feat: WP5 1단계 — 2-point front (상부 C-D / 하부 C-B)

- ColumnState UpperFrontBase/LowerFrontBase, 엔진 ApplyFront2Point(C=pivot temps[n-2], 느린 baseline 편차→중립 상태 정상/상승/하강)
- AdvisoryResult Upper/LowerFrontState·Metric + 컨트롤러 노출 + ff.js/css 표시
- 단위 3건(상/하 격리 perturb, metric 노출). 45/45. 2단계(trim)·3단계(조성base) 미구현

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

plans/안전피드램프-후속작업-작업지시서-WP4-7.md

@@ -87,7 +87,9 @@ pi-6111b를 활용해 **전탑 ΔP**(flooding) + **압력 프로파일 기반 PC
 
 ---
 
-## WP5 — 편차 trim + 2-point sensitive tray (§8·§8.8) (난이도 高, 설계결정 필요)
+## WP5 — 편차 trim + 2-point sensitive tray (§8·§8.8) (난이도 高) — **1단계 완료 ✅ 2026-06-01**
+
+> **1단계 완료**: 2-point front 인프라(ColumnState `UpperFrontBase`/`LowerFrontBase`, 엔진 `ApplyFront2Point`, AdvisoryResult `Upper/LowerFrontState`·`Metric`, 컨트롤러·UI 노출, 단위 3건). 상부=ΔT(C−D)·하부=ΔT(C−B), C=pivot(temps[n-2]), 중립 상태(정상/상승/하강). **2단계(trim ±5%+귀속)·3단계(조성base SP)는 미구현.**
 
 ### 목적
 LevelDriven 드로우 권장을 `K×feed`(무한상승)에서 **[조성목표(분율×feed)] + [bounded 편차 trim]** 구조로. 편차는 §8.4 2-타임스케일.

src/Core/Application/Feedforward/FeedforwardModels.cs

@@ -120,6 +120,11 @@ public sealed record AdvisoryResult(
     public string?    InversionPair    { get; init; }
     public double?    TempSpan         { get; init; }
     public double?    TempSpanRef      { get; init; }
+    // WP5 1단계: 2-point front (C pivot 기준 상/하 분리)
+    public string?    UpperFrontState  { get; init; }   // 상부 ΔT(C−D): 정상/상승/하강/정착대기
+    public string?    LowerFrontState  { get; init; }   // 하부 ΔT(C−B): 정상/상승/하강/정착대기
+    public double?    UpperFrontMetric { get; init; }
+    public double?    LowerFrontMetric { get; init; }
     public double?    FeedRecommendedSp  { get; init; }   // WO-6 전환류 시 FEED 권장(0=차단), 그 외 null
     // Phase II: auto-write 상태
     public bool      AutoWriteActive   { get; init; }

src/Infrastructure/Control/FeedforwardEngine.cs

@@ -32,6 +32,9 @@ public sealed class ColumnState
     public MovingAverage? VLossMaBlock { get; set; }
     public Dictionary<string, MovingAverage> KObsMa { get; } = new();
     public FrontPositionIndicator? FrontInd { get; set; }   // WO-5
+    // WP5 1단계: 2-point front baseline (C pivot 기준 상/하 차온의 느린 baseline)
+    public FirstOrderLag UpperFrontBase { get; } = new();   // ΔT(C−D) 상부
+    public FirstOrderLag LowerFrontBase { get; } = new();   // ΔT(C−B) 하부
     // WO-6 전환류 상태기계
     public ColumnMode Mode { get; set; } = ColumnMode.Normal;
     public double ImbalanceTimerSec { get; set; }
@@ -134,6 +137,7 @@ public sealed class FeedforwardEngine
         ApplyBias(cfg, pv, st, ff, vloss, transient, ref outs, out var vLossMa);   // WO-4 느린 바이어스
         var (frontState, frontTrim) = ApplyFront(cfg, st, ts, temps, transient);   // WO-5 프론트 위치
         var tp = JudgeTempProfile(temps, st, transient);                           // §10 역전 판정
+        var f2 = ApplyFront2Point(st, ts, temps, transient);                       // WP5 1단계 2-point front
         // 역전/붕괴 시 front 트림 보류(방향 신뢰 불가)
         if (tp.State is "온도역전" or "프로파일붕괴") frontTrim = null;
         var (mode, modeReason, feedRecSp) = ApplyRecovery(
@@ -142,7 +146,9 @@ public sealed class FeedforwardEngine
             transient, treason, ff, outs, vloss, yield, mbState)
             { Temps = temps, VLossMa = vLossMa, FrontPositionState = frontState, FrontTrimAdvice = frontTrim,
               Mode = mode, ModeReason = modeReason, FeedRecommendedSp = feedRecSp,
-              TempProfileState = tp.State, InversionPair = tp.InversionPair, TempSpan = tp.Span, TempSpanRef = tp.SpanRef };
+              TempProfileState = tp.State, InversionPair = tp.InversionPair, TempSpan = tp.Span, TempSpanRef = tp.SpanRef,
+              UpperFrontState = f2.upState, LowerFrontState = f2.loState,
+              UpperFrontMetric = f2.upMetric, LowerFrontMetric = f2.loMetric };
     }
 
     // ── WO-2 P-2 + WP6: 압력보정온도(PCT) 모니터 — 국소 압력 프로파일 적용 ──
@@ -297,6 +303,40 @@ public sealed class FeedforwardEngine
         return (state, trim);
     }
 
+    // ── WP5 1단계: 2-point front (C=제품 pivot=temps[n-2]). 상부=ΔT(C−D), 하부=ΔT(C−B). 느린 baseline 편차로 판정. ──
+    // 상태는 중립(정상/상승/하강) — 섹션별 액션(B↑/환류↑) 매핑은 2단계(trim). D는 유효온도라 ΔT(C−D) 정상 사용.
+    private static (string? upState, double? upMetric, string? loState, double? loMetric)
+        ApplyFront2Point(ColumnState st, double ts, IReadOnlyList<TempPoint>? temps, bool transient)
+    {
+        if (temps is null || temps.Count < 3) return (null, null, null, null);
+        if (transient) return ("정착대기", null, "정착대기", null);
+
+        const double bw = 0.3, refTau = 1800.0;
+        int n = temps.Count;
+        var C = temps[n - 2];  // 제품 pivot
+        var D = temps[n - 1];  // 상단
+        var B = temps[n - 3];  // 하부
+
+        static string Classify(double dev, double band)
+            => Math.Abs(dev) <= band ? "정상" : dev > 0 ? "상승" : "하강";
+
+        string? upState = null; double? upMetric = null;
+        if (C.Good && D.Good && Num.IsFinite(C.Pct) && Num.IsFinite(D.Pct))
+        {
+            double m = C.Pct - D.Pct;                                  // 상부 ΔT(C−D)
+            double bl = st.UpperFrontBase.Step(m, refTau, ts);
+            upState = Classify(m - bl, bw); upMetric = m;
+        }
+        string? loState = null; double? loMetric = null;
+        if (C.Good && B.Good && Num.IsFinite(C.Pct) && Num.IsFinite(B.Pct))
+        {
+            double m = C.Pct - B.Pct;                                  // 하부 ΔT(C−B)
+            double bl = st.LowerFrontBase.Step(m, refTau, ts);
+            loState = Classify(m - bl, bw); loMetric = m;
+        }
+        return (upState, upMetric, loState, loMetric);
+    }
+
     // ── §10: 온도 프로파일 역전 판정 (조성 트레이 A,B,C — 환류오염 탑정 D는 제외) ──────────
     private static TempProfileResult JudgeTempProfile(IReadOnlyList<TempPoint>? temps, ColumnState st, bool transient)
     {

src/Web/Controllers/FeedforwardController.cs

@@ -277,6 +277,10 @@ public sealed class FeedforwardController : ControllerBase
             inversionPair    = r.InversionPair,
             tempSpan         = (r.TempSpan is double ts2 && !double.IsNaN(ts2)) ? ts2 : (double?)null,
             tempSpanRef      = r.TempSpanRef,
+            upperFrontState  = r.UpperFrontState,
+            lowerFrontState  = r.LowerFrontState,
+            upperFrontMetric = r.UpperFrontMetric,
+            lowerFrontMetric = r.LowerFrontMetric,
             autoWriteActive  = r.AutoWriteActive,
             writeGuardBlockedSp = r.WriteGuardBlockedSp,
             writeGuardReason = r.WriteGuardReason,

src/Web/wwwroot/css/ff.css

@@ -109,3 +109,10 @@
 .ff-sim-body{display:flex;flex-direction:column;gap:8px}
 .ff-sim-body textarea{background:var(--bg1);color:var(--t0);border:1px solid var(--bd);border-radius:4px;padding:6px;font-size:12px;font-family:monospace;width:100%}
 .ff-sim-actions{display:flex;gap:8px;align-items:center}
+
+/* WP5 1단계: 2-point front */
+.ff-front2 { display:flex; gap:8px; margin-top:4px; flex-wrap:wrap; }
+.ff-f2 { font-size:12px; padding:2px 8px; border-radius:4px; background:#1e2733; color:#cbd5e1; }
+.ff-f2-up { background:#7c2d12; color:#fed7aa; }
+.ff-f2-dn { background:#1e3a5f; color:#bfdbfe; }
+.ff-f2-ok { background:#14532d; color:#bbf7d0; }

src/Web/wwwroot/js/ff.js

@@ -184,6 +184,13 @@ function ffCard(c) {
     return `<div class="ff-tp-badge ${tpClass}">${esc(c.tempProfileState)}${invStr}${spanStr}</div>`;
   })() : '';
 
+  // WP5 1단계: 2-point front (상부 C−D / 하부 C−B)
+  const f2cls = s => s === '상승' ? 'ff-f2-up' : s === '하강' ? 'ff-f2-dn' : 'ff-f2-ok';
+  const front2 = (c.upperFrontState || c.lowerFrontState) ? `<div class="ff-front2">
+    <span class="ff-f2 ${f2cls(c.lowerFrontState)}">하부(B) ${esc(c.lowerFrontState||'–')}${c.lowerFrontMetric!=null?` <small>ΔT ${fmtVal(c.lowerFrontMetric)}</small>`:''}</span>
+    <span class="ff-f2 ${f2cls(c.upperFrontState)}">상부(D) ${esc(c.upperFrontState||'–')}${c.upperFrontMetric!=null?` <small>ΔT ${fmtVal(c.upperFrontMetric)}</small>`:''}</span>
+  </div>` : '';
+
   const armWait = (c.mode === 'Normal' && c.modeReason && c.modeReason.indexOf('ARM 대기') >= 0);
   const modeBadge =
       c.mode === 'Recovering' ? '<span class="ff-mode ff-mode-rec">전환류 복귀중 ●</span>'
@@ -217,6 +224,7 @@ function ffCard(c) {
     ${theta}
     ${front}
     ${tpBadge}
+    ${front2}
     <div class="ff-note">LevelDriven(D·B)은 레벨 제어(LIC)가 SP를 결정. 권장값은 참고 — 인가는 운전원.</div>
   </div>`;
 }

tests/ExperionCrawler.Tests/FeedforwardFront2PointTests.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Collections.Generic;
+using ExperionCrawler.Core.Application.Feedforward;
+using ExperionCrawler.Infrastructure.Control;
+using Xunit;
+
+namespace ExperionCrawler.Tests;
+
+// WP5 1단계: 2-point front (C=제품 pivot=temps[n-2]). 상부=ΔT(C−D), 하부=ΔT(C−B).
+// temp_tags 하단→상단 [A,B,C,D]. dtdp=0 → pct=raw. 한 섹션만 perturb 시 그 front만 반응.
+public class FeedforwardFront2PointTests
+{
+    private static ColumnConfig Cfg() => new()
+    {
+        Id = 1, Name = "C-F2", Enabled = true, FeedTag = "f", ProductKey = "P", ScanSec = 2,
+        DTdP = 0.0, PRef = double.NaN, PressureTag = null, FeedMoveThresholdPerMin = 0.0,
+        TempTags = new[] { "a", "b", "c", "d" },
+        Streams = new[] { new StreamConfig { Key = "P", FlowTag = "ficq-6118", Role = StreamRole.Commanded, Grade = Confidence.A, TargetCoeff = 0.95 } }
+    };
+
+    private static PvSnapshot Snap(double a, double b, double c, double d) => new(
+        new TagSample("f", 100, true, DateTime.UtcNow), null, Array.Empty<TagSample>(),
+        new Dictionary<string, TagSample> { ["P"] = new TagSample("ficq-6118", 95, true, DateTime.UtcNow) })
+        {
+            Temps = new[]
+            {
+                new TagSample("a", a, true, DateTime.UtcNow), new TagSample("b", b, true, DateTime.UtcNow),
+                new TagSample("c", c, true, DateTime.UtcNow), new TagSample("d", d, true, DateTime.UtcNow)
+            }
+        };
+
+    [Fact]
+    public void Lower_front_isolates_from_upper()
+    {
+        var engine = new FeedforwardEngine(); var st = new ColumnState();
+        // 정상 단조 A110>B105>C100>D90 으로 baseline 시드
+        for (int i = 0; i < 5; i++) engine.Tick(Cfg(), Snap(110, 105, 100, 90), st, DateTime.UtcNow);
+        // 하부만 perturb: B 강하(105→95) → C−B 증가 → 하부 "상승". 상부(C,D 불변) "정상"
+        var res = engine.Tick(Cfg(), Snap(110, 95, 100, 90), st, DateTime.UtcNow);
+        Assert.Equal("상승", res.LowerFrontState);
+        Assert.Equal("정상", res.UpperFrontState);
+    }
+
+    [Fact]
+    public void Upper_front_isolates_from_lower()
+    {
+        var engine = new FeedforwardEngine(); var st = new ColumnState();
+        for (int i = 0; i < 5; i++) engine.Tick(Cfg(), Snap(110, 105, 100, 90), st, DateTime.UtcNow);
+        // 상부만 perturb: D 가열(90→98) → C−D 감소 → 상부 "하강". 하부(C,B 불변) "정상"
+        var res = engine.Tick(Cfg(), Snap(110, 105, 100, 98), st, DateTime.UtcNow);
+        Assert.Equal("하강", res.UpperFrontState);
+        Assert.Equal("정상", res.LowerFrontState);
+    }
+
+    [Fact]
+    public void Metrics_exposed()
+    {
+        var engine = new FeedforwardEngine(); var st = new ColumnState();
+        var res = engine.Tick(Cfg(), Snap(110, 105, 100, 90), st, DateTime.UtcNow);
+        Assert.Equal(10.0, res.UpperFrontMetric!.Value, 6);   // C−D = 100−90
+        Assert.Equal(-5.0, res.LowerFrontMetric!.Value, 6);   // C−B = 100−105
+    }
+}