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) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
15 * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
16 * </p>
17 * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
18 * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
19 * @param radius Length; curvature radius
20 */
21 public record SpeedInfoCurvature(Length radius) implements Serializable
22 {
23
24 /** */
25 private static final long serialVersionUID = 20160501L;
26
27 /**
28 * Constructor with curvature radius.
29 * @param radius Length; curvature radius
30 * @throws NullPointerException if radius is null
31 */
32 public SpeedInfoCurvature
33 {
34 Throw.whenNull(radius, "Radius may not be null.");
35 }
36
37 /**
38 * Returns the speed for which the current lateral acceleration follows in the corner.
39 * @param acceleration Acceleration; acceleration to result from speed in corner
40 * @return speed for which the current lateral acceleration follows in the corner
41 * @throws NullPointerException if acceleration is null
42 */
43 public final Speed getSpeedForLateralAcceleration(final Acceleration acceleration)
44 {
45 Throw.whenNull(acceleration, "Acceleration may not be null.");
46 // a=v*v/r => v=sqrt(a*r)
47 return new Speed(Math.sqrt(acceleration.si * this.radius.si), SpeedUnit.SI);
48 }
49
50 }