Aircraft Air Data System Using Acoustic Sensors
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Solution Overview
Problem
Modern aircraft air data systems require redundant and dissimilar sources of air data to prevent common mode errors, but existing systems lack sufficient independence and redundancy, particularly in highly integrated and automated flight control systems.
Innovation Solution
An air data system architecture that combines traditional sensors like pitot probes, angle of attack vanes, and static ports with an acoustic sensor system, which uses multiple acoustic sensors positioned in separate geometric planes to emit and sense acoustic signals, providing independent sets of air data parameters, including angle of attack, angle of sideslip, static air temperature, and static pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional air data systems use redundant sensors, then reliability improves, but the sensors are still susceptible to common mode errors due to similar measurement principles
Solution Approach 1:
The patent replaces traditional mechanical pressure sensors (pitot tubes, static ports) with acoustic sensors that use sound wave propagation to measure air data parameters. This substitution of measurement physics creates dissimilar measurement principles, eliminating common mode errors that affect traditional pressure-based sensors while maintaining redundancy and reliability.
2Productivity
If aircraft systems become more highly integrated and automated, then productivity improves, but the risk of common mode errors increases
Solution Approach 1:
The patent changes the fundamental measurement parameter from pressure (traditional) to acoustic wave propagation time (innovative). By measuring airspeed and other parameters through sound travel time between sensors rather than pressure differentials, the system provides dissimilar measurement data that breaks common mode error chains, enabling higher automation with improved reliability.
3Reliability
If redundant air data sources are derived from dissimilar equipment, then common mode error risk reduces, but device complexity increases
Solution Approach 1:
The acoustic sensor system performs multiple air data measurement functions (airspeed, altitude, temperature) using a single measurement principle based on sound wave propagation. This multi-functionality provides dissimilar measurement data for multiple parameters simultaneously, reducing the need for separate traditional sensor systems while maintaining independence and reducing common mode error risk.
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
This architecture enhances the integrity of air data by providing three independent sets of redundant air data outputs, reducing the risk of common mode failures and improving the reliability of flight control systems by using dissimilar measurement methods, including acoustic technology that can operate under icing conditions.
Implementation Method 1
Each acoustic sensor is configured to emit acoustic signals, such as acoustic pulses, for example, into an airflow about the aircraft exterior and sense the emitted signals
Implementation Method 2
the second aircraft air data parameter outputs are generated based at least in part on a time of flight of the acoustic signals
Data Source
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Figure 2A
Figure 2B
AI summary
A system and method for an aircraft (30; 30') includes an air data system and an acoustic sensing system. The air data system includes a pitot tube (32a) positioned to sense a pitot pressure of an airflow about an exterior of the aircraft (30; 30'), and an angle of attack vane (36a) positioned to sense an angle of attack of the aircraft (30; 30'). The pitot pressure and the angle of attack are used to determine first air data parameters. The acoustic sensing system is configured to emit acoustic signals about the exterior of the aircraft (30; 30') and sense the acoustic signals as sensed data. The sensed data is used to determine second air data parameters.