page_title: 4D-RCS Reference Model Architecture
section_title: 4D/RCS control loop
hierarchical_section_title: 4D-RCS Reference Model Architecture / 4D/RCS Building blocks / 4D/RCS control loop
caption_attribution_description: English: The basic internal structure of a 4D/RCS control loop. Sensory processing performs the functions of windowing, grouping, computation, estimation, and classification on input from sensors. World modeling maintains knowledge in the form of images, maps, entities, and events with states, attributes, and values. Relationships between images, maps, entities, and events are defined by pointers. These relationships include class membership, ontologies, situations, and inheritance. Value judgment provides criteria for decision making. Behavior generation is responsible for planning and execution of behaviors.
context_page_description: The 4D/RCS Reference Model Architecture is a reference model for military unmanned vehicles on how their software components should be identified and organized.
  The 4D/RCS has been developed by the Intelligent Systems Division of the National Institute of Standards and Technology since the 1980s.
  This reference model is based on the general Real-time Control System Reference Model Architecture, and has been applied to many kinds of robot control, including autonomous vehicle control.
context_section_description: At the heart of the control loop through each node is the world model, which provides the node with an internal model of the external world. The world model provides a site for data fusion, acts as a buffer between perception and behavior, and supports both sensory processing and behavior generation.
  A high level diagram of the internal structure of the world model and value judgment system is shown in the figure. Within the knowledge database, iconic information (images and maps) is linked to each other and to symbolic information (entities and events). Situations and relationships between entities, events, images, and maps are represented by pointers. Pointers that link symbolic data structures to each other form syntactic, semantic, causal, and situational networks. Pointers that link symbolic data structures to regions in images and maps provide symbol grounding and enable the world model to project its understanding of reality onto the physical world.
  Sensory processing performs the functions of windowing, grouping, computation, estimation, and classification on input from sensors. World modeling maintains knowledge in the form of images, maps, entities, and events with states, attributes, and values. Relationships between images, maps, entities, and events are defined by pointers. These relationships include class membership, ontologies, situations, and inheritance. Value judgment provides criteria for decision making. Behavior generation is responsible for planning and execution of behaviors.
caption: 4D-RCS control loop basic internal structure.
exif: {}