Both trucks haul the same shuttle route between the load face and the dump point. An invisible gas pocket — a stand-in for methane buildup or oxygen-depleted "black damp" — forms at a random position and time along the tunnel each run, rises to a peak, then disperses, exactly like a real ventilation dead-spot.
reading(z,t) = peak · exp(-(z-zₚ)²/2σz²) · exp(-(t-tₚ)²/2σt²)
- Sensor truck continuously samples gas concentration. The instant its reading crosses the caution threshold, it halts and reverses to the marked safe zone well before the danger level — a real retreat maneuver, not a scripted stop.
- Blind truck has no sensor at all. It keeps executing its normal haul cycle straight through the pocket, exactly as if nothing were different, accumulating dangerous exposure with no reaction.
- Lower the caution threshold to see the sensor truck retreat earlier (safer, more downtime); raise it to see how close a real system can safely cut it.
Real-world relevance: this is the core safety case for gas-sensing autonomy in underground mining — a robot that senses hazard can retreat minutes before a human crew — or an unmonitored machine — would ever notice.