Line data Source code
1 : /****************************************************************************/
2 : // Eclipse SUMO, Simulation of Urban MObility; see https://eclipse.dev/sumo
3 : // Copyright (C) 2001-2026 German Aerospace Center (DLR) and others.
4 : // This program and the accompanying materials are made available under the
5 : // terms of the Eclipse Public License 2.0 which is available at
6 : // https://www.eclipse.org/legal/epl-2.0/
7 : // This Source Code may also be made available under the following Secondary
8 : // Licenses when the conditions for such availability set forth in the Eclipse
9 : // Public License 2.0 are satisfied: GNU General Public License, version 2
10 : // or later which is available at
11 : // https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
12 : // SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
13 : /****************************************************************************/
14 : /// @file MSCFModel_Kerner.cpp
15 : /// @author Daniel Krajzewicz
16 : /// @author Laura Bieker
17 : /// @author Michael Behrisch
18 : /// @date 03.04.2010
19 : ///
20 : // car-following model by B. Kerner
21 : // Implementation based on "B. S. Kerner, S. L. Klenov, A. Brakemeier, Testbed for Wireless Vehicle Communication: a
22 : // Simulation Approach based on Three-Phase Traffic Theory"
23 : // https://arxiv.org/abs/0712.2711
24 : /****************************************************************************/
25 : #include <config.h>
26 :
27 : #include <microsim/MSVehicle.h>
28 : #include <microsim/MSLane.h>
29 : #include "MSCFModel_Kerner.h"
30 : #include <utils/common/RandHelper.h>
31 : #include <utils/xml/SUMOSAXAttributes.h>
32 :
33 :
34 : // ===========================================================================
35 : // method definitions
36 : // ===========================================================================
37 242 : MSCFModel_Kerner::MSCFModel_Kerner(const MSVehicleType* vtype) :
38 : MSCFModel(vtype),
39 242 : myK(vtype->getParameter().getCFParam(SUMO_ATTR_K, 0.5)),
40 242 : myPhi(vtype->getParameter().getCFParam(SUMO_ATTR_CF_KERNER_PHI, 5.0)),
41 242 : myTauDecel(myDecel * myHeadwayTime) {
42 : // Kerner does not drive very precise and may violate minGap on occasion
43 242 : myCollisionMinGapFactor = vtype->getParameter().getCFParam(SUMO_ATTR_COLLISION_MINGAP_FACTOR, 0.1);
44 242 : }
45 :
46 :
47 484 : MSCFModel_Kerner::~MSCFModel_Kerner() {}
48 :
49 :
50 : void
51 10 : MSCFModel_Kerner::VehicleVariables::saveState(OutputDevice& out, const MSCFModel& /*cfm*/) const {
52 10 : out.openTag(SUMO_TAG_CFM_VARIABLES);
53 10 : out.writeAttr(SUMO_ATTR_ID, "BKerner");
54 10 : std::ostringstream internals;
55 10 : internals << rand;
56 10 : out.writeAttr(SUMO_ATTR_STATE, internals.str());
57 10 : out.closeTag();
58 10 : }
59 :
60 :
61 : void
62 10 : MSCFModel_Kerner::VehicleVariables::loadState(const SUMOSAXAttributes& attrs) {
63 10 : bool ok = true;
64 10 : const std::string cfmID = attrs.get<std::string>(SUMO_ATTR_ID, nullptr, ok);
65 10 : if (cfmID != "BKerner") {
66 0 : throw ProcessError(TLF("incompatible carFollowModel '%' when loading state for BKerner", cfmID));
67 : }
68 10 : std::istringstream bis(attrs.getString(SUMO_ATTR_STATE));
69 10 : bis >> rand;
70 20 : }
71 :
72 : double
73 4313791 : MSCFModel_Kerner::finalizeSpeed(MSVehicle* const veh, double vPos) const {
74 4313791 : const double vNext = MSCFModel::finalizeSpeed(veh, vPos);
75 : VehicleVariables* vars = (VehicleVariables*)veh->getCarFollowVariables();
76 4313791 : vars->rand = RandHelper::rand(veh->getRNG());
77 4313791 : return vNext;
78 : }
79 :
80 :
81 : double
82 29732124 : MSCFModel_Kerner::followSpeed(const MSVehicle* const veh, double speed, double gap, double predSpeed, double /*predMaxDecel*/, const MSVehicle* const /*pred*/, const CalcReason /*usage*/) const {
83 29732124 : return MIN2(_v(veh, speed, maxNextSpeed(speed, veh), gap, predSpeed), maxNextSpeed(speed, veh));
84 : }
85 :
86 :
87 : double
88 12307369 : MSCFModel_Kerner::stopSpeed(const MSVehicle* const veh, const double speed, double gap, double /*decel*/, const CalcReason /*usage*/) const {
89 12307369 : return MIN2(_v(veh, speed, maxNextSpeed(speed, veh), gap, 0), maxNextSpeed(speed, veh));
90 : }
91 :
92 :
93 : MSCFModel::VehicleVariables*
94 6874 : MSCFModel_Kerner::createVehicleVariables() const {
95 6874 : VehicleVariables* ret = new VehicleVariables();
96 : /// XXX should use egoVehicle->getRNG()
97 6874 : ret->rand = RandHelper::rand();
98 6874 : return ret;
99 : }
100 :
101 :
102 : double
103 42039493 : MSCFModel_Kerner::_v(const MSVehicle* const veh, double speed, double vfree, double gap, double predSpeed) const {
104 42039493 : if (predSpeed == 0 && gap < 0.01) {
105 : return 0;
106 : }
107 : // !!! in the following, the prior step is not considered!!!
108 41964735 : double G = MAX2((double) 0, (double)(SPEED2DIST(myK * speed) + myPhi / myAccel * speed * (speed - predSpeed)));
109 50472279 : double vcond = gap > G ? speed + ACCEL2SPEED(myAccel) : speed + MAX2(ACCEL2SPEED(-myDecel), MIN2(ACCEL2SPEED(myAccel), predSpeed - speed));
110 41964735 : double vsafe = (double)(-1. * myTauDecel + sqrt(myTauDecel * myTauDecel + (predSpeed * predSpeed) + (2. * myDecel * gap)));
111 : VehicleVariables* vars = (VehicleVariables*)veh->getCarFollowVariables();
112 41964735 : double va = MAX2((double) 0, MIN3(vfree, vsafe, vcond)) + vars->rand;
113 : //std::cout << SIMTIME << " veh=" << veh->getID() << " speed=" << speed << " gap=" << gap << " G=" << G << " predSpeed=" << predSpeed << " vfree=" << vfree << " vsafe=" << vsafe << " vcond=" << vcond << " rand=" << vars->rand << "\n";
114 41964735 : double v = MAX2((double) 0, MIN4(vfree, va, speed + ACCEL2SPEED(myAccel), vsafe));
115 : return v;
116 : }
117 :
118 :
119 : MSCFModel*
120 0 : MSCFModel_Kerner::duplicate(const MSVehicleType* vtype) const {
121 0 : return new MSCFModel_Kerner(vtype);
122 : }
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