Aircraft Uplock Retention Detection Using Dual Proximity Sensors
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Solution Overview
Problem
Existing uplocks in aircraft fail to reliably detect whether a capture pin is retained by a hook, as the bulky hook can mask the capture pin, leading to incorrect detection of retention status.
Innovation Solution
An uplock system utilizing a first sensor to detect the hook's retaining position and a second sensor to confirm the presence of the movable element near the uplock when the capture pin is in the hook, without requiring additional movable parts, using proximity sensors or microswitches to ensure accurate detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single proximity sensor is used to detect the hook position, then the device complexity is low, but the measurement precision of retention status is insufficient due to false positives from hook breakage
Solution Approach 1:
The detection function is segmented into two independent sensors: a first proximity sensor for detecting hook position and a second proximity sensor for detecting capture pin presence. This segmentation allows each sensor to perform a specific detection task, improving overall measurement precision while keeping individual sensor complexity low
Solution Approach 2:
An indicator lever is introduced as an intermediary element that translates the presence of the capture pin into a detectable position for the second proximity sensor. The indicator lever acts as a mediator between the capture pin and the sensor, enabling indirect detection of pin presence without requiring direct sensor-to-pin alignment
2Measurement precision
If an indicator lever is added to detect capture pin presence, then the measurement precision improves, but the device complexity increases due to additional movable parts
Solution Approach 1:
The indicator lever serves multiple functions: it detects capture pin presence, provides a mechanical linkage for the second sensor, and works in conjunction with the first sensor to provide comprehensive retention status information. This multi-functionality reduces the need for separate dedicated components
Solution Approach 2:
The patent replaces direct mechanical contact detection with proximity sensor-based detection. The first and second proximity sensors use non-contact sensing methods to detect the positions of the locking member and indicator lever respectively, eliminating the need for complex mechanical switches or direct mechanical linkages between sensors and detected components
3Strength
If the hook is made bulky to ensure capture pin retention, then the strength improves, but the difficulty of detecting and measuring increases due to masking of the capture pin
Solution Approach 1:
The indicator lever serves as an intermediary that translates the presence of the capture pin (which is masked by the bulky hook) into a detectable position. Instead of attempting to directly sense the captured pin through the hook structure, the indicator lever provides an external reference point that the second proximity sensor can detect
Solution Approach 2:
The patent replaces direct mechanical detection of the capture pin with non-contact proximity sensing. The second proximity sensor detects the position of the indicator lever without physical contact, and through the logical relationship between the indicator lever position and capture pin presence, infers pin retention status without needing to physically access or see the pin itself
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 allows for simple and accurate verification that the hook is in the retaining position and the movable element is correctly positioned when the capture pin is retained, distinguishing between actual retention and false positives due to hook breakage.
Implementation Method 1
the locking member is equipped with a target which is movable between a position that is remote from the proximity sensor and a position that is proximate to the proximity sensor, each position of the target being associated with one of the positions of the locking member, so that the electrical signal generated by the proximity sensor changes when the locking member passes from the unlocked position to the locked position and vice versa
Implementation Method 2
a second proximity sensor to detect whether the capture pin is in fact present in the hook when the latter is in its retaining position
Data Source
AI summary
An uplock for retaining a capture pin of a movable part includes a hook that is movable between a release position and a retaining position, a locking part that interacts with the hook and is movable between a locking position and an unlocking position, and a detector. The detector includes a first sensor for detecting whether the hook is in the retaining position, and a second sensor for detecting a presence of the mobile part in the immediate vicinity of the uplock in the position occupied by the mobile part when the capture pin is in the hook.