Air Data Probe Life Prediction via Thermal Stress Monitoring

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Solution Overview

Problem

Current systems for predicting the end of life of air data probes are unreliable, often leading to unscheduled maintenance and premature replacement, as they fail to accurately track the onset of degradation due to abrupt heater cable failures, necessitating a more effective method to predict probe failure.

Innovation Solution

A system and method that estimate the operating temperature of air data probes using available sensor data from aircraft buses, employing a power law relationship and modified Miner's rule to predict remaining life, allowing for scheduled replacement based on cumulative thermal stress and operational conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If operators pre-emptively replace pitot and air data probes before they show signs of aging, then reliability is improved by avoiding unscheduled maintenance, but productivity deteriorates due to premature replacement and increased maintenance costs

Engineering Contradiction:
Improveprobe reliabilityVSAvoidmaintenance efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system monitors changes in electrical parameters (current, voltage, resistance) of the probe's heating element to detect degradation. By tracking parameter drift over time, the system can predict failure before it occurs, allowing replacement to be scheduled at the optimal moment - neither too early nor too late - thus improving both reliability and maintenance efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system continuously monitors probe health parameters and provides feedback about the probe's actual condition. This feedback loop enables dynamic adjustment of maintenance scheduling based on real-time probe status, replacing probes only when degradation indicators suggest imminent failure, thereby avoiding both premature replacement and unexpected failures.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If air data probes are monitored using current systems, then manufacturing precision is maintained, but measurement precision deteriorates due to inability to accurately detect degradation onset

Engineering Contradiction:
Improveprobe qualityVSAvoiddegradation detection accuracy
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The system replaces mechanical inspection methods with electrical parameter monitoring. By measuring electrical characteristics (current, voltage, resistance) of the heating element, the system can detect degradation at the electrical level before it manifests as mechanical failure, significantly improving measurement precision of degradation onset while maintaining manufacturing quality standards.

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

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 approach provides a reliable prediction of air data probe failure, reducing unscheduled maintenance, extending the life of probes, and optimizing spare inventory management by allowing for timely replacement during scheduled maintenance, without the need for additional sensors.

Implementation Method 1

The probe includes a heater that includes a resistive heating element routed through the probe, wherein an operational current is provided to the resistive heating element to provide heating for the probe.

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Implementation Method 2

The first current sensor is configured to sense a first current through the resistive heating element, and the second current sensor is configured to sense a second current through the resistive heating element.

Methodology Applied
Scientific EffectElectrical resistance measurement: Electrical Resistance

Data Source

PatentEP3855189B1Air data probe replacement determination system
Publication Date: 2023.07.26 HONEYWELL INTERNATIONAL INC
  • EP3855189B1 patent drawingFigure 1
  • EP3855189B1 patent drawingFigure 2
  • EP3855189B1 patent drawingFigure 3

AI summary

Method and systems of determining when to replace an air data probe are provided. The method includes estimating air data probe temperatures based at least in part on available vehicle sensor data; tracking an amount of time an estimated temperature of the heating element is within at least one temperature range; and providing an air data probe replacement indication when a replacement threshold is met that is at least in part based on reaching a cumulative amount of time the heating element has an estimated temperature within the at least one temperature range.