1. Decision Support Tools CBR & Modeling Jeff Allan University of Sheffield

2. Distributed Aircraft Maintenance Environment - DAME DAME: Technology Pull Rolls-Royce build competitive gas turbine engines: –Ever more reliable –Greener –Quieter DS&S provide effective and efficient after market services: –On time every time, 24hours a day, 7 days a week –Need to understand GT engine behaviour/performance –Predict, diagnose & inform

3. Distributed Aircraft Maintenance Environment - DAME Engineering Trends Tools change but the inherent nature of collaboration to achieve business objectives doesn’t! a car a gas turbine engine Technology integration: active suspension more electric gas turbines Knowledge increasingly the value added.

4. Distributed Aircraft Maintenance Environment - DAME DAME: Sheffield Challenge Challenge 1 –Provide a means to enable our specialist tools, techniques, and expertise into the collaborative domain: MOGA Engine Modelling & FDI Intelligent Systems Approaches, e.g. CBR Challenge 2 –To provide a framework to capture process knowledge and enable decision support: Fault Ranking Tool Workflow Advisor

5. Xiaoxu Ren Rolls-Royce UTC in Control and Systems Engineering Department of Automatic Control and Systems Engineering University of Sheffield An Engine Simulation Grid Service for DAME

6. Distributed Aircraft Maintenance Environment - DAME Outline Project goals Integration of fault diagnostic tools on the Grid Engine simulation as a Grid service Demonstration and application Security Issues Conclusions and future work

7. Distributed Aircraft Maintenance Environment - DAME Project Goals Integration of modelling, estimation and analysis tools for engine fault diagnostics Provide a visualisation and decision support environment for engine fault diagnosis and maintenance

8. Distributed Aircraft Maintenance Environment - DAME Integration of FDI Tools based on SOA Different Fault Detection and Isolation (FDI) approaches. Each approach has its own focus; no “silver bullet” Integration of several FDI tools will provide better decision support for fault diagnosis and condition-based maintenance The Grid provides the potential HPC power and large data storage capability for implementation of different algorithms Service-Oriented Architecture (SOA) and the Open Grid Services Architecture (OGSA) for the integration

9. Distributed Aircraft Maintenance Environment - DAME Engine Simulation as a Grid Service An Grid service for engine simulation based on the Rolls-Royce engine performance model Based on the Globus Toolkit 3 (GT3) and the Open Grid Service Architecture (OGSA) for distributed systems integration The engine simulation Grid service can be invoked simultaneously in different “Virtual Organisations” for different applications

10. Distributed Aircraft Maintenance Environment - DAME Features of the Engine Simulation Grid Service The simulation: –can simulate for different flight operational conditions and requirements, e.g. Idle, Take-off, Climb, Cruise –takes different variables, including Net Thrust, Turbine Temperature, Spool Speed and Fuel Flow, as control input As Grid services: –GSI enabled secure engine performance simulation via Internet –a bunch of simulation instances generated by the factory service ; different engine simulation can be performed simultaneously –Only lightweight computers or PDAs are needed to perform the engine simulation, while still benefit from high-performance/high-throughput computing power provided by the Grid

11. Distributed Aircraft Maintenance Environment - DAME Access the Grid Service through Web Browsers A Web server for accessing the Engine Simulation Grid Service has been developed Use JSP to invoke the simulation service Use Web browser to view the engine performance data and the simulation result Two way SSL authentication via server and client certificates

12. Distributed Aircraft Maintenance Environment - DAME Engine Simulation for DAME

13. Distributed Aircraft Maintenance Environment - DAME Applications A simulation-based fault detection can be performed Experienced maintenance engineers can use this service to find the problem via on-line simulation Can be used to confirm the fault assumption Can be invoked by different fault diagnostic algorithms Residual generation: Simulator-based approach

14. Distributed Aircraft Maintenance Environment - DAME Security Issues Challenges: –Eavesdropping –Tampering –Impersonation Current solutions: –Symmetric-Key encryption –Public-Key encryption –Digital Signatures using PKI –Certificate-Based Authentication The secure sensitive engine model and user data need to be protected! The Engine Simulation Grid Service uses GSI to secure the model and user data SSL is used to secure the Web and database server

15. Distributed Aircraft Maintenance Environment - DAME GSI and SSL Implementation Grid Security Infrastructure(GSI) – the security functionality implemented by Globus Toolkit Secure Socket Layer(SSL) –a technology for secure connection between Web browsers and servers. Both use certificates for authentication SSL uses public key encryption to generate shared secrets; then performs the symmetric encryption GSI provides the Transport Layer Security and Message Level Security –Transport Layer Security: a grid version of SSL –Message Level Security: based on WS-Security, XML Encryption and XML Signature standards

16. Distributed Aircraft Maintenance Environment - DAME Conclusions and Future Work Integration of different fault diagnostic approaches on the Grid The Engine Simulation Grid Service The security requirements and current efforts Potential demonstrations of using the simulation for fault diagnosis will be addressed in the next stage Further research on the performance-based engine fault diagnosis