Variable Alert Lift Coefficient for Aircraft Stall Prediction
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Solution Overview
Problem
Current aircraft alert systems generate alerts based on a fixed alert lift coefficient, which does not account for changes in the aircraft's state during flight, leading to potentially conservative alert speeds that may not accurately predict stall conditions, resulting in unnecessary alerts or failure to alert operators before the aircraft reaches stall speed.
Innovation Solution
A method and apparatus that identify an alert speed for an aircraft using a variable alert lift coefficient, which changes in response to the aircraft's state, by calculating an alert angle of attack and lift coefficient, and using these to set dynamic thresholds for generating alerts, ensuring the alert speed remains above the stall speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed alert lift coefficient is used in current aircraft alert systems, then the alert speed can be determined using a simple fixed threshold, but the alert system generates unnecessary alerts or fails to alert operators before stall because it does not account for changes in aircraft state during flight
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed alert lift coefficient to a variable alert lift coefficient that changes in response to aircraft state. The system dynamically adjusts the alert speed threshold based on real-time aircraft parameters including angle of attack, lift coefficient, and flight conditions, allowing the alert system to adapt to changing aircraft states during flight phases such as takeoff, landing, and maneuvering.
Solution Approach 2:
The patent implements parameter changes by modifying the alert lift coefficient from a constant value to a variable parameter that responds to aircraft state changes. The system calculates alert speed using the variable alert lift coefficient alongside other aircraft parameters (angle of attack, lift coefficient, flight conditions) to generate accurate stall predictions that adapt to different flight scenarios.
2Reliability
If a higher fixed alert speed is used to increase safety, then operators receive earlier warnings, but the aircraft's maneuvering capabilities are reduced and takeoff and landing distances increase
Solution Approach 1:
The system dynamically adjusts alert speed thresholds based on real-time aircraft state rather than using fixed conservative values. By calculating alert speed using variable alert lift coefficient and current aircraft parameters, the system provides safety warnings only when genuinely needed, maintaining maneuvering capabilities during normal operations while ensuring safety during critical phases like takeoff and landing.
Solution Approach 2:
The patent applies local quality by providing different alert speed thresholds for different flight conditions and phases. Rather than using a single conservative threshold for all situations, the system tailors the alert speed to specific flight scenarios (takeoff, landing, cruise, maneuvering) based on aircraft state, ensuring appropriate safety margins are maintained locally for each flight condition without unnecessarily limiting overall maneuvering capability.
3Ease of operation
If a fixed alert speed threshold is used, then the system is simple to operate, but it cannot accurately predict stall conditions across different flight phases and aircraft configurations
Solution Approach 1:
The system implements self-service by automatically calculating and adjusting alert speed thresholds based on real-time aircraft state without requiring manual intervention. The variable alert lift coefficient system self-adapts to different flight phases, configurations, and conditions by processing aircraft parameters (angle of attack, lift coefficient, flight conditions) autonomously, maintaining ease of operation while achieving high adaptability.
Solution Approach 2:
The patent applies universality by creating an alert system that functions across all flight phases and configurations using a unified variable threshold approach. The system based on variable alert lift coefficient and aircraft state parameters provides consistent stall prediction accuracy whether the aircraft is taking off, landing, cruising, or maneuvering, replacing multiple fixed thresholds with a single adaptive mechanism that works universally.
Data Source
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AI summary
The invention relates to a method and system for indicating a potential stall condition (256) for an aircraft (202) during flight. An alert lift coefficient (244) is identified for the aircraft (202). The alert lift coefficient (244) is adjusted in response to a number of changes in a current state of the aircraft (202). A set of thresholds (228) is identified for use in generating an alert (230) indicating that the aircraft (230) has reached the potential stall condition (256) using the alert lift coefficient (244).