Line data Source code
1 : /****************************************************************************/
2 : // Eclipse SUMO, Simulation of Urban MObility; see https://eclipse.dev/sumo
3 : // Copyright (C) 2001-2024 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_IDM.cpp
15 : /// @author Tobias Mayer
16 : /// @author Daniel Krajzewicz
17 : /// @author Michael Behrisch
18 : /// @date Thu, 03 Sep 2009
19 : ///
20 : // The Intelligent Driver Model (IDM) car-following model
21 : /****************************************************************************/
22 : #include <config.h>
23 :
24 : #include "MSCFModel_IDM.h"
25 : #include <microsim/MSVehicle.h>
26 :
27 : //#define DEBUG_V
28 : //#define DEBUG_INSERTION_SPEED
29 :
30 : #define DEBUG_COND (veh->isSelected())
31 : //#define DEBUG_COND true
32 :
33 :
34 : // ===========================================================================
35 : // method definitions
36 : // ===========================================================================
37 7698 : MSCFModel_IDM::MSCFModel_IDM(const MSVehicleType* vtype, bool idmm) :
38 : MSCFModel(vtype),
39 7698 : myIDMM(idmm),
40 7433 : myDelta(idmm ? 4.0 : vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDM_DELTA, 4.)),
41 7698 : myAdaptationFactor(idmm ? vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDMM_ADAPT_FACTOR, 1.8) : 1.0),
42 7698 : myAdaptationTime(idmm ? vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDMM_ADAPT_TIME, 600.0) : 0.0),
43 7698 : myIterations(MAX2(1, int(TS / vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDM_STEPPING, .25) + .5))),
44 7698 : myTwoSqrtAccelDecel(double(2 * sqrt(myAccel * myDecel))) {
45 : // IDM does not drive very precise and may violate minGap on occasion
46 7698 : myCollisionMinGapFactor = vtype->getParameter().getCFParam(SUMO_ATTR_COLLISION_MINGAP_FACTOR, 0.1);
47 7698 : }
48 :
49 15260 : MSCFModel_IDM::~MSCFModel_IDM() {}
50 :
51 :
52 : double
53 66243139 : MSCFModel_IDM::minNextSpeed(double speed, const MSVehicle* const /*veh*/) const {
54 : // permit exceeding myDecel when approaching stops
55 132480594 : const double decel = MAX2(myDecel, MIN2(myEmergencyDecel, 1.5));
56 66243139 : if (MSGlobals::gSemiImplicitEulerUpdate) {
57 64106147 : return MAX2(speed - ACCEL2SPEED(decel), 0.);
58 : } else {
59 : // NOTE: ballistic update allows for negative speeds to indicate a stop within the next timestep
60 2136992 : return speed - ACCEL2SPEED(decel);
61 : }
62 : }
63 :
64 :
65 :
66 : double
67 32913278 : MSCFModel_IDM::finalizeSpeed(MSVehicle* const veh, double vPos) const {
68 32913278 : const double vNext = MSCFModel::finalizeSpeed(veh, vPos);
69 32913278 : if (myAdaptationFactor != 1.) {
70 : VehicleVariables* vars = (VehicleVariables*)veh->getCarFollowVariables();
71 3668010 : vars->levelOfService += (vNext / veh->getLane()->getVehicleMaxSpeed(veh) - vars->levelOfService) / myAdaptationTime * TS;
72 : }
73 32913278 : return vNext;
74 : }
75 :
76 :
77 : double
78 57649270 : MSCFModel_IDM::freeSpeed(const MSVehicle* const veh, double speed, double seen, double maxSpeed, const bool /*onInsertion*/, const CalcReason /*usage*/) const {
79 57649270 : if (maxSpeed < 0.) {
80 : // can occur for ballistic update (in context of driving at red light)
81 : return maxSpeed;
82 : }
83 57649270 : const double secGap = getSecureGap(veh, nullptr, maxSpeed, 0, myDecel);
84 : double vSafe;
85 57649270 : if (speed <= maxSpeed) {
86 : // accelerate
87 56835164 : vSafe = _v(veh, 1e6, speed, maxSpeed, veh->getLane()->getVehicleMaxSpeed(veh), false);
88 : } else {
89 : // decelerate
90 : // @note relax gap to avoid emergency braking
91 : // @note since the transition point does not move we set the leader speed to 0
92 1628212 : vSafe = _v(veh, MAX2(seen, secGap), speed, 0, veh->getLane()->getVehicleMaxSpeed(veh), false);
93 : }
94 57649270 : if (seen < secGap) {
95 : // avoid overshoot when close to change in speed limit
96 : vSafe = MIN2(vSafe, maxSpeed);
97 : }
98 : //std::cout << SIMTIME << " speed=" << speed << " maxSpeed=" << maxSpeed << " seen=" << seen << " secGap=" << secGap << " vSafe=" << vSafe << "\n";
99 : return vSafe;
100 : }
101 :
102 :
103 : double
104 210684354 : MSCFModel_IDM::followSpeed(const MSVehicle* const veh, double speed, double gap2pred, double predSpeed, double predMaxDecel, const MSVehicle* const pred, const CalcReason /*usage*/) const {
105 210684354 : applyHeadwayAndSpeedDifferencePerceptionErrors(veh, speed, gap2pred, predSpeed, predMaxDecel, pred);
106 210684354 : return _v(veh, gap2pred, speed, predSpeed, veh->getLane()->getVehicleMaxSpeed(veh));
107 : }
108 :
109 :
110 : double
111 965491 : MSCFModel_IDM::insertionFollowSpeed(const MSVehicle* const v, double speed, double gap2pred, double predSpeed, double predMaxDecel, const MSVehicle* const pred) const {
112 : // see definition of s in _v()
113 965491 : double s = MAX2(0., speed * myHeadwayTime + speed * (speed - predSpeed) / myTwoSqrtAccelDecel);
114 965491 : if (gap2pred >= s) {
115 : // followSpeed always stays below speed because s*s / (gap2pred * gap2pred) > 0. This would prevent insertion with maximum speed at all distances
116 : return speed;
117 : } else {
118 : // we cannot call follow speed directly because it assumes that 'speed'
119 : // is the current speed rather than the desired insertion speed.
120 : // If the safe speed is much lower than the desired speed, the
121 : // followSpeed function would still return a new speed that involves
122 : // reasonable braking rather than the actual safe speed (and cause
123 : // emergency braking in a subsequent step)
124 595370 : const double speed2 = followSpeed(v, speed, gap2pred, predSpeed, predMaxDecel, pred, CalcReason::FUTURE);
125 595370 : const double speed3 = followSpeed(v, speed2, gap2pred, predSpeed, predMaxDecel, pred, CalcReason::FUTURE);
126 595370 : if (speed2 - speed3 < ACCEL2SPEED(1)) {
127 : return speed2;
128 : } else {
129 : #ifdef DEBUG_INSERTION_SPEED
130 : std::cout << SIMTIME << " veh=" << v->getID() << " speed=" << speed << " gap2pred=" << gap2pred << " predSpeed=" << predSpeed << " predMaxDecel=" << predMaxDecel << " pred=" << Named::getIDSecure(pred) << " s=" << s << " speed2=" << speed2 << " speed3=" << speed3 << "\n";
131 : #endif
132 448890 : return insertionFollowSpeed(v, speed2, gap2pred, predSpeed, predMaxDecel, pred);
133 : }
134 : }
135 : }
136 :
137 :
138 : double
139 4086 : MSCFModel_IDM::insertionStopSpeed(const MSVehicle* const veh, double speed, double gap) const {
140 : // we want to insert the vehicle in an equilibrium state
141 4086 : double result = MSCFModel::insertionStopSpeed(veh, speed, gap);
142 : int i = 0;
143 13774 : while (result - speed < -ACCEL2SPEED(myDecel) && ++i < 10) {
144 : speed = result;
145 9688 : result = MSCFModel::insertionStopSpeed(veh, speed, gap);
146 : }
147 4086 : return result;
148 : }
149 :
150 :
151 : double
152 73100994 : MSCFModel_IDM::stopSpeed(const MSVehicle* const veh, const double speed, double gap, double decel, const CalcReason /*usage*/) const {
153 73100994 : applyHeadwayPerceptionError(veh, speed, gap);
154 73100994 : if (gap < 0.01) {
155 : return 0;
156 : }
157 72569655 : double result = _v(veh, gap, speed, 0, veh->getLane()->getVehicleMaxSpeed(veh), false);
158 : //std::cout << SIMTIME << " stopSpeed speed=" << speed << " gap=" << gap << " decel=" << decel << " result=" << result << "\n";
159 72569655 : if (gap > 0 && speed < NUMERICAL_EPS && result < NUMERICAL_EPS) {
160 : // ensure that stops can be reached:
161 : //std::cout << " switching to krauss: " << veh->getID() << " gap=" << gap << " speed=" << speed << " res1=" << result << " res2=" << maximumSafeStopSpeed(gap, speed, false, veh->getActionStepLengthSecs())<< "\n";
162 17206 : result = maximumSafeStopSpeed(gap, decel, speed, false, veh->getActionStepLengthSecs());
163 : }
164 : // avoid overshooting the stop location
165 72569655 : if (gap >= 0) {
166 72569655 : result = MIN2(result, DIST2SPEED(gap));
167 : //if (result * TS > gap) {
168 : // std::cout << "Maximum stop speed exceeded for gap=" << gap << " result=" << result << " veh=" << veh->getID() << " speed=" << speed << " t=" << SIMTIME << "\n";
169 : //}
170 : }
171 :
172 : return result;
173 : }
174 :
175 :
176 : /// @todo update interactionGap logic to IDM
177 : double
178 0 : MSCFModel_IDM::interactionGap(const MSVehicle* const veh, double vL) const {
179 : // Resolve the IDM equation to gap. Assume predecessor has
180 : // speed != 0 and that vsafe will be the current speed plus acceleration,
181 : // i.e that with this gap there will be no interaction.
182 0 : const double acc = myAccel * (1. - pow(veh->getSpeed() / veh->getLane()->getVehicleMaxSpeed(veh), myDelta));
183 0 : const double vNext = veh->getSpeed() + acc;
184 0 : const double gap = (vNext - vL) * (veh->getSpeed() + vL) / (2 * myDecel) + vL;
185 :
186 : // Don't allow timeHeadWay < deltaT situations.
187 0 : return MAX2(gap, SPEED2DIST(vNext));
188 : }
189 :
190 : double
191 367920261 : MSCFModel_IDM::getSecureGap(const MSVehicle* const /*veh*/, const MSVehicle* const /*pred*/, const double speed, const double leaderSpeed, const double /*leaderMaxDecel*/) const {
192 367920261 : const double delta_v = speed - leaderSpeed;
193 367920261 : return MAX2(0.0, speed * myHeadwayTime + speed * delta_v / myTwoSqrtAccelDecel);
194 : }
195 :
196 :
197 : double
198 340903279 : MSCFModel_IDM::_v(const MSVehicle* const veh, const double gap2pred, const double egoSpeed,
199 : const double predSpeed, const double desSpeed, const bool respectMinGap) const {
200 : // this is more or less based on http://www.vwi.tu-dresden.de/~treiber/MicroApplet/IDM.html
201 : // and http://arxiv.org/abs/cond-mat/0304337
202 : // we assume however constant speed for the leader
203 340903279 : double headwayTime = myHeadwayTime;
204 340903279 : if (myAdaptationFactor != 1.) {
205 : const VehicleVariables* vars = (VehicleVariables*)veh->getCarFollowVariables();
206 42761535 : headwayTime *= myAdaptationFactor + vars->levelOfService * (1. - myAdaptationFactor);
207 : }
208 : double newSpeed = egoSpeed;
209 : double gap = gap2pred;
210 340903279 : if (respectMinGap) {
211 : // gap2pred comes with minGap already subtracted so we need to add it here again
212 210684354 : gap += myType->getMinGap();
213 : }
214 : #ifdef DEBUG_V
215 : if (DEBUG_COND) {
216 : std::cout << SIMTIME << " veh=" << veh->getID() << " gap2pred=" << gap2pred << " egoSpeed=" << egoSpeed << " predSpeed=" << predSpeed << " desSpeed=" << desSpeed << " rMG=" << respectMinGap << " hw=" << headwayTime << "\n";
217 : }
218 : #endif
219 1589949883 : for (int i = 0; i < myIterations; i++) {
220 1249046604 : const double delta_v = newSpeed - predSpeed;
221 1249046604 : double s = MAX2(0., newSpeed * headwayTime + newSpeed * delta_v / myTwoSqrtAccelDecel);
222 1249046604 : if (respectMinGap) {
223 770539543 : s += myType->getMinGap();
224 : }
225 : gap = MAX2(NUMERICAL_EPS, gap); // avoid singularity
226 1249046604 : const double acc = myAccel * (1. - pow(newSpeed / MAX2(NUMERICAL_EPS, desSpeed), myDelta) - (s * s) / (gap * gap));
227 : #ifdef DEBUG_V
228 : if (DEBUG_COND) {
229 : std::cout << " i=" << i << " gap=" << gap << " t=" << myHeadwayTime << " t2=" << headwayTime << " s=" << s << " pow=" << pow(newSpeed / desSpeed, myDelta) << " gapDecel=" << (s * s) / (gap * gap) << " a=" << acc;
230 : }
231 : #endif
232 1249046604 : newSpeed = MAX2(0.0, newSpeed + ACCEL2SPEED(acc) / myIterations);
233 : #ifdef DEBUG_V
234 : if (DEBUG_COND) {
235 : std::cout << " v2=" << newSpeed << " gLC=" << MSGlobals::gComputeLC << "\n";
236 : }
237 : #endif
238 : //TODO use more realistic position update which takes accelerated motion into account
239 2007040266 : gap -= MAX2(0., SPEED2DIST(newSpeed - predSpeed) / myIterations);
240 : }
241 340903279 : return MAX2(0., newSpeed);
242 : }
243 :
244 :
245 : MSCFModel*
246 0 : MSCFModel_IDM::duplicate(const MSVehicleType* vtype) const {
247 0 : return new MSCFModel_IDM(vtype, myIDMM);
248 : }
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