Information Technology Reference
In-Depth Information
Jadex, and the Xaitment
9
game AI engine). Every ISReal agent is equipped with a
Lo-
cal Semantic Environment
(LSE) which is an agent's local knowledge base. The LSE
stores the perceived information and enables the agent to reason about it. Moreover, the
LSE is equipped with an AI planner.
Graphics Environment.
The user interface of the ISReal platform is realized by a
XML3D
10
-enabled standard web browser. The 3D scene graph is part of the browser's
Document Object Model
(DOM) and can be manipulated using Java Script. It also con-
tains RDFa
11
-based semantic annotations of the 3D-objects such as the concept URI, the
object URI, and the semantic object service URIs. Moreover, we extended the browser
with an agent sensor which allows agents to perceive the annotated 3D objects.
An intelligent ISReal avatar consists of (i) the geometrical shape (body) and ani-
mations, (ii) a perception component, (iii) semantic annotations, and (iv) an agent that
processes the perceived information and controls the body. Artifacts such as the ge-
ometrical shape, animations, or ontologies are developed using specialized 3rd party
tools. We decided to base the development environment for ISReal agents on B
OCHICA
and use Jadex as the target agent platform. This has several advantages: (i) B
OCHICA
already provides the core concepts, diagrams, etc. for modeling agent systems, (ii) we
can reuse the existing base transformation to Jadex, (iii) we only need to customize the
missing aspects of B
OCHICA
for creating an individual development environment for
agents in semantic virtual worlds, and (iv) it enables the reuse of existing model arti-
facts (e.g. interaction protocols). Figure 5 depicts the big picture of how we think that
intelligent agents for the ISReal platform should be developed. For a detailed introduc-
tion to the ISReal platform we refer to [11]. The remainder of this section discusses the
extensions of the B
OCHICA
framework for developing ISReal agents.
5.1
Conceptual Extension
Figure 6 depicts some of the conceptual extensions for ISReal. The upper row shows
interface concepts of B
OCHICA
.The
OMSConfig
concept is the root of a metamodel
which is used in the ISReal platform for configuring the LSE with concrete ontolo-
gies, object services, etc. The imported
OMSConfig
concept of the ISReal platform
is reused by the extension plug-in. The bottom row depicts the actual conceptual ex-
tensions. The
ISRealAgent
specializes the concept
Agent
and has an URI which
defines an agent's ontological type, an
ISRealRaySensor
(resolution, update rate), a
LSE, and a (not visualized) reference to an existing graphical avatar (the agent's body).
Some concepts of B
OCHICA
change their technical meaning when they are transformed
to the ISReal platform. For example, ISReal agents use their plans to orchestrate object
services. B
OCHICA
already provides support for orchestrating web services by plans.
Since ISReal object services are very similar to web services, the existing concepts can
be reused without modification. Figure 7 depicts a simple plan that is triggered by the
MoveNearGoal
and invokes the
MoveNearService
with the according parame-
ters. The
MoveNearService
is used for in-room navigation (no path finding across
