Chamberless Smoke Detector Using Angled Light Cones
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Solution Overview
Problem
Conventional chambered smoke detectors in aircraft suffer from false alarms due to unwanted airborne particles entering the chamber, which can collect and reduce detection accuracy, while chamberless detectors lack a well-defined measurement volume and consume more power with constantly active lights.
Innovation Solution
A chamberless particulate detection system using at least two light sources emitting cones with angled emission and acceptance cones, positioned to increase overlap and sensitivity, along with a processor to evaluate scattered light for particulate presence, and optionally incorporating polarizing filters for particle discrimination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a chamber is used in smoke detectors, then particles are prevented from entering, but false alarms occur due to unwanted particles collecting at inlets and chamber surfaces
Solution Approach 1:
The patent removes the chamber structure entirely from the smoke detector design. By extracting the chamber that caused particle accumulation and false alarms, the system achieves more reliable detection without the harmful effect of particle collection on chamber surfaces and inlets.
Solution Approach 2:
The patent divides the detection function into multiple light sources and light sensing devices positioned at specific angles. This segmentation allows the system to create overlapping measurement volumes that improve detection accuracy while avoiding the single-point failure mode of chamber-based designs.
2Object-affected harmful factors
If a chamberless design is used, then false alarms are reduced, but measurement integrity becomes difficult to maintain without a protected measurement volume
Solution Approach 1:
The patent employs multiple light sources and sensing devices positioned at angled orientations to dynamically create overlapping measurement volumes. This dynamic geometric arrangement maintains measurement integrity without requiring a physical chamber, as the overlapping volumes provide redundant measurement capability and robustness against environmental interference.
3Reliability
If lights are constantly on for detection, then detection capability is maintained, but power consumption increases and user nuisance occurs
Solution Approach 1:
The patent utilizes the angled emission and acceptance cones to create overlapping measurement volumes that maintain detection capability while allowing for periodic or intermittent light activation. The geometric configuration ensures that detection remains effective even when lights are not continuously on, reducing power consumption and user nuisance.
4Measurement precision
If conventional single light source and sensor are used, then device complexity is low, but detection accuracy and sensitivity are insufficient
Solution Approach 1:
The patent introduces angular orientation as a new dimension in the detection system design. By positioning multiple light sources and sensing devices at specific angles to create overlapping measurement volumes, the system achieves superior detection accuracy without proportionally increasing complexity, as the angular arrangement provides geometric optimization rather than simply adding more components.
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
Enhances detection accuracy and reduces false alarms by optimizing light overlap and usage, while maintaining robust detection capabilities for various particles and air quality monitoring without the need for additional sensors.
Implementation Method 1
at least two light sources configured to emit light into a monitored space... at least two light sensing devices configured to receive scattered light
Implementation Method 2
the system includes a polarizing filter optically coupled to at least one of the light sensing devices, or the light sources. An airborne particle type can be discriminated via the use of the polarizing filter
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3A~3C
AI summary
A system for detection and monitoring includes one or more light sources configured to emit light into a monitored space. At least one of the light sources is configured to emit a respective emission cone having a respective emission cone axis. One or more light sensing devices are configured to receive scattered light. At least one of the one or more light sensing devices defines a respective acceptance cone having a respective acceptance cone axis. The emission cone axis of the emission cone, and/or the acceptance cone axis of the light sensing device is angled toward the other. A processor is operatively connected to the at least one light sensing devices to evaluate the scattered light for the presence of particulates in the monitored space.