviewed.pdf">LMRS: Integrated Lane Change Model with Relaxation
   * and Synchronization</a>, Transportation Research Records: Journal of the Transportation Research Board, No. 2316, pp. 47-57.
   * Note in the official versions of TRB and TRR some errors appeared due to the typesetting of the papers (not in the preprint
   * provided here). A list of errata for the official versions is found
   * <a href="http://victorknoop.eu/research/papers/Erratum_LMRS.pdf">here</a>.
   * <p>
   * Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
   */
  public class IdmPlus extends AbstractIdm
  {
  
      /**
       * Default constructor using default models for desired headway and desired speed.
       */
      public IdmPlus()
      {
          super(HEADWAY, DESIRED_SPEED);
      }
  
      /**
       * Constructor with modular models for desired headway and desired speed.
       * @param desiredHeadwayModel desired headway model
       * @param desiredSpeedModel desired speed model
       */
      public IdmPlus(final DesiredHeadwayModel desiredHeadwayModel, final DesiredSpeedModel desiredSpeedModel)
      {
          super(desiredHeadwayModel, desiredSpeedModel);
      }
  
      @Override
      public final String getName()
      {
          return "IDM+";
      }
  
      @Override
      public final String getLongName()
      {
          return "Intelligent Driver Model+";
      }
  
      @Override
      protected final Acceleration combineInteractionTerm(final Acceleration aFree, final Parameters parameters,
              final Speed speed, final Speed desiredSpeed, final Length desiredHeadway,
              final PerceptionIterable<? extends Headway> leaders) throws ParameterException
      {
          Acceleration a = parameters.getParameter(A);
          Headway leader = leaders.first();
          double sRatio =
                  dynamicDesiredHeadway(parameters, speed, desiredHeadway, leader.getSpeed()).si / leader.getDistance().si;
          double aInt = a.si * (1 - sRatio * sRatio);
          return new Acceleration(aInt < aFree.si ? aInt : aFree.si, AccelerationUnit.SI);
      }
  
  }