Aircraft Angle-of-Attack Estimation Without Dedicated Sensors
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Solution Overview
Problem
Existing angle of attack systems for aircraft require dedicated sensors and knowledge of aerodynamic parameters, making them complex to install and unreliable in modified aircraft, and often provide inaccurate information in windy and turbulent conditions.
Innovation Solution
A system and method that determines angle of attack using a calibration process to estimate aerodynamic parameters, utilizing a processor with algorithms like the Extended Kalman Filter, which combines sensor data with an estimated aerodynamic model, independent of aircraft weight, and provides graphical indications through avionics devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dedicated sensors are used to measure angle of attack, then measurement precision is improved, but device complexity and installation difficulty increase
Solution Approach 1:
The patent replaces dedicated mechanical angle of attack sensors with a computational system that uses data from existing navigation sensors (accelerometers, GPS, attitude indicators) combined with aerodynamic models to calculate angle of attack. This substitution eliminates the need for specialized mechanical sensors while achieving comparable measurement precision through mathematical computation and sensor fusion algorithms.
2Reliability
If dedicated sensors are installed, then angle of attack indication reliability is improved, but ease of manufacture and installation deteriorate
Solution Approach 1:
The patent creates a universal angle of attack indication system that works across multiple aircraft types by using standard navigation sensors already present in modern aircraft. The system employs configurable aerodynamic models that can be adapted to different aircraft configurations through calibration, making it universally applicable without requiring aircraft-specific modifications or dedicated sensor installations.
Solution Approach 2:
The system performs self-calibration and adaptation by using flight test data to automatically tune its aerodynamic models to the specific aircraft configuration. This self-service capability eliminates the need for complex manual calibration procedures and allows the system to maintain reliability across different operational conditions and aircraft modifications.
3Measurement precision
If aerodynamic parameters are used in calculation, then angle of attack accuracy is improved, but adaptability to modified aircraft deteriorates
Solution Approach 1:
The patent implements dynamic aerodynamic models that can be adjusted and recalibrated based on aircraft modifications. Rather than using fixed static parameters, the system continuously adapts its aerodynamic model through calibration flights that capture the actual flight characteristics of the modified aircraft, allowing it to maintain accuracy despite changes in wing configuration, fuselage shape, or other aerodynamic modifications.
4Device complexity
If simple inertial data is used, then device complexity is reduced, but measurement precision in turbulent conditions deteriorates
Solution Approach 1:
The patent merges data from multiple independent navigation sensors including accelerometers, GPS velocity data, attitude indicator information, and barometric altitude data to compute angle of attack. This multi-sensor fusion approach combines the strengths of different measurement systems to compensate for individual sensor limitations during turbulent flight, maintaining precision without requiring complex dedicated angle of attack sensors.
Data Source
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AI summary
A system for and method of indicating an angle of attack of an aircraft is provided. The system utilizes measurements from existing aircraft sensors so that a dedicated angle of attack sensor is not required. The system enables and benefits from a unique method that includes performing standard flight operations during a calibration flight. The system does not need any aerodynamic model of the aircraft because it utilizes information from the calibration flight to develop an estimated aerodynamic model of the specific airplane. The system utilizes the aerodynamic model and other information to estimate an angle of attack of the aircraft during flight. Finally, the system utilizes additional information to indicate the estimated angle of attack of the aircraft relative to an optimum angle of attack for the aircraft and/or a critical angle of attack of the aircraft. The system further enables recalibration, so as to accommodate aircraft aerodynamic modifications.