Data Model

Sample datasets and the knowledge graph structure.

Dual Graph Architecture

The system uses a single Oxigraph store with two named graphs:

Schema Graph (<urn:graph:schema>)

Contains the ontology definitions — OWL class hierarchies, SHACL shapes with sh:in value constraints, property definitions. Raw SHACL files are read directly for the LLM prompt (via SHACL reader), and schema-queries.ts runs SPARQL against this graph to derive asset domains, domain references, shape groups, and other compiler metadata.

Default Graph (instance data)

Contains 267 simulation assets — the actual data that users search:

Asset Type	Count	Example Properties
HD Maps	117	roadTypes, laneCount, formatType, country, length
Scenarios	50	scenarioCategory, weather, timeOfDay
OSI Traces	50	roadTypes, granularity, fileFormat, numberFrames
Environment Models	30	terrainType, vegetationType, weatherCondition
Surface Models	20	materialType, frictionCoefficient, textureFormat

RDF Structure

Each asset follows the ENVITED-X pattern:

# An HD Map asset
<did:web:provider35.net:HdMap:karlsruhe-parking-garage-001> a hdmap:HdMap ;
  rdfs:label "Karlsruhe Parking Garage HD Map"@en ;
  hdmap:hasResourceDescription [
    a envited-x:ResourceDescription ;
    gx:name "Karlsruhe Parking Garage HD Map" ;
    gx:license "CC0-1.0"
  ] ;
  hdmap:hasDomainSpecification [
    a hdmap:DomainSpecification ;
    hdmap:hasContent [
      a hdmap:Content ;
      hdmap:roadTypes "custom" ;
      hdmap:laneCount 3 ;
      hdmap:trafficDirection "right-hand"
    ] ;
    hdmap:hasFormat [
      a hdmap:Format ;
      hdmap:formatType "Lanelet2"
    ] ;
    hdmap:hasGeoreference [
      a georeference:Georeference ;
      georeference:hasProjectLocation [
        a georeference:ProjectLocation ;
        georeference:country "DE" ;
        georeference:region "Baden-Wuerttemberg"
      ]
    ]
  ] .

Dataset Sources

Ontology schema files are resolved from ontology-sources.json. Runtime sample instance data is loaded by packages/search/src/data-loader.ts from 5 TTL files in packages/search/data/:

• sample-assets.ttl — 117 HD maps
• sample-scenarios.ttl — 50 scenarios
• sample-ositrace.ttl — 50 OSI traces
• sample-environment-models.ttl — 30 environment models
• sample-surface-models.ttl — 20 surface models

SPARQL Store Abstraction

The SparqlStore interface decouples the application from any specific triplestore:

interface SparqlStore {
  query(sparql: string): Promise<SparqlResults>
  update(sparql: string): Promise<void>
  loadTurtle(data: string, graphUri?: string): Promise<void>
  loadJsonLd(data: string, graphUri?: string): Promise<void>
  isReady(): Promise<boolean>
}

Implementation	Description
OxigraphStore	WASM-based, runs in-process, zero infrastructure
RemoteSparqlStore	HTTP client for any SPARQL 1.1 endpoint
CachedSparqlStore	LRU query cache decorator (wraps either)

Query Results

SPARQL SELECT queries return bindings as key-value pairs, streamed via SSE:

[
  {
    "asset": "manifest:asset-autobahn-a9",
    "name": "Autobahn A9 Munich-Nuremberg",
    "roadTypes": "motorway",
    "country": "DE"
  },
  {
    "asset": "manifest:asset-i95",
    "name": "US Interstate I-95 Section",
    "roadTypes": "interstate",
    "country": "US"
  }
]