SUMO - Simulation of Urban MObility
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MSCFModel_Kerner.cpp
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1 /****************************************************************************/
9 // car-following model by B. Kerner
10 /****************************************************************************/
11 // SUMO, Simulation of Urban MObility; see http://sumo.sourceforge.net/
12 // Copyright (C) 2001-2012 DLR (http://www.dlr.de/) and contributors
13 /****************************************************************************/
14 //
15 // This file is part of SUMO.
16 // SUMO is free software: you can redistribute it and/or modify
17 // it under the terms of the GNU General Public License as published by
18 // the Free Software Foundation, either version 3 of the License, or
19 // (at your option) any later version.
20 //
21 /****************************************************************************/
22 
23 
24 // ===========================================================================
25 // included modules
26 // ===========================================================================
27 #ifdef _MSC_VER
28 #include <windows_config.h>
29 #else
30 #include <config.h>
31 #endif
32 
33 #include <microsim/MSVehicle.h>
34 #include <microsim/MSLane.h>
35 #include "MSCFModel_Kerner.h"
37 
38 
39 // ===========================================================================
40 // method definitions
41 // ===========================================================================
43  SUMOReal decel, SUMOReal headwayTime, SUMOReal k, SUMOReal phi)
44  : MSCFModel(vtype, accel, decel, headwayTime), myK(k), myPhi(phi), myTauDecel(decel* headwayTime) {
45 }
46 
47 
49 
50 
52 MSCFModel_Kerner::followSpeed(const MSVehicle* const /*veh*/, SUMOReal speed, SUMOReal gap, SUMOReal predSpeed, SUMOReal /*predMaxDecel*/) const {
53  return MIN2(_v(speed, maxNextSpeed(speed), gap, predSpeed), maxNextSpeed(speed));
54 }
55 
56 
58 MSCFModel_Kerner::stopSpeed(const MSVehicle* const veh, SUMOReal gap) const {
59  const SUMOReal speed = veh->getSpeed();
60  return MIN2(_v(speed, maxNextSpeed(speed), gap, 0), maxNextSpeed(speed));
61 }
62 
63 
65 MSCFModel_Kerner::_v(SUMOReal speed, SUMOReal vfree, SUMOReal gap, SUMOReal predSpeed) const {
66  if (predSpeed == 0 && gap < 0.01) {
67  return 0;
68  }
69  // !!! in the following, the prior step is not considered!!!
70  SUMOReal G = MAX2((SUMOReal) 0, (SUMOReal)(SPEED2DIST(myK * speed) + myPhi / myAccel * speed * (speed - predSpeed)));
71  SUMOReal vcond = gap > G ? speed + ACCEL2SPEED(myAccel) : speed + MAX2(ACCEL2SPEED(-myDecel), MIN2(ACCEL2SPEED(myAccel), predSpeed - speed));
72  SUMOReal vsafe = (SUMOReal)(-1. * myTauDecel + sqrt(myTauDecel * myTauDecel + (predSpeed * predSpeed) + (2. * myDecel * gap)));
73  SUMOReal va = MAX2((SUMOReal) 0, MIN3(vfree, vsafe, vcond)) + RandHelper::rand();
74  SUMOReal v = MAX2((SUMOReal) 0, MIN4(vfree, va, speed + ACCEL2SPEED(myAccel), vsafe));
75  return v;
76 }
77 
78 
79 MSCFModel*
81  return new MSCFModel_Kerner(vtype, myAccel, myDecel, myHeadwayTime, myK, myPhi);
82 }