Ralf Waspe

Control by 3d simulation --- a new erobotics approach to control design in automation

This paper introduces new so-called control by 3D simulation concepts which are the basis for the simulation based development of complex control algorithms e. g. in the field of robotics and automation. Now, a controller design can be developed, parameterized, tested and verified using so called Virtual Testbeds until they perform adequately in simulation. Then a stripped down version of the same simulation system uses the same simulation model and the same simulation algorithms on the real hardware implementing a real-time capable controller. This results in an integrated development approach, which brings simulation technology on the real hardware to bridge the gap between simulation and real world operation. In this way, Virtual Testbeds and control by 3D simulation provide major building blocks in the emerging field of eRobotics to keep manageable the ever increasing complexity of current computer-aided solutions.

Simulation in the woods: from remote sensing based data acquisition and processing to various simulation applications

This paper focuses on joint work towards the development of simulation applications in the forest sector. They are based on advanced “semantic” world modeling techniques which use remote sensing data and processing algorithms to derive tree species classification maps, as well as forest stand attributes and single tree databases over large areas. The resulting databases are the basis for a variety of different simulation applications in an integrated system approach. Forest growth simulations aim to predict the appearance of the forest in the next decades. Forest machine simulators allow for an efficient development of forest machines and their control algorithms, as well as for cost-effective driver training. Harvesting cost simulations calculate the harvesting costs long before the lumbermen start to work. Decision support systems enable wood owners and the wood industry to compare different treatment scenarios based on simulations and thus to comprehensively assess ecological and economical chances and consequences.

Geometric Interpretation and Optimization of Large Semantic Data Sets in Real-Time VR Applications

Current real-time VR applications are based on well-defined digital representations of the environment. In order to render a realistic looking environment with good performance, artists and developers with specific expertise are indispensable to create optimized data. However modern applications, especially those incorporating data from geo information (GIS) or product data management (PDM) systems, need to be able to use unrefined data without offline conversion or loss of render performance. In this paper we present an extensible object oriented graph database, which further embraces the paradigm of object orientation by incorporating the simulation functionality into the database itself. Whole scene descriptions including all functionalities can be described by one single database. Optimization techniques will be introduced, which are automatically applied to the simulation data, in order to extract a render-friendly structure. Specific semantic objects can be interpreted by the render framework to enhance the simulation, in both function and visual representation.Copyright

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.

Creating Hybrid Simulation Systems Using a Flexible Meta Data Approach

Our goal was to realize a truly hybrid simulation system, which allows the simultaneous use of discreet event simulation and continuous 3D-simulation on a unified database. The key component is an active real-time simulation database, which is an object-oriented, self-reflecting graph database, with a powerful meta-information system. We achieve this by using State Oriented Modeling, which combines the ideas of object-oriented Petri-nets and supervisory control (using discreet event simulation as a control component). The object-oriented Petri-nets are formally described in the State Oriented Modeling Language, which is itself an extension scheme of the simulation database.

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

3D Discrete Event Systems: An Efficient Way to Model and Supervise Dynamic Behavior in Virtual Environments

The combination of Discrete Event Systems with 3D simulation and control technology to set up versatile virtual environments seems to be at the first glance a contradiction in terms because of mixing up two totally different application classes. But here, the newly developed State Oriented Modeling methodology comes into play providing a comprehensive and flexible object oriented framework for the development of complex Discrete Event Systems. State Oriented Modeling establishes a link between these two worlds using object oriented Petri Nets [10] for the discrete part as well as application specific mappings between continuous and discrete state variables realizing so called 3D Discrete Event Systems. Integrated in a versatile 3D simulation system, State Oriented Modeling allows for the efficient realization of a large class of applications within the large field of virtual environments. It provides a comprehensive, easy-to-use but nevertheless efficient framework for behavior modeling in virtual worlds and real-time simulation applications. When modeling virtual production lines for example, State Oriented Modeling provides an easy way for a close-to-reality simulation of automation systems starting with the control of simple actuators or sensors and ending with the supervisory control of the entire virtual factory. In the field of Projective Virtual Reality [4] State Oriented Modeling supervises the user’s work in the virtual environment to derive his “intention” and then generates appropriate command sequences for intelligent automation hardware. This way, even complex automation systems which may be far away or even in space can be controlled — and the user must not be an automation expert. In the field of interactive visualization and training environments State Oriented Modeling simulates a variety of dynamic objects in the virtual world, integrates interaction components like 2D control elements or application specific driver seats into the virtual environment and supervises training sessions to derive performance indicators. And, in addition to this, State Oriented Modeling is the basis for a new multi-agent and discrete event based approach to realize the virtual human.Copyright

3D simulation-based user interfaces for a highly-reconfigurable industrial assembly cell

Although SMEs would benefit from robotic solutions in assembly, the required invests and efforts for their implementation are often too risky and costly for them. Here, the Horizon 2020 project “ReconCell” aims at developing a new type of highy-reconfigurable multi-robot assembly cell which adresses the particular needs of SMEs. At the Institute for Man- Machine Interaction (MMI), we are developing 3D simulation-based user interfaces for ReconCell as the central technology to enable the fast, easy and safe programming of the system. ReconCell heavily builds on previous developments that are transferred from research and prepared for industrial partners with real use cases and demands. Thus, in this contribution, we describe MMIs software platform that will be the basis of the desired user interfaces for robot simulation and control, assembly simulation and execution, Visual Programming and sensor simulation.

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