fault tolerant control n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Fault-tolerant Control PowerPoint Presentation
Download Presentation
Fault-tolerant Control

Loading in 2 Seconds...

play fullscreen
1 / 28

Fault-tolerant Control - PowerPoint PPT Presentation


  • 271 Views
  • Uploaded on

Fault-tolerant Control. Motivation Definitions A general overview on the research area. Active Fault Tolerant Control (FTC) FTC- Analysis and Development procedure Supervisor architecture Logic realization Design and development tools Implementation. Fault Tolerant Control. Motivation :

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Fault-tolerant Control' - astra-gallegos


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
fault tolerant control
Fault-tolerant Control
  • Motivation
  • Definitions
  • A general overview on the research area.
  • Active Fault Tolerant Control (FTC)
  • FTC- Analysis and Development procedure
  • Supervisor architecture
  • Logic realization
  • Design and development tools
  • Implementation
fault tolerant control1
Fault Tolerant Control
  • Motivation:
    • Demand for higher autonomy and reliability requires considering all possible situations to guarantee correct and consistent operation
  • Purpose:
    • Using a logically sound stepwise guideline to achieve
      • Complete coverage of possible single faults.
      • Supportive software tools.
      • Avoiding unnecessary plant modelling.
      • Automatic code generation.
  • Initial Prerequisites:
    • Initial system concept is established.
    • Systems requirements are specified: (operating modes and functions, required performance, environmental, safety, or regularity requirements)
failure mode and effect analysis fmea
Failure Mode and Effect Analysis -FMEA

FMEA scheme for the Wheel system

fmea other examples
FMEA – Other examples

FMEA scheme for the GPS

fault assessment i
Fault assessment - I
  • Severity Occurrence Index (SO)
    • SeverityPotential harm that fault effect inflicts the system; Severity is quantified by severity scale from 1 to 10.
    • Occurrence; the frequency of fault occurrence during expected operational time interval; is quantified by by scale from 1 (unlikely to occure) to 10 (persistent failure)
    • SO index:SO = Severity . Occurrence
fault assessment ii
Fault Assessment II

Severity and Occurrence analysis of the Wheel system

fault assessment iii
Fault Assessment III

Evaluation guidelines and identification of severe failures that need to be handled

fault assessment list of faults
Fault Assessment – List of faults

Periority assignment to different fault types

fault assessment causality analysis
Fault Assessment – Causality Analysis

Identifying possible causes of failures by backwardsearch through the Wheel system

supervisory control definitions
Supervisory Control - Definitions
  • To supervise:To oversee and guide the work or activities of a group of people/system, etc.
  • Supervision:
    • Monitoring a physical system and taking appropriate actions to maintain the operation in the case of faults
    • The ability to monitor whether control objectives are met. If not, obtain/calculate a revised control objective and a new control structure and parameters that make a faulty closed-loop system meet the new modified objectives. Supervision should take effect if faults occur and it is not possible to meet the original control objective within the fault-tolerant scheme.
logic realization
Logic realization
  • Language approach - a component based method
  • State-event machines

Figure- Control system hierarchy consists of four principle components

aausat ii example
AAUSAT-II example
  • Process starts with defining
    • Mission objectives
      • Mission modes
        • Control modes
  • The priority of the modes are established
aausat ii example2
AAUSAT-II example
  • Generating the boolean strings for the magnetorquer system

The prioritized representation becomes

aausat ii example3
AAUSAT-II example
  • Building the decision logic for the supervisor

Where ’*’ means a chosen logical string

The mission is defined by

where

aausat ii example4
AAUSAT-II example
  • The operator involvment can be represented by introducing additional logic
design tools and implementaion
Tools

Statecharts

Hierarchy/depth

Concurrency

Comunication

Stateflow (Matlab)

Beologic (B&O)

Consistency/correctness

Beologic

Implementation

IF-THEN rules

Object Oriented structure

Design Tools and implementaion
exercise and next lecture
Exercise and next lecture
  • Exercise
      • Objectives:
          • System analysis and knowledge acquisition about faults and their effect on the system operation.
          • Consider reconfiguration possibilities
  • Next lecture
      • Structural analysis approach:
        • Monitorable vs. non-monitoravble part of the systems