Acoustic Air Data System Radial Receiver Array
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional air data systems, particularly those using pneumatic and rotating vane sensors, are susceptible to failures due to icing and particulate buildup, leading to inaccurate measurements and system performance degradation, necessitating redundancy for fault detection and isolation without loss of function.
Innovation Solution
An acoustic air data system comprising two acoustic transmitters and an array of radially paired receivers, where the transmitters emit signals that are received at varying distances and angles, allowing for the determination of time difference of arrival and signal velocity, which are used to estimate airflow parameters like wind angle, speed of sound, Mach number, and true airspeed, providing redundancy and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pneumatic and rotating vane sensors are used to measure airflow parameters, then measurement capability is provided, but susceptibility to icing and particulate buildup increases
Solution Approach 1:
The patent replaces mechanical pneumatic sensors and rotating vane sensors with an acoustic measurement system. Acoustic transmitters emit sound waves that propagate through the airflow to receivers, eliminating mechanical components that are susceptible to icing and particulate buildup. The acoustic signals measure airflow parameters without physical contact with the airflow, thereby resolving the contradiction between providing measurement capability and avoiding harmful effects from icing and particles.
2Reliability
If redundancy is added to detect and isolate faults, then system reliability improves, but device complexity increases
Solution Approach 1:
The acoustic receiver array serves multiple functions: it detects acoustic signals from transmitters, determines time difference of arrival for airflow parameter measurement, and provides redundancy for fault detection and isolation. By making the receiver array multi-functional, the system achieves fault detection capability without proportionally increasing device complexity, as the same hardware components perform multiple roles.
Solution Approach 2:
The system uses multiple acoustic transmitters and receivers that create redundant measurement paths. If one transmitter or receiver fails, others can continue providing measurements. This copying approach provides fault tolerance without requiring completely separate backup systems, thereby limiting the increase in device complexity while improving reliability.
3Measurement precision
If traditional rotating vane sensors are used to measure angle of attack, then measurement is achieved, but rotation mechanism fails under icing conditions
Solution Approach 1:
The patent replaces the mechanical rotating vane sensor with an acoustic measurement system. Acoustic transmitters emit signals that are received by receivers at different positions, and the time difference of arrival of these signals provides angle of attack information without any moving parts. This eliminates the rotation mechanism that fails under icing conditions while maintaining measurement precision.
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
The acoustic air data system effectively determines airflow parameters without direct pressure measurements or angular rotation, offering redundancy to detect and isolate faults, enhancing system reliability and accuracy.
Implementation Method 1
The first acoustic transmitter is located to transmit a first acoustic signal into airflow about an exterior of a vehicle... The array is positioned to receive both the first and second acoustic signals
Implementation Method 2
The control circuitry determines, for each of the first and second sets of acoustic receiver pairs, time difference of arrival (TDOA) of the first and second acoustic signals, respectively
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
An acoustic air data system includes first and second acoustic transmitters, T1, T2, an array of acoustic receivers, and control circuitry (16). The array is positioned to receive first and second acoustic signals. The control circuitry determines time difference of arrival (TDOA) of the first and second acoustic signals. The control circuitry determines, for each of a first and second set of acoustic receiver pairs, a signal velocity of the first and second acoustic signals, respectively, based on a distance between an inner acoustic receiver and an outer acoustic receiver and a corresponding TDOA for each pair of acoustic receivers. The control circuitry estimates one or more of wind angle, speed of sound, Mach number, and true airspeed of the airflow about the exterior of the vehicle based on parameters of a best fit circle.