diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs
index 671f3ca..cd45f80 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransition.cs
@@ -6,6 +6,16 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 /// <summary>同一方向原语边界两侧车辆曲率的离散跳变。</summary>
 internal sealed class CurvatureTransition
 {
+    /// <summary>记录同一方向段内相邻粗路径采样点之间的车辆曲率跳变。</summary>
+    /// <param name="segmentIndex">所属方向段在预处理路径中的从零开始索引。</param>
+    /// <param name="leftCoarsePathIndex">跳变左侧粗路径采样点索引。</param>
+    /// <param name="rightCoarsePathIndex">跳变右侧粗路径采样点索引，必须等于左索引加一。</param>
+    /// <param name="localArcLengthMeters">跳变位置在方向段内的局部弧长，单位 m。</param>
+    /// <param name="x">跳变位置世界 X 坐标，单位 m。</param>
+    /// <param name="y">跳变位置世界 Y 坐标，单位 m。</param>
+    /// <param name="vehicleHeadingRadians">跳变位置的车辆航向，单位 rad。</param>
+    /// <param name="leftVehicleCurvaturePerMeter">左侧车辆曲率，单位 1/m。</param>
+    /// <param name="rightVehicleCurvaturePerMeter">右侧车辆曲率，单位 1/m。</param>
     internal CurvatureTransition(
         int segmentIndex,
         int leftCoarsePathIndex,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs
index 54d95ba..2cd7b4c 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/CurvatureTransitionDetector.cs
@@ -9,6 +9,13 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 /// <summary>从原始粗路径的同向相邻点中识别恒曲率原语边界。</summary>
 internal sealed class CurvatureTransitionDetector
 {
+    /// <summary>检测同一行驶方向内超过阈值的相邻车辆曲率跳变，不跨越换向边界。</summary>
+    /// <param name="request">含粗路径、方向段和配置的平滑请求。</param>
+    /// <param name="maximumVehicleCurvaturePerMeter">车辆允许的最大曲率，单位 1/m。</param>
+    /// <param name="options">已校验的跳变绝对阈值与相对阈值选项。</param>
+    /// <param name="transitions">成功时为只读曲率跳变集合；失败时为空集合。</param>
+    /// <param name="reason">失败原因；成功时为空字符串。</param>
+    /// <returns>输入与检测过程有效时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     internal bool TryDetect(
         PathSmoothingRequest request,
         double maximumVehicleCurvaturePerMeter,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateBuilder.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateBuilder.cs
index fdf7756..2f8c0ab 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateBuilder.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateBuilder.cs
@@ -18,6 +18,13 @@ internal sealed class LocalG2CandidateBuilder
     private const int MaximumSubdivisionDepth = 32;
     private static readonly double[] DerivativeScaleMultipliers = { 1d, 0.85d, 1.15d };
 
+    /// <summary>按确定的窗口与导数尺度顺序生成有限个五次 Hermite 局部 G2 候选。</summary>
+    /// <param name="originalSegment">候选所属、未经替换的单方向预处理段。</param>
+    /// <param name="region">包含曲率跳变和可用窗口变体的局部平滑区域。</param>
+    /// <param name="outputSpacingMeters">候选采样间距，单位 m，必须为正且有限。</param>
+    /// <param name="options">已校验的局部 G2 窗口、偏差和候选数限制。</param>
+    /// <param name="cancellationToken">取消令牌；取消时抛出 <see cref="OperationCanceledException"/>。</param>
+    /// <returns>只读的候选几何集合；没有可构造候选时返回空集合而非 <see langword="null"/>。</returns>
     internal IReadOnlyList<LocalG2CandidateGeometry> Build(
         PreparedDirectionSegment originalSegment,
         LocalG2SmoothingRegion region,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateGeometry.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateGeometry.cs
index 22161f7..11495a2 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateGeometry.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2CandidateGeometry.cs
@@ -9,6 +9,19 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 /// <summary>一个尚未经过安全和质量评价的局部 G2 替换几何。</summary>
 internal sealed class LocalG2CandidateGeometry
 {
+    /// <summary>创建尚未通过安全与质量门的局部 G2 候选几何快照。</summary>
+    /// <param name="candidateIndex">区域内候选的稳定从零开始索引。</param>
+    /// <param name="segmentIndex">候选所属方向段索引。</param>
+    /// <param name="startArcLengthMeters">替换窗口起点弧长，单位 m。</param>
+    /// <param name="endArcLengthMeters">替换窗口终点弧长，单位 m。</param>
+    /// <param name="leftWindowLengthMeters">过渡点左侧窗口长度，单位 m。</param>
+    /// <param name="rightWindowLengthMeters">过渡点右侧窗口长度，单位 m。</param>
+    /// <param name="regionPoints">含精确边界端点的候选采样点只读集合。</param>
+    /// <param name="startVehicleCurvaturePerMeter">窗口起点车辆曲率，单位 1/m。</param>
+    /// <param name="endVehicleCurvaturePerMeter">窗口终点车辆曲率，单位 1/m。</param>
+    /// <param name="startGeometricCurvaturePerMeter">窗口起点几何曲率，单位 1/m。</param>
+    /// <param name="endGeometricCurvaturePerMeter">窗口终点几何曲率，单位 1/m。</param>
+    /// <param name="internalConnectionsAreG2">候选内部连接是否满足 G2 连续性。</param>
     internal LocalG2CandidateGeometry(
         int candidateIndex,
         int segmentIndex,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2OptionsSnapshot.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2OptionsSnapshot.cs
index 3fddd10..b816723 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2OptionsSnapshot.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2OptionsSnapshot.cs
@@ -6,6 +6,8 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 /// <summary>局部 G2 预平滑一次运行使用的已校验不可变选项。</summary>
 internal sealed class LocalG2OptionsSnapshot
 {
+    /// <summary>从已配置的请求选项提取并校验一次局部 G2 平滑运行所需的不可变阈值。</summary>
+    /// <param name="configuration">包含 <see cref="LocalG2QuinticOptions"/> 的路径平滑配置。</param>
     internal LocalG2OptionsSnapshot(PathSmoothingConfiguration configuration)
     {
         if (configuration == null) throw new ArgumentNullException(nameof(configuration));
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2PathSplicer.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2PathSplicer.cs
index 294efe0..31d5704 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2PathSplicer.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2PathSplicer.cs
@@ -5,9 +5,15 @@ using MultiWheelC.TrajectoryPlanning.Utils;
 
 namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 
-/// <summary>只替换一个方向段内局部窗口，并保持其余方向拓扑不变。</summary>
+/// <summary>将已验证的局部候选替换进同方向预处理路径；保持窗口外点、端点和换向拓扑不变。</summary>
 internal sealed class LocalG2PathSplicer
 {
+    /// <summary>用候选窗口点替换目标方向段的局部弧长区间。</summary>
+    /// <param name="currentPath">当前已接受替换的预处理路径。</param>
+    /// <param name="candidate">候选替换几何；位置和局部弧长单位为 m。</param>
+    /// <param name="replacedPath">成功时为保持其他段与边界不变的新预处理路径；失败时为 <see langword="null"/>。</param>
+    /// <param name="reason">失败原因；成功时为空字符串。</param>
+    /// <returns>替换范围、端点和方向拓扑均合法时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     internal bool TryReplace(
         PreparedPath currentPath,
         LocalG2CandidateGeometry candidate,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2SmoothingRegion.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2SmoothingRegion.cs
index e2e102a..cb59af2 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2SmoothingRegion.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2SmoothingRegion.cs
@@ -8,6 +8,12 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 /// <summary>一个局部 G2 候选可替换的弧长窗口。</summary>
 internal sealed class LocalG2WindowVariant
 {
+    /// <summary>创建同一平滑区域内一个可尝试替换的弧长窗口变体。</summary>
+    /// <param name="candidateIndex">区域内候选的稳定从零开始索引。</param>
+    /// <param name="startArcLengthMeters">窗口起点弧长，单位 m。</param>
+    /// <param name="endArcLengthMeters">窗口终点弧长，单位 m。</param>
+    /// <param name="leftWindowLengthMeters">过渡点左侧窗口长度，单位 m。</param>
+    /// <param name="rightWindowLengthMeters">过渡点右侧窗口长度，单位 m。</param>
     internal LocalG2WindowVariant(int candidateIndex, double startArcLengthMeters, double endArcLengthMeters,
         double leftWindowLengthMeters, double rightWindowLengthMeters)
     {
@@ -33,6 +39,12 @@ internal sealed class LocalG2WindowVariant
 /// <summary>至少存在一个联合合法生成窗口变体的一组曲率过渡。</summary>
 internal sealed class LocalG2SmoothingRegion
 {
+    /// <summary>创建一个包含共同可用窗口变体的局部曲率过渡区域。</summary>
+    /// <param name="segmentIndex">所属方向段在预处理路径中的从零开始索引。</param>
+    /// <param name="transitions">归并到该区域的曲率跳变集合。</param>
+    /// <param name="maximumStartArcLengthMeters">所有候选允许的最晚窗口起点，单位 m。</param>
+    /// <param name="maximumEndArcLengthMeters">所有候选允许的最早窗口终点，单位 m。</param>
+    /// <param name="windowVariants">至少一个合法的窗口变体集合。</param>
     internal LocalG2SmoothingRegion(
         int segmentIndex,
         IReadOnlyList<CurvatureTransition> transitions,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2WindowPlanner.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2WindowPlanner.cs
index 6b351e0..813e584 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2WindowPlanner.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2WindowPlanner.cs
@@ -7,11 +7,18 @@ using MultiWheelC.TrajectoryPlanning.Utils;
 
 namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 
-/// <summary>按硬方向边界生成并合并局部 G2 曲率事件的候选窗口。</summary>
+/// <summary>在硬方向边界内为局部 G2 曲率事件生成、合并候选窗口；绝不让窗口跨越换向段。</summary>
 internal sealed class LocalG2WindowPlanner
 {
     private const double MergeToleranceMeters = 1e-9d;
 
+    /// <summary>按段索引排序曲率事件并生成每个区域可用的窗口变体。</summary>
+    /// <param name="originalPath">已准备的方向段路径，提供每段局部弧长范围。</param>
+    /// <param name="transitions">检测到的曲率过渡事件；局部弧长单位为 m。</param>
+    /// <param name="options">窗口长度、候选上限和偏移相关的 Local G2 只读选项。</param>
+    /// <param name="regions">成功时为按路径顺序排列的只读平滑区域；失败时为空集合。</param>
+    /// <param name="reason">失败时描述事件、段或窗口长度问题；成功时为空字符串。</param>
+    /// <returns>所有事件可在所属方向段内构造合法窗口时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     internal bool TryPlan(
         PreparedPath originalPath,
         IReadOnlyList<CurvatureTransition> transitions,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/QuinticHermiteCurve2D.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/QuinticHermiteCurve2D.cs
index 006189f..19503bf 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/QuinticHermiteCurve2D.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/QuinticHermiteCurve2D.cs
@@ -36,6 +36,22 @@ internal sealed class QuinticHermiteCurve2D
         _y5 = y5;
     }
 
+    /// <summary>从两个端点的位置、一阶导数和二阶导数创建参数区间 [0, 1] 上的五次 Hermite 曲线。</summary>
+    /// <param name="x0">起点 X 坐标，单位 m。</param>
+    /// <param name="y0">起点 Y 坐标，单位 m。</param>
+    /// <param name="dx0">起点对参数的 X 一阶导数。</param>
+    /// <param name="dy0">起点对参数的 Y 一阶导数。</param>
+    /// <param name="ddx0">起点对参数的 X 二阶导数。</param>
+    /// <param name="ddy0">起点对参数的 Y 二阶导数。</param>
+    /// <param name="x1">终点 X 坐标，单位 m。</param>
+    /// <param name="y1">终点 Y 坐标，单位 m。</param>
+    /// <param name="dx1">终点对参数的 X 一阶导数。</param>
+    /// <param name="dy1">终点对参数的 Y 一阶导数。</param>
+    /// <param name="ddx1">终点对参数的 X 二阶导数。</param>
+    /// <param name="ddy1">终点对参数的 Y 二阶导数。</param>
+    /// <param name="curve">成功时为可求值曲线；失败时为 <see langword="null"/>。</param>
+    /// <param name="reason">失败原因；成功时为空字符串。</param>
+    /// <returns>全部边界条件有限且一阶导数非零时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     internal static bool TryCreate(
         double x0, double y0, double dx0, double dy0, double ddx0, double ddy0,
         double x1, double y1, double dx1, double dy1, double ddx1, double ddy1,
@@ -69,6 +85,14 @@ internal sealed class QuinticHermiteCurve2D
         return true;
     }
 
+    /// <summary>在归一化参数处求曲线位置及其一阶、二阶导数。</summary>
+    /// <param name="u">闭区间 [0, 1] 内的无量纲曲线参数。</param>
+    /// <param name="x">返回位置 X，单位 m。</param>
+    /// <param name="y">返回位置 Y，单位 m。</param>
+    /// <param name="dx">返回 X 对参数的一阶导数。</param>
+    /// <param name="dy">返回 Y 对参数的一阶导数。</param>
+    /// <param name="ddx">返回 X 对参数的二阶导数。</param>
+    /// <param name="ddy">返回 Y 对参数的二阶导数。</param>
     internal void Evaluate(
         double u,
         out double x, out double y,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/ArcLengthResampler.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/ArcLengthResampler.cs
index 1205368..a918758 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/ArcLengthResampler.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/ArcLengthResampler.cs
@@ -11,7 +11,12 @@ public sealed class ArcLengthResampler
 {
     private const double Tolerance = 1e-10d;
 
-    /// <summary>以目标间距重采样一个方向段；段末锚点始终原样保留。</summary>
+    /// <summary>以目标间距重采样单一方向段；段首/段末精确锚点始终原样保留。</summary>
+    /// <param name="points">同一方向段内按严格递增局部弧长排序的点集合；位置和弧长单位为 m，航向为 rad。</param>
+    /// <param name="spacingMeters">目标采样间距，单位 m，必须为有限正数。</param>
+    /// <param name="resampled">成功时为只读重采样点集合；失败时为空只读集合。</param>
+    /// <param name="reason">失败时描述非法点、退化几何或间距；成功时为空字符串。</param>
+    /// <returns>输入属于一个有效同方向区间且可安全插值时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     public bool TryResample(
         IReadOnlyList<SmoothingPoint2D> points,
         double spacingMeters,
@@ -89,7 +94,12 @@ public sealed class ArcLengthResampler
         return true;
     }
 
-    /// <summary>重采样一个完整方向段并保留其换向拓扑标记。</summary>
+    /// <summary>重采样完整预处理方向段并保留段编号、方向和换向拓扑标记。</summary>
+    /// <param name="segment">待重采样的单一前进或倒车方向段。</param>
+    /// <param name="spacingMeters">目标局部弧长间距，单位 m。</param>
+    /// <param name="resampled">成功时为新不可变预处理方向段；失败时为 <see langword="null"/>。</param>
+    /// <param name="reason">失败原因；成功时为空字符串。</param>
+    /// <returns>底层点集重采样成功时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     public bool TryResample(
         PreparedDirectionSegment segment,
         double spacingMeters,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalysis.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalysis.cs
index 4736eca..75919be 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalysis.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalysis.cs
@@ -8,6 +8,16 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.Processing;
 /// <summary>同一几何分析器产生的路径、方向段和未验证质量统计。</summary>
 public sealed class PathGeometryAnalysis
 {
+    /// <summary>创建一次几何重算的只读结果快照。</summary>
+    /// <param name="path">重算后的完整路径点集合。</param>
+    /// <param name="segments">完整覆盖 <paramref name="path"/> 的方向段集合。</param>
+    /// <param name="pathLengthMeters">路径总弧长，单位 m。</param>
+    /// <param name="maximumAbsoluteVehicleCurvaturePerMeter">车辆曲率绝对值峰值，单位 1/m。</param>
+    /// <param name="maximumAbsoluteVehicleCurvatureDerivativePerSquareMeter">车辆曲率导数绝对值峰值，单位 1/m²。</param>
+    /// <param name="rootMeanSquareVehicleCurvaturePerMeter">车辆曲率均方根，单位 1/m。</param>
+    /// <param name="totalAbsoluteCurvatureVariationPerMeter">不跨换向点的累计绝对曲率变化，单位 1/m。</param>
+    /// <param name="curvatureVariationEnergy">不跨换向点的曲率变化代价。</param>
+    /// <param name="minimumBodyClearanceMeters">输入点携带的最小保守车体净空，单位 m。</param>
     internal PathGeometryAnalysis(
         IReadOnlyList<SmoothedPathPoint> path,
         IReadOnlyList<SmoothedPathSegment> segments,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalyzer.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalyzer.cs
index 6153af8..5d51fd0 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalyzer.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathGeometryAnalyzer.cs
@@ -12,9 +12,12 @@ public sealed class PathGeometryAnalyzer
     private const double MinimumDistanceMeters = 1e-10d;
     private const double BoundaryToleranceMeters = 1e-8d;
 
-    /// <summary>
-    /// 对候选方向段进行确定性几何分析。换向点两侧永不参与同一次差分。
-    /// </summary>
+    /// <summary>对候选方向段执行确定性几何分析；换向点两侧永不参与同一次航向或曲率差分。</summary>
+    /// <param name="candidateSegments">按段索引排列的候选前进/倒车段；每段点位置为 m、航向为 rad。</param>
+    /// <param name="spacingMeters">最终几何采样间距，单位 m，必须为有限正数。</param>
+    /// <param name="analysis">成功时为完整路径、方向段、弧长、曲率、曲率导数和净空统计；失败时为 <see langword="null"/>。</param>
+    /// <param name="reason">失败时描述输入、边界、退化几何或曲率估计问题；成功时为空字符串。</param>
+    /// <returns>所有方向段和换向拓扑可重采样、可分析且总弧长保持严格递增时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     public bool TryAnalyze(
         IReadOnlyList<PreparedDirectionSegment> candidateSegments,
         double spacingMeters,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathReferenceInterpolator.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathReferenceInterpolator.cs
index f8cf80b..535ea44 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathReferenceInterpolator.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathReferenceInterpolator.cs
@@ -8,6 +8,12 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.Processing;
 /// <summary>按方向段局部弧长插值平滑算法的原始路径参考。</summary>
 internal static class PathReferenceInterpolator
 {
+    /// <summary>在同一方向段内按局部弧长线性插值一个几何参考点。</summary>
+    /// <param name="points">弧长非递减的原始段采样点集合。</param>
+    /// <param name="targetArcLength">欲查询的局部弧长，单位 m。</param>
+    /// <param name="reference">成功时为插值或精确命中的参考点；失败时为 <see langword="null"/>。</param>
+    /// <param name="reason">失败原因；成功时为空字符串。</param>
+    /// <returns>目标弧长位于有效输入范围内时为 <see langword="true"/>；否则为 <see langword="false"/>。</returns>
     internal static bool TryInterpolateByArcLength(
         IReadOnlyList<SmoothingPoint2D> points,
         double targetArcLength,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathSmoothingPreprocessor.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathSmoothingPreprocessor.cs
index 23aaa63..f3474b0 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathSmoothingPreprocessor.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PathSmoothingPreprocessor.cs
@@ -18,13 +18,18 @@ public sealed class PathSmoothingPreprocessor
     {
     }
 
-    /// <summary>创建使用指定重采样器的预处理器。</summary>
+    /// <summary>创建使用指定确定性弧长重采样器的预处理器。</summary>
+    /// <param name="resampler">同一方向段内按 m 为单位弧长重采样的组件，不能为 <see langword="null"/>。</param>
     public PathSmoothingPreprocessor(ArcLengthResampler resampler)
     {
         _resampler = resampler ?? throw new ArgumentNullException(nameof(resampler));
     }
 
-    /// <summary>将一条粗路径请求校验、按方向拆分并按配置间距重采样。</summary>
+    /// <summary>校验粗路径契约、保留换向拓扑，并按配置间距拆分和重采样方向段。</summary>
+    /// <param name="request">不可变平滑请求；粗路径位置/弧长单位为 m、航向为 rad，且必须携带地图、车辆和配置。</param>
+    /// <param name="preparedPath">成功时为包含只读、同方向严格递增弧长段的预处理路径；失败时为 <see langword="null"/>。</param>
+    /// <param name="reason">失败时说明输入、拓扑或采样间距约束；成功时为空字符串。</param>
+    /// <returns>所有输入、方向分段、换向锚点和重采样检查通过时为 <see langword="true"/>；否则为 <see langword="false"/> 且不产生部分路径。</returns>
     public bool TryPrepare(PathSmoothingRequest request, out PreparedPath preparedPath, out string reason)
     {
         preparedPath = null;
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedDirectionSegment.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedDirectionSegment.cs
index 0f58727..746ca08 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedDirectionSegment.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedDirectionSegment.cs
@@ -9,6 +9,11 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.Processing;
 public sealed class PreparedDirectionSegment
 {
     /// <summary>创建不可变方向段。</summary>
+    /// <param name="segmentIndex">在 <see cref="PreparedPath.Segments"/> 中从零开始的段索引。</param>
+    /// <param name="direction">本段唯一的车辆行驶方向。</param>
+    /// <param name="points">本段的非空采样点集合；构造后会复制为只读快照。</param>
+    /// <param name="startsAtGearSwitch">若首点紧随换向，则为 <see langword="true"/>。</param>
+    /// <param name="endsAtGearSwitch">若末点紧邻换向，则为 <see langword="true"/>。</param>
     public PreparedDirectionSegment(
         int segmentIndex,
         TravelDirection direction,
@@ -20,6 +25,12 @@ public sealed class PreparedDirectionSegment
     }
 
     /// <summary>创建带有真实起始车辆曲率边界状态的不可变方向段。</summary>
+    /// <param name="segmentIndex">在 <see cref="PreparedPath.Segments"/> 中从零开始的段索引。</param>
+    /// <param name="direction">本段唯一的车辆行驶方向。</param>
+    /// <param name="points">本段的非空采样点集合；构造后会复制为只读快照。</param>
+    /// <param name="startsAtGearSwitch">若首点紧随换向，则为 <see langword="true"/>。</param>
+    /// <param name="endsAtGearSwitch">若末点紧邻换向，则为 <see langword="true"/>。</param>
+    /// <param name="startVehicleCurvaturePerMeter">物理起点车辆曲率边界，单位 1/m；未知时为 <see langword="null"/>。</param>
     public PreparedDirectionSegment(
         int segmentIndex,
         TravelDirection direction,
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedPath.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedPath.cs
index 379c33c..10e11e9 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedPath.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/PreparedPath.cs
@@ -8,6 +8,7 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.Processing;
 public sealed class PreparedPath
 {
     /// <summary>创建不可变预处理路径。</summary>
+    /// <param name="segments">按原始行驶顺序排列的非空方向段集合；构造后会复制为只读快照。</param>
     public PreparedPath(IReadOnlyList<PreparedDirectionSegment> segments)
     {
         if (segments == null || segments.Count == 0)
@@ -22,10 +23,10 @@ public sealed class PreparedPath
         Points = Flatten(Segments);
     }
 
-    /// <summary>按原始前进/倒车拓扑排列的方向段。</summary>
+    /// <summary>按原始前进/倒车拓扑排列的 <see cref="PreparedDirectionSegment"/> 只读集合。</summary>
     public IReadOnlyList<PreparedDirectionSegment> Segments { get; }
 
-    /// <summary>将所有方向段顺序拼接后的点；换向重复点保留两次。</summary>
+    /// <summary>将所有方向段顺序拼接后的 <see cref="SmoothingPoint2D"/> 只读集合；换向重复点保留两次。</summary>
     public IReadOnlyList<SmoothingPoint2D> Points { get; }
 
     private static IReadOnlyList<T> CopyReadOnly<T>(IReadOnlyList<T> source)
diff --git a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/SmoothingPoint2D.cs b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/SmoothingPoint2D.cs
index 1ca0e05..98ce84c 100644
--- a/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/SmoothingPoint2D.cs
+++ b/ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Processing/SmoothingPoint2D.cs
@@ -7,6 +7,14 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.Processing;
 public sealed class SmoothingPoint2D
 {
     /// <summary>创建不可变二维路径点。</summary>
+    /// <param name="xMeters">世界坐标 X，单位 m。</param>
+    /// <param name="yMeters">世界坐标 Y，单位 m。</param>
+    /// <param name="arcLengthMeters">本方向段内从零开始的累计弧长，单位 m。</param>
+    /// <param name="headingRadians">归一化车辆航向，单位 rad。</param>
+    /// <param name="unwrappedHeadingRadians">连续展开的车辆航向，单位 rad。</param>
+    /// <param name="bodyClearanceMeters">路径点携带的保守车体净空，单位 m。</param>
+    /// <param name="isGearSwitchPoint">该点是否标记新方向段的换向边界。</param>
+    /// <param name="source">点在平滑处理流中的来源枚举。</param>
     public SmoothingPoint2D(
         double xMeters,
         double yMeters,