Hydra ontology




There are several ontologies developed in the Hydra project, but for the purpose of the Smart Appliances project we are mainly interested in the Device ontology, which consists of the following modules:

  • Basic Device Information
  • Device Services
  • Device Events
  • Device Malfunctions
  • Device Capabilities and State Machine

The Basic Device Information module represents general device information. The HydraDevice is the main ontology class, which is further divided in the PhysicalDevice and the SemanticDevice classes. Physical and semantic devices share common device properties, such as deviceId or inLocation, but have different semantic interpretation and behaviour. The HydraDevice class refers to the InfoDescription class using the info property. The InfoDescription class contains basic information about device friendlyName, manufacturer data, i.e., manufacturerName and manufacturerURL, and device model data, i.e., modelName, modelDescription and modelNumber. An important part of the basic device information is the representation of device type modelled as sub classes of the PhysicalDevice concept, such as SensorDevice, ActuatorDevice, MediaDevice and MobileDevice. Further, the hasEmbeddedDevice property of the SemanticDevice class recursively refers to HydraDevice concept. This property enables the creation of models of composite devices, such as in case of the HeatingSystem device, which can be, for example, composed of Thermometer and Pump devices.


  • We did not create the Hydra ontology in the context of Smart Appliances project. We are reusing the description of the ontology in the 'Deliverable D6.6 Updated MDA Design Document' and the OWL files provided by the authors of this document.