Angle-of-Attack Probe Self-Test Using Sinusoidal Excitation
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Solution Overview
Problem
Existing methods for verifying the integrity of angle-of-attack probes during flight are inadequate, relying on data from multiple systems that can lead to false alarms and uncertainties, especially in critical flight phases where small angular differences exist between normal flight and stall.
Innovation Solution
A self-test method for angle-of-attack probes that uses a rotating element under airflow influence, with a sinusoidal excitation and parasitic torque analysis to detect malfunctions without relying on other sensors, combined with a verification process for airflow velocity using multiple probes to ensure reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data from multiple systems (airspeed sensors, accelerometers, other probes) are fused to verify angle of attack probe integrity, then measurement reliability is improved, but device complexity and false alarm risk increase
Solution Approach 1:
The probe performs self-verification by injecting a known test signal and measuring its own response. The integrity verification system uses the probe's inherent sinusoidal motion capability to generate self-test data, eliminating the need for external verification systems and reducing overall system complexity while maintaining reliability
Solution Approach 2:
The invention uses airflow dynamics as the verification mechanism. By analyzing the probe's response to sinusoidal angular excitation in the airflow, the system verifies probe integrity through aerodynamic forces rather than mechanical or electronic sensor fusion, simplifying the verification approach
2Reliability
If data from multiple systems are used to determine angle of attack likelihood, then measurement robustness is improved, but uncertainty in critical flight phases increases
Solution Approach 1:
The system performs preliminary integrity verification before using probe data for flight control. By checking probe responsiveness and linearity through sinusoidal excitation tests, the system ensures measurement accuracy is maintained, particularly in critical flight phases where precision is paramount
Solution Approach 2:
The verification system continuously monitors probe response to test signals and provides feedback on probe health status. This feedback mechanism allows the system to detect degradation early and maintain measurement precision by adjusting or flagging data from probes showing signs of malfunction
3Manufacturing precision
If static testing of the probe is performed on the ground, then probe positioning accuracy is improved, but in-flight verification capability is reduced
Solution Approach 1:
The system transitions from static ground testing to dynamic in-flight verification. By using sinusoidal angular excitation during flight, the probe's dynamic response characteristics are tested, providing ongoing verification of probe functionality in the actual operating environment rather than relying solely on pre-flight static calibration
4Stability of the object's composition
If the rotating element is stabilized by airflow, then measurement stability is improved, but susceptibility to parasitic torques increases
Solution Approach 1:
The system uses sinusoidal vibration/excitation of the rotating element to detect parasitic torques. By analyzing the probe's vibrational response characteristics, the system can identify and compensate for parasitic torque effects while maintaining the stability benefits of airflow stabilization
Solution Approach 2:
The verification system converts the harmful effect of parasitic torques into a useful diagnostic tool. By measuring deviations in the expected sinusoidal response caused by parasitic torques, the system detects probe malfunctions such as icing or mechanical binding, turning a destabilizing factor into a detection mechanism
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
Ensures reliable in-flight probe integrity verification by detecting failures independently and improving fault localization, enhancing reliability and integrity in aircraft systems with multiple probes.
Implementation Method 1
a rotating element (31) capable of rotating around an axis of rotation (Z) under the influence of an airflow (F)
Implementation Method 2
a sinusoidal excitation of the rotating element around its equilibrium position
Implementation Method 3
a sensor (24) capable of measuring an angle of rotation of the rotating element (31) around the axis of rotation (Z)
Data Source
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AI summary
The present invention relates to a method (100) for self-testing an angle-of-attack probe comprising the steps of controlling (110) an angular excitation of a rotary element that is rotatable about its equilibrium position according to known excitation characteristics; acquiring (120) angular measurements relating to the rotation of the rotary element, determining (130) a parasitic torque applied to the rotary element on the basis of the angular measurements and of the excitation characteristics; comparing (160) at least one component of the parasitic torque with at least one predetermined threshold and detecting (170) an operating fault in the probe when said component exceeds the predetermined threshold.