Automatic model construction and extension for distributed simulation

Abstract

The High Level Architecture (HLA) is widely used in Modeling & Simulation as acommon structure which aims to facilitate the reusability of simulation models andthe interoperability among the models. In order to support these goals, the HLAFederation Development and Execution Process (FEDEP) [1] was defined to providea high-level framework to build a set of multiple interacting simulation models, theHLA federation. It is a generalized process for building HLA federations fromscratch. However, simulation model development, implementation, testing, andexecution are time consuming and expensive processes. So, is there a way to reusethe existing simulation models and develop new models more efficiently?In the year 2001, a project a??A net based modeling and simulation platform(NetMas)a?? [2] was initiated aiming at developing a platform to utilize the simulationmodels/codes and computing resources more efficiently. One of the main parts of theNetMas platform is the Model Construction (Design) Environment (MCE), in whicha model builder may use the existing sub-models to compose new models. Themodels used here are Federation Object Model (FOM) and Simulation ObjectModels (SOM) based on the HLA OMT [3]. The key aspect of the MCE is to ensurethat the models are compatible and interoperable, which is named the a??MatchingAlgorithma?? here. Also the comparison process has to be done automatically.This thesis describes the design and development of the current MCE, in which thecomposing FOM/SOMs are checked by the Matching Algorithm and the new FOM is developed. In addition, it examines whether the HLA OMT is sufficient forensuring the compatibility and interoperability among federates in the federation.After performing two case studies and theoretical research, it is found that the HLAOMT may bring some substantive interoperability problems and non-exchange dataproblems. An Extensible Element scheme is introduced in this thesis later to improvethe semantics of the federate/federations. The scheme is helpful to strengthen theidentity and accuracy of the object models.This work attempts to investigate the possibility to build HLA federationsautomatically. Meanwhile, it argues for an alternative method for federationdevelopment. It can be useful to further facilitate the reusability and interoperabilityof the HLA federate/federations.