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 7886 : MSCFModel_IDM::MSCFModel_IDM(const MSVehicleType* vtype, bool idmm) :
38 : MSCFModel(vtype),
39 7886 : myIDMM(idmm),
40 7626 : myDelta(idmm ? 4.0 : vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDM_DELTA, 4.)),
41 7886 : myAdaptationFactor(idmm ? vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDMM_ADAPT_FACTOR, 1.8) : 1.0),
42 7886 : myAdaptationTime(idmm ? vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDMM_ADAPT_TIME, 600.0) : 0.0),
43 7886 : myIterations(MAX2(1, int(TS / vtype->getParameter().getCFParam(SUMO_ATTR_CF_IDM_STEPPING, .25) + .5))),
44 7886 : myTwoSqrtAccelDecel(double(2 * sqrt(myAccel * myDecel))) {
45 : // IDM does not drive very precise and may violate minGap on occasion
46 7886 : myCollisionMinGapFactor = vtype->getParameter().getCFParam(SUMO_ATTR_COLLISION_MINGAP_FACTOR, 0.1);
47 7886 : if (TS / myIterations > 0.25) {
48 24 : WRITE_WARNINGF("Stepping duration of % for % model in vType % is unsafe", (TS / myIterations), myIDMM ? "IDMM" : "IDM", vtype->getID());
49 : }
50 7886 : }
51 :
52 15612 : MSCFModel_IDM::~MSCFModel_IDM() {}
53 :
54 :
55 : double
56 66849753 : MSCFModel_IDM::minNextSpeed(double speed, const MSVehicle* const /*veh*/) const {
57 : // permit exceeding myDecel when approaching stops
58 133693822 : const double decel = MAX2(myDecel, MIN2(myEmergencyDecel, 1.5));
59 66849753 : if (MSGlobals::gSemiImplicitEulerUpdate) {
60 64400039 : return MAX2(speed - ACCEL2SPEED(decel), 0.);
61 : } else {
62 : // NOTE: ballistic update allows for negative speeds to indicate a stop within the next timestep
63 2449714 : return speed - ACCEL2SPEED(decel);
64 : }
65 : }
66 :
67 :
68 :
69 : double
70 33232266 : MSCFModel_IDM::finalizeSpeed(MSVehicle* const veh, double vPos) const {
71 33232266 : const double vNext = MSCFModel::finalizeSpeed(veh, vPos);
72 33232266 : if (myAdaptationFactor != 1.) {
73 : VehicleVariables* vars = (VehicleVariables*)veh->getCarFollowVariables();
74 3653034 : vars->levelOfService += (vNext / veh->getLane()->getVehicleMaxSpeed(veh) - vars->levelOfService) / myAdaptationTime * TS;
75 : }
76 33232266 : return vNext;
77 : }
78 :
79 :
80 : double
81 58230815 : MSCFModel_IDM::freeSpeed(const MSVehicle* const veh, double speed, double seen, double maxSpeed, const bool /*onInsertion*/, const CalcReason /*usage*/) const {
82 58230815 : if (maxSpeed < 0.) {
83 : // can occur for ballistic update (in context of driving at red light)
84 : return maxSpeed;
85 : }
86 58230815 : const double secGap = getSecureGap(veh, nullptr, maxSpeed, 0, myDecel);
87 : double vSafe;
88 58230815 : if (speed <= maxSpeed) {
89 : // accelerate
90 57396190 : vSafe = _v(veh, 1e6, speed, maxSpeed, veh->getLane()->getVehicleMaxSpeed(veh), false);
91 : } else {
92 : // decelerate
93 : // @note relax gap to avoid emergency braking
94 : // @note since the transition point does not move we set the leader speed to 0
95 1669250 : vSafe = _v(veh, MAX2(seen, secGap), speed, 0, veh->getLane()->getVehicleMaxSpeed(veh), false);
96 : }
97 58230815 : if (seen < secGap) {
98 : // avoid overshoot when close to change in speed limit
99 : vSafe = MIN2(vSafe, maxSpeed);
100 : }
101 : //std::cout << SIMTIME << " speed=" << speed << " maxSpeed=" << maxSpeed << " seen=" << seen << " secGap=" << secGap << " vSafe=" << vSafe << "\n";
102 : return vSafe;
103 : }
104 :
105 :
106 : double
107 214256464 : MSCFModel_IDM::followSpeed(const MSVehicle* const veh, double speed, double gap2pred, double predSpeed, double predMaxDecel, const MSVehicle* const pred, const CalcReason /*usage*/) const {
108 214256464 : applyHeadwayAndSpeedDifferencePerceptionErrors(veh, speed, gap2pred, predSpeed, predMaxDecel, pred);
109 214256464 : return _v(veh, gap2pred, speed, predSpeed, veh->getLane()->getVehicleMaxSpeed(veh));
110 : }
111 :
112 :
113 : double
114 1869744 : MSCFModel_IDM::insertionFollowSpeed(const MSVehicle* const v, double speed, double gap2pred, double predSpeed, double predMaxDecel, const MSVehicle* const pred) const {
115 : // see definition of s in _v()
116 1869744 : double s = MAX2(0., speed * myHeadwayTime + speed * (speed - predSpeed) / myTwoSqrtAccelDecel);
117 1869744 : if (gap2pred >= s) {
118 : // followSpeed always stays below speed because s*s / (gap2pred * gap2pred) > 0. This would prevent insertion with maximum speed at all distances
119 : return speed;
120 : } else {
121 : // we cannot call follow speed directly because it assumes that 'speed'
122 : // is the current speed rather than the desired insertion speed.
123 : // If the safe speed is much lower than the desired speed, the
124 : // followSpeed function would still return a new speed that involves
125 : // reasonable braking rather than the actual safe speed (and cause
126 : // emergency braking in a subsequent step)
127 1400027 : const double speed2 = followSpeed(v, speed, gap2pred, predSpeed, predMaxDecel, pred, CalcReason::FUTURE);
128 1400027 : const double speed3 = followSpeed(v, speed2, gap2pred, predSpeed, predMaxDecel, pred, CalcReason::FUTURE);
129 1400027 : if (speed2 - speed3 < ACCEL2SPEED(1)) {
130 : return speed2;
131 : } else {
132 : #ifdef DEBUG_INSERTION_SPEED
133 : 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";
134 : #endif
135 1233687 : return insertionFollowSpeed(v, speed2, gap2pred, predSpeed, predMaxDecel, pred);
136 : }
137 : }
138 : }
139 :
140 :
141 : double
142 4665 : MSCFModel_IDM::insertionStopSpeed(const MSVehicle* const veh, double speed, double gap) const {
143 : // we want to insert the vehicle in an equilibrium state
144 4665 : double result = MSCFModel::insertionStopSpeed(veh, speed, gap);
145 : int i = 0;
146 13986 : while (result - speed < -ACCEL2SPEED(myDecel) && ++i < 10) {
147 : speed = result;
148 9321 : result = MSCFModel::insertionStopSpeed(veh, speed, gap);
149 : }
150 4665 : return result;
151 : }
152 :
153 :
154 : double
155 73407944 : MSCFModel_IDM::stopSpeed(const MSVehicle* const veh, const double speed, double gap, double decel, const CalcReason /*usage*/) const {
156 73407944 : applyHeadwayPerceptionError(veh, speed, gap);
157 73407944 : if (gap < 0.01) {
158 : return 0;
159 : }
160 72876568 : double result = _v(veh, gap, speed, 0, veh->getLane()->getVehicleMaxSpeed(veh), false);
161 : //std::cout << SIMTIME << " stopSpeed speed=" << speed << " gap=" << gap << " decel=" << decel << " result=" << result << "\n";
162 72876568 : if (gap > 0 && speed < NUMERICAL_EPS && result < NUMERICAL_EPS) {
163 : // ensure that stops can be reached:
164 : //std::cout << " switching to krauss: " << veh->getID() << " gap=" << gap << " speed=" << speed << " res1=" << result << " res2=" << maximumSafeStopSpeed(gap, speed, false, veh->getActionStepLengthSecs())<< "\n";
165 18225 : result = maximumSafeStopSpeed(gap, decel, speed, false, veh->getActionStepLengthSecs());
166 : }
167 : // avoid overshooting the stop location
168 72876568 : if (gap >= 0) {
169 72876568 : result = MIN2(result, DIST2SPEED(gap));
170 : //if (result * TS > gap) {
171 : // std::cout << "Maximum stop speed exceeded for gap=" << gap << " result=" << result << " veh=" << veh->getID() << " speed=" << speed << " t=" << SIMTIME << "\n";
172 : //}
173 : }
174 :
175 : return result;
176 : }
177 :
178 :
179 : /// @todo update interactionGap logic to IDM
180 : double
181 0 : MSCFModel_IDM::interactionGap(const MSVehicle* const veh, double vL) const {
182 : // Resolve the IDM equation to gap. Assume predecessor has
183 : // speed != 0 and that vsafe will be the current speed plus acceleration,
184 : // i.e that with this gap there will be no interaction.
185 0 : const double acc = myAccel * (1. - pow(veh->getSpeed() / veh->getLane()->getVehicleMaxSpeed(veh), myDelta));
186 0 : const double vNext = veh->getSpeed() + acc;
187 0 : const double gap = (vNext - vL) * (veh->getSpeed() + vL) / (2 * myDecel) + vL;
188 :
189 : // Don't allow timeHeadWay < deltaT situations.
190 0 : return MAX2(gap, SPEED2DIST(vNext));
191 : }
192 :
193 : double
194 368675672 : MSCFModel_IDM::getSecureGap(const MSVehicle* const /*veh*/, const MSVehicle* const /*pred*/, const double speed, const double leaderSpeed, const double /*leaderMaxDecel*/) const {
195 368675672 : const double delta_v = speed - leaderSpeed;
196 368675672 : return MAX2(0.0, speed * myHeadwayTime + speed * delta_v / myTwoSqrtAccelDecel);
197 : }
198 :
199 :
200 : double
201 345363847 : MSCFModel_IDM::_v(const MSVehicle* const veh, const double gap2pred, const double egoSpeed,
202 : const double predSpeed, const double desSpeed, const bool respectMinGap) const {
203 : // this is more or less based on http://www.vwi.tu-dresden.de/~treiber/MicroApplet/IDM.html
204 : // and http://arxiv.org/abs/cond-mat/0304337
205 : // we assume however constant speed for the leader
206 345363847 : double headwayTime = myHeadwayTime;
207 345363847 : if (myAdaptationFactor != 1.) {
208 : const VehicleVariables* vars = (VehicleVariables*)veh->getCarFollowVariables();
209 42655249 : headwayTime *= myAdaptationFactor + vars->levelOfService * (1. - myAdaptationFactor);
210 : }
211 : double newSpeed = egoSpeed;
212 : double gap = gap2pred;
213 345363847 : if (respectMinGap) {
214 : // gap2pred comes with minGap already subtracted so we need to add it here again
215 214256464 : gap += myType->getMinGap();
216 : }
217 : #ifdef DEBUG_V
218 : if (DEBUG_COND) {
219 : std::cout << SIMTIME << " veh=" << veh->getID() << " gap2pred=" << gap2pred << " egoSpeed=" << egoSpeed << " predSpeed=" << predSpeed << " desSpeed=" << desSpeed << " rMG=" << respectMinGap << " hw=" << headwayTime << "\n";
220 : }
221 : #endif
222 1601436647 : for (int i = 0; i < myIterations; i++) {
223 1256072800 : const double delta_v = newSpeed - predSpeed;
224 1256072800 : double s = MAX2(0., newSpeed * headwayTime + newSpeed * delta_v / myTwoSqrtAccelDecel);
225 1256072800 : if (respectMinGap) {
226 776844329 : s += myType->getMinGap();
227 : }
228 : gap = MAX2(NUMERICAL_EPS, gap); // avoid singularity
229 1256072800 : const double acc = myAccel * (1. - pow(newSpeed / MAX2(NUMERICAL_EPS, desSpeed), myDelta) - (s * s) / (gap * gap));
230 : #ifdef DEBUG_V
231 : if (DEBUG_COND) {
232 : std::cout << " i=" << i << " gap=" << gap << " t=" << myHeadwayTime << " t2=" << headwayTime << " s=" << s << " pow=" << pow(newSpeed / desSpeed, myDelta) << " gapDecel=" << (s * s) / (gap * gap) << " a=" << acc;
233 : }
234 : #endif
235 1256072800 : newSpeed = MAX2(0.0, newSpeed + ACCEL2SPEED(acc) / myIterations);
236 : #ifdef DEBUG_V
237 : if (DEBUG_COND) {
238 : std::cout << " v2=" << newSpeed << " gLC=" << MSGlobals::gComputeLC << "\n";
239 : }
240 : #endif
241 : //TODO use more realistic position update which takes accelerated motion into account
242 2018142556 : gap -= MAX2(0., SPEED2DIST(newSpeed - predSpeed) / myIterations);
243 : }
244 345363847 : return MAX2(0., newSpeed);
245 : }
246 :
247 :
248 : MSCFModel*
249 0 : MSCFModel_IDM::duplicate(const MSVehicleType* vtype) const {
250 0 : return new MSCFModel_IDM(vtype, myIDMM);
251 : }
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