1 package org.opentrafficsim.road.network.speed;
2
3 import org.djunits.unit.SpeedUnit;
4 import org.djunits.value.vdouble.scalar.Acceleration;
5 import org.djunits.value.vdouble.scalar.Length;
6 import org.djunits.value.vdouble.scalar.Speed;
7 import org.djutils.exceptions.Throw;
8
9 /**
10 * Class with curvature info for curvature speed limit type.
11 * <p>
12 * Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
13 * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
14 * </p>
15 * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
16 * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
17 * @param radius curvature radius
18 */
19 public record SpeedInfoCurvature(Length radius)
20 {
21
22 /**
23 * Constructor with curvature radius.
24 * @param radius curvature radius
25 * @throws NullPointerException if radius is null
26 */
27 public SpeedInfoCurvature
28 {
29 Throw.whenNull(radius, "Radius may not be null.");
30 }
31
32 /**
33 * Returns the speed for which the current lateral acceleration follows in the corner.
34 * @param acceleration acceleration to result from speed in corner
35 * @return speed for which the current lateral acceleration follows in the corner
36 * @throws NullPointerException if acceleration is null
37 */
38 public final Speed getSpeedForLateralAcceleration(final Acceleration acceleration)
39 {
40 Throw.whenNull(acceleration, "Acceleration may not be null.");
41 // a=v*v/r => v=sqrt(a*r)
42 return new Speed(Math.sqrt(acceleration.si * this.radius.si), SpeedUnit.SI);
43 }
44
45 }