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rooms). The plan's precondition checks whether the target object is located in the same
room. The ISReal model transformation generates code for invoking an ISReal object
service instead of code for invoking an ordinary web service (see Section 5.3).
5.2
Language Extension
In order to make rational decisions, it is essential for agents to reason about the per-
ceived information. The interface to a knowledge base is usually defined by a query
language. As ISReal agents are based on semantic web technology, we decided to use
SPARQL queries to access the LSE. Two of the application scenarios are (i) to use
SPARQL-Ask queries to define the target condition of achieve goals and (ii) to specify
the context condition of plans with SPARQL-Select queries. As explained in Section
4.3, B
OCHICA
defines language interface concepts such as
BooleanExpression
that are used throughout the framework. We reused an Ecore-based SPARQL DSL
which is provided by the EMFText concrete syntax zoo to extend B
OCHICA
(see Section
4.3). The
BooleanExpression
was extended with SPARQL-Ask and the
ContextCondition
with SPARQL-Select. We also reused the automatically gener-
ated parser of EMFText for parsing SPARQL text queries into SPARQL models that are
plugged into the B
OCHICA
extension slot. Figure 7 depicts an example
AchieveGoal
for walking to an object. The target condition
isNearAt(self, object)
is val-
idated in the agent's LSE. The predicate is perceived by the agent through its sensor
after it has been computed by the graphics environment and the GSE.
I
SR
eal Agent Modeling Enviro
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ISReal Agent Execution Platform (Jadex)
Fig. 8.
a) depicts an overview of the transformation architecture and b) an example mapping rule
in XPand
5.3
Transformations
A Jadex application consists of XML-based configuration files for applications, agents,
and capabilities. Behaviors are encoded in Java-based plans. The base transformation
from B
OCHICA
to Jadex consists of the four modules Application, BDI, Interaction, and
Behavior (see Figure 8 a). The first three modules map concepts from B
OCHICA
to the
Jadex
Platform Specific Metamodel
(PSM) (green arrows) using QVT model-to-model
transformations. The generated Jadex model is automatically serialized to valid Jadex
XML files by EMF. We decided not to create a separate Jadex metamodel for plans.
This decision was made due to experiences with previous transformations to Jack and
