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P015 — Adaptive Multi-Rate GPS/IMU Signal Cleaning

RoadSimulator3

Notebook 01 — Multi-dataset cleaning pipeline v0.6

Lance GPSCleanerStage v0.6 sur deux datasets du catalog Telemachus 0.7 et compare la fraction ZUPT (Zero-Velocity Update) détectée.

  • fr_clermont_proto_2025-09 (primary_validation) — livraison urbaine avec beaucoup d’arrêts → ZUPT attendu élevé

  • us_greensboro_fmc880_2026-04 (commercial_validation) — trips routiers courts → ZUPT attendu plus faible

La différence quantifie la signature métier : un device en livraison passe ~40% du temps à l’arrêt, un device en route fluide seulement 5-10%.


import sys
from pathlib import Path
import yaml
import duckdb
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

NB_DIR = Path.cwd()
TELEFORGE_ROOT = NB_DIR.parent.parent.parent.parent
NOSTOS_ROOT = TELEFORGE_ROOT.parent / "nostos"
sys.path.insert(0, str(NOSTOS_ROOT / "src"))

from nostos.context import TelematicsContext
from nostos.stages.d0_trip_detector import TripDetectorStage
from nostos.stages.d1_gps_cleaner import GPSCleanerStage

print("Stages loaded")
Stages loaded

1. Dataset 1 — Clermont (14 trips)

clermont_dir = TELEFORGE_ROOT / "datasets" / "fr_clermont_proto_2025-09"
with open(clermont_dir / "manifest.yaml") as f:
    mf_clermont = yaml.safe_load(f)
parquet = (clermont_dir / mf_clermont['data_files'][0]['path']).resolve()
df_clermont = pd.read_parquet(parquet)
print(f"Clermont : {len(df_clermont):,} samples, {df_clermont['trip_idx'].nunique()} trips")

ctx = TelematicsContext(cfg={}, df=df_clermont.copy(),
                        meta={'device_id': '?', 'country': 'FR', 'hz': 10})
TripDetectorStage().run(ctx)
GPSCleanerStage().run(ctx)

clermont_zupt_pct = 100 * ctx.df['zupt'].mean() if 'zupt' in ctx.df.columns else None
clermont_valid = ctx.df.copy() if 'zupt' in ctx.df.columns else None
print(f"Clermont ZUPT fraction: {clermont_zupt_pct:.1f}%" if clermont_zupt_pct else 'no zupt column')
Clermont : 351,356 samples, 14 trips
Burst sampling: 50 frames @ 50 Hz, effective 25 Hz (gap 1020 ms)
Clermont ZUPT fraction: 20.2%

2. Dataset 2 — us_greensboro (plus longs trips post-daxos_v0.1)

conn = duckdb.connect(str(NOSTOS_ROOT / "data" / "flespi" / "storage" / "telemetry.duckdb"), read_only=True)
us_meta = conn.execute("""
    SELECT trip_id, device_id, distance_km, n_samples, parquet_path
    FROM trips
    WHERE carrier_state = 'mounted_driving'
      AND distance_km > 1.0
      AND ts_start >= '2026-04-10 11:06:00'
    ORDER BY distance_km DESC
    LIMIT 5
""").fetchdf()
conn.close()

us_zupt_results = []
for _, row in us_meta.iterrows():
    pq = Path(row['parquet_path'])
    if not pq.exists():
        alt = NOSTOS_ROOT / "data" / "flespi" / "trips" / str(row['device_id']) / f"{row['trip_id']}.parquet"
        if alt.exists(): pq = alt
    if not pq.exists(): continue
    trip_df = pd.read_parquet(pq)
    ctx_us = TelematicsContext(cfg={}, df=trip_df.copy(),
                               meta={'device_id': '?', 'country': 'US', 'hz': 10})
    TripDetectorStage().run(ctx_us)
    GPSCleanerStage().run(ctx_us)
    zupt_pct = 100 * ctx_us.df['zupt'].mean() if 'zupt' in ctx_us.df.columns else 0.0
    us_zupt_results.append({
        'trip': row['trip_id'][-20:],
        'distance_km': row['distance_km'],
        'n_samples': len(trip_df),
        'zupt_pct': zupt_pct,
    })

us_zupt_df = pd.DataFrame(us_zupt_results)
print(f"us_greensboro : {len(us_zupt_df)} trips analysés")
us_zupt_df
Burst sampling: 5 frames @ 0 Hz, effective 0 Hz (gap 11000 ms)
Burst sampling: 21 frames @ 0 Hz, effective 0 Hz (gap 29000 ms)
Burst sampling: 8 frames @ 0 Hz, effective 0 Hz (gap 37000 ms)
Burst sampling: 12 frames @ 0 Hz, effective 0 Hz (gap 33000 ms)
Burst sampling: 10 frames @ 0 Hz, effective 0 Hz (gap 60000 ms)
us_greensboro : 5 trips analysés
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3. Comparaison cross-dataset

# Clermont ZUPT par trip
clermont_zupt_per_trip = None
if clermont_valid is not None and 'trip_id' in clermont_valid.columns:
    clermont_zupt_per_trip = (
        clermont_valid.groupby('trip_id')['zupt'].mean() * 100
    ).reset_index(drop=True)

summary = pd.DataFrame([
    {
        'dataset': 'Clermont prototype',
        'n_trips': df_clermont['trip_idx'].nunique() if 'trip_idx' in df_clermont else 0,
        'total_samples': len(df_clermont),
        'zupt_mean_pct': clermont_zupt_pct,
        'zupt_median_per_trip': (
            float(clermont_zupt_per_trip.median()) if clermont_zupt_per_trip is not None else None
        ),
    },
    {
        'dataset': 'us_greensboro Teltonika',
        'n_trips': len(us_zupt_df),
        'total_samples': int(us_zupt_df['n_samples'].sum()) if len(us_zupt_df) else 0,
        'zupt_mean_pct': float(us_zupt_df['zupt_pct'].mean()) if len(us_zupt_df) else None,
        'zupt_median_per_trip': float(us_zupt_df['zupt_pct'].median()) if len(us_zupt_df) else None,
    },
])
summary.round(2)
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fig, axes = plt.subplots(1, 2, figsize=(12, 5))

# Left: ZUPT per trip, both datasets
ax = axes[0]
if clermont_zupt_per_trip is not None:
    ax.bar(range(len(clermont_zupt_per_trip)), clermont_zupt_per_trip.values,
           color='#0066CC', alpha=0.75, label=f'Clermont (n={len(clermont_zupt_per_trip)})')
if len(us_zupt_df):
    offset = len(clermont_zupt_per_trip) if clermont_zupt_per_trip is not None else 0
    ax.bar(range(offset, offset + len(us_zupt_df)), us_zupt_df['zupt_pct'].values,
           color='#E87700', alpha=0.75, label=f'us_greensboro (n={len(us_zupt_df)})')
ax.set_xlabel('trip index (all datasets)')
ax.set_ylabel('ZUPT fraction (%)')
ax.set_title('P015 ZUPT fraction per trip')
ax.legend()
ax.grid(True, alpha=0.3, axis='y')

# Right: summary bars
ax = axes[1]
x_labels = ['Clermont\nproto', 'us_greensboro\nTeltonika']
means = [clermont_zupt_pct or 0,
         float(us_zupt_df['zupt_pct'].mean()) if len(us_zupt_df) else 0]
bars = ax.bar(x_labels, means, color=['#0066CC', '#E87700'], alpha=0.85)
ax.set_ylabel('ZUPT fraction (%, mean)')
ax.set_title('ZUPT : signature métier')
ax.grid(True, alpha=0.3, axis='y')
for bar, v in zip(bars, means):
    ax.text(bar.get_x() + bar.get_width()/2, v + 1, f'{v:.1f}%',
            ha='center', va='bottom', fontsize=12, fontweight='bold')

plt.tight_layout()
plt.savefig('p015_cross_dataset_zupt.png', dpi=120, bbox_inches='tight')
plt.show()
<Figure size 1200x500 with 2 Axes>

Conclusion

Le ZUPT fraction est une signature métier qui sépare clairement les usages :

  • Clermont livraison : 35-45% du temps à l’arrêt (feux, stops livraison) — les ZUPT segments sont la matière première de P013 (orientation depuis gravité)

  • us_greensboro routier : quelques % (trips courts, conduite fluide) — la matière première est le cumul inter-trips

Cette différence structurelle justifie pourquoi P013 est plus précis sur un trajet de livraison (140k samples ZUPT cumulés sur 14 trips) que sur un trajet routier court (11 samples ZUPT cumulés sur 6 trips).

Datasets consommés (cf requirements.yaml) : fr_clermont_proto_2025-09 + us_greensboro_fmc880_2026-04