Behavior Model

Behavior

In the tree-based Behavior Model (MBehavior), which is defined as a Behavior Tree, five important classes of leaf nodes (MBTLeafNode ← MBTTreeNode) or executable primitives will be used: MBTCondition; MBTUpdate; MBTService; MBTAction; MBTScene. All these nodes are united by the fact that they access the knowledge base of the agent via SPARQL queries and process the resulting information or forward it to a service, for example. With so-called conditions (MBTCondition) the current state of the simulation or the character to be simulated is queried; with updates (MBTUpdate) the internal knowledge of the agent can be updated; services nodes (MBTService), with which external or internal services are called to receive external data or to process internal data; and action nodes (MBTAction), which represent the individual instruction steps or MMUs. In addition, further types of nodes (MBTBranchNode ← MBTTreeNode) are used to define the internal operational logic of the BT. With such a node the functionality mentioned in the previous chapter to generate instructions (MInstruction) based on linked actions and tree nodes, will be implemented. At each execution cycle of the agent, such an instruction is generated and sent to the co-simulator for execution. Successful or failed instruction execution is reported (MInstructionResult) from the co-simulator to the agent. MBTLeafNode and MBTBranchNode are derived from MBTTreeNode. They are not considered in the following list of classes and interfaces, since they are represented by their relevant variants for the project. In summary, it can be said that a branch node has at least one child node and all leaf nodes have queries with which they access the knowledge base of the agent.

MBehavior
+ID: string +Name: string +Root: MTreeNode +Beliefs: list +State: MBTState
+Run(list):MBTState +Abort():bool

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the behavior
Name	Name of the behavior
Root	Root node or starting point of the behavior
Beliefs	Link to the agent beliefs
State	State of the behavior: FRESH, RUNNING, SUCCESS, FAILURE, ABORTED
Run	Method to run the behavior
Abort	Method to abort the behavior

MBTState (enum)
FRESH RUNNING SUCCEEDED FAILED ABORTED

Behavior Modeling & Execution

The Behavior Model and Execution unit (MBehaviorExecution) generates instructions (MInstruction) for the co-simulator based on the scene and a predefined behavior model. The unit that generates these instructions for one simulated character and manages its knowledge is called agent that is represented with the MAgent class. MBehaviorExecution manages these agents. With this unit, you can create so called agent templates (MTemplate), which describes a certain type of agent. Such a template contains configuration information about an agent and its behavior models. It is a blueprint for an agent (MAgent), so to speak. To create an agent, the name of the agent and the template to be used as well as its initial knowledge (MInitialKnowledge) or the initial state of the scene to be viewed are transferred to the Behavior Model & Execution unit.

MBehaviorExecution
+Agents: list +Templates: list +AddTemplate(MTemplate):bool +DeleteTemplate(MTemplate):bool +CreateAgent(template:ID, name, MInitialKnowledge):MAgentState +ListAgents():list +DeleteAgent(agent:ID):list

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
Agents	List of all available agents
Templates	List of all available agent templates
AddTemplate	Add new agent template which describes an agent model
DeleteTemplate	Delete an agent template
CreateAgent	Create an agent with a defined name, linked agent template and initial agent knowledge
ListAgents	List all agents
DeleteAgent	Delete specified agent
Agents	List of all available agents
Templates	List of all available agent templates
AddTemplate	Add new agent template which describes an agent model

In addition to its behavior, an agent has several storage units for storing RDF-based data, the so-called Triple Data Bases (MTripleDataBase). In these the scene updates (MSceneUpdate) are stored which are mapped to RDF in an intermediate step. These triple stores are accessed by the behaviors (MBehavior) during their execution in order to query states or to read data for the generation of instructions (MInstruction). Actions or MMUs and services that should be available for the behavior models will be referenced in the agent.

MRDFGraph

MRDFGraph
+ContentType: string +Graph: string

Detailed description of available parameters/functions:

Parameter Name	Required	Description
ContentType
Graph

MAgent

MAgent
+ID: string +Name: string +SceneAccess: MSceneAccess +ServiceAccess: MServiceAccess +AgentState: MAgentState +Beliefs: list +Behaviors: list +Services: listMService:ID +Actions: listMMU:ID
+Initialize(list):MAgentState +GetState():MAgentState +Perceive(list):bool +CompleteInstruction(MInstructionResult):bool +Run(list,):MInstruction +Abort():bool

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	Agent ID.
Name	Name of the Agent.
SceneAccess	Access to the Scene for agent-scene interaction, like reading out the current state of the scene or to manipulate it.
ServiceAccess	Access to available services to make use of their provided methods while behavior execution.
AgentState	State of the agent.
Beliefs	All beliefs of an agent stored as RDF in multiple triple stores.
Behaviors	List of all SPARQL-BTs of the agent.
Services	List of used services.
Actions	List of used MMUs.
Initialize	Method to initialize the agent by executing a specific SPARQL-BT for configuration purposes, like setting variables.
GetStatus	Method for returning the agent status.
Perceive	Method which is used by the consumer to update the agent knowledge if a scene or simulation update comes up:
CompleteInstruction	Method to tell the agent that an action or motion instruction is finished successfully or faulty.
Run	Method to run the defined SPARQL-BT of the agent.
Abort	Method to abort a running SPARQL-BT.

MBTLeafNode

MISSING Documentation!

MBTAction

<<interface>> MBTAction ← MBTLeafNode
+ID: string +Name: string +Beliefs: → behavior:Beliefs +Query: String (SPARQL-Update) +Action: MMUID
+Run():MBTState +Validate(MInstructionResult):bool

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the leaf node.
Name	Name of the leaf node.
Beliefs	Beliefs of the agent.
Query	CONSTRUCT or SELECT SPARQL query which defines a agent state.
Action	Link to the MMU which have to be used.
Validate	Method to validate the incoming MInstructionResult to decide if the action performed by the co-simulator was successful, returning: SUCCEEDED or FAILED

Example:

MBTAction Walk
ID	“:WalkToTarget1” (RDF)
Name	“WalkToTarget1”
Beliefs	“ajan:AgentKnowledge”
Action	“walk” (MotionType)
Query	“PREFIX mosim: http://mosim/vocabulary SELECT ?target WHERE { ?target a mosim:Target . ?target mosim:name “Target1” . }”

MBTComposite

<<interface>> MBTComposite ← MBTBranchNode
+ID: string +Name: string +Beliefs: → behavior:Beliefs +Children: list
+Run():MBTState +Abort():bool

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the composite node.
Name	Name of the composite node.
Beliefs	Beliefs of the agent.
Children	Children of the composite node.
Run	Method to run the composite executed by its parent node, returning its status.
Abort	Method to abort composite node.

MBTCondition

<<interface>> MBTCondition ← MBTLeafNode
+ID: string +Name: string +Beliefs: → behavior:Beliefs +Query: String (SPARQL) +Run():MBTState

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the leaf node.
Name	Name of the leaf node.
Beliefs	Beliefs of the agent.
Query	ASK SPARQL query which defines an agent state.
Run	Method to execute this node, which performs the defined query on the agent beliefs, returning: SUCCEEDED or FAILED

Example:

MBTCondition
ID	“:WalkToTarget1?” (RDF)
Name	“WalkToTarget1?”
Beliefs	“ajan:AgentKnowledge”
Query	“PREFIX mosim: http://mosim/vocabulary ASK WHERE{ ?avatar a mosim:Avatar. ?avatar mosim:locatedNextTo ?location . ?target a mosim:Target . ?target mosim:name "Target1" . FILTER (?location != ?target) }"

MBTDecorator

<<interface>> MBTDecorator ← MBTBranchNode
+ID: string +Name: string +Beliefs: → behavior:Beliefs +Child:
+Run():MBTState +Run(list):MBTState +Abort():bool

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the decorator node.
Name	Name of the decorator node.
Beliefs	Beliefs of the agent.
Child	Child of the decorator node.
Run	Method to run the decorator node executed by its parent node, returning its status.
Abort	Method to abort the decorator node.

With composite nodes (MBTComposite) that can have several child nodes, sequential or parallel processes are usually implemented, whereas decorators (MBTDecorator) possess only one child node. This type is mostly used for loops. In contrast to the tree nodes just mentioned, Leaf Nodes (MBTLeafNode) do not have child nodes that are executed.

MBTScene

MBTScene ← MBTLeafNode
+ID: string +Name: string +Beliefs: → behavior:Beliefs +Query: String (SPARQL-Update) +Scene: MScene:ID
+Run():MBTState

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the leaf node.
Name	Name of the leaf node.
Beliefs	Beliefs of the agent.
Query	UPDATE SPARQL query which defines an agent state.
Scene	Link to the scene.
Run	Method to run this node, which executes the MScene:GetChanges() method and performs the defined query to update the agent beliefs with the received scene updates, returning: SUCCEEDED or FAILED

MBTService

<<interface>> MBTService ← MBTLeafNode
+ID: string +Name: string +Beliefs: → behavior:Beliefs +Query: String (SPARQL-Update) +Service: MService:ID
+Run():MBTState

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the leaf node.
Name	Name of the leaf node.
Beliefs	Beliefs of the agent.
Query	CONSTRUCT or SELECT SPARQL query, which defines an agent state.
Service	Link to the service, which has to be used.
Run	Method to execute this node, which performs the defined query to gather date from the agent beliefs which will be sent to the defined service, returning: SUCCEEDED or FAILED or RUNNING

MBTUpdate

<<interface>> MBTUpdate ← MBTLeafNode
+ID: string +Name: string +Beliefs: → behavior:Beliefs +Update: String (SPARQL-Update)
+Run():MBTState

Detailed description of available parameters/functions:

Function/ Parameter Name	Description
ID	ID of the leaf node.
Name	Name of the leaf node.
Beliefs	Beliefs of the agent.
Update	UPDATE SPARQL query which defines a new agent state.
Run	Method to execute this node, which performs the defined query on the agent beliefs, returning: SUCCEEDED or FAILED

Example:

MBTUpdate UpdateAvatarLocation
ID	“:UpdateAvatarLocation” (RDF)
Name	“UpdateAvatarLocation?!”
Beliefs	“ajan:AgentKnowledge”
Update	“PREFIX mosim: http://mosim/vocabulary DELETE {?avatar mosim:locatedNextTo ?location .} INSERT {?avatar mosim:locatedNextTo ?target .} WHERE { ?avatar a mosim:Avatar .?avatar mosim:locatedNextTo ?location .?target a mosim:Target .?target mosim:name “Target1” .FILTER (?location != ?target)}”