Aircraft Bleed Air Duct Sensor Self-Testing via Alternating Current

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Solution Overview

Problem

Conventional methods for testing bleed duct air system sensors in aircraft require removing the control system from the electronics bay and using expensive testing devices, making frequent maintenance testing impractical due to cost and availability issues.

Innovation Solution

An interactive duct leak detection system that allows in-situ testing of sensors by sending alternating current through them to measure resistance, determining sensor health without depowering the aircraft or removing the control system, using an interface to display test results and alert faulty sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional testing methods are used to test sensors, then sensor health can be determined, but the control system must be removed from the electronics bay and expensive testing devices must be used

Engineering Contradiction:
Improvesensor health determinationVSAvoidtesting accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The control system tests the sensors itself using its own microcontroller and circuitry, eliminating the need for external testing devices. The microcontroller activates a test switch that connects test circuitry to the sensors, allowing the system to self-diagnose sensor health without requiring external equipment or removal from the aircraft.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control system performs multiple functions: it normally controls the bleed duct air system and also performs sensor testing functions. By integrating the testing capability into the existing control system, the patent eliminates the need for separate expensive testing devices and makes testing accessible whenever the control system is operational.

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

2Reliability

If conventional testing methods are used, then sensor testing can be performed, but frequent maintenance testing is impractical due to cost and availability issues

Engineering Contradiction:
Improvesensor testing capabilityVSAvoidmaintenance frequency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control system tests the sensors itself using its own microcontroller and circuitry, eliminating the need for external testing devices. The microcontroller activates a test switch that connects test circuitry to the sensors, allowing the system to self-diagnose sensor health without requiring external equipment or removal from the aircraft.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses the existing control system's microcontroller and circuitry for testing instead of requiring expensive external testing devices. This approach makes frequent testing practical by eliminating the cost barrier associated with specialized testing equipment.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If direct current is sent through sensors for testing, then sensor resistance can be measured, but the sensors may be destroyed

Engineering Contradiction:
Improveresistance measurementVSAvoidsensor damage
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the electrical parameter used for testing from direct current to alternating current. The microcontroller generates an alternating current signal that passes through the sensor, and the resulting signal is analyzed to determine sensor health. This parameter change allows measurement while preventing the destructive effects of direct current.

Inventive Principle:
Principle #35Parameter changes

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 real-time monitoring and testing of bleed duct air system sensors, reducing maintenance costs and frequency by allowing testing without removing the control system from the aircraft, thus improving operational efficiency and safety.

Implementation Method 1

sends alternating current through them to measure resistance

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP3021100B1Real-time fault detection of a bleed air duct system
Publication Date: 2018.04.04 KIDDE TECHNOLOGIES INC
  • EP3021100B1 patent drawingFigure 1
  • EP3021100B1 patent drawingFigure 2
  • EP3021100B1 patent drawingFigure 3

AI summary

A method and apparatus for testing a duct leak detection system of an aircraft is disclosed. A sensor (212) of the duct leak detection system is selected at an interface (202) of the duct leak detection system. An alternating current is sent through the selected sensor (212) and a resistance of the selected sensor (212) is measured using the alternating current. An indicative signal is generated at the interface (202) when the measured resistance of the selected sensor (212) is outside of a specification of the selected sensor (212).