Health Monitoring and its Role in Safety John McDermid, OBE FREng , University of York

1. HealthMonitoring and itsRole in Safety John McDermid, OBE FREng, University of York with thanks to Bombardier and ESIM

2. Overview • Health monitoring concepts • The role of health monitoring in safety • Examples of health monitoring • Aero engines, courtesy of Rolls-Royce • Railways, courtesy of Bombardier and ESIM • Benefits and opportunities • Challenges • Conclusions

3. Health Monitoring Concepts (1) • Health monitoring involves assessing system components, for deterioration in their state, e.g. • Ageing • Damage • Unexpected/undesirable properties • Often health monitoring involves • Measurement • Detection of “deviations” from expected state • Diagnosis of root causes • Recommendation of actions, e.g. maintenance or more immediate change in operation • Details depend on the technology

4. Health Monitoring Concepts (2) • Health monitoring is concerned with • What has happened • What is happening • May be a focus on known faults or failure modes • Prognosis (prognostics) involves • Predicting future states, including failures • Suggesting courses of action to prevent failure, or to extend time until failure occurs • In practice, distinction may be blurred • Monitoring may recommend a “time for service”, i.e. implicitly predict a safe operating period

5. Health Monitoring and Safety • Health monitoring often focused on availability • Ensuring action taken to avoid loss of capability • e.g. replace a motor which operates a switch • e.g. correct degradation of a track • Health monitoring can positively impact safety • Detect a failure/impending failure and prevent a damaged/failing component from being used • Health monitoring can negatively impact safety • e.g. the recommended “time for service” may be too long, and a failure occurs prior to the action • Greater concern with prognosis

6. Health Monitoring in Aerospace • Health monitoring capabilities now widespread • Main focus is on mechanical elements • Structural and rotating machinery • Also considering electrical parts, e.g. generators • Rolls-Royce monitor key engine parameters • Speeds, vibration, pressures, etc. • Some on-board analysis, and data transmitted for further analysis on the ground • Provide a service to airlines • Includes comparison of “signatures” with known problems from other engines

7. Reportsvia Satellite Ground-based information, e.g. oil uplift FlightLogSheets 24x7 Engine Health Centre Customer Condition monitoring,Data processing & storage,Data access & reports, Forecasting services Maintenance Centre OEM Rolls-Royce Example Sense Global Network Acquire Engine Monitoring Unit Transfer Continuously recorded data Analyse Ground Station Exploitation relies on the efficient operation of the complete system Act Internet, e-mail, pager

8. Monitoring for damage to compressor blades Comparison –pressure signals before and after icing damage to compressor blades: HP 1st tracked order quadrupled IP 1st tracked order doubled

9. Bombardier/ESIM Example • System for monitoring track “health” • Changes in gauge, alignment, and unintended cant (angle) or twist • Track moves in use, but excessive change may necessitate maintenance (with loss of availability) • Monitoring cannot make things worse, but missed degradation may “allow” unsafe situations • System enables cost-effective approaches • Use commercial trains to carry sensors • Monitor more cheaply • Monitor more thoroughly • Significant return on investment

10. The RailwayInfrastructure Gauge Cant Twist Curvature Alignment Longitudinallevel Geometry ofthe track

11. Optical Measurement System DigitalCameras DigitalCameras Laserbeams Laserbeam Rotation The measurement of track parameters is done using laser beams and triangulation

12. MeasuringTrackGeometry Parameters can be measuredas the trainmoves down the track. For exampleany “twists” will be detected by changes in trackrotation/angle.

13. RecalibrationGantry Static Gantry used for Recalibration of Systems on Trains

14. Odometrysystems Odometry Measurementsystems Encoding System Operator ProcessingSystem Localisation and Synchronisation

15. Rolling Stock in Commercial Operation

16. ESIM TrackGeometryDiagnostic SystemArchitecture & Rolling Stock in Commercial Operation GPS Positioning System OnBoard Wayside Opto Electronic Railway Analisys (OpeRA) RF 868 MHz Data Processing Centre (CED) Gantry Recalibration service InertialMovementUnit (IMU) Recalibration Service OpeRA RailCar-Bogie Acceleration Location and Synchronisation Of Rolling Stock Assets Wi-Fi 2,4 GHz Remote User Odometer Accelerometer Web • - Acquisitions • Processing • - Results CED Laser 3D profiling

17. ESIM TrackGeometryDiagnostic System Process of generating and analysing data 1. System initialisationbeforeleaving the station 100 Acquisitions Measurementsystemscalibrated to relevantstandards 2 .SpatialSynchronisation and Trigger Generation 3. Information Acquisition via SSB sensorsusing the Triggersgeneratedat the previousstep 10 ValidMeasurements 4.Acquisition of Recalibraion Information bySST 5. Download data to SST-CED on return to station 6. Data Acquisition and Validation/Reduction (10010) 1 ImportantEvent 7. Calibration of data and calculation of measures Classificationof the defect 8. Calculation of Importance and Classification For traffic Cagliari-San Gavino: Significanteventsevery 2 monthsinsteadof 6 months (todaydiagnosticplanofrailway company) 9. Automatic ReportGeneration

18. Integration of Diagnostic Systems: Bombardier/ESIM • Bombardier and ESIM are evaluating the nextgeneration system, investigating the feasibility of integratingtrackgeometrydiagnosis with the telediagnosticsystem in order to have an integratedsystem for the vehicle and the track. BombardierTelediagnostic System ESIM TrackGeometryDiagnostic System Bombardier/ESIM “next generation” Diagnostic System

19. Status of Work • Contractsignedbetween ESIM and ItalianRailwaystopermanentlyinstall system on secondarylines • Testing completed, document provided to safety agency • Certification from homologation authority expected by end of 2013 • Bombardier and ESIM collaborating on the Next Generation Product • Thanks to ESIM and Bombardier for use of material

20. Benefits and Opportunities • Health monitoring has significant potential benefits • Better availability of track and rolling stock • Fewer disruptions to operations • More cost-effective maintenance • Take action prior to (secondary) damage • Note: in some cases, e.g. track gauge, relatively easy to determine abnormal situations • Opportunities • Generic capabilities which can be applied widely • Integration of systems, making them more cost-effective, e.g. sharing communications • Avoidance of unsafe failures

21. Challenges • For some diagnoses, e.g. impending failures, need historical data as a comparator or “baseline” • May be hard to collect • Inevitably some time before benefits obtained • The more often elements are changed, the lower the benefits (return on investment) • To take “safety credit” need to be able to show the performance of the system is trustworthy • Often use complex databases, pattern matching and heuristics, so are hard to assess against standards, e.g. EN 51028 • A research problem

22. Conclusions • Health monitoring used in a number of industries • Aerospace perhaps the most advanced • Some applications use historical data to give accurate diagnosis of abnormal behaviour • Significant opportunities for rail systems • Infrastructure, e.g. track • Rolling stock, especially moving parts • Can learn from others, e.g. aerospace • Most immediate benefits in availability • Are potential safety benefits, but some issues to be addressed to get “credit” for capability