fix(telemetry): stabilize 20Hz clock driver, fix moving time accumulator & prevent derivative spikes

field_test_export_unzipped/field_test_session/README.txt

@@ -0,0 +1,29 @@
+=====================================================
+MOTORCYCLE DASH — FORENSIC FIELD TEST SESSION REPORT
+=====================================================
+Application Version: 1.0.0
+Build Number: 100
+Git Revision: e700ca64fdb6365d30a76d81236c912a730bfad2
+Git Branch: master
+Release Channel: release
+Telemetry Schema Version: 5
+Export Format Version: 1
+Build Timestamp: 2026-08-28T05:00:00Z
+Field Test Session / Ride ID: 2
+Session Start: 2026-08-28T14:30:56.000
+Session End: 2026-08-28T14:38:04.000
+Export Timestamp: 2026-08-28T17:01:07.396703
+Summary Result: POOR
+Ride Quality Score: 51 / 100
+Total Telemetry Samples: 34524
+Total Forensic Events: 5482
+Major Warnings Count: 5471
+Major Errors Count: 3
+=====================================================
+Files Included:
+  - field_test_session.json : Full structured session dump with software identity
+  - field_test_events.csv   : Standard 15-column forensic timeline
+  - telemetry.csv          : 20Hz sensor sample trace
+  - telemetry.gpx          : GPS trace with lean/speed extensions
+  - ride_summary.json      : High-level ride performance stats
+  - README.txt             : This audit header

field_test_export_unzipped/field_test_session/ride_summary.json

@@ -0,0 +1,26 @@
+{
+  "rideId": 2,
+  "startTime": "2026-08-28T14:30:56.000",
+  "endTime": "2026-08-28T14:38:04.000",
+  "distanceMiles": 8.731763512731801,
+  "topSpeedMph": 96.60996890916071,
+  "maxLeanLeft": 12.298980710271698,
+  "maxLeanRight": 29.149395821947344,
+  "maxAccelG": 0.5371292156727665,
+  "maxBrakingG": 1.04340023436231,
+  "averageSpeed": 0.0,
+  "movingTime": 0,
+  "stoppedTime": 0,
+  "qualityScore": 51,
+  "qualityRating": "POOR",
+  "software": {
+    "version": "1.0.0",
+    "build": 100,
+    "gitCommit": "e700ca64fdb6365d30a76d81236c912a730bfad2",
+    "gitBranch": "master",
+    "releaseChannel": "release",
+    "telemetrySchemaVersion": 5,
+    "exportSchemaVersion": 1,
+    "buildTimestamp": "2026-08-28T05:00:00Z"
+  }
+}

lib/features/rides/ride_state_machine.dart

@@ -108,6 +108,8 @@ class RideStateMachine extends StateNotifier<RideSession> {
   
   TelemetrySample? _lastSample;
   double _accumulatedDistance = 0; // meters internally
+  double _movingTimeAccumulator = 0.0; // seconds internally
+  double _stoppedTimeAccumulator = 0.0; // seconds internally
   
   // Batching
   final List<TelemetrySamplesCompanion> _telemetryBatch = [];
@@ -234,6 +236,8 @@ class RideStateMachine extends StateNotifier<RideSession> {
     );
     _lastSample = null;
     _accumulatedDistance = 0;
+    _movingTimeAccumulator = 0.0;
+    _stoppedTimeAccumulator = 0.0;
     _lastTelemetryReceivedTime = DateTime.now();
 
     try {
@@ -514,21 +518,18 @@ class RideStateMachine extends StateNotifier<RideSession> {
       }
     }
     
-    // Better Time tracking logic (internal doubles)
-    double internalMoving = state.movingTimeSeconds.toDouble();
-    double internalStopped = state.stoppedTimeSeconds.toDouble();
-    
+    // Continuous sub-second time accumulation across 20Hz frames
     if (_lastSample != null && sample.speed != null) {
-       final dt = sample.timestamp.difference(_lastSample!.timestamp).inMilliseconds / 1000.0;
-       if (dt > 0 && dt < 2.0) {
-         if (sample.speed! > 1.8) {
-           internalMoving += dt;
-         } else {
-           internalStopped += dt;
-         }
-         newMovingTime = internalMoving.floor();
-         newStoppedTime = internalStopped.floor();
-       }
+      final dt = sample.timestamp.difference(_lastSample!.timestamp).inMilliseconds / 1000.0;
+      if (dt > 0 && dt < 2.0) {
+        if (sample.speed! > 1.8) {
+          _movingTimeAccumulator += dt;
+        } else {
+          _stoppedTimeAccumulator += dt;
+        }
+        newMovingTime = _movingTimeAccumulator.floor();
+        newStoppedTime = _stoppedTimeAccumulator.floor();
+      }
     }
 
     if (sample.leanAngle != null && sample.leanAngle!.abs() <= 65.0) {

lib/services/field_test/field_test_logger.dart

@@ -143,9 +143,9 @@ class FieldTestLogger {
   AppIdentity? _sessionIdentity;
   AppIdentity get sessionIdentity => _sessionIdentity ?? AppIdentity.current();
 
-  void startSession(int rideId, {String? notes}) {
+  void startSession(int rideId, {String? notes, DateTime? timestamp}) {
     _activeRideId = rideId;
-    _sessionStartTime = DateTime.now();
+    _sessionStartTime = timestamp ?? DateTime.now();
     _sessionIdentity = AppIdentity.current();
     _timelineBuffer.clear();
     _eventBatch.clear();
@@ -156,6 +156,7 @@ class FieldTestLogger {
       severity: EventSeverity.info,
       message: 'Field test session started for ride #$rideId [v${sessionIdentity.displayString}]',
       rideId: rideId,
+      timestamp: _sessionStartTime,
       metadata: {
         'software': sessionIdentity.toJson(),
         'notes': ?notes,

lib/services/telemetry_service.dart

@@ -78,7 +78,6 @@ class TelemetryService {
 
     _locationSub = _locationService.getFilteredPositionStream().listen((pos) {
       _latestPosition = pos;
-      _emitSample();
     });
 
     _leanSub = _sensorFusionService.leanAngleStream.listen((lean) {
@@ -94,19 +93,20 @@ class TelemetryService {
     _gForceSub = _sensorFusionService.gForceStream.listen((gForce) {
       _latestGForce = gForce;
       _latestImuTimestamp = DateTime.now();
-      _emitSample();
     });
 
     _compassSub = _compassService.headingStream.listen((heading) {
       _latestCompassHeading = heading;
     });
 
-    // High-rate refresh at 20Hz (50ms) for ultra-fluid digital speedometer
+    // High-rate refresh at strictly 20Hz (50ms) as the single authoritative telemetry clock
     _samplingTimer = Timer.periodic(const Duration(milliseconds: 50), (_) {
       _emitSample();
     });
   }
 
+  DateTime? _lastSuspectLogTime;
+
   void _emitSample() {
     final now = DateTime.now();
     final speedMph = _latestPosition != null ? _latestPosition!.speed * 2.23694 : 0.0;
@@ -142,16 +142,31 @@ class TelemetryService {
     final quality = _validator.validate(rawSample);
     final validatedSample = rawSample.copyWith(quality: quality);
 
-    // Log diagnostic if sample is suspect or rejected during an active field test
-    if (_fieldTestLogger.isSessionActive && (quality.isSuspect || quality.isRejected)) {
-      _fieldTestLogger.log(
-        eventType: quality.isRejected ? FieldTestEventType.sampleRejected : FieldTestEventType.sampleSuspect,
-        message: 'Sample validation ${quality.status.name}: ${quality.reasons.join(", ")}',
-        severity: quality.isRejected ? EventSeverity.critical : EventSeverity.warning,
-        telemetryTimestamp: rawSample.timestamp,
-        speed: speedMph,
-        overallConfidence: quality.overallConfidence,
-      );
+    // Log diagnostic if sample is suspect or rejected during an active field test (throttled for suspect)
+    if (_fieldTestLogger.isSessionActive) {
+      if (quality.isRejected) {
+        _fieldTestLogger.log(
+          eventType: FieldTestEventType.sampleRejected,
+          message: 'Sample validation rejected: ${quality.reasons.join(", ")}',
+          severity: EventSeverity.critical,
+          telemetryTimestamp: rawSample.timestamp,
+          speed: speedMph,
+          overallConfidence: quality.overallConfidence,
+        );
+      } else if (quality.isSuspect) {
+        final shouldLogSuspect = _lastSuspectLogTime == null || now.difference(_lastSuspectLogTime!).inMilliseconds >= 2000;
+        if (shouldLogSuspect) {
+          _lastSuspectLogTime = now;
+          _fieldTestLogger.log(
+            eventType: FieldTestEventType.sampleSuspect,
+            message: 'Sample validation suspect: ${quality.reasons.join(", ")}',
+            severity: EventSeverity.warning,
+            telemetryTimestamp: rawSample.timestamp,
+            speed: speedMph,
+            overallConfidence: quality.overallConfidence,
+          );
+        }
+      }
     }
 
     _telemetryController.add(validatedSample);

lib/services/validation/telemetry_validator.dart

@@ -52,6 +52,7 @@ final telemetryValidatorProvider = Provider<TelemetryValidator>((ref) {
 
 class TelemetryValidator {
   DateTime? _lastTimestamp;
+  DateTime? _lastGpsTimestamp;
   double? _lastSpeedMph;
   double? _lastLeanAngle;
   double? _lastLat;
@@ -72,6 +73,7 @@ class TelemetryValidator {
 
   void reset() {
     _lastTimestamp = null;
+    _lastGpsTimestamp = null;
     _lastSpeedMph = null;
     _lastLeanAngle = null;
     _lastLat = null;
@@ -150,7 +152,7 @@ class TelemetryValidator {
           if (status == ValidationStatus.valid) status = ValidationStatus.suspect;
           reasons.add('Stale GPS fix (${(sample.gpsAgeMs! / 1000).toStringAsFixed(1)}s old)');
         }
-      } else if (sample.gpsAgeMs! > 1000) {
+      } else if (sample.gpsAgeMs! > 1200) {
         gpsConf = math.min(gpsConf, 0.40);
         if (currentSpeed > 10.0 && status == ValidationStatus.valid) {
           status = ValidationStatus.suspect;
@@ -164,15 +166,21 @@ class TelemetryValidator {
     }
 
     // GPS Position Teleportation Check
-    if (_lastLat != null && _lastLng != null && sample.latitude != null && sample.longitude != null && deltaMs > 0 && deltaMs < 3000) {
-      final latDiff = (sample.latitude! - _lastLat!).abs() * 111139.0;
-      final lngDiff = (sample.longitude! - _lastLng!).abs() * 111139.0 * math.cos(sample.latitude! * (math.pi / 180.0));
-      final distMeters = math.sqrt(latDiff * latDiff + lngDiff * lngDiff);
-      final derivedSpeedMps = distMeters / (deltaMs / 1000.0);
-      if (derivedSpeedMps > 110.0 && distMeters > 50.0) {
-        status = ValidationStatus.rejected;
-        gpsConf = 0.0;
-        reasons.add('GPS position jump detected (${distMeters.toStringAsFixed(0)}m in ${deltaMs}ms)');
+    if (_lastLat != null && _lastLng != null && sample.latitude != null && sample.longitude != null) {
+      final dtSec = (sample.gpsTimestamp != null && _lastGpsTimestamp != null && sample.gpsTimestamp != _lastGpsTimestamp)
+          ? sample.gpsTimestamp!.difference(_lastGpsTimestamp!).inMilliseconds / 1000.0
+          : (deltaMs > 0 ? deltaMs / 1000.0 : 0.05);
+
+      if (dtSec > 0.02 && dtSec < 5.0) {
+        final latDiff = (sample.latitude! - _lastLat!).abs() * 111139.0;
+        final lngDiff = (sample.longitude! - _lastLng!).abs() * 111139.0 * math.cos(sample.latitude! * (math.pi / 180.0));
+        final distMeters = math.sqrt(latDiff * latDiff + lngDiff * lngDiff);
+        final derivedSpeedMps = distMeters / dtSec;
+        if (derivedSpeedMps > 110.0 && distMeters > 50.0) {
+          status = ValidationStatus.rejected;
+          gpsConf = 0.0;
+          reasons.add('GPS position jump detected (${distMeters.toStringAsFixed(0)}m in ${(dtSec * 1000).toStringAsFixed(0)}ms)');
+        }
       }
     }
 
@@ -182,20 +190,22 @@ class TelemetryValidator {
       status = ValidationStatus.rejected;
       speedConf = 0.0;
       reasons.add('Impossible vehicle speed (${currentSpeed.toStringAsFixed(1)} MPH > 220 MPH)');
-    } else if (_lastSpeedMph != null && deltaMs > 0 && deltaMs < 2000) {
+    } else if (_lastSpeedMph != null && deltaMs >= 40 && deltaMs < 2000) {
       final deltaSpeedMph = (currentSpeed - _lastSpeedMph!).abs();
-      final dtSec = deltaMs / 1000.0;
-      final accelMps2 = (deltaSpeedMph / 2.23694) / dtSec;
+      if (deltaSpeedMph >= 1.5) {
+        final dtSec = deltaMs / 1000.0;
+        final accelMps2 = (deltaSpeedMph / 2.23694) / dtSec;
 
-      // Realistic motorcycle acceleration ceiling: ~15 m/s² (~1.5g), spike ceiling: 25 m/s²
-      if (accelMps2 > 25.0 && dtSec >= 0.1) {
-        status = ValidationStatus.rejected;
-        speedConf = 0.1;
-        reasons.add('Impossible acceleration (${accelMps2.toStringAsFixed(1)} m/s² > 25 m/s²)');
-      } else if (accelMps2 > 16.0) {
-        if (status == ValidationStatus.valid) status = ValidationStatus.suspect;
-        speedConf = math.min(speedConf, 0.5);
-        reasons.add('Suspicious acceleration spike (${accelMps2.toStringAsFixed(1)} m/s²)');
+        // Realistic motorcycle acceleration ceiling: ~15 m/s² (~1.5g), physical crash/spike ceiling: 30 m/s²
+        if (accelMps2 > 35.0 && dtSec >= 0.1) {
+          status = ValidationStatus.rejected;
+          speedConf = 0.1;
+          reasons.add('Impossible acceleration (${accelMps2.toStringAsFixed(1)} m/s² > 35 m/s²)');
+        } else if (accelMps2 > 20.0) {
+          if (status == ValidationStatus.valid) status = ValidationStatus.suspect;
+          speedConf = math.min(speedConf, 0.5);
+          reasons.add('Suspicious acceleration spike (${accelMps2.toStringAsFixed(1)} m/s²)');
+        }
       }
     }
 
@@ -206,14 +216,16 @@ class TelemetryValidator {
       status = ValidationStatus.suspect;
       leanConf = 0.3;
       reasons.add('Extreme lean angle beyond physical motorcycle limit (${currentLean.toStringAsFixed(1)}° > 65°)');
-    } else if (_lastLeanAngle != null && deltaMs > 0 && deltaMs < 1000) {
+    } else if (_lastLeanAngle != null && deltaMs >= 40 && deltaMs < 1000) {
       final deltaLean = (currentLean - _lastLeanAngle!).abs();
-      final rollRateDegPerSec = deltaLean / (deltaMs / 1000.0);
-      // Motorcycle flick roll-rate ceiling is ~120 deg/sec
-      if (rollRateDegPerSec > 180.0) {
-        if (status == ValidationStatus.valid) status = ValidationStatus.suspect;
-        leanConf = 0.4;
-        reasons.add('Excessive roll rate (${rollRateDegPerSec.toStringAsFixed(0)}°/s)');
+      // Only evaluate roll rate if angular change exceeds engine vibration noise (> 3.0 deg)
+      if (deltaLean > 3.0) {
+        final rollRateDegPerSec = deltaLean / (deltaMs / 1000.0);
+        if (rollRateDegPerSec > 250.0) {
+          if (status == ValidationStatus.valid) status = ValidationStatus.suspect;
+          leanConf = 0.5;
+          reasons.add('Excessive roll rate (${rollRateDegPerSec.toStringAsFixed(0)}°/s)');
+        }
       }
     }
 
@@ -254,6 +266,7 @@ class TelemetryValidator {
       _lastLeanAngle = currentLean;
       if (sample.latitude != null) _lastLat = sample.latitude;
       if (sample.longitude != null) _lastLng = sample.longitude;
+      if (sample.gpsTimestamp != null) _lastGpsTimestamp = sample.gpsTimestamp;
     }
 
     return TelemetryQuality(

test/phase10_forensic_logger_test.dart

@@ -153,8 +153,8 @@ void main() {
 
   group('Phase 10: Database Persistence & Crash Recovery', () {
     test('Batch flushes events to SQLite with chronological ordering and ride filtering', () async {
-      logger.startSession(42);
       final now = DateTime(2026, 8, 28, 14, 0, 0);
+      logger.startSession(42, timestamp: now.subtract(const Duration(seconds: 1)));
 
       logger.log(
         eventType: FieldTestEventType.gpsStale,