PROPOSED STATE: This integration profile is currently in a proposed state and is under community review. The specification may change based on feedback and implementation experience.

Digital Twin Integration Profile

Purpose and Use Cases

The Digital Twin profile defines metadata for digital representations of physical objects, places, or systems. This profile enables synchronization between physical and virtual entities, supporting simulation, monitoring, and interactive experiences.

Key Use Cases:

• Industrial equipment simulation and monitoring
• Urban planning and smart city applications
• Physical product visualization and configuration
• Education and training for physical systems
• Remote monitoring and control systems

Required Properties

Basic Information

• @context
• @type: Typically "DigitalDocument" or "Dataset"
• name
• description
• identifier
• subjectOf: The physical entity being represented

Digital Twin Properties

• Physical entity identification
• Synchronization mechanism
• Update frequency
• Sensor mappings
• Historical data configuration

Technical Specifications

Physical Entity Mapping

{
  "@context": {
    "@vocab": "https://schema.org/",
    "mvmd": "https://mvmd.org/v1/"
  },
  "subjectOf": {
    "@type": "Thing",
    "name": "Industrial Robot Arm",
    "manufacturer": "Industrial Robotics Inc.",
    "serialNumber": "IR-2024-X7-42",
    "productionDate": "2024-01-15",
    "location": {
      "@type": "Place",
      "name": "Factory Floor - Section B",
      "address": {
        "@type": "PostalAddress",
        "streetAddress": "123 Manufacturing Way",
        "addressLocality": "Industry City",
        "postalCode": "12345",
        "addressCountry": "US"
      },
      "geo": {
        "@type": "GeoCoordinates",
        "latitude": 37.7749,
        "longitude": -122.4194
      }
    }
  }
}

Synchronization Configuration

{
  "@context": {
    "@vocab": "https://schema.org/",
    "mvmd": "https://mvmd.org/v1/"
  },
  "synchronization": {
    "mechanism": "MQTT",
    "endpoint": "mqtt://example.com/twins/robot-42",
    "updateFrequency": "realtime",
    "lastSynced": "2024-03-15T14:30:00Z",
    "connectionStatus": "active",
    "latency": 120
  }
}

Complete Example

{
  "@context": {
    "@vocab": "https://schema.org/",
    "mvmd": "https://mvmd.org/v1/"
  },
  "@type": "DigitalDocument",
  
  "name": "Manufacturing Robot Digital Twin",
  "description": "Comprehensive digital twin of industrial robot arm with real-time sensor data, maintenance history, and predictive analytics",
  
  "identifier": {
    "@type": "PropertyValue",
    "propertyID": "MVMD-ID",
    "value": "twin-2024-001"
  },
  
  "creator": {
    "@type": "Organization",
    "name": "Digital Twin Solutions Inc.",
    "url": "https://example.com/digital-twins"
  },
  
  "dateCreated": "2024-01-15",
  "dateModified": "2024-03-15",
  
  "subjectOf": {
    "@type": "Thing",
    "name": "Industrial Robot Arm",
    "manufacturer": "Industrial Robotics Inc.",
    "model": "PrecisionArm X7",
    "serialNumber": "IR-2024-X7-42",
    "productionDate": "2024-01-10",
    "installDate": "2024-01-15",
    "location": {
      "@type": "Place",
      "name": "Factory Floor - Section B",
      "address": {
        "@type": "PostalAddress",
        "streetAddress": "123 Manufacturing Way",
        "addressLocality": "Industry City",
        "postalCode": "12345",
        "addressCountry": "US"
      },
      "geo": {
        "@type": "GeoCoordinates",
        "latitude": 37.7749,
        "longitude": -122.4194
      }
    },
    "productionLine": "Assembly Line 3"
  },
  
  "associatedMedia": [
    {
      "@type": "3DModel",
      "name": "Robot Arm 3D Model",
      "contentUrl": "https://example.com/models/robot-x7.glb",
      "encodingFormat": "model/gltf-binary"
    },
    {
      "@type": "ImageObject",
      "name": "Robot Installation Photo",
      "contentUrl": "https://example.com/images/robot-installed.jpg",
      "encodingFormat": "image/jpeg"
    }
  ],
  
  "synchronization": {
    "mechanism": "MQTT",
    "endpoint": "mqtt://example.com/twins/robot-42",
    "updateFrequency": "realtime",
    "lastSynced": "2024-03-15T14:30:00Z",
    "connectionStatus": "active",
    "latency": 120
  },
  
  "sensors": [
    {
      "id": "temp-1",
      "name": "Joint Temperature",
      "type": "temperature",
      "unit": "celsius",
      "location": "main_joint",
      "updateFrequency": 10,
      "currentValue": 42.3,
      "timestamp": "2024-03-15T14:30:00Z",
      "normalRange": [30, 65],
      "criticalRange": [75, 90]
    },
    {
      "id": "motion-1",
      "name": "Arm Position",
      "type": "position",
      "unit": "degrees",
      "location": "arm_angle",
      "updateFrequency": 50,
      "currentValue": 45.2,
      "timestamp": "2024-03-15T14:30:00Z",
      "accuracy": 0.1
    },
    {
      "id": "pressure-1",
      "name": "Hydraulic Pressure",
      "type": "pressure",
      "unit": "psi",
      "location": "hydraulic_system",
      "updateFrequency": 5,
      "currentValue": 1200,
      "timestamp": "2024-03-15T14:30:00Z",
      "normalRange": [1000, 1500],
      "criticalRange": [1800, 2000]
    }
  ],
  
  "dataStorage": {
    "historicalData": {
      "retentionPeriod": "90d",
      "storageLocation": "cloud",
      "samplingRate": "1m",
      "compressionLevel": "high"
    },
    "analytics": {
      "predictionModels": ["failure_prediction", "maintenance_scheduling"],
      "alertThresholds": {
        "temperature": 70,
        "pressure": 1700
      }
    }
  },
  
  "maintenance": {
    "history": [
      {
        "date": "2024-02-15",
        "type": "scheduled",
        "description": "30-day checkup",
        "technician": "J. Smith",
        "findings": "All systems nominal"
      }
    ],
    "schedule": {
      "nextMaintenance": "2024-04-15",
      "type": "scheduled",
      "description": "90-day full inspection"
    },
    "predictedIssues": [
      {
        "component": "hydraulic_pump",
        "probability": 0.23,
        "timeframe": "30d",
        "recommendedAction": "Visual inspection at next maintenance"
      }
    ]
  },
  
  "performance": {
    "uptime": "99.7%",
    "productivity": [
      {
        "metric": "units_processed",
        "value": 12500,
        "period": "30d"
      },
      {
        "metric": "cycle_time",
        "value": 45.2,
        "unit": "seconds"
      }
    ],
    "alerts": [
      {
        "date": "2024-03-10T08:42:15Z",
        "type": "warning",
        "source": "temp-1",
        "message": "Temperature spike detected",
        "value": 68.5,
        "resolution": "auto-resolved"
      }
    ]
  }
}

Validation Rules

Required Properties

• Valid physical entity mapping
• Complete synchronization configuration
• Proper sensor definitions
• Data storage configuration
• Maintenance information

Technical Properties

• Valid endpoints
• Proper update frequencies
• Complete sensor metadata
• Appropriate value ranges
• Timestamp formatting

Best Practices

1. Physical Entity Mapping

   • Include complete identification
   • Provide accurate location
   • Document physical characteristics
   • Include manufacturer information
   • Add installation details

2. Synchronization Configuration

   • Define clear update mechanisms
   • Document endpoint security
   • Set appropriate update frequencies
   • Include status monitoring
   • Plan for connection loss

3. Sensor Integration

   • Document all connected sensors
   • Define clear measurement units
   • Set normal and critical ranges
   • Include calibration information
   • Plan update frequencies

4. Data Management

   • Define storage requirements
   • Document retention policies
   • Plan data compression
   • Consider privacy requirements
   • Include backup procedures

Common Issues

1. Data Synchronization

   • Connection reliability
   • Update frequency balancing
   • Data validation challenges
   • System latency management
   • Authentication requirements

2. Sensor Integration

   • Sensor data accuracy
   • Calibration drift
   • Unit conversion issues
   • Timestamp synchronization
   • Data filtering requirements

Next Steps

• Review Integration Patterns for physical-digital synchronization
• See Data Storage Best Practices for time-series data management
• Check Validation Tools for testing