Landing Gear Retraction Using Strut Position Feedback
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Solution Overview
Problem
Existing aircraft landing gear retraction systems require manual pilot intervention during take-off, leading to delayed retraction, increased drag, noise, and potential damage risks due to extended landing gear exposure.
Innovation Solution
A landing gear system with a controller that automatically initiates retraction based on sensor inputs, such as strut position and bogie angle, to reduce manual workload and expedite the retraction process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual pilot intervention is used to control landing gear retraction, then the pilot maintains control over the process, but retraction is delayed and increases drag, noise, and damage risks
Solution Approach 1:
The landing gear system automatically monitors its own position via the position sensor and initiates retraction without pilot intervention. The controller detects when the landing gear is in the extended position and automatically commands retraction, allowing the system to serve itself rather than requiring continuous manual oversight.
Solution Approach 2:
The position sensor provides continuous feedback to the controller about the landing gear's position. This feedback loop enables the controller to make real-time decisions about when to initiate retraction, creating an automated closed-loop control system that responds to actual system state rather than pilot input delays.
2Device complexity
If landing gear remains in extended position longer, then manual control is simpler, but aircraft drag and noise increase
Solution Approach 1:
The patent replaces manual mechanical control with an automated electronic control system. The position sensor and controller form an electronic feedback system that automatically manages landing gear retraction, substituting pilot manual operations with an electronic control loop that optimizes retraction timing to reduce drag and noise.
3Loss of time
If automatic retraction is implemented, then retraction timing is optimized, but system complexity increases with sensors and controllers
Solution Approach 1:
The position sensor serves multiple functions: it monitors landing gear position for automatic retraction initiation, provides feedback for control system operation, and enables the controller to make informed decisions about retraction timing. This multi-functionality reduces the need for separate dedicated components for each function.
4Extent of automation
If retraction is delayed, then manual monitoring is sufficient, but damage risks increase due to extended exposure
Solution Approach 1:
The position sensor continuously monitors the landing gear position in advance, and the controller is pre-programmed with the criteria for initiating retraction. When the predetermined conditions are met (landing gear in extended position for greater than a predetermined time period), the system automatically initiates retraction before damage can occur, performing the protective action in advance based on monitored conditions.
Data Source
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AI summary
Disclosed is a landing gear system (100) for an aircraft, the landing gear system comprising: a landing gear (130) that is movable between an extended position and a retracted position, the landing gear comprising an extendible strut (136); a position sensor (140) configured to detect a position of a part of the extendible strut and output a signal indicative of the position; and a landing gear controller (150) that is communicably connected to the position sensor and is configured, in use, to: receive the signal from the position sensor; and, on the basis of the signal, determine that the strut has extended and the landing gear is in contact with the ground and automatically cause performance of at least a portion of a procedure to move the landing gear from the extended position to the retracted position