Multi-Sensor Fire Detector Using Acoustic Resonators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fire detection devices often generate nuisance alarms due to false triggers, such as dust being mistaken for fire-produced smoke, and struggle to differentiate between fires and non-fires efficiently, requiring a cost-effective solution that enhances response speed to real fires while minimizing false alarms.
Innovation Solution
Incorporating multiple ambient condition sensors, including acoustic resonators like quartz crystal oscillators, which measure changes in resonant frequency, Q-factor, speed of sound, and attenuation to accurately detect fire conditions, combined with other sensors like smoke, gas, and thermal sensors, processed by a unit to generate a reliable alarm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple sensors are used to improve fire detection accuracy, then false alarms are reduced, but device complexity increases
Solution Approach 1:
The patent combines multiple different sensing elements (acoustic resonator, smoke sensor, heat sensor, gas sensor) into a single integrated detector unit. This merging approach allows the system to monitor multiple fire indicators simultaneously while maintaining a compact form factor, thus improving detection reliability without proportionally increasing device complexity.
Solution Approach 2:
The detector is designed as a multi-functional device that can detect various fire characteristics including acoustic changes, smoke concentration, temperature rise, and gas composition. This universal approach enables a single device to perform multiple detection functions, reducing the need for separate specialized sensors and thereby managing complexity while improving overall detection accuracy.
2Speed
If acoustic resonators are used to detect fire conditions, then response speed is enhanced, but manufacturing cost increases
Solution Approach 1:
The patent employs acoustic resonators made from inexpensive materials such as quartz crystals or ceramic resonators that can be mass-produced at low cost. These resonators are designed to be simple, robust components that do not require complex manufacturing processes, thereby maintaining ease of manufacture while providing fast response to fire conditions through their sensitive acoustic detection capability.
3Measurement precision
If multiple sensing elements are incorporated, then discrimination between fires and nuisances is improved, but power consumption increases
Solution Approach 1:
The detector employs periodic sampling of sensor data rather than continuous monitoring of all sensing elements. The microcontroller periodically reads sensor values and processes them to determine fire conditions, which significantly reduces power consumption compared to continuous operation. This periodic action maintains adequate discrimination accuracy between fires and nuisances while managing power usage in battery-operated or energy-constrained applications.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This multi-sensor approach reduces false alarms by accurately distinguishing fire-related changes in ambient conditions, enhancing response speed to real fires with sensors that are reliable, rugged, inexpensive, and consume low power.
Implementation Method 1
acoustic resonators like quartz crystal oscillators, which measure changes in resonant frequency, Q-factor, speed of sound, and attenuation
Implementation Method 2
measure changes in resonant frequency, Q-factor, speed of sound, and attenuation
Implementation Method 3
acoustic resonators like quartz crystal oscillators, which measure changes in resonant frequency, Q-factor, speed of sound, and attenuation to accurately detect fire conditions
Data Source
AI summary
A multi-sensor fire detector incorporates at least one acoustic resonator and other type or types of fire sensor. Other types include smoke sensors, gas sensors or optically based fire sensors. Outputs from the acoustic resonator can be processed with or without outputs from the other type or types of fire sensors to establish the presence of an alarm condition. Multiple acoustic resonators can be incorporated into the same detector.