High Level Architecture Federation Research Articles

Real-time distributed simulations in an HLA framework: Application to aircraft simulation

This paper presents some ongoing research carried out in the context of the PRISE Project (Research Platform for Embedded Systems Engineering). This platform has been designed to evaluate and validate new embedded system concepts and techniques through a special hardware and software environment. Since much actual embedded equipment is not available, corresponding behavior is simulated within a high-level architecture (HLA) federation implemented with a run-time infrastructure (RTI) called CERTI and developed at ONERA. HLA is currently largely used in many simulation applications, but the limited performances of the RTIs raise doubts over the feasibility of HLA federations with real-time requirements. This paper addresses the problem of achieving real-time performances with the HLA standard. Several experiments are discussed using well-known aircraft simulators such as Microsoft Flight Simulator, FlightGear, and X-plane connected with the CERTI RTI. The added value of these activities is to demonstrate that according to a set of innovative solutions, HLA architecture is well suited to achieve hard real-time constraints. Finally, a formal model guaranteeing the schedulability of concurrent processes is also proposed.

Development planning based on interoperable agent driven simulation

The paper presents the potential of using interoperable agent driven simulation to support development planning; indeed the use of simulation represents a strong benefit to improve planning of infrastructures and plants devoted to disaster relief, civil protection and/or support to country development; the paper describes models used to face these challenges and last updates in population modeling for these applications. The proposed models include population characteristics, need as well as their social networks. In humanitarian support operations and country reconstruction there is a huge potential to use simulators; the paper describes how these models should be designed to support training as well operational planning. The models should be able to consider the impacts of contingencies as well as to guarantee the quick responsiveness requirements for humanitarian crisis management. The authors propose a simulator to be shared and used among Armed Forces and Civil Agencies for addressing Crisis Management, Humanitarian Missions, Country Reconstruction and Development considering joint operations (i.e. Civil Military Cooperation); indeed the paper outlines the importance of training people devoted to guarantee interoperability among civil organization and military units in this sector. The paper describes the models based on interoperable simulation as well as the agents driving the entities during the simulation to create quickly complex scenarios able to consider the impact on population and communities of the different actions by including human behavioral models. The proposed approach guarantees interoperability among different simulators within an HLA (High Level Architecture) federation in order to recreate crisis scenarios combining detailed simulation of multiple factors. The proposed approach is verified and validated by proposing an experimental analysis where it is evaluated a set of construction projects (i.e. digging wells) in a stabilization area and their effectiveness both in terms of direct result (i.e. water availability) as well as of population consensus and disaster relief (i.e. stress mitigation, trustiness respect supporting players).

An Introduction of BOM Modeling Framework

Component based modeling has been a research hotpot in the area of Modeling and Simulation for a long time. In order to increase the reusability and interoperability of models, this paper put forward a component based modeling framework called BOM Modeling Framework (BMF) based on BOM specification. The structure, principles, formalisms and behaviors of BMF were presented in detail first. The description and framework of Atomic BOM model and coupled BOM model in BMF were studied in succession. At last, the developing process of BMF models was introduced. The prototype developed showed that BMF could not only promote the reusability and interoperability of models but also improve the efficiency and easy the process of M&S. To simplify model development and further promote the reusability and interoperability of models, SISO (Simulation Interoperability Standards Organization) put forward the BOM (Base Object Model) specification (1)(2) which was proposed as a SISO standard in 2006. The BOM concept is based on the assumption that piece-parts of models, simulations, and federations can be extracted and reused as modeling building-blocks or components. The interplay within a simulation or federation can also be captured and characterized in the form of reusable patterns. These patterns of interplay are sequences of events between simulation elements. The representation of the pattern of interplay is captured in the BOM. BOM has an obvious brand of High Level Architecture (HLA) (3)(4). The origin of BOM is to overcome the shortcoming that HLA federates are highly coupled with the used Federation Object Model (FOM) of federation which makes federates hard to reuse and interoperate directly. If federation's FOM changes, the federates can't be reused anymore and need lots of modification along with FOM. BOM provides an important component modeling mechanism for M&S. And it is considered as a key technology for the next-generation simulation, for that it can enhance standardization, encapsulation, composability, interoperability and reusability

Guest Editorial: Advanced and Distributed Simulation

This special issue on Advanced and Distributed Simulation features four articles extended from papers previously published at the 22nd ACM/IEEE/SCS Workshop on Principles of Advanced and Distributed Simulation (PADS 2008). The original papers are all candidates for the Best Paper Award at the conference. The paper by Nicol and Schear actually won the Best Paper Award. As a common practice, all articles in this issue have been extended significantly from the original papers and have undergone rigorous peer reviews and necessary revisions. These four articles cover a variety of advanced simulation and modeling techniques and applications, with topics ranging from distributed simulation management, wireless simulation, to analytical models, and peer-to-peer gaming applications. This diversity reflects the growing importance of simulation and modeling in facilitating understanding of the increasingly complex systems that we have to deal with nowadays. The article by Pan, Turner, Cai, and Li addresses a well-known performance issue in conservatively synchronized parallel simulation—in this case, in the management of distributed simulations using the High-Level Architecture (HLA). The proposed hybrid approach combines the traditional synchronous methods, which may suffer from performance problems caused by bottlenecks formed by HLA federates with slow advancement, and the asynchronous methods, which may run into the time creep problem in the presence of small lookahead. The proposed hybrid approach promises better perfor-

Systematic Component-Oriented development with Axiomatic Design

A form of design guidance is offered through a process that applies Axiomatic Design Theory to Component-Orientation. Axiomatic Design has been proposed by Do and Suh for object-oriented software development. Our approach leverages divide-and-conquer and find-integrate techniques that support service-based development as an alternative to developing code from scratch. Using this process, missing or conflicting components can be identified, and missing components can be defined. The effectiveness of our proposed system is demonstrated through an example based on High Level Architecture (HLA) simulations. Our Component-Oriented approach utilizing axiomatic design theory has been adapted to HLA Federation Development and Execution Process (FEDEP). As one of the Component-Oriented approaches proposed, FEDEP is able to obtain interoperability and reusability of available components, namely federates.

A HLA federation simulation modelling approach for multimodal transportation system of ports

This paper proposes a modelling approach for a simulation model of multimodal transportation system of ports in High-Level Architecture (HLA) distributed federation simulation environment. In this model, the simulation federation consists of Operation Federates (OFs) and a Coordination Management Federate (CMF). The OF simulates the local logistics operation subsystems such as port, road and railway operation with the discrete event system simulation model. The CMF coordinates the total operation according to the system status of OFs. The modelling process has five steps including analysis of the system structure, establishment of the simulation federation, design of OFs and the CMF, establishment of the Federation Object Model (FOM) and implemention of the simulation federation. An actual case is illustrated to show the modelling steps and advantages in decreasing difficulty and complexity in modelling.

An Approach for the Unified Time Management Mechanism for HLA

The High Level Architecture (HLA) is the IEEE 1516 standard to model and design a distributive simulation environment. It establishes a common distributed simulation framework, which facilitates the interoperability and reuse of simulation components. However, some HLA services are very low level and difficult to use, especially when a simulation is designed with a particular time synchronization mechanism. This article describes an agent interface, called Smart Time Management (STM). The capabilities of the STM include the following: taking over the event’s time-stamp tagging work, maintaining a lookahead value, and unifying different time advance approaches provided by the HLA runtime infrastructure. In addition, it adopts the time warp mechanism for optimistic simulation. In conclusion, the STM presents a unified and scalable middle layer to allow the user to construct an HLA federation with a unanimous Time Management interface when solving the synchronization issue.

Smart Time Management—the unified time synchronization interface for the distributed simulation

Distributed simulation is a widely studied technique for the networked virtual environment. Among existing technologies, High Level Architecture (HLA) establishes a common distributed simulation framework that facilitates the interoperability and reuse of simulation components. However, some HLA services are very low-level and difficult to use, especially when a simulation is designed using a particular time synchronization mechanism. This paper describes an agent interface called Smart Time Management (STM). STM is used to unify the time management services of the time-stepped, event-driven, and optimistic time advancement in HLA specification. The capabilities of the STM include the followings: taking over events timestamp tagging work, maintaining a look-ahead value, and unifying different time advance approaches provided by the HLA Run Time Infrastructure (RTI). In addition, it adopts the time warp mechanism for optimistic simulation. In summary, STM presents a unified and scalable middle layer to allow the user to construct an HLA federation with a unanimous time management interface when solving the synchronization issue. The presented middle layer enables the user to deploy the conservative and optimistic synchronization mechanisms in a unanimous way.

Peer-to-Peer-Based Resource Management in Support of HLA-Based Distributed Simulations

In recent years, the concept of peer-to-peer computing has gained renewed interest for sharing resources within and between organizations or individuals. This article describes a decentralized resource management system (DRMS) that uses a network of workstations for the execution and storage of high-level architecture (HLA) federations/federates in a peer-to-peer environment. The implementation of DRMS is based on the open-source project JXTA, which represents an attempt to standardize the peer-to-peer domain. DRMS is part of a Web-based simulation environment supporting collaborative design, development, and execution of HLA federations. This study evaluates the possibilities of using peer-to-peer technology for increasing the reuse and availability of simulation components within the defense modelling and simulation community. More specifically, it addresses the necessary adjustments of simulation components to conform to the requirements of the DRMS and shows that JXTA could provide the foundation for a distributed system that increases the possibilities for reusing simulation components.

An approach to integrating HLA federations and genetic algorithms to support automatic design evaluation for multi-agent systems

We propose a novel design environment for developing multi-agent systems (MASs) for applications in mobile robotics. Because emergent behavior phenomena make it next to impossible to directly synthesize viable MAS designs from specifications, extensive simulation studies are needed to evaluate these designs. Furthermore, due to the fact that the design space for MASs systems is combinatorially large, the evaluation of candidate designs must be done in a hierarchical, multi-resolution, parallel and distributed manner. Our proposed design environment is based on US Department of Defense's high-level architecture (HLA), an established software infrastructure for heterogeneous, distributed simulations. The proposed environment automatically generates and manages HLA federations (i.e., collections of distributed and/or parallel simulation and service federates) that communicate over runtime infrastructure (RTI) software buses. Each federation simulates a different candidate design for the MAS under development. Federations execute independently and in parallel. Our proposed design environment's refinement component uses a genetic algorithm (GA) to select the best candidate designs from the current generation and generates a set of refined, next-generation, candidate designs. A federation is created and managed for each of the next-generation designs and the automatic design process is repeated.

Supporting large-scale distributed simulation using HLA

This article describes the design of a Web-based environment to support large-scale distributed simulation using Java and IEEE standard P1516 high level architecture (HLA) framework and rules. Based on the run-time infrastructure (RTI) services within the HLA and Java application programmer's interfaces (APIs) of the RTI, the proposed HLA-based environment provides an architectural foundation to enhance interactivity, portability, and interoperability for Web-based simulations. In addition, the proposed architectural design not only provides a client/server mechanism for simulation on the Web, but also supports a distributed federation execution over the network. A 3-level control mechanism (3LCM) was implemented to HLA-based middleware federateServer, in order to adaptively maintain information consistency and minimize message traffic for distributing information among client hosts and the federateServers. A dynamic filtering strategy (DFS), associated with the data distribution management (DDM) in the HLA RTI, is proposed to minimize false positive updates and enhance the filtering efficiency of subscription regions within an HLA federation. To verify the feasibility of this prototype, a distributed discrete event simulation application in Java was developed and performance of the proposed modeling design and Java RMI's distributed object model presented. From the experimental results, we show that the proposed environment based on HLA using 3LCM and DFS is workable and practical for supporting a large-scale distributed simulation.

The High Level Architecture for Simulations

T Special Issue of SIMULATION is devoted to the “High Level Architecture for Simulation,” with a focus on simulation applications which have been implemented using the HLA. The High Level Architecture (HLA) is a general-purpose software architecture for distributed simulation designed to support a wide range of simulation approaches and applications. The architecture itself is openly available, as is software to support its implementation. It is being used for a variety of simulation applications, including linked high-fidelity simulators for mission rehearsal, Internet games, distributed virtual learning applications for team skill building, large distributed discrete event simulations for training, analysis of international space station developments, and distributed medical applications. These diverse applications are examples of different forms of ‘simulation’ which come from different technical heritages and have historically supported different user communities. With the advent of general-purpose software capabilities such as the HLA, once-isolated technical approaches are beginning to become a readily available part of the simulation developers’ toolkit, opening up new possibilities for simulation applications for new users. This issue includes a series of articles that describe applications of HLA in multiple domains across the international community. “TRAILBLAZER: An Application of the High Level Architecture to Joint Experimentation” describes a project created to examine the application of an HLA federation of simulations to support joint experimentation. In “Developing An HLA Virtual Command Post,” the authors discuss the development an HLA-compliant version of the Virtual Command Post (VCP), a distributed simulation providing a The High Level Architecture for Simulations