DIAGNOSTICS, PROGNOSTICS AND HEALTH

MONITORING FOR OPERATIONAL GAS TURBINE

ENGINES

Konstantino Kouris

November 3, 2005

RESTRICTIONPAGES OF THIS DOCUMENT MARKED WITH THE NOTICES SET FORTH BELOW CONTAIN PRATT & WHITNEY PROPRIETARY DATA WHICH IS SUBMITTED IN CONFIDENCE. NO DISCLOSURE OR USE OF THIS INFORMATION IS PERMISSIBLE WITHOUT PRIOR WRITTEN CONSENT OF UNITED TECHNOLOGIES CORPORATION EXCEPT FOR OFFICIAL PURPOSES WITHIN THE U.S. GOVERNMENT.

NOTICESPRATT & WHITNEY PROPRIETARY – MIGHT CONTAIN LOCKHEED MARTIN / NORTHROP GRUMMAN / BOEING PROPRIETARY INFORMATION

October 2005UTC Proprietary 2

Diagnostics, Prognostics, and Health

Management

Diagnostics:

Estimate failure state at

time now

Health Management:

Take action based on

diagnostics/prognostics

Health Management: The capability to make

intelligent, informed, & appropriate decisions

about maintenance and logistics actions based

on diagnostics/prognostics information,

available resources and operational demand.

Prognostics:

Predict degraded state at

time > now

Prognostics: Material condition assessment which

includes predicting and determining the useful life and

performance life remaining of components

Diagnostics: The process of determining

the state of a system to perform its

functions.

With definitions borrowed from a Lockheed Martin presentation

October 2005UTC Proprietary 3

Optimizing Removals And Workscope

Early

Late

Time on wing (EFH)

MA

INT

EN

AN

CE

CO

ST

S

($ /

EF

H)

Monitor Health and Safety -- Prevent Unscheduled Engine Removals (UERs), Optimize performance

Proactively Manage Configuration – Extend Average Time On Wing (ATOW)

Plan Removals -- Minimize Disruptions

Optimize Workscopes – Reduce Shop Visit Cost (SVC) and Minimize Turn Around Time (TAT)

BUSINESS PROPOSITION:

LIFE CYCLE COST MANAGEMENT

REMOVALTODAY

IMP. PRODUCTCAPABILITY

EXTENDED TIME ON WING

RE

DU

CE

D M

RO

CO

ST

OPTIMIZEDREMOVAL

October 2005UTC Proprietary 4

Engine Health Monitoring Roadmap

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2014

Sys

tem

Ca

pa

bil

ity

Transitioning Capability Programs

On-board Anomaly

DetectionLife

modelsLife

models

Oil Debris

Vibrations

Vibrations

Vibrations

Oil Debris

Oil Condition

Oil Condition

Oil Debris

APHM

Board

Filter

HealthFuel/Oil Filter

Health

Life

models

Off-board

Diagnostics

Mature Set of

Diagnostics Solutions

Off-Board

Gather engine data

reduce data

variation

Validate model

accuracy and false

detect rate

Execute

October 2005UTC Proprietary 5

Technology Transition Process

Measure of Technical Readiness

Technology

Demonstration

Fielded

Systems

Technology

Maturation

& TransitionNew

F100-PW-229

F119

Technology

Readiness

Level

9

8

7

6

5

4

3

2

1

TRL

Levels

In Service

Qualification/

Certification

Flight Test

System-level

Validation

Rig/Core

(Expanded

Design Space)

Rig Test (Minimal

Design Space)

Proof-of-Concept

Technology

Application

Basic Principles

October 2005UTC Proprietary 6

Off Board Diagnostics Facilitates On-

Board PHM Systems

A Mature Set of Diagnostics Solutions

Data collected few

times per flight

Filter, remove

outliers, validate data

Model parameters

Kalman Filter

based isolation

Off-board diagnostics

algorithms hosted within

secure database

Infrastructure facilitates

engine/fleet management

solutions as well

Detect trends

KF estimation of

deterioration

Report on the

web

October 2005UTC Proprietary 7

P&W Tools to Support DPHM

On Ground

Diagnostics and

Prognostics

Isolation

Trending

Early Warning

Detection

On-Condition

Management

Configuration and

Utilization Tracking

Modification

Standardization

Fleet Alert Summary

and Watchlists

Removal and Shop

Visit Planning

Shop Maintenance

Instructions

PWxxxx Operator: xxx

PW4074 Shipped Configuration: Bare

8848:52 Engine Time Since Last Shop Visit (TSLV): 2048:03

7451 Engine Cycles Since Last Shop Visit (CSLV): 1734

Document Number:

Revision Date:

Oil Type: Mobil Jet Oil 254

Test As Received: No

Preservation Method: Method II

Contract TAT Contract term 110

days from receipt.

Next Shop Visit SMI-

Planned O/H Location

Cheshire Other

Requirements:

Photos Required. Fit Requirements. Oil Sample

Analysis. Cleaning Requirement.

Engine Time Since New (TSN):

PW4000 112-Inch Fan Engine Maintenance Planning Guide

05-Oct-01

4. Life Limited Parts Summary (Optional - Provided Electronic

Attachment of Data is accomplished)

9. Last Shop Visit Information - Engine Test Results / MAP Results (Optional)

Test 9, Test as PW4077 and ship as PW4074. Post test MAP analysis required.

Engine removed for high time to perform Heavy Maintenance.

Expectations are to Heavy Maintenance the major modules so the engine can be returned to service for a full run interval of 7500 cycles or greater.

Additionally reliability and durability mods are called out for incorporation per Worksheet "11. SB Requir

Hold material for review with FMP Representative

5. Engine and Module Time and Cycle Information (Optional -

Provided Electronic Attachment of Data is accomplished)

3. Known Shortages at Time of Shipment (Optional)

1. Summary and General Information

Shop Maintenance Instruction - P777xxx

Records Included

Scrap Material

Requirements:

Engine Cycles Since New (CSN):

Summary and General Information

Shop Visit Expectations

All work performed in accordance with the following worksope specification

Engine Type:

Engine Serial Number:

Special Items

13. Service Bulletin Incorporation Status

12. Industry Item List from Production New (Optional)

11. Service Bulletin Incorporation Requirements

10. Engine and Module Basic Shop Requirements

Reason for Removal

2. Document Revision

Test

Requirements:

16. Additional Requirements (Optional)

7. Airworthiness Directive / Alert SB Compliance Status

6. Engine Condition Monitoring Trends (Optional) 14. ETOPS Requirements (Optional)

15. Records Requirements

8. Last Shop Visit Information - Engine and Module Work

(Optional)

Removal Planning /

Event Tracking

Modification Incorporation

On-board

Anomaly Detection

Models

Sensors

Algorithms

On Board

October 2005UTC Proprietary 8

ADEM Portal for Trending and Alerting

Engine Data

AD

EM

: A

dva

nce

d D

iagn

ostics a

nd

En

gin

e M

an

age

ment

October 2005UTC Proprietary 9

Engine Life Algorithms

Crack growth models

Thermal/stress analysis

Gas pathparameters

Missionanalysis

Advanced sensor data if any

Engine control parameters

Measure factors affecting actual life remaining

Engine used differently than worst-case

assumption

Aircraft flown differently

than expected

Engine-to-engine

variations

Finite element models

Thermal / stress algorithms

Reduction

Methods

On-board host (DEEC)

On-Board Life Management Algorithms

Flight Data

Life models

(probabilistic)

October 2005UTC Proprietary 10

On-Board Anomaly Detection

DEEC (with PHM board) has

new STORM

Normal continuous data & physics

used to build real-time engine models

Transient data and

real-time models used

to detect anomalies

Anomaly Detection:

• Provides trigger to capture real-time data for subsequent off-board analysis

• Additional data to support fault isolation

• Can facilitate long-term performance deterioration tracking

Causes for anomalies

• Deterioration

• Physical faults

• Operational abnormalities

• Flight domain excursions

Anomalies: Deviations from “Normal” Operation

October 2005UTC Proprietary 11

Advanced PHM Sensors

Early Detection of Various Problems

• Oil condition monitor

• Oil debris sensor

• Oil and fuel filter health

• Inductive / microwave probes

• Vibration pickups

October 2005UTC Proprietary 12

Oil Health Monitoring

• Sensors installed on production military

engines

• Condition monitoring added to OLS

• Tubes form capacitors for level and

conductivity

• A single probe provides lube oil capacity,

condition, and calibration signal to the box

• ODM located on supply side of main oil

pump

Technology Matured

Oil Level Sensor

Oil Debris Monitor

Transition process

• Analyze & develop algorithms

• Increase inputs in APHM board

• Prototype, test, and qualify APHM board

• Develop software

• Test and qualify system

October 2005UTC Proprietary 13

Data Normalization Leads to Enhanced

Fault Diagnostics

Normalized

inputs

Empirical prediction

models

Predicted

Deterioration

+ -

X (predicted)

Flight data is

gathered from

engine

Xnom

Ground Station

Monitored

Parameters

October 2005UTC Proprietary 14

Examples Of Data Normalization

Empirical models allowed reduction in variance by as much as

17 times while maintaining fault sensitivity

Reduction in variance for DWF = 4.7

DT6 = 17.5

Reductions for other variables: DT41 = 6.7

DN2 = 15.5

October 2005UTC Proprietary 15

Hybrid Modeling: eSTORM

eSTORM Implementation Phase

SVM

EngineANN

KF

+-Inputs ( u )

Residuals ( r )

Estimated residualsr̂

Tuners )ˆ( x

+

+

Adjusted EstimatedParameters

}*ˆ{ P

MeasuredParameters

}{ P

EstimatedParameters

}ˆ{ P

Standard STORM configuration

with feedback

Trained ANN will estimate Model/Engine

difference and adjust the estimated

parameters accordingly

Residuals will now track

performance changes

Hybrid Model

October 2005UTC Proprietary 16

Diagnostics Using Hybrid Models:

eSTORMSTORM vs eSTORM : Performance Fault Visibility

eSTORM disabled

eSTORM enabled

Performance

deviation

becomes visible

Module Performance

Deltas (Tuners) absorb

mismatch

October 2005UTC Proprietary 17

Diagnostics / PHM Needs

Diagnostics & Prognostics Analysis Tools• Signal processing (primarily vibrations)

• Empirical modeling techniques (Neural Networks, Support Vector

Machines, Partial Least Square, Nonlinear regression, etc.)

• Anomaly detection and fault isolation

• Directed troubleshooting

• Data mining

Diagnostics Sensors and Computing Hardware• Oil condition, debris, level – preferably low cost

• Robust clearance monitoring

• Acoustic sensors

• Aerospace qualified wireless and self powered sensors

• Distributed computing for health management and controls

• Data compression, storage, and secure transmission

Military engine Applications

Solutions Partially

availableSolutions available

Solutions Needed