Files
ParkingRobot/ClumsyPilot/ParkrobTrajplanner/EMPlanner/Segmentation/ReferenceHorizonSlicer.cs
T

106 lines
4.5 KiB
C#

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using MultiWheelC.TrajectoryPlanning.PathSmoothing;
using MultiWheelC.TrajectoryPlanning.Utils;
namespace MultiWheelC.TrajectoryPlanning.EMPlanner;
public sealed class ReferenceHorizonSlice
{
public ReferenceHorizonSlice(DirectionSegmentView segment, IReadOnlyList<SmoothedPathPoint> points,
ReferenceBoundary terminalBoundary)
{
if (segment == null)
throw new ArgumentNullException(nameof(segment));
if (points == null || points.Count == 0)
throw new ArgumentException("A horizon slice requires points.", nameof(points));
if (terminalBoundary == null || terminalBoundary.SegmentIndex != segment.SegmentIndex)
throw new ArgumentException("A matching terminal boundary is required.", nameof(terminalBoundary));
var copy = new List<SmoothedPathPoint>(points.Count);
for (int index = 0; index < points.Count; index++) copy.Add(points[index]);
Segment = segment;
Points = new ReadOnlyCollection<SmoothedPathPoint>(copy);
TerminalBoundary = terminalBoundary;
}
public DirectionSegmentView Segment { get; }
public IReadOnlyList<SmoothedPathPoint> Points { get; }
public ReferenceBoundary TerminalBoundary { get; }
}
public static class ReferenceHorizonSlicer
{
private const double Epsilon = 1e-12d;
public static ReferenceHorizonSlice Slice(DirectionSegmentView segment, double requestedEndSegmentLocalS)
{
if (segment == null)
throw new ArgumentNullException(nameof(segment));
if (double.IsNaN(requestedEndSegmentLocalS) || double.IsInfinity(requestedEndSegmentLocalS) || requestedEndSegmentLocalS < 0d)
throw new ArgumentOutOfRangeException(nameof(requestedEndSegmentLocalS));
double terminalS = Math.Min(requestedEndSegmentLocalS, segment.LengthMeters);
var points = new List<SmoothedPathPoint>();
for (int index = 0; index < segment.Points.Count; index++)
{
SmoothedPathPoint point = segment.Points[index];
if (point.ArcLength < terminalS - Epsilon)
points.Add(point);
}
points.Add(GetExactTerminalPoint(segment, terminalS));
ReferenceBoundary terminal = terminalS >= segment.LengthMeters - Epsilon
? segment.EndBoundary
: new ReferenceBoundary(segment.SegmentIndex, terminalS, EmBoundaryType.RollingSafetyStop,
segment.SourceStartArcLength + terminalS);
return new ReferenceHorizonSlice(segment, points, terminal);
}
private static SmoothedPathPoint GetExactTerminalPoint(DirectionSegmentView segment, double terminalS)
{
for (int index = 0; index < segment.Points.Count; index++)
{
SmoothedPathPoint point = segment.Points[index];
if (Math.Abs(point.ArcLength - terminalS) <= Epsilon)
return point;
if (point.ArcLength > terminalS)
{
SmoothedPathPoint previous = segment.Points[index - 1];
return Interpolate(previous, point, terminalS);
}
}
return segment.Points[segment.Points.Count - 1];
}
private static SmoothedPathPoint Interpolate(SmoothedPathPoint lower, SmoothedPathPoint upper, double localS)
{
double interval = upper.ArcLength - lower.ArcLength;
if (interval <= 0d)
throw new ArgumentException("Reference points do not bracket a positive interval.");
double fraction = (localS - lower.ArcLength) / interval;
double unwrappedHeading = lower.UnwrappedHeading + (upper.UnwrappedHeading - lower.UnwrappedHeading) * fraction;
return new SmoothedPathPoint(
Interpolate(lower.X, upper.X, fraction),
Interpolate(lower.Y, upper.Y, fraction),
AngleMath.NormalizeRadians(unwrappedHeading),
unwrappedHeading,
localS,
lower.Direction,
Interpolate(lower.GeometricCurvature, upper.GeometricCurvature, fraction),
Interpolate(lower.VehicleCurvature, upper.VehicleCurvature, fraction),
Interpolate(lower.VehicleCurvatureDerivative, upper.VehicleCurvatureDerivative, fraction),
Interpolate(lower.BodyClearance, upper.BodyClearance, fraction),
false,
SmoothedPathPointSource.Interpolated);
}
private static double Interpolate(double lower, double upper, double fraction)
{
return lower + (upper - lower) * fraction;
}
}