WF24: Generate Automated Sensor Sets

Pre-requisites

• PHM Module: Prognostics and Health Management (PHM) Module enables Diagnostic Analyses.
• FBD Model: defined with functions, functional flows and failure diagrams.
• Test Points: to indicate Legacy sensors existing within the model (see WF23).

Detailed Descriptions (numbered steps)

1. Access Diagnostic Analyses under 'Analyses' in the main menu bar or via the right-click context menu opened in Project Explorer or System Model viewer.
2. Click the 'New...' button to create analysis, defining focus with selection of level of indenture and ensuring 'Automated' analysis type. Provide Name and Description, then select Propagation Type and Symptoms are to be included.
3. Select Response State from drop-down menu and also the Propagation Focuses via the check boxes.
4. Open 'Inclusions' tab to define Failures / Sensor Locations or Legacy sensors to include.
5. Open 'Exclusions' tab to apply a Criticality Thresholding, or define Failures / Sensor Locations to exclude.
6. Open 'Sensor Set Analysis' and set up preferences regarding Number of Sets and Depth of Analysis, which can be further limited by Coverage and / or number of Test Points. Then select 'Analyze' to generate Sensor Sets.
7. Open 'Ambiguity Groups' tab to review failures that could not be uniquely identified.
8. Open 'Sensor Allocation' tab and use the Sensor Library to allocate appropriate sensors to Flows and / or Symptoms via dragging and dropping sensors from the Sensor Library.
9. Open 'Sensor Parameters' tab, to edit sensor details and parameters. To edit Legacy sensors, see WF23.
10. Open 'Metric Optimization' tab to review sensor sets, filtering based on certain metrics. Sensor sets can be exported for further analysis.
11. Open 'Comparison' tab to compare sensor sets based on Coverage, Number of Sensors, Cost, Weight, Probability of Detection (POD), POD (Physical) and Cost of Detection.
12. Determine if Sensor Sets are applicable, reiterate through above process, until satisfactory.
13. Select an item in the diagnostic sets table to view the diagnostic rules to determine whether the item failure is present. The user can choose to minimize the diagnostic set to determine the minimum amount of sensors required to diagnose that failure.

Fields referenced in the diagram

• Create New Automated Diagnostic Analysis: Indenture Selection, Analysis Name, Description, Propagation Type, Include Symptoms?
• Define Diagnostic Analysis Details: Response State, Indenture Selection, Propagation Focuses
• Define Diagnostic Inclusions: Failures?, Sensor Locations?, Legacy Sensors?
• Define Diagnostic Exclusions: Criticality Threshold?, Detectable Causes?, Sensor Locations?
• Generate Sensor Sets: Legacy Sensor Set?, Limit Coverage?, Limit Test Points?, Analysis Options
• Review Ambiguity Groups: Criticality Type, Minimum Group Size
• Conduct Metric Optimization: Maximum Cost, Maximum Weight, Maximum Coverage

Decision points

• Sensor Sets Applicable? — No → loop back to Generate Sensor Sets; Yes → Review & Minimize Diagnostic Sets.

Outputs

• Ambiguity Groups Data: exported as a .csv file for external use.
• Comparison Graphs: exported as a .png file for external use.
• Diagnostic Sets: exported as a .csv file for external use.
• Sensor Set Details Report: summarizes all Diagnostic Analysis sections including diagnostic sets, sensor parameters, etc.
• Sensor Set can be exported to a User-defined Diagnostic Analysis (see WF25).

Screenshot walkthrough (captions/labels extracted)

Step 1: Access Diagnostic Analyses

• 'File Edit View Modeling Analyses Reports Preferences Integrati...' menu bar with 'Analyses' open: Diagnostic Analyses (highlighted), New Diagnostic Analysis, Fault Tree, Response Paths, Connection Matrix, Common Mode Analysis, Critical Item Analysis, Criticality & Reliability Editor, Technical Budget Analysis, Failure Rate Prediction, Markov Analysis, RBD Analysis, Reliability Allocation Editor, Back-Fit RCM, Model-based RCM, Maintenance Cost Estimates. Project Explorer: Vehicle System [4/29] > Functions, Coupling, Driveline [11], Power Generation [3/14], Vehicle.
• Project Explorer right-click context menu on Vehicle System: New, New Diagnostic Analysis, Diagnostic Analyses (highlighted), Cut/Copy/Paste, Delete.
• System Model viewer "Vehicle System" (Mission Profile "Regular Trip", End Effect Item "Vehicle System") with diagram nodes Power Generation, Coupling, Driveline, Vehicle (flow labels Flow rate, Mass flow rate, Voltage, Torque, Angular velocity); context menu: New, New Diagnostic Analysis, Bond Graph, Diagnostic Analyses (highlighted), Cut/Copy/Paste, Zoom In/Out, Propagate All...

Step 2: Create New Automated Diagnostic Analysis

• "Create a Diagnostic Analysis" wizard, page 1 "Level of Indenture and Group Type": Indenture Selection tree Vehicle System > Driveline, Power Generation (checked) > Diesel Engine. "Type of Diagnostic Analysis": Automated (selected) "An Automated Diagnostic Analysis is used to generate Sensor Sets based on analysis of the existing model. Sensors may only be placed at locations that the analysis has determined to be required."; User-defined "A User-defined Diagnostic Analysis allows for the creation of a single manually created Sensor Set. The location of sensors can be manually assigned and, optionally, specific Sensors assigned to the included locations." Buttons Back/Next/Finish/Cancel.
• Page 2 "Details and Propagation Type": Name "Diagnostic Analysis 1", Description "For demonstration purposes." "Propagation Type": FCM (selected) "Generate the propagation table using Fuzzy Cognitive Mapping."; Bond "Generate the propagation table using Bond Simulation. This method is only applicable to valid Bond models." "Symptom Sensing": checkbox "Include symptom information" (checked).

Step 3: Define Diagnostic Analysis

• "Diagnostic Analysis - Diagnostic Analysis 1": left nav Overview/Management, Diagnostic Analysis 1 > Propagation Table, Inclusions, Exclusions, Sensor Set Analysis, Ambiguity Groups, Sensor Allocation, Sensor Parameters, Diagnostic Sets, Metric Optimization, Comparison. "Basic Details": Name "Diagnostic Analysis 1", Description "For demonstration purposes.", Type "Automated", Propagation type "FCM", Response State dropdown open: Steady State (highlighted)/Transient State/Steady and Transient States. "Indenture Selection": tree Power Generation > Diesel Engine (checked). "Propagation Focuses" tree (right): FCM > Energy > Mechanical - linear (Linear velocity), Mechanical - rotational (Angular velocity, Torque); Material > Gas (Mass flow rate), Liquid (Dynamic pressure, Flow rate, Static pressure); Signal > Continuous (Amplitude) — all checked.

Step 4: Define Diagnostic Inclusions

• "Inclusions" tab: "Must Detect Failures" — "Choose any functional failure that must be detected (must detect) or covered (must cover) in the analysis... " Table (Item/Flow Property/Failure Mode/Must Cover): Power Generation > Diesel Engine > Mechanical - rotational / Torque / Low (SS,TR) (checkbox unchecked). "Legacy Sensor Set" (right): checkboxes "Use TP sensors and locations", "Show inactive Test Points"; tree Power Generation > Diesel Engine > Injector Pump > Liquid, Property "Dynamic pressure". "Must Use Sensor Locations": tree Power Generation > Fuel Tank > Liquid, Property "Static pressure".
• Two popup dialogs: "Must Detect Failures" (Selected Failures / Available list with Item/Flow Property/Failure Mode columns showing extensive tree: Power Generation, Control Unit, Diesel Engine, Air Filter, Coupling 1, Engine, Governor, Injector Pump, Lift Pump, Primary/Secondary Fuel Filter, Fuel Tank — various flow properties Amplitude/Angular velocity/Torque/Mass flow rate/Dynamic pressure/Linear velocity/Flow rate/Static pressure with failure modes Low/Decrease (SS,TR)); "Must Use Sensor Locations" (Available Sensor Locations / Selected Sensor Locations, similar tree with Property column only). OK/Cancel buttons.

Step 5: Define Diagnostic Exclusions

• "Exclusions" tab: "Set and update the cause and location exclusions..." "Criticality Thresholding": Criticality Profile "PHMT RPN Criticality" dropdown. "Criticality Threshold": Fuzzy Criticality Threshold "8", RPN Threshold "1000", MIL-STD-1629A Criticality Number (Cm) "1.00E+00", MIL-STD-882E Risk "Eliminated", ARP4761 Risk "High", ISO 26262 ASIL Risk "ASIL D". Button "Apply". "Detectable Cause Exclusions (1 of 11 excluded)" table: Power Generation > Control Unit > Continuous / Amplitude / Decrease (SS,TR) excluded. "Sensor Location Exclusions (1 of 10 excluded)" table: Power Generation excluded.
• Popup "Detectable Failures" dialog: Detectable Failure Modes / Excluded Failure Modes lists with tree Power Generation > Diesel Engine > Air Filter, Coupling 1, Engine, Governor, Injector Pump, Lift Pump, Primary/Secondary Fuel Filter, Fuel Tank; excluded: Power Generation > Control Unit > Continuous / Amplitude / Decrease (SS...). OK/Cancel.

Step 6: Generate Sensor Sets

• "Sensor Set Analysis" tab: "Display Options": checkbox "Include Legacy Sensor Set". "Analysis Parameters": "Coverage & Detection" — checkbox "Limit Coverage", Best Possible Coverage "40%", Best Possible Detection "100%", Target Coverage (%) "40". "Test Points": checkbox "Limit Test Points", Test Points "1", Range (+/-) "1"; note "The maximum number of test points that can be allocated is 10." "Analysis Options": Number of Sets "10", Depth of Analysis "Low". Button "Analyze". "Sensor Sets" table (Name/Status/Sensed Responses/Coverage/Coverage Δ/Detection/Fitness): Analysis 1 - Set 1 through Set 6 shown (New status), each 0/5 or 1/5 Sensed Responses, 40% Coverage, 100% Detection, ~40.74%-67.38% Fitness, listing component paths e.g. "Regulate Liquid - Dynamic pressure (Injector Pump)", "Provide Liquid - Static pressure (Fuel Tank)", "Refine Gas - Mass flow rate (Air Filter)", "Control Mechanical - linear - Linear velocity (Governor)", "Convert Mechanical - rotational - Torque (Diesel Engine)". Footer "Showing 6 of 10 results".

Step 7: Review Ambiguity Groups

• "Ambiguity Groups" tab: "Ambiguity Settings": Criticality type "RPN", Minimum group size "2". "Sensor Sets" table (Name/Ambiguous Failures/Coverage/Detection): Analysis 1 - Set 1 (40%, 100%) > Ambiguity Group 1 (60%, 100%); Sets 2-6 similar. "Ambiguity Group" table (Component/Flow Property/Failure): Coupling 1 (Mechanical - rotational - Angular velocity, Low (SS,TR)), Engine (Mechanical - rotational - Torque, Low (SS,TR)), Injector Pump (Liquid - Dynamic pressure, Low (SS,TR)), Lift Pump (Liquid - Flow rate, Low (SS,TR)), Primary Fuel Filter (Liquid - Flow rate, Low (SS,TR)), Secondary Fuel Filter (Liquid - Flow rate, Low (SS,TR)).

Step 8: Allocate Sensors

• "Sensor Allocation" tab: "Sensor Library" tree: Sample Sensor Library > Built-In-Test, Flow rate > Differential Pressure Device > Capacitance Tomography [Sample Sen...], Coriolis flow meter [Sample Sensor], Flapper valve or vane [Sample Sensor], Hot wire sensor (MAF) [Sample Sensor]; Pressure Anemometry, Velocimeter, Velocity Anemometry (wind), inductive proximity, User defined, New User Library. Checkbox "Filter by selected Component." "Recently Used Sensors": Cold wire sensor [Sample Sensor]. "Sensor Allocation" panel: "Air Filter" — "Refine" / "Gas": Mass flow rate (checked) allocated "Cold wire sensor [Sample Sensor]" (highlighted). "Items" panel (right): Status Filter "New or higher"; tree Diesel Engine > Air Filter (1/1, highlighted), Coupling 1, Engine, Governor, Injector Pump, Lift Pump, Primary/Secondary Fuel Filter; Fuel Tank — Sensors count column (e.g. "0/1", "1/1").

Steps 9-1/9-2: Edit Sensor Parameters

• "Sensor Parameters" tab: "Allocated Sensors" table (Name/Location/Source/POD/SPC/FNR/FAR/PPV/NPV/ACC/Bal.ACC/LRP/LRN/MCC): Pressure Sensor (Injector Pump - Regulate Liquid Dy..., Direct Entry, 98%/90%/2%/10%/N/A/N/A/94%/94%/9.80/0.02/0.88); Rotary transformer (Strain Gauge) [Sample Sensor] (Engine - Convert Mechanical - rotat..., Direct Entry, 100%/100%/0%/0%/N/A/N/A/100%/100%/0.00/0.00/1.00); Cold wire sensor [Sample Sensor] (Air Filter - Refine Gas Mass flow rate, Direct Entry, 100%/100%/0%/0%/N/A/N/A/100%/100%/0.00/0.00/1.00). "Sensor Details" for Pressure Sensor: Name "Pressure Sensor", Part Number "PS1", Vendor "Sensor Company Inc.", Vendor Number "PS1-A", Dimensions 50.00/20.00/20.00 mm, Weight 100.0 grams, Description "COTS Fuel Tank Pressure Sensor"; Operation type Automatic, Detection Method Passive, Signal Type Digital, Operating Environment "Dry environment", Constraints "External temperature not exceeding 80 degre...", MTTF 100000.000 hours, MTTR 5.000 minutes, Sampling interval 0.000 minutes, Test duration 0.000 seconds. "Additional Sensor Details" tabs: Costs & Materiel (Acquisition Cost $100.00, Replacement Cost $50.00, False Alarm Cost $10.00, Detection Cost $2.00, Operational Cost $0.01/hr, Testing Cost $0.02/hr; Personnel/Equipment empty), Parameters (Direct entry, Probability of Detection 98%, Specificity 90%; Calculated Parameters: POD 98%, SPC 90%, FNR 2%, FAR 10%, PPV N/A, NPV N/A, ACC N/A, BACC 94%, LRP 9.80, LRN 0.02, MCC N/A), Custom Properties (empty Name/Type/Value table).

Step 10: Conduct Metric Optimization

• "Metric Optimization" tab: "Filters": checkbox "Max Cost (USD)" $1,500.00; unchecked Max Weight, Min Coverage(%), Min Detection(%). Button "Reset Filters". "Sensor Set Details": Name "Analysis 1 - Set 1", Description "This Sensor Set was created as a result of Sensor Analysis.", Status "Selected - Sam - 2026/03/30 18:36:04", Comments "Sensor Set for Demonstration Purpose". "Sensor Sets" table (Name/Status/Sensed Responses/Coverage/Detection/Fitness/# of Sensors/Replacem.../Weight/POD (Phys...): Analysis 1 - Set 1 (Selected, 5/5, 40%, 100%, N/A, 5, $1,170.00, 2.535lb), Set 2 (New, 5/5, 40%, 100%, 40.74%, 5, $1,320.00, 2.359lb), Set 3 (New, 5/5, 40%, 100%, 40.74%, 5, $1,170.00, 2.866lb) — each with component task rows e.g. "Regulate Liquid - Dynamic pressure (Injector Pump)", "Provide Liquid - Static pressure (Fuel Tank)", "Refine Gas - Mass flow rate (Air Filter)", "Control Mechanical - linear - Linear velocity (Governor)", "Convert Mechanical - rotational - Torque (Diesel Engine)", "Increase Liquid - Flow rate (Lift Pump)".

Step 11: Review Comparison Graphs

• "Comparison" tab: checked sets "Analysis 1 - Set 1/2/3" listed with summary cards: Analysis 1 - Set 3 (Coverage 40%, Number of Sensors 5, Weight Sum 2.866lb, Replacement Cost Sum $1,170.00), Set 2 (40%, 5, 2.359lb, $1,320.00), Set 1 (40%, 5, 2.535lb, $1,170.00), Average — All Sets (40%, 5, 2.572lb, $2,086.67). Bar charts: "Coverage" (Coverage %), "Number of Sensors", "Weight of Sensors" (Weight Sum (lb)), "Replacement Cost Sum" (Replacement Cost Sum ($)) — each comparing Set 3/Set 2/Set 1.

Step 13: Review Diagnostic Sets

• "Diagnostic Sets" tab: "Sensor Sets" list (Name/Coverage/Detection): Analysis 1 - Set 1 through Set 6, all 40%/100%. "Diagnostic Sets" table (Component/Flow Property/Failure/POD/Air Filter - Refine Gas Mass flow rate/Diesel Engine - Convert Mechanical - rotational Torq...): Air Filter (Refine Gas - Mass flow rate, Low (SS,TR), -, Low, -), Diesel Engine (Convert Mechanical - rotational - Torque, Low (SS,TR), -, Nominal, Nominal), Fuel Tank (Provide Liquid - Static pressure, Decrease (SS,TR)), Governor (Control Mechanical - linear - Linear velocity, Low (SS,TR)), Power Generation (Healthy System, No Failure), plus Ambiguity Group 1 rows for Coupling 1, Engine, Injector Pump, Lift Pump, Primary Fuel Filter, Secondary Fuel Filter (all Low (SS,TR), Nominal/Low mixed). "Diagnostic Rule" panel: "Diagnostic Rule for: Air Filter - Mass flow rate Low (SS,TR) (Gas)" — "IF [Injector Pump - Regulate Liquid Dynamic pressure IS Low] AND [Governor - Control Mechanical - linear Linear velocity IS Nominal] AND [Air Filter - Refine Gas Mass flow rate IS Low] AND [Fuel Tank - Provide Liquid Static pressure IS Nominal] AND [Diesel Engine - Convert Mechanical - rotational Torque IS Low] THEN [Air Filter - Refine Gas Mass flow rate IS Low (SS,TR)]".

Step 14: Sensor Sets Generated

• "Test Point Report" (2-page excerpt): "DIAGNOSTIC ANALYSIS SUMMARY" — Name "Diagnostic Analysis 1", Type "Automated", Propagation Focuses "No propagation focuses set", Description "For demonstration purposes.", Criticality Threshold "None", Propagation Type "FCM". "INCLUSIONS": "Must Cover Failures - No cause inclusions have been set for this analysis." "Must Detect Failures" table (Item/Failure Mode): Diesel Engine / "Mechanical - rotational Torque Low (SS,TR)", Fuel Tank / "Liquid Static pressure". "Must Use Sensor Locations (Legacy Sensor Set)" — none set. "Must Use Sensor Locations (Manual)" table: Diesel Engine / "Mechanical - rotational Torque Low (SS,TR)", Fuel Tank / "Liquid Static pressure" (columns Item/Flow Property, showing "Mechanical - rotational Torque Low (SS,TR)" duplicated as Flow Property heading in original). "EXCLUSIONS": "Cause Exclusions (Criticality Threshold)" — Criticality Threshold "None", no cause exclusions applied. "Cause Exclusions (Manual)" table: Control Unit / "Continuous Amplitude Decrease (SS,TR)". "Sensor Location Exclusions (Manual)" — none set.
• "SENSOR SET SUMMARY" — "ANALYSIS 1 - SET 1": Test Points 5, Coverage 40%, Detection 100%, Cost $1,170.00, Weight 2.535lb, Description "This Sensor Set was created as a result of Sensor Analysis." "Sensor Set POD": Unknown; "Sensor Set Cost of Detection": $0.13. "Sensor Parameters" table (Test Point/Sensor/Source/Occurrence/POD/SPC/FNR/FAR/PPV/NPV/ACC/BACC/LRP/LRN/MCC): Control Mechanical - linear Linear velocity (Governor) / Hall effect sensor [Sample Sensor] / Direct Entry / Failure Prevalence 1 / 100%/100%/0%/0%/100%/100%/100%/100%/0.00/0.00/1.00; Convert Mechanical - rotational Torque (Diesel Engine) / Built-In-Test [Built-In-Test] / Direct Entry / Failure Prevalence 5,121.995 / 100%/100%/0%/0%/100%/100%/100%/100%/0.00/0.00/1.00; Provide Liquid Static pressure (Fuel Tank) / User defined [Sample Sensor] / Direct Entry / Failure Prevalence 385.524 / 100%/100%/0%/0%/100%/100%/100%/100%/0.00/0.00/1.00; Refine Gas Mass flow rate (Air Filter) / Cold wire sensor [Sample Sensor] / Direct Entry / Failure Prevalence 552.82 / 100%/100%/0%/0%/100%/100%/100%/100%/0.00/0.00/1.00; Regulate Liquid Dynamic pressure (Injector Pump) / Pressure Sensor / Direct Entry / Failure Prevalence 77.105 / 98%/90%/2%/10%/90.74%/97.83%/94%/94%/9.80/0.02/0.88. "ANALYSIS 1 - SET 1" (repeated section) "AMBIGUITY GROUPS" table (Group/Coverage/Detection/Ambiguous Failures): Ambiguity Group 1 / 60% / 100% / "Coupling 1 Mechanical - rotational Angular velocity Low (SS,TR)", "Engine Mechanical - rotational Torque Low (SS,TR)", "Injector Pump Liquid Dynamic pressure Low (SS,TR)", "Lift Pump Liquid Flow rate Low (SS,TR)", "Primary Fuel Filter Liquid Flow rate Low (SS,TR)", "Secondary Fuel Filter Liquid Flow rate Low (SS,TR)".

Related workflows

• WF23 – Define Test Point
• WF25 – Generate User-defined Sensor Sets