8.6 - The Aggregate Entity Behavior Model

Table of Contents

• 8.6.1 Core Elements of Aggregate Entities
  • 8.6.1.1 Specifying Subordinates
• 8.6.2 Component Systems that make up an Aggregate
  • 8.6.2.1 A Specific Example: Armor Plt (US)
  • 8.6.2.2 Systems
  • 8.6.2.3 Other Simulation Components
  • 8.6.2.4 Sensors
  • 8.6.2.5 Controllers
  • 8.6.2.6 Actuators

VR-Forces includes an aggregate model for simulating the organization of entities in a hierarchical command structure.

The aggregate entities in VR-Forces are multi-resolution models. Their components enable them to be simulated in either of two states:

• Disaggregated: Subordinates are separately simulated and published entities. Aggregates in this state can be tasked and given plans, but usually pass responsibility for execution to their subordinates.
• Aggregated: Subordinates are not simulated separately. Tasks and plans are executed by the aggregate.

8.6.1 Core Elements of Aggregate Entities

Aggregates in VR-Forces share certain common elements. An aggregate in VR-Forces is always configured with the following:

• DtVrfAggregateStateRepository – Holds state information specific to aggregates, such as formation state.
• DtSimPseudoAggregateLocalEntityNetInterface – Handles network publishing of aggregate entities.

Aggregates are also always configured with a DtVrfRadio, which enables radio-like communication between entities in the same unit.

8.6.1.1 Specifying Subordinates

Aggregates also typically specify a list of subordinate entities to create when the aggregate entity gets created. Each entry in the list specifies the DIS/RPR FOM entity type of the subordinate to create, and its initial position and heading. Below is an excerpt from the subordinate list of the Armor Plt (US) aggregate OPE file:

(subordinate-objects
    (sub1
        (object-type  1 (1 1 225 1 1 3 0))
        (position-offset  0.000000 0.000000 0.000000)
        (heading-offset  0.000000)
   )
   (sub2
       ...

Aggregates may have individual (platform-level) subordinates, aggregate subordinates, or a combination of both.

8.6.2 Component Systems that make up an Aggregate

Aggregates share many of the same systems and simulation components (sensors, controllers, and actuators). To examine the systems typically configured on an aggregate, we'll look at a specific instance of an aggregate, the Armor Plt (US) entity.

It is a representative example that includes all of the common systems and components that make up an aggregate. The differences between the various types of aggregates supported in VR-Forces arise from the types of subordinates a given aggregate is configured with, and the parameter values used in configuring certain behaviors, such as moving in formation.

8.6.2.1 A Specific Example: Armor Plt (US)

Defined in parameter file Armor_Plt_US_3_11_1_225_3_2_-1_-1.ope.

The figure below shows which systems and simulation components are configured as part of an Armor platoon. The boxes (nodes) represent either a system of components (DtComponentSystem) or indivdiual DtSimComponent classes.

8.6.2.2 Systems

• Ground Aggregated Movement – Models movement of aggregate while in aggregate state.
• Ground Disaggregated Movement – Models movement of aggregate while in disaggregated state.

8.6.2.3 Other Simulation Components

Individual DtSimComponents (not organized as part of a system) that make up the rest of entity:

8.6.2.4 Sensors

There are no sensors configured as part of this aggregate.

8.6.2.5 Controllers

• Send Radio Message Controller (DtSendRadioMessageController) – Send text or task messages through the radio.
• Disaggregated Set (DtDisaggregatedSetController) – Respond to DtSetDataRequests, such as set location, set heading. Pass down requests to subordinates (disaggregated mode only).
• Organization (DtAggregateOrganizationController) – Maintain my position in the aggregate organizational hierarchy.
• Embarkation (DtDisaggregatedEmbarkationController) – Support entity's ability to embark on other entities.
• Auto Aggregate/Disaggregate (DtAutoAggregateDisaggregateController) – Automatically switch between aggregated/disaggregated modes, depending on proximity to hostile entities, disaggregation areas.
• Aggregate Model Resolution (DtAggregateModelResolutionController) – Manage the switch between aggregated/disaggregated modes. Activates/deactivates systems and components as appropriate for the mode.
• Aggregated Set (DtAggregatedSetController) – Respond to DtSetDataRequests, such as set location, set heading (aggregated mode only).
• Path Movement (DtPathMovementController) – Find the best path to take to a given location, using A* algorithm.
• Occupancy Director (DtDisaggregatedOccupancyDirectorController) – Allocate/reserve embarkation slots on the entity.

8.6.2.6 Actuators

Disaggregated Damage (DtDisaggregatedDamageActuator) – Models damage of aggregate (disaggreated state only).

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