Martin Hoppen

Database-driven distributed 3D simulation

Distributed 3D simulations are used in various fields of application like geo information systems (GIS), space robotics or industrial automation. We present a new database-driven approach that combines 3D real-time simulation techniques with object-oriented data management. It consists of simulation clients that replicate from a central database object data as well as the data schema itself. The central database stores static and dynamic parts of a simulation model, distributes changes caused by the simulation, and logs the simulation run. Compared to standard decentralized methods this approach has several advantages like persistence for state and course of time, object identification, standardized interfaces for simulation, modeling and evaluation, as well as a consistent data schema and world model for the overall system, which at the same time serves as a means for communication.

Integrating semantic world modeling, 3D-simulation, Virtual Reality and remote sensing techniques for a new class of interactive GIS-based simulation systems

Integrating well known GIS functionalities, object-oriented modeling, 3D simulation, Virtual Reality, space robotics and remote sensing methods with new semantic world modeling techniques, from the point of view of an industrial automation and 3D simulation expert, leads to a new approach to GIS.

Distributed Information Processing and Rendering for 3D Simulation Applications

The growing demand for 3D simulation techniques in various application domains leads to more and more specialized tools and complex frameworks. Between homogeneous or inhomogeneous clients, data has to be distributed and synchronized in centralized or decentralized setups. Hardware/Software-in-the-Loop and Co-Simulation are common tasks in virtual prototyping. Load balancing and parallelization is necessary for computationally intensive simulations. Spatially distributed developers and designers collaborate in networked virtual environments. All these different applications impose different requirements on the data distribution and synchronization mechanism. In this paper, we categorize distribution scenarios, their requirements and according synchronization techniques. Four different approaches with different key aspects are presented and compared by means of a reference implementation and several application examples. This overview shall enable the reader to choose the approach best suited for his particular distribution problem.

Combining 3D Simulation Technology With Object-Oriented Databases: A Database Oriented Approach to Virtual Reality Systems

Using object-oriented databases as the primary data source in VR applications has a variety of advantages, but requires the development of new techniques concerning data modeling, data handling and data transfer from a Virtual Reality system’s point of view. The many advantages are outlined in the first part of this paper. We first introduce versioning and collaboration techniques as our main motivation. These can also be used in the traditional file based approach, but are much more powerful when realized with a database on an object and attribute level. Using an object-oriented approach to data modeling, objects of the real world can be modeled more intuitively by defining appropriate classes with their relevant attributes. Furthermore, databases can function as central communication hubs for consistent multi user interaction. Besides, the use of databases with open interface standards allows to easily cooperate with other applications such as modeling tools and other data generators. The second part of this paper focuses on our approach to seamlessly integrate such databases in Virtual Reality systems. For this we developed an object-oriented internal graph database and linked it to object-oriented external databases for central storage and collaboration. Object classes defined by XML data schemata allow to easily integrate new data models in VR applications at run-time. A fully transparent database layer in the simulation system makes it easy to interchange the external database. We present the basic structure of our simulation graph database, as well as the mechanisms which are used to transparently map data and meta-data from the external database to the simulation database. To show the validity and flexibility of our approach selected applications realized with our simulation system so far e. g. applications based on geoinformation databases such as forest inventory systems and city models, applications in the field of distributed control and simulation of assembly lines or database-driven virtual testbeds applications for automatic map generation in planetary landing missions are introduced.© 2011 ASME

Architecture for Integrated Development of Complex Systems With Model-Based System Specification and Simulation

R&D projects in space robotics are characterized by the profound integration of various disciplines and the associated complexity of the systems to be designed. To support this multidisciplinary collaboration, the paradigm of Model-Based Systems Engineering (MBSE) is a suitable approach. Another essential challenge of space projects is the early verification and validation of the model-based design. Tests with physical prototypes give rise to considerable costs and can reproduce the real conditions only to a certain extent.In this paper, we present an approach to integrate the cross-domain system specification with the cross-domain test design with Virtual Testbeds to a comprehensive system model. This enables a continuous simulation-based engineering in the design of space applications. Requirements from the early design phase can be used systematically to test and integrate detailed models from the various disciplines.The presented system model offers the potential to efficiently integrate national and international know-how to support the development phases of a mission from the requirements analysis to design, visualization, control, operation, training up to marketing and technology transfer. Future projects can be realized faster, less expensive and more robust.Copyright

GIS-Based Virtual Testbeds and Their Application to Forestry and City Simulation

In this paper we present a new interdisciplinary approach to geographic information systems. The integration of object-oriented data modeling, 3D real-time simulation, virtual reality techniques and remote sensing methods with new semantic world modeling techniques and well known geo information system (GIS) functionalities provides the basis for a new class of “Virtual Testbeds”. These testbeds build on a new approach which combines state-of-the-art GIS functionalities to deal with complex and large geographical data sets with the intuitive operability and the advanced simulation capabilities of latest robotic and automation simulation components. Besides the simulation algorithms, the testbeds take advantage of advanced modeling capabilities to (semi) automatic ally generate models of “natural” environments in e.g. forests or cities. Based on remote sensing data, not only geometric shapes are derived, but also an object’s “function” or “semantics”. The new ideas have already been applied to various applications of which the most successful will also be described in this paper.Copyright