Patent · 2026 · published application
Hazards that no single sensor sees
A reaction starting in a fume hood raises solvent vapour and bench temperature together, each to well below its own alarm. Fixed thresholds stay silent until one of them crosses. This application fuses five cheap, different sensors through pairwise products, so two sensors that are both somewhat up count for more than either alone, and protects the self-learning baseline so the hazard cannot teach the system that it is normal. Both labs below use the published weights, coefficients and thresholds.
- Indian Patent Application No.
- 202641115711
- Status
- Published, 2026
- Sensors fused
- Gas · heat · flame · humidity · light
- Decision cycle
- 500 ms
Try it
1. Five sensors, each below its alarm
The patent's worked example: every reading below its own alarm, yet gas, heat and a faint flame signal rising together.
Bars mark 2σ (warning) and 3.5σ (critical) for each channel on its own.
Composite index 2.34warning at 1.0, critical at 3.0
individual 1.12pairwise 1.22
Each cell is c × nᵢ × nⱼ for one pair: it only lights up when both sensors are up at once. Gas with heat (0.30) and gas with flame (0.25) are the strongest couplings.
Paths: index warning, single channel safe, absolute limits safe. The highest wins.
2. Why the baseline has to be protected
- Gas reading, ppm (a leak starts at 8 min)
- What the unit thinks normal is
- Ventilation running
The reference is frozen once the reading departs from it, so the leak stays visible: still 18.7σ above normal at 30 min, ventilating for 22 min.
What is claimed, in plain words
Put every sensor on one scale. Each reading is compared with its own learned normal and divided by its own usual spread, so gas in ppm and temperature in °C become comparable numbers of standard deviations. Only that makes multiplying them meaningful.
Add the pairs. The index adds each sensor's weighted deviation to a weighted product for every pair. A product is large only when both are up, the signature of a compound hazard. The coefficients are set by a fixed commissioning procedure from staged and benign events, not by judgement.
Protect what was learned. The spread is frozen the moment any sensor departs from normal, and the baseline is frozen while ventilation runs, so neither the hazard nor the response to it is learned as the new normal.
Three paths, highest wins. The fused index, each sensor on its own, and hard absolute limits run in parallel; the strongest call drives the fan, vent, buzzer and light.
The application can be looked up by its number on the Indian Patent Office public search. Team invention.