Showing papers by "Bernard P. Zeigler published in 2004"

Forest Fire Spread and Suppression in DEVS

Abstract: In this article, the authors discuss modeling and simulation of forest fire spread and suppression using the discrete event system specification (DEVS) cell space approach in DEVSJAVA. The event-based modeling approach enables efficient simulation of cell space and allows one to obtain timely simulation-based predictions of forest fire spread and suppression in uniform and nonuniform environmental conditions. This model represents an advance toward developing a real-time decision support simulation system for predicting forest fire spread and the effects of water-based suppression attempts.

Model Continuity to Support Software Development for Distributed Robotic Systems: A Team Formation Example

Abstract: Modeling, design and testing of the software underlying distributed robotic systems is a challenging task, especially when a large number of mobile robots and task coordination are involved. Model continuity, the ability to use the same model of a system throughout its design phases, provides an effective way to manage this development complexity and maintain consistency of the software. In this paper, we describe the design and implementation of a team-formation multi-robot system. This is used as an example to demonstrate how a modeling and simulation environment, based on the DEVS formalism, can support model continuity in the design of distributed robotic systems. This example shows how the intelligent control models of the robots are first designed and tested via simulation and, when verified mapped to physical robots with DEVS-on-a-chip “brains” for execution.

A simulation-based software development methodology for distributed real-time systems

Abstract: Powered by the rapid advance of computer, network, and sensor/actuator technologies, distributed real-time systems that continually and autonomously control and react to the environment have been widely used. The combination of temporal requirements, concurrent environmental entities, and high reliability requirements, together with distributed processing make the software to control these systems extremely hard to design and difficult to verify. In this work, we developed a simulation-based software development methodology to manage the complexity of distributed real-time software. This methodology, based on discrete event system specification (DEVS), overcomes the “incoherence problem” between different design stages by emphasizing “model continuity” through the development process. Specifically, techniques have been developed so that the same control models that are designed can be tested and analyzed by simulation methods and then easily deployed to the distributed target system for execution. To improve the traditional software testing process where real-time embedded software needs to be hooked up with real sensor/actuators and placed in a physical environment for meaningful test and analysis, we developed a virtual test environment that allows software to be effectively tested and analyzed in a virtual environment, using virtual sensor/actuators. Within this environment, stepwise simulation methods have been developed so that different aspects, such as logic and temporal behaviors, of a real-time system can be tested and analyzed incrementally. Based on this methodology, a simulation and testing environment for distributed autonomous robotic systems is developed. This environment has successfully supported the development and investigation of several distributed autonomous robotic systems. One of them is a “dynamic team formation” system in which mobile robots search for each other, and then form a team dynamically through self-organization. Another system is a scalable robot convoy system in which robots convoy and maintain a line formation in a coordinated way.

Continuity and change (activity) are fundamentally related in DEVS simulation of continuous systems

Abstract: The success of DEVS methods for simulating large continuous models calls for more in-depth examination of the applicability of discrete events in modeling continuous phenomena. We present a concept of event set and an associated measure of activity that fundamentally characterize discrete representation of continuous behavior. This metric captures the underlying intuition of continuity as well as providing a direct measure of the computational work needed to represent continuity on a digital computer. We discuss several application possibilities beyond high performance simulation such as data compression, digital filtering, and soft computation. Perhaps most fundamentally we suggest the possibility of dispensing with the mysteries of traditional calculus to revolutionize the prevailing educational paradigm.

Graduate Education in Modeling & Simulation: Rationale and Organization of an Online Masters Program

Abstract: The lack of education in modeling and simulation is acknowledged by corporations, government, and academia alike. In order to respond to increasing demand for simulation-based system development, we have established an online Modeling & Simulation Master of Engineering Program where a mixture of foundational modeling and simulation courses are enriched with stateof-the-art advances in computer science and industrial engineering. This program offers online delivery to serve traditional students as well as professionals in industry, government, and universities. This paper describes the program and its uniqueness with emphasis on the foundational and applied aspects of modeling and simulation.

Measuring Cooperative Robotic Systems Using Simulation-Based Virtual Environment

Abstract: : Simulation-based study plays an important role in experimenting, understanding, and evaluating intelligent robotic systems While robot models can be created and studied in a simulated environment, replacing some of the robot models with their real robot counterparts brings simulation-based study one step closer to the reality It also provides the flexibility to allow real robots to be experimented within a virtual environment This capability of robot-in-the-loop simulation is especially useful for large-scale cooperative robotic systems whose complexity and scalability severely limit the possibility for study and evaluation in a physical environment with real robots This paper presents a simulation-based approach that allows a cooperative robotic system to be effectively evaluated in a virtual environment with combined real and virtual robots This capability adds to conventional simulation-based study to form an integrated measuring process An example of robotic convoy system is presented together with metrics to measure the formation coherence of cooperative robotic system Some preliminary simulation results are presented

04041 Abstracts Collection - Component-Based Modeling and Simulation.

Abstract: From 18.01.04 to 23.01.04, the Dagstuhl Seminar 04041 ``Component-Based Modeling and Simulation'' was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available.

A Multiconstraint-based Real-time Routing Scheme using Simulation Methodology

Abstract: In this paper, we propose a multiconstraint-based real-time network routing scheme using simulation methodology. We first discuss how to resolve the multi-constrained path (MCP) problem with a discrete event simulation method. Our proposed Path Selection using Simulation Method (PSSM) can work with a wide class of constraints that properly include the additive constraint assumption required by most graph-search algorithms for the MCP problem. Then we show how to implement the PSSM algorithm with DEVS (Discrete Event System Specification). Finally we discuss the application of PSSM method into Automatically Switched Optical Network (ASON), developing a multiconstraint-based real-time routing scheme using simulation methodology.