WF25: Generate User-defined 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 context menu opened in Project Explorer or System Model viewer.
2. If sensor set exists from another Diagnostic Analysis, it can be exported into an automatically created User-defined Analysis.
3. Click 'New...' button to create analysis, defining focus with selection of level of indenture and ensuring 'User-defined' analysis type. Provide Name and Description, then select Propagation Type and if include Symptoms.
4. Open 'Propagation Table' to review the resultant table.
5. Open 'Exclusions' tab to apply a Criticality Thresholding, or define Failures / Sensor Locations to exclude.
6. Open 'Sensor Set Analysis' tab to create sets for analysis, with combinations of sensors already pre-defined. This requires Test Points to have been created for all Legacy sensor locations and all other possible sensor locations (see WF23).
7. Open 'Sensor Allocation' tab and use the Sensor Library to allocate appropriate sensors to Flows and / or Symptoms.
8. Open 'Ambiguity Groups' tab to review failures that could not be uniquely identified.
9. Open 'Sensor Parameters' tab and edit sensor details and parameters.
10. Open 'Metric Optimization' tab to review sensor sets, filtering based on certain metrics.
11. Open 'Comparison' tab to further compare sensor sets based on Coverage, Number of Sensors, Cost, Weight, Probability of Detection (POD), POD (Physical) or 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.

Fields referenced in the diagram

• Create User-defined Diagnostic Analysis: Indenture Selection, Analysis Name, Description, Propagation Type, Include Symptoms?
• Define Diagnostic Exclusions: Criticality Threshold?, Detectable Causes?, Sensor Locations?
• Review Ambiguity Groups: Criticality Type, Minimum Group Size
• Conduct Metric Optimization: Maximum Cost, Maximum Weight, Maximum Coverage

Decision points

• Existing Sensor Set? — Yes → Export Sensor Set; No → Create User-defined Diagnostic Analysis.
• Sensor Sets Applicable? — No → loop back to Create Sensor Sets for Analysis; Yes → Review 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.

Screenshot walkthrough (captions/labels extracted)

Step 1: Access Diagnostic Analyses

• Project Explorer right-click context menu on Vehicle System [4/29]: New, New Diagnostic Analysis, Diagnostic Analyses (highlighted), Cut/Copy/Paste, Delete. 'File Edit View Modeling Analyses Reports Preferences Integration' menu with 'Analyses' expanded: 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.
• System Model viewer "Vehicle System" (Mission Profile "Regular Trip") with Power Generation, Coupling, Driveline, Vehicle nodes; context menu: New, New Diagnostic Analysis, Bond Graph, Diagnostic Analyses (highlighted), Cut/Copy/Paste, Zoom In/Out, Propagate All...

Step 2: Export Existing Sensor Set

• "Diagnostic Analysis - Diagnostic Analysis 1": "Sensor Set Analysis" tab. "Display Options": checkbox "Include Legacy Sensor Set" (checked). "Analysis Parameters": "Coverage & Detection" unchecked Limit Coverage, Best Possible Coverage 85.29%, Best Possible Detection 100%, Target Coverage (%) 85. "Test Points": unchecked Limit Test Points, Test Points 1, Range (+/-) 1; note "The maximum number of test points that can be allocated is 28." "Analysis Options": Number of Sets 10, Depth of Analysis "High". Button "Analyze". "Sensor Sets" table (Name/Status/Sensed Responses/Test Point Δ/Coverage/Coverage Δ/Detection/Fitness): Legacy Sensor Set (New, 2/2, N/A, 0%, N/A, 55.88%, N/A); Analysis 1 - Set 1 (Selected, 20/20, 18, 85.29%, 85.29%, 100%, N/A) highlighted with export icon; Sets 2-10 (New, 20/20, 18, 85.29%, 85.29%, 100%, 67.38%).
• Second view: "Diagnostic Analysis - Exported Group - Diagnostic Analysis 1": "Diagnostic Analysis" — Name "Exported Group - Diagnostic Analysis 1", Description "Exported from Diagnostic Analysis 1 Date: 2026/03/25 15:11:42", Type "User-defined", Propagation type "FCM", Response State "Steady and Transient States". "Propagation Focuses" tree: 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; note tooltip about settings only changeable if no generated/user defined Sensor Sets exist. "Indenture Selection" tree: Vehicle System > Driveline, Power Generation > Diesel Engine (checked).

Step 3: Create User-defined 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 "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 (selected) "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."
• 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 5: Define Diagnostic Exclusions

• "Diagnostic Analysis - Exported Group - Diagnostic Analysis 1": "Exclusions" tab. "Criticality Thresholding": Criticality Profile "PHMT RPN Criticality". "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". "Criticality Cause Exclusions (0 of 7 excluded)" table: Vehicle System (row shown, not excluded). "Detectable Cause Exclusions (1 of 7 excluded)" table: Vehicle System excluded. "Sensor Location Exclusions (0 of 6 excluded)" table: Vehicle System (not excluded).

Step 6: Create Sensor Sets

• "Diagnostic Analysis - Exported Group - Diagnostic Analysis 1": "Sensor Sets" tab — "Create, copy or remove Sensor Sets from the user defined Diagnostic Analysis. Newly created groups will have any currently active Test Point sensors automatically added to them. Sensor Locations and Sensors can be allocated or removed in the Sensor Allocation page." "Display Options": checkbox "Include Legacy Sensor Set" (unchecked). "Sensor Set Details": Name "Sensor Set", Description, Status "New", Comments. "Sensor Sets" table (Name/Sensed Responses/Coverage/Detection): Analysis 1 - Set 1 (20/80, 85.29%, 100%); Sensor Set (2/2, 0%, 55.88%).

Step 7: Allocate Sensors

• "Diagnostic Analysis - Exported Group - Diagnostic Analysis 1": "Sensor Allocation" tab. Two checked sensor sets: Analysis 1 - Set 1 (Coverage 85.29%, Number of Sensors 20, Weight Sum 2.601lb, Replacement Cost Sum $88,750.00) and Sensor Set (Coverage 2.94%, Number of Sensors 3, Weight Sum 0.65lb, Replacement Cost Sum $3,250.00). "Sensor Library" tree: Sample Sensor Library > Flow rate > Differential Pressure Device > Pitot tube [Sample Sensor], Pressure Anemometry > Tube anemometer [Sample Sensor], inductive proximity > Venturi meter & Dall tube [Sample Sens...]; New User Library > Sample Category 4 > Tube Anemonmeter. Checkbox "Filter by selected Component." "Recently Used Sensors": Tube Anemonmeter. "Sensor Allocation" panel: "Air Filter" — "Refine" / "Gas": Mass flow rate (checked) allocated "Tube Anemometer" (highlighted). "Items" panel: Status Filter blank; tree Coupling, Driveline > Differential, Driveshaft, Half Shaft Front/Rear, Planetary Geabox Front/Rear, Transmission, Wheel Front/Rear, Wheel Resistance Rear/Front (Sensors column, e.g. "0/0"); Power Generation > Control Unit, Diesel Engine > Air Filter (1/1, highlighted), Coupling 1, Engine, Governor, Injector Pump, Lift Pump, Primary/Secondary Fuel Filter, Fuel Tank; Vehicle.

Step 8: 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 (85.29%, 100%) > Ambiguity Group 1 (5, 14.71%, 100%); Sensor Set (2.94%, 55.88%) > Ambiguity Group 1 (15, 44.12%, 0%), Ambiguity Group 2 (8, 23.53%, 100%), Ambiguity Group 3 (4, 11.76%, 100%), Ambiguity Group 4 (6, 17.65%, 100%). "Ambiguity Group" table (Component/Flow Property/Failure/Driveline (Mechanical - rotational - Angular velocity)/Driveline (Me...): Vehicle System (Healthy System, No Failure), Half Shaft Front/Rear (Mechanical - rotational - Torque, High/Low (SS,TR)), Planetary Gearbox Front/Rear (Mechanical - rotational - Angular velocity, High/Low (SS,TR)), Vehicle (Mechanical - rotational - Angular velocity, High/Low (SS,TR) x2), Wheel Front/Rear (Mechanical - rotational - Angular velocity, Low (SS,TR)), Wheel Resistance Rear/Resistane Front (Mechanical - rotational - Angular velocity, Low (SS,TR)) — with High/Low indicator columns for Driveline Angular velocity.

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): Angular Velocity Sensor 2 (Differential - Divide Mechanical - rota..., Direct Entry, 100%/100%/0%/0%/N/A/N/A/100%/100%/0.00/0.00/1.00); Pressure Sensor (Injector Pump - Regulate Liquid Dyna..., Direct Entry, 98%/90%/2%/10%/N/A/N/A/94%/94%/9.80/0.02/0.88); Tube Anemonmeter (Air Filter - Refine Gas Mass flow rate, Direct Entry, 80.7%/67%/19.3%/33%/N/A/N/A/73.9%/73.9%/2.45/0.29/0.48). "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, 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), Parameters (Direct entry, POD 98%, Specificity 90%; Calculated: 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).

Step 10: Conduct Metric Optimization

• "Metric Optimization" tab: "Filters": unchecked Max Cost (USD) $0.00, unchecked Max Weight 0.0 kilograms, unchecked Min Coverage(%) 0, unchecked Min Detection(%) 0. Button "Reset Filters". "Sensor Set Details" empty (Name/Description/Status/Comments blank). "Sensor Sets" table (Name/Sensed Responses/Coverage/Detection/# of Sensors/Replacement C.../Weight): Analysis 1 - Set 1 (20/20, 85.29%, 100%, 20, $88,750.00, 2.601lb) with 20 component rows e.g. "Branch Mechanical - rotational - Angular velocity (Driveline)" x2, "Connect Mechanical - rotational - Angular velocity (Vehicle)" x2, "Control Mechanical - linear - Linear velocity (Governor)", "Convert Mechanical - rotational - Torque (Diesel Engine)", "Convert Mechanical - rotational - Torque (Power Generation)", "Couple Mechanical - rotational - Torque (Coupling)", "Distribute Mechanical - rotational - Angular velocity (Transmission)", "Process Continuous - Amplitude (Control Unit)", "Provide Liquid - Static pressure (Fuel Tank)", "Refine Gas - Mass flow rate (Air Filter)", "Refine Liquid - Flow rate (Secondary Fuel Filter)", "Rotate Mechanical - rotational - Angular velocity (Wheel Resistance Front/Rear)", "Store Mechanical - rotational - Angular velocity (Planetary Gearbox Rear/Front)", "Support Mechanical - rotational - Torque (Driveshaft)", "Transmit Mechanical - rotational - Torque (Half Shaft Rear/Front)"; Sensor Set (3/3, 2.94%, 55.88%, 3, $3,250.00, 10.406oz) with rows "Divide Mechanical - rotational - Angular velocity (Differential)", "Refine Gas - Mass flow rate (Air Filter)", "Regulate Liquid - Dynamic pressure (Injector Pump)".

Step 11: Review Comparison Graphs

• "Comparison" tab: checked "Analysis 1 - Set 1" and "Sensor Set". Summary cards: Sensor Set (Coverage 2.94%, Number of Sensors 3, Weight Sum 0.65lb, Replacement Cost Sum $3,250.00), Analysis 1 - Set 1 (Coverage 85.29%, Number of Sensors 20, Weight Sum 2.601lb, Replacement Cost Sum $88,750.00), Average — All Sets (Coverage 44.12%, Number of Sensors 11.5, Weight Sum 1.626lb, Replacement Cost Sum $46,000.00). Bar charts: "Coverage" (Coverage %), "Number of Sensors", "Weight of Sensors" (Weight Sum (lb)), "Replacement Cost Sum" (Replacement Cost Sum ($)) comparing Sensor Set vs Analysis 1 - Set 1.

Step 13: Review Diagnostic Sets

• "Diagnostic Sets" tab: "Sensor Sets" list (Name/Coverage/Detection): Analysis 1 - Set 1 (85.29%, 100%), Sensor Set (2.94%, 55.88%, selected). "Diagnostic Sets" table (Component/Flow Property/Failure/POD/Air Filter - Refine Gas Mass flow rate/Differential - Divide Mechanical - rotational): extensive Ambiguity Group rows for Group 1-4 covering Half Shaft Front/Rear, Planetary Gearbox Front/Rear, Vehicle, Wheel Front/Rear/Resistance Rear/Front (Transmit/Store/Connect/Rotate Mechanical - rotational Angular velocity/Torque, various High/Low(SS,TR)), Control Unit (Process Continuous - Amplitude, Decrease (SS,TR)), Coupling (Couple Mechanical - rotational - Torque, High(SS,TR)), Engine (Convert Mechanical - rotational - Torque, Low(SS,TR)), Fuel Tank (Provide Liquid - Static pressure), Governor (Control Mechanical - linear - Linear velocity), Injector Pump (Regulate Liquid - Dynamic pressure, Increase Liquid - Flow rate), Vehicle System (Healthy System, No Failure) all with Nominal/High/Low POD indicators. "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 [Air Filter - Refine Gas Mass flow rate IS Low] AND [Differential - Divide Mechanical - rotational Angular velocity IS Low] THEN [Air Filter - Refine Gas Mass flow rate IS Low (SS,TR)]".

Step 14: User-defined Sensor Sets Generated

• "DIAGNOSTIC ANALYSIS SUMMARY" report: Name "Exported Group - Diagnostic Analysis 1", Type "User-defined", Propagation Focuses "No propagation focuses set", Description "Exported from Diagnostic Analysis 1 / Date: 2026/03/25 15:11:42", Criticality Threshold "None", Propagation Type "FCM". "SENSOR SET" table (Sensor Set/Test Points/Coverage/Detection/Cost/Weight): Analysis 1 - Set 1 (20, 85.29%, 100%, $88,750.00, 2.601lb); Sensor Set (3, 2.94%, 55.88%, $3,250.00, 10.406oz). "INCLUSIONS": "Must Cover Failures" / "Must Detect Failures" — "No cause inclusions have been set for this analysis." "Must Use Sensor Locations (Legacy Sensor Set)" — "There are no legacy sensor set inclusions for this analysis." "Must Use Sensor Locations (Manual)" — "No manual sensor location inclusions have been set for this analysis." "EXCLUSIONS": "Cause Exclusions (Criticality Threshold)" — Criticality Threshold "None", no cause exclusions applied. "Cause Exclusions (Manual)" table: Item "Secondary Fuel Filter" / Failure Mode "Liquid Flow rate Low (SS,TR)". "Sensor Location Exclusions (Manual)" — none set.
• "SENSOR SET SUMMARY" — "ANALYSIS 1 - SET 1": Test Points 20, Coverage 85.29%, Detection 100%, Cost $88,750.00, Weight 2.601lb. "Sensor Details" table (Test Point/Sensor/Vendor/Part Number/Cost/Cost of Monitoring/Weight/MTTF/Replacement Time/Dimensions), sample rows: "Branch Mechanical - rotational Angular velocity (Driveline)" x2 / Angular Velocity Sensor 1 / — / — / $6,000.00 / $0.30 / 2.116oz / 0.00h / 0.00s / (w:10mm,h:10mm,d:10mm); "Connect Mechanical - rotational Angular velocity (Vehicle)" x2 / Angular Velocity Sensor 1 / $6,000.00 / $0.30 / 2.116oz; "Control Mechanical - linear Linear velocity (Governor)" / Optical Tracker and Velocimeter / $10,000.00 / $0.30 / 3.175oz; "Convert Mechanical - rotational Torque (Diesel Engine)" / Rotary Transformer / $1,500.00 / $0.01 / 0.353oz / MTTF 200000.00h / Replacement Time 1.00m; "Convert Mechanical - rotational Torque (Power Generation)" / Rotary Transformer / $3,500.00 / $0.35 / 0.353oz; "Couple Mechanical - rotational Torque (Coupling)" / Rotary Transformer / $3,500.00 / $0.35 / 0.353oz; "Distribute Mechanical - rotational Angular velocity (Transmission)" / Angular Velocity Sensor 1 / $6,000.00 / $0.30 / 2.116oz; "Process Continuous Amplitude (Control Unit)" / Amplitude Detector / $1,500.00 / $0.10 / 0.529oz; "Provide Liquid Static pressure (Fuel Tank)" / Pressure Sensor / Sensor Company Inc. [PS1-A] / $50.00 / $2.00 / 3.527oz / MTTF 100000.00h / Replacement Time 5.00m / (w:20mm,h:50mm,d:20mm); "Refine Gas Mass flow rate (Air Filter)" / Tube Anemometer / $1,200.00 / $2.00 / 2.646oz; "Refine Liquid Flow rate (Secondary Fuel Filter)" / Orifice Plate / $3,000.00 / $0.80 / 10.582oz / (w:20mm,h:10mm,d:20mm).

Related workflows

• WF23 – Define Test Point
• WF24 – Generate Automated Sensor Sets