Decision Support Tools CBR

1
Decision Support ToolsCBR Modeling

• Jeff Allan
• University of Sheffield

2
DAME Technology Pull

• Rolls-Royce build competitive gas turbine
  engines
• Ever more reliable
• Greener
• Quieter
• DSS 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
Engineering Trends

• Tools change but the inherent nature of
  collaboration to achieve business objectives
  doesnt!
• a car
• a gas turbine engine
• Technology integration
• active suspension
• more electric gas turbines
• Knowledge increasingly the value added.

4
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
An Engine Simulation Grid Service for DAME

• Xiaoxu Ren
• Rolls-Royce UTC in Control and Systems
  Engineering
• Department of Automatic Control and Systems
  Engineering
• University of Sheffield

6
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
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
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
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

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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
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

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Engine Simulation for DAME
13
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
Security Issues

• The secure sensitive engine model and user data
  need to be protected!

• Challenges
• Eavesdropping
• Tampering
• Impersonation

• Current solutions
• Symmetric-Key encryption
• Public-Key encryption
• Digital Signatures using PKI
• Certificate-Based Authentication

• 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
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
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