Inflatable Restraint Sensor Housing with Magnetic Envelope
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Solution Overview
Problem
Inflatable personal restraint systems in aircraft face challenges due to varying seating arrangements and lack of stationary structures for airbag deployment, leading to potential inadvertent activation by external magnetic fields, which existing technologies attempt to mitigate with costly and heavy magnetic shields.
Innovation Solution
The development of an electronics module assembly (EMA) with a domed protrusion around the crash sensor and integrated magnetic field sensors that detect and prevent external magnetic interference, eliminating the need for a magnetic shield by creating a physical envelope around the sensor to prevent inadvertent airbag deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a magnetic shield (Mu-metal) is positioned over the crash sensor to prevent external magnetic field interference, then the reliability of the crash sensor is improved, but the weight, cost, and device complexity increase
Solution Approach 1:
The patent removes the magnetic shield (Mu-metal) from the EMA assembly, extracting the harmful component that caused weight and cost issues. Instead of shielding the crash sensor with heavy magnetic material, the design relies on the inherent magnetic field detection capabilities of the crash sensor itself to distinguish between external magnetic fields and actual crash conditions.
Solution Approach 2:
The patent introduces magnetic field sensors as intermediary components that detect external magnetic fields and provide this information to the control unit. The control unit then uses this information to differentiate between external magnetic interference and actual crash conditions, eliminating the need for heavy magnetic shields while maintaining reliable operation.
2Reliability
If a magnetic shield (Mu-metal) is positioned over the crash sensor to prevent external magnetic field interference, then the reliability of the crash sensor is improved, but the cost increases
Solution Approach 1:
The patent removes the expensive Mu-metal magnetic shield from the EMA assembly, extracting the harmful component that caused high manufacturing costs. This elimination of expensive materials directly reduces the cost of manufacturing the restraint system while maintaining functionality through alternative means.
Solution Approach 2:
The patent introduces magnetic field sensors and a control unit as intermediary components that detect and process magnetic field information. This approach replaces expensive passive magnetic shielding with active detection and processing, which uses less expensive electronic components rather than costly Mu-metal materials.
3Reliability
If a magnetic shield (Mu-metal) is positioned over the crash sensor to prevent external magnetic field interference, then the reliability of the crash sensor is improved, but the device complexity increases
Solution Approach 1:
The patent removes the magnetic shield component from the EMA assembly, extracting the complex element that required precise positioning and integration. This simplification eliminates the need for complex magnetic shielding structures while maintaining reliability through alternative detection methods.
Solution Approach 2:
The patent makes the control unit multi-functional by giving it the additional responsibility of processing magnetic field sensor data alongside crash sensor data. This consolidation of functions into existing components avoids adding separate complex subsystems, thereby maintaining reliability while minimizing increases in overall device complexity.
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 solution effectively reduces the likelihood of airbag deployment due to external magnetic fields, eliminating the need for expensive Mu-metal shields, thereby reducing weight, cost, and size while ensuring reliable airbag activation during crashes.
Implementation Method 1
an electronic activation system positioned on or proximate to the seat to initiate airbag inflation. Electronic activation systems typically include a crash sensor (e.g., Hall effect sensors) that uses a magnetic field to detect rapid decelerations
Implementation Method 2
The EMA includes a magnetic field sensor that detects the presence of an external magnetic field
Data Source
AI summary
Electronics module assemblies (“EMAs”) for inflatable personal restraints and associated systems are described herein. An EMA configured in accordance with an embodiment of the present technology can include, for example, a housing having a body portion, cover portion that attaches to the body portion to form an enclosure, and protrusion extending outwardly from the cover portion. The protrusion can have an outer boundary at which the protrusion projects away from the cover portion. The EMA can further include a crash sensor within the enclosure in an area defined by the outer boundary of the protrusion. The protrusion can form an envelope of space around the crash sensor that defines a minimum distance an external object with a magnetic field can come to the crash sensor without activating it. The EMA can optionally include a magnetic field configured to disable the crash sensor upon the detection of an external magnetic field.