Aircraft Wheel Pulse Voting for Reliable Landing Identification
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Solution Overview
Problem
Conventional aircraft systems fail to accurately identify landing events when landing systems, such as weight on wheels (WOW) or landing gear down lock, malfunction, leading to suboptimal performance in aircraft components that rely on these signals.
Innovation Solution
A method and system that measure angular displacement of aircraft wheels over time to determine wheel velocity, comparing it to a threshold value to output a 'landing likely' or 'landing unlikely' message, utilizing a voting scheme across multiple wheels to verify the occurrence of a landing event and reduce noise and transient anomalies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional aircraft systems use landing systems signals (WOW or landing gear down lock) to identify landing events, then the landing identification is simple to implement, but the system reliability deteriorates when landing systems fail
Solution Approach 1:
The patent introduces an intermediary system (wheel speed sensor, timer, counter, comparator) that mediates between the wheel rotation and the landing identification function. This intermediary measures wheel angular displacement independently of the landing gear system, providing a reliable landing detection mechanism that does not depend on landing system signals.
Solution Approach 2:
The patent replaces the mechanical/structural landing system signals (WOW, gear down lock) with an electronic measurement system based on wheel speed sensing. By substituting the mechanical detection method with an electronic wheel rotation measurement system, the patent achieves independent landing identification that is not affected by landing system failures.
2Measurement precision
If the system uses wheel angular displacement measurement to identify landing events, then the landing detection accuracy improves, but the device complexity increases due to additional components
Solution Approach 1:
The patent segments the landing detection function into distinct modular components: wheel speed sensor for angular displacement measurement, timer for time period generation, counter for pulse counting, and comparator for threshold evaluation. This segmentation allows each component to perform a specific function with high precision while maintaining overall system manageability.
Solution Approach 2:
The wheel speed sensor serves multiple functions: it provides angular displacement information for landing detection, wheel speed information for other aircraft systems, and rotation status monitoring. This multi-functionality reduces the need for dedicated components solely for landing detection, thereby limiting the increase in device complexity.
3Reliability
If the system implements a voting scheme across multiple wheels, then the false positive rate reduces, but the measurement and processing complexity increases
Solution Approach 1:
The patent merges the landing detection logic for multiple wheels into a unified voting scheme implemented through logical operations. The voting comparator combines results from multiple wheel comparators using logical AND/OR operations, simplifying the complexity of implementing a voting mechanism across multiple sensors while maintaining high reliability and false positive reduction.
4Measurement precision
If the system uses a time period threshold for pulse counting, then the landing event identification accuracy improves, but the processing time increases
Solution Approach 1:
The patent optimizes the time period parameter (set between 50-500 milliseconds) to achieve the best balance between measurement precision and processing time. By carefully selecting this parameter, the system ensures sufficient accuracy in landing event identification while minimizing the time delay in detection and response.
Data Source
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AI summary
Systems and methods disclosed herein may be useful for use in landing identification. In this regard, a method is provided comprising receiving pulse information (102) over a first time period, wherein the pulse information is indicative of an angular distance traveled by a first wheel, comparing (108) the pulse information to a threshold value (110), and determining a likelihood of a landing event based upon the comparison. In various embodiments, a system is provided comprising a monstable multivibrator in electrical communication with a metal-oxide-semiconductor field-effect transistor (MOSFET), a resistor-capacitor network in electrical communication with the MOSFET, and a comparator that receives a voltage from the resistor-capacitor network and a reference voltage.