Aircraft Angle of Attack Probe with Dual-Axis Articulation

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Solution Overview

Problem

Existing aircraft angle of attack measurement systems are not capable of accurately measuring sideslip and total pressure, and are sensitive to Mach number and temperature variations.

Innovation Solution

A device with a probe equipped with central and eccentric directional sensors, capable of rotating around two axes, aligns itself with the relative wind to measure angle of attack and sideslip, using actuators and control units to equalize sensor measurements and ensure accurate alignment, with sensors like pressure or thermocouples for various flight conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a probe with central and eccentric directional sensors is used to measure angle of attack, then angle of attack measurement is achieved, but sideslip and total pressure measurement capabilities are lacking

Engineering Contradiction:
Improveangle of attack measurementVSAvoidmeasurement capabilities
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The probe is equipped with multiple directional sensors (central and eccentric) that enable the same device to measure angle of attack, sideslip angle, and total pressure simultaneously, making a single instrument serve multiple measurement functions

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If conventional pressure sensors are used for subsonic flight, then angle of attack measurement works, but measurements become sensitive to Mach number and temperature variations

Engineering Contradiction:
Improveangle of attack measurementVSAvoidsensitivity to Mach number and temperature
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The invention switches the sensing mechanism based on flight conditions: using pressure sensors for subsonic flight and thermocouples for supersonic or hypersonic flight, thereby adapting the measurement parameters to the operating regime and eliminating sensitivity to Mach number and temperature variations

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the probe is fixed to the aircraft, then installation is simple, but the probe cannot align with relative wind to measure sideslip accurately

Engineering Contradiction:
Improveinstallation simplicityVSAvoidsideslip measurement
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The probe is made dynamically adjustable through articulation mechanisms that allow it to rotate around two axes, enabling real-time alignment with the relative wind direction while maintaining a relatively simple fixed mounting structure on the aircraft

Inventive Principle:
Principle #15Dynamics

4Measurement precision

If the probe rotates around one axis only, then angle of attack measurement is possible, but sideslip measurement capability is lost

Engineering Contradiction:
Improveangle of attack measurementVSAvoidsideslip measurement capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The probe's articulation system is extended from single-axis rotation to dual-axis rotation, adding a second rotational degree of freedom that enables measurement of both angle of attack and sideslip angle by capturing wind direction information in two independent directions

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Enables continuous and accurate measurement of aircraft angle of attack and sideslip, while being insensitive to Mach number and temperature, providing reliable total pressure readings.

Implementation Method 1

the probe (11) aligns itself with the relative wind (VR) by rotating, around a first articulation axis (8), an angle corresponding to the angle of attack (a) and, around a second articulation axis (XX), an angle corresponding to the sideslip angle (e)

Methodology Applied
Scientific EffectAerodynamic alignment:

Implementation Method 2

The central directional sensor, the aforementioned eccentric median directional sensors, and the aforementioned lateral directional sensors can be pressure sensors, particularly effective for subsonic aerobic flight

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 3

For example, for supersonic or hypersonic flight, it is advantageous for these sensors to be thermocouples

Methodology Applied
Scientific EffectThermocouple effect: Thermocouple

Data Source

PatentEP3060929B1Method and device for measuring the angle of attack and the sideslip of an aircraft
Publication Date: 2020.01.15 ARIANEGRP SAS
  • EP3060929B1 patent drawingFigure 1~4

AI summary

According to the present invention, use is made of a probe (11) provided with a central sensor (3), with off-centred sensors (4, 5) and lateral sensors (13, 14) and said probe (11) is articulated on the aircraft around two orthogonal axes (8, X-X).