1 package org.opentrafficsim.road.gtu.lane.tactical.following;
2
3 import java.io.Serializable;
4 import java.util.SortedMap;
5
6 import org.djunits.unit.AccelerationUnit;
7 import org.djunits.unit.LengthUnit;
8 import org.djunits.unit.SpeedUnit;
9 import org.djunits.unit.TimeUnit;
10 import org.djunits.value.vdouble.scalar.Acceleration;
11 import org.djunits.value.vdouble.scalar.Duration;
12 import org.djunits.value.vdouble.scalar.Length;
13 import org.djunits.value.vdouble.scalar.Speed;
14 import org.opentrafficsim.core.gtu.behavioralcharacteristics.BehavioralCharacteristics;
15 import org.opentrafficsim.core.gtu.behavioralcharacteristics.ParameterException;
16 import org.opentrafficsim.road.network.speed.SpeedLimitInfo;
17
18
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29
30
31 public class IDMPlusOld extends AbstractGTUFollowingModelMobil implements Serializable
32 {
33
34 private static final long serialVersionUID = 20140704L;
35
36
37 private final Length s0;
38
39
40 private final Acceleration a;
41
42
43 private final Acceleration b;
44
45
46 private final Duration tSafe;
47
48
49
50
51
52 private final double delta;
53
54
55
56
57
58 private final Duration stepSize = new Duration(0.5, TimeUnit.SECOND);
59
60
61
62
63
64
65
66 public IDMPlusOld()
67 {
68 this.a = new Acceleration(1.56, AccelerationUnit.METER_PER_SECOND_2);
69 this.b = new Acceleration(2.09, AccelerationUnit.METER_PER_SECOND_2);
70 this.s0 = new Length(3, LengthUnit.METER);
71 this.tSafe = new Duration(1.2, TimeUnit.SECOND);
72 this.delta = 1d;
73 }
74
75
76
77
78
79
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81
82
83
84 public IDMPlusOld(final Acceleration a, final Acceleration b, final Length s0, final Duration tSafe,
85 final double delta)
86 {
87 this.a = a;
88 this.b = b;
89 this.s0 = s0;
90 this.tSafe = tSafe;
91 this.delta = delta;
92 }
93
94
95
96
97
98
99
100 private Speed vDes(final Speed speedLimit, final Speed followerMaximumSpeed)
101 {
102 return new Speed(Math.min(this.delta * speedLimit.getSI(), followerMaximumSpeed.getSI()), SpeedUnit.SI);
103 }
104
105
106 public final Acceleration computeAcceleration(final Speed followerSpeed, final Speed followerMaximumSpeed,
107 final Speed leaderSpeed, final Length headway, final Speed speedLimit)
108 {
109 return computeAcceleration(followerSpeed, followerMaximumSpeed, leaderSpeed, headway, speedLimit, this.stepSize);
110 }
111
112
113 public final Acceleration computeAcceleration(final Speed followerSpeed, final Speed followerMaximumSpeed,
114 final Speed leaderSpeed, final Length headway, final Speed speedLimit, final Duration stepSize)
115 {
116
117 double leftComponent = 1 - Math.pow(followerSpeed.getSI() / vDes(speedLimit, followerMaximumSpeed).getSI(), 4);
118 if (Double.isNaN(leftComponent))
119 {
120 leftComponent = 0;
121 }
122
123 if (leftComponent * this.a.si < -0.5)
124 {
125 leftComponent = -0.5 / this.a.si;
126 }
127 Acceleration logWeightedAccelerationTimes2 =
128 new Acceleration(Math.sqrt(this.a.getSI() * this.b.getSI()), AccelerationUnit.SI).multiplyBy(2);
129
130
131 Speed dV = followerSpeed.minus(leaderSpeed);
132 Length sStar =
133 this.s0.plus(followerSpeed.multiplyBy(this.tSafe)).plus(
134 dV.multiplyBy(followerSpeed.divideBy(logWeightedAccelerationTimes2)));
135
136
137
138
139
140 if (sStar.getSI() < 0)
141 {
142
143
144 sStar = new Length(0, LengthUnit.SI);
145 }
146
147 double rightComponent = 1 - Math.pow(sStar.getSI() / headway.getSI(), 2);
148 Acceleration newAcceleration = new Acceleration(this.a).multiplyBy(Math.min(leftComponent, rightComponent));
149 if (newAcceleration.getSI() * stepSize.getSI() + followerSpeed.getSI() < 0)
150 {
151 newAcceleration = new Acceleration(-followerSpeed.getSI() / stepSize.getSI(), AccelerationUnit.SI);
152 }
153 return newAcceleration;
154 }
155
156
157 @Override
158 public final Duration getStepSize()
159 {
160 return this.stepSize;
161 }
162
163
164 @Override
165 public final Acceleration getMaximumSafeDeceleration()
166 {
167 return this.b;
168 }
169
170
171 @Override
172 public final String getName()
173 {
174 return "IDM+";
175 }
176
177
178 @Override
179 public final String getLongName()
180 {
181 return String.format("%s (a=%.1fm/s\u00b2, b=%.1fm/s\u00b2, s0=%.1fm, tSafe=%.1fs, delta=%.2f)", getName(), this.a
182 .getSI(), this.b.getSI(), this.s0.getSI(), this.tSafe.getSI(), this.delta);
183 }
184
185
186
187
188 @Override
189 public final Speed desiredSpeed(final BehavioralCharacteristics behavioralCharacteristics, final SpeedLimitInfo speedInfo)
190 throws ParameterException
191 {
192 return null;
193 }
194
195
196 @Override
197 public final Length desiredHeadway(final BehavioralCharacteristics behavioralCharacteristics, final Speed speed)
198 throws ParameterException
199 {
200 return null;
201 }
202
203
204 @Override
205 public final Acceleration followingAcceleration(final BehavioralCharacteristics behavioralCharacteristics,
206 final Speed speed, final SpeedLimitInfo speedInfo, final SortedMap<Length, Speed> leaders) throws ParameterException
207 {
208 return null;
209 }
210
211
212 @Override
213 public final String toString()
214 {
215 return "IDMPlusOld [s0=" + this.s0 + ", a=" + this.a + ", b=" + this.b + ", tSafe=" + this.tSafe + ", delta="
216 + this.delta + ", stepSize=" + this.stepSize + "]";
217 }
218
219 }