Aircraft Hose Movement Sensor for Snag Detection
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Solution Overview
Problem
Existing hose management systems for aircraft conditioned air supply struggle to accurately detect when a hose is snagged, leading to potential damage due to continued motor operation despite the hose being unable to move, as torque sensing circuitry may fail to differentiate between snagging forces and surface friction.
Innovation Solution
A hose movement detector using a rotating member with apertures and a proximity sensor to generate a signal indicating hose movement, which disables drive motors when a fault condition is detected, such as snagging, to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If torque sensing circuitry is used to detect hose snagging, then the system can detect some obstruction forces, but it fails to differentiate between snagging forces and surface friction, leading to false negatives
Solution Approach 1:
The patent replaces the torque sensing mechanism with a direct mechanical motion detection system. A sensor (such as a Hall effect sensor, optical sensor, or proximity sensor) directly detects the motion state of the hose or the drive mechanism, substituting the indirect torque measurement approach with a direct position/velocity measurement approach. This eliminates the ambiguity between friction and snagging forces that plagues torque-based systems.
Solution Approach 2:
The patent introduces an intermediary mechanical element (such as a flag, magnet, or reflective surface) attached to the hose or drive mechanism that serves as a mediator for motion detection. This intermediary element interacts with the sensor to provide clear, unambiguous signals about hose motion, allowing the system to distinguish between normal friction (where motion occurs) and snagging (where motion stops) without relying on force magnitude interpretation.
2Reliability
If the torque sensing threshold is set high to avoid false positives from friction, then false negatives increase and hose damage occurs, but if set low then false positives increase causing unnecessary motor shutdown
Solution Approach 1:
By replacing the torque sensing system with a direct motion detection system, the patent eliminates the threshold-setting dilemma entirely. The sensor directly detects whether the hose is moving or stationary, providing binary motion state information that does not require threshold calibration. This substitution removes the trade-off between sensitivity and false alarms, as the system responds to actual motion cessation rather than interpreted force levels.
Solution Approach 2:
The motion detection system allows the hose itself to provide the detection signal through its motion state. When the hose moves normally, the attached intermediary element triggers the sensor; when the hose stops due to snagging, the signal changes. The system uses the hose's own mechanical behavior as the detection mechanism, eliminating the need for external force application and interpretation.
3Measurement precision
If a rotating member with apertures and proximity sensor is used to detect hose movement, then accurate motion detection is achieved, but device complexity increases
Solution Approach 1:
The patent uses parameter changes in the rotating member (such as varying aperture patterns, magnet positions, or reflective surface characteristics) to encode motion information. By changing the physical parameters of the rotating component, the system can detect both presence and direction of motion using a single sensor, reducing the need for multiple sensors while maintaining detection accuracy.
Solution Approach 2:
The rotating member with apertures serves multiple functions: it acts as a motion indicator, a signal generator, and a reference for direction detection. This single component performs what would otherwise require multiple separate sensors or mechanisms, reducing overall system complexity while maintaining accurate motion detection capability.
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
Effectively prevents hose damage by accurately detecting when the hose is caught and disabling the drive motors, reducing the risk of abrasion and damage from continued motor operation.
Implementation Method 1
A sensor senses rotation of the rotating member to provide the signal; in the illustrated embodiment the sensor is a proximity detector which detects holes in the rotating member which pass under the sensor as the rotating member is rotated.
Data Source
AI summary
A hose movement detector for an aircraft PCA hose management system comprises a sensor that provides a signal to indicate a first condition when a hose is moving into an aircraft ventilation hose management system or out of the aircraft ventilation hose management system and that does not provide the signal when the hose is not moving. The output of the sensor is usable to disable hose drive motors when a fault condition is preventing the hose from moving, such as the hose being caught by an obstruction, and thus avoid damage to the hose management system or its hose.