Aircraft Control Surface Boarding Detection via Current Error Signal
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Solution Overview
Problem
Current methods for detecting uncontrolled movements of aircraft control surfaces, known as 'boarding,' in servo-controlled systems are not robust enough to identify failures regardless of their dynamic profile or origin, leading to potential structural damage and loss of control.
Innovation Solution
A method that compares theoretical and actual servo currents to detect boarding by calculating an error signal and confirming it against a threshold value, using a Kalman filter for improved detection and stability, allowing for quick identification and mitigation of failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current detection methods are used for detecting boarding in servo-controlled systems, then the detection process is simple, but the detection reliability is insufficient and cannot identify failures regardless of their dynamic profile or origin
Solution Approach 1:
The patent implements a feedback mechanism by continuously comparing the theoretical servo current (calculated from control commands and system model) with the actual measured servo current, generating an error signal that feeds back into the detection logic. This closed-loop feedback enables reliable detection of boarding failures by monitoring deviations between expected and actual system behavior, resolving the contradiction between detection reliability and system complexity.
Solution Approach 2:
The patent replaces traditional mechanical or simple electrical detection methods with an electrical signal processing approach. By substituting physical measurement mechanisms with electrical current comparison and digital signal processing (including Kalman filtering), the system achieves higher detection reliability while maintaining manageable complexity through software-based solutions.
2Speed
If traditional detection methods are used, then the system complexity is low, but the detection speed is insufficient to prevent structural damage
Solution Approach 1:
The patent applies preliminary action by continuously calculating and comparing theoretical versus actual servo currents in real-time, maintaining a ready-to-detect state. The error signal is continuously generated and processed through confirmation logic and Kalman filtering, enabling rapid detection of boarding failures the moment they occur, thus achieving high detection speed without excessive complexity through efficient real-time processing.
Solution Approach 2:
The patent introduces an intermediary error signal that mediates between the theoretical servo current calculation and the actual measured current. This error signal serves as an intermediate representation that captures deviations indicating boarding failures, allowing the system to detect issues rapidly through simple threshold comparisons and filtering operations on this intermediary variable, balancing speed and complexity.
3Measurement precision
If detection threshold is set low for quick detection, then detection sensitivity increases, but false alarms increase
Solution Approach 1:
The patent applies partial action by requiring confirmation of the error signal above the threshold for a specified duration before triggering a boarding detection. This partial confirmation requirement filters out transient noise and false signals while maintaining sensitivity to genuine boarding failures, effectively balancing detection sensitivity with false alarm reduction.
Solution Approach 2:
The patent dynamically adjusts detection parameters through the Kalman filter, which adapts to system conditions and optimizes the error signal processing. By changing the filtering parameters and confirmation thresholds based on system behavior, the system maintains high detection sensitivity while minimizing false alarms through adaptive parameter tuning rather than fixed threshold settings.
Data Source
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AI summary
The method involves determining theoretical feedback current representing a feedback command emitted by a controller (10). A parameter of the feedback command is measured by using an auxiliary sensor (21), and effective feedback current is determined by the measured parameter. Difference between the theoretical feedback current and the effective feedback current is calculated to form an error signal. Uncontrolled movement of a control surface (3) is detected if comparison value depending on the error signal is higher than threshold value during confirmation time. Independent claims are also included for the following: (1) a device for detecting uncontrolled movement of a control surface of an aircraft (2) an electrical flying command system of an aircraft.