Pitot-Static Port Blockage Detection via Dual-Sensor Frequency Analysis

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Solution Overview

Problem

Current systems lack a reliable method to detect blockages in pitot tubes and static ports of an aircraft's air data system, which can lead to inaccurate airspeed and altitude measurements due to foreign debris, and often cannot distinguish between faulty sensors and blocked ports.

Innovation Solution

An air pressure measurement system with a primary sensor and a secondary sensor having a higher frequency response is used, where the air data computer analyzes the frequency content and amplitude of the secondary sensor's output to determine if the air inlet is blocked or if the primary sensor is faulty, allowing for accurate aircraft movement measurements even if the primary sensor fails.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single pressure sensor is used to measure air data, then the device complexity is reduced, but the reliability of detection is insufficient because blockages cannot be reliably distinguished from sensor failures

Engineering Contradiction:
Improveblockage detection reliabilityVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The air data sensing function is segmented into two independent pressure sensors with different characteristics. The first pressure sensor provides standard air data measurements, while the second pressure sensor specifically monitors for blockage conditions through frequency analysis of pressure fluctuations. This segmentation allows the system to detect blockages reliably without requiring a completely redundant sensing system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adapts its detection strategy by analyzing the frequency content of pressure signals from the second sensor. When blockage conditions are detected through frequency analysis, the system dynamically switches to using the second sensor's data for air speed and altitude calculations, maintaining reliability without constant complexity.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If pressure sensors with high frequency response are used, then the measurement precision for detecting blockages is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveblockage detection precisionVSAvoidsensor specification complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Different quality requirements are applied to different sensors based on their specific functions. The first pressure sensor uses standard specifications suitable for general air data measurement, while the second pressure sensor uses higher frequency response specifications specifically tailored for blockage detection. This local quality approach optimizes measurement precision for blockage detection without unnecessarily specifying high-performance sensors for all functions.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If current blockage detection methods are used, then the device complexity remains low, but the measurement precision for distinguishing blockages from sensor failures is insufficient

Engineering Contradiction:
Improvefault discrimination precisionVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The second pressure sensor provides excessive measurement capability by capturing high-frequency pressure fluctuations that are beyond what is needed for standard air data measurement. This partial redundancy in measurement capability enables precise discrimination between blockages and sensor failures through frequency analysis, without requiring a complete duplicate of the sensing system.

Inventive Principle:
Principle #16Partial or excessive action

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 solution enables reliable detection of blockages and sensor malfunctions, ensuring accurate airspeed and altitude data by utilizing the secondary sensor's higher frequency response to provide backup measurements for gust load alleviation and stable flight control systems.

Implementation Method 1

a second sensor that is separate and independent from the first pressure sensor, the second pressure sensor having a frequency response higher than the frequency response of the first pressure sensor

Methodology Applied
Scientific EffectPressure fluctuation detection:

Data Source

PatentEP2453245B1System and method for detecting blocked Pitot-Static Ports
Publication Date: 2018.08.01 ROSEMOUNT AEROSPACE INC
  • EP2453245B1 patent drawingFigure 1
  • EP2453245B1 patent drawingFigure 2A~2B
  • EP2453245B1 patent drawingFigure 3

AI summary

An avionics system and process for detecting pneumatic blockages having an air pressure measurement system including a first sensor positioned in association with the air inlet of an air probe component. The air pressure measurement system having a second sensor positioned in association with the air inlet for detecting air pressure in which the second sensor has a frequency response higher than that of the first sensor. An air data computer is coupled to each of the first and second sensors being configured and operable to calculate a first aircraft movement measurement using detected air pressure from the first sensor and is further operative to determine if the first sensor is faulty or if the air inlet is blocked in dependence upon the frequency content and amplitude of the output from the second sensor.