1 package org.opentrafficsim.road.network.speed;
2
3 import java.io.Serializable;
4
5 import org.djunits.unit.SpeedUnit;
6 import org.djunits.value.vdouble.scalar.Acceleration;
7 import org.djunits.value.vdouble.scalar.Length;
8 import org.djunits.value.vdouble.scalar.Speed;
9 import org.djutils.exceptions.Throw;
10
11 /**
12 * Class with curvature info for curvature speed limit type.
13 * <p>
14 * Copyright (c) 2013-2022 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
15 * BSD-style license. See <a href="http://opentrafficsim.org/docs/current/license.html">OpenTrafficSim License</a>.
16 * <p>
17 * @version $Revision$, $LastChangedDate$, by $Author$, initial version Apr 30, 2016 <br>
18 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
19 * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
20 */
21 public class SpeedInfoCurvature implements Serializable
22 {
23
24 /** */
25 private static final long serialVersionUID = 20160501L;
26
27 /** Curvature radius. */
28 private final Length radius;
29
30 /**
31 * Constructor with curvature radius.
32 * @param radius Length; curvature radius
33 * @throws NullPointerException if radius is null
34 */
35 public SpeedInfoCurvature(final Length radius)
36 {
37 Throw.whenNull(radius, "Radius may not be null.");
38 this.radius = radius;
39 }
40
41 /**
42 * Returns the curvature radius.
43 * @return curvature radius
44 */
45 public final Length getRadius()
46 {
47 return this.radius;
48 }
49
50 /**
51 * Returns the speed for which the current lateral acceleration follows in the corner.
52 * @param acceleration Acceleration; acceleration to result from speed in corner
53 * @return speed for which the current lateral acceleration follows in the corner
54 * @throws NullPointerException if acceleration is null
55 */
56 public final Speed getSpeedForLateralAcceleration(final Acceleration acceleration)
57 {
58 Throw.whenNull(acceleration, "Acceleration may not be null.");
59 // a=v*v/r => v=sqrt(a*r)
60 return new Speed(Math.sqrt(acceleration.si * this.radius.si), SpeedUnit.SI);
61 }
62
63 /** {@inheritDoc} */
64 @Override
65 public final int hashCode()
66 {
67 return this.radius.hashCode();
68 }
69
70 /** {@inheritDoc} */
71 @Override
72 public final boolean equals(final Object obj)
73 {
74 if (this == obj)
75 {
76 return true;
77 }
78 if (obj == null)
79 {
80 return false;
81 }
82 if (getClass() != obj.getClass())
83 {
84 return false;
85 }
86 SpeedInfoCurvature other = (SpeedInfoCurvature) obj;
87 if (!this.radius.equals(other.radius))
88 {
89 return false;
90 }
91 return true;
92 }
93
94 /** {@inheritDoc} */
95 @Override
96 public final String toString()
97 {
98 return "SpeedInfoCurvature [radius=" + this.radius + "]";
99 }
100
101 }