COPC Sensor for Aircraft Hydraulic Leakage Detection

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Solution Overview

Problem

Current hydraulic system leak detection methods in aircraft are inadequate as they require the system to be running, are difficult to implement without major modifications, and struggle with accessing hidden spaces, leading to potential safety risks and increased maintenance costs.

Innovation Solution

A system utilizing extended sensors based on the collapse of percolation conductivity (COPC) with a conducting compound embedded in a solvable matrix, which increases resistance upon exposure to hydraulic liquids, allowing for early detection without the need for the hydraulic system to be operational and without calibration, using a digital multi-channel multimeter for data logging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If visual inspection methods are used to detect hydraulic liquid leakage, then the system requires no additional sensors or modifications, but hidden spaces cannot be accessed and leakage can only be detected at regular heavy inspections or when leakage becomes obvious

Engineering Contradiction:
Improveleakage detection capabilityVSAvoidaccess to hidden spaces
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sensing system is divided into multiple discrete sensor elements that can be strategically placed in different locations including hidden spaces. Each sensor independently monitors its local area, and collectively they provide comprehensive coverage of the entire hydraulic system, including difficult-to-reach regions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A permeable membrane or barrier layer is introduced as an intermediary between the hydraulic system and the sensor. This membrane allows hydraulic liquid to pass through while enabling the sensor to detect the liquid's presence without requiring direct access to the hydraulic components, thus facilitating monitoring in hidden spaces

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If current sensor systems are implemented for continuous monitoring, then early detection of leakage is possible, but the hydraulic system must remain running and major modifications are required

Engineering Contradiction:
Improvecontinuous monitoring capabilityVSAvoidsystem modifications required
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sensor system utilizes the hydraulic liquid itself as the sensing medium. When hydraulic liquid leaks, it directly interacts with the sensor material, causing a measurable change in electrical resistance. The system self-detects the leak without requiring external power sources, complex electronics, or activation of the hydraulic system

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces complex mechanical sensor systems with a simple electrical resistance-based detection method. Instead of using mechanical switches, pressure sensors, or flow meters that require power and calibration, the system uses the inherent electrical properties of conductive composite materials that change resistance when exposed to hydraulic liquid

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Area of stationary object

If extended sensors based on COPC are deployed to cover large areas, then comprehensive monitoring is achieved, but the cost of instrumentation increases

Engineering Contradiction:
Improvesensor coverage areaVSAvoidinstrumentation cost
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The electrical resistance of the conductive composite material changes dramatically (by several orders of magnitude) when exposed to hydraulic liquid. This large parameter change provides a clear, unambiguous detection signal that can be measured with simple, low-cost electronics, reducing the overall instrumentation cost despite extended sensor coverage

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sensor utilizes a composite material consisting of conductive particles dispersed in a polymer matrix. This composite provides both the necessary electrical conductivity for sensing and the mechanical flexibility for large-area deployment. The composite material can be manufactured using cost-effective techniques such as spray coating, dip coating, or lamination, making extended coverage economically feasible

Inventive Principle:
Principle #40Composite materials

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, in-situ monitoring of hydraulic system health, reducing the risk of pressure drops and passenger safety incidents by detecting leaks in hard-to-reach areas without requiring the system to be operational or modified, and providing early warning for maintenance.

Implementation Method 1

extended sensors based on the collapse of percolation conductivity (COPC) which sensors are covering an area in the aircraft

Methodology Applied
Scientific EffectCollapse of percolation conductivity (COPC): Conduction (electrical)

Implementation Method 2

the detection of corrosive and hydraulic liquids by gauges based on the collapse of percolation conductivity

Methodology Applied
Scientific EffectPercolation conductivity: Conduction (electrical)

Data Source

PatentEP2627562B1Sensor for detecting hydraulic liquids in aircraft
Publication Date: 2017.04.26 KATHOLIEKE UNIV LEUVEN
  • EP2627562B1 patent drawingFigure 1
  • EP2627562B1 patent drawingFigure 2
  • EP2627562B1 patent drawingFigure 3

AI summary

The present invention relates generally to a system that monitors the condition of hydraulic systems for an aircraft or for other applications and, more particularly, to a system and method for detecting leakage within the hydraulic system aboard an aircraft. Such system is detecting hydraulic liquids by extended sensors based on the collapse of percolation conductivity (COPC) which sensors are covering an area in the aircraft.