Members

Prof. András Jávor. Ph.D., D.Sc.

director


Attila Fűr, M. Sc. E.E.

vice director

Applied simulation tools

 

CASSANDRA

Our research results have been implemented in the CASSANDRA (Cognizant Adaptive Simulation System for Applications in Numerous Different Relevant Areas) object oriented simulation system. The main feature of the system is that intelligent demons (agents) can monitor the trajectory of the dynamic simulation and modify the model structure, parameters and object interactions to attain adequate models. The simulator has a universal internal core in which the models are built from Knowledge Attributed Petri Nets. The system is equipped with graphic I/O layers and animation features providing user-friendly interface for various fields of application. CASSANDRA has been applied for solving problems in various fields including EU, international and national projects.

A novel approach to modeling and simulation, a breakthrough in providing an Artificial Intelligence (AI) controlled tool to enhance the efficiency and supply new possibilities.

A universal object oriented kernel is provided - based on which - problem oriented simulators specially customized for the special requirements and man-machine communication style for users in a wide range of applications fields can be supplied.

Single universal core

It provides for enhancing the effectivity of simulation by removing a considerable amount of the burden of the iterative process of evaluating the results and by model parameter and structure modifications achieving the required goals using demons with artificial intelligence.

Intelligent Demon controlled simulation experiments

The system provides for applying intelligent mobile entities represented internally by a special sort of high level, so called "Knowledge Attributed Petri Nets". This enables the easy representation of the movement of e.g. human beings or other entities with complex knowledge attributed as technological description and processing trajectories of workpieces etc.

Intelligent mobile entities (using knowledge attributed Petri Nets internally)

The system enables handling and automatic detection of conflict situations, hazards, undetermined states. The system is aimed at the solution of problems in a wide range of application fields.

CASSANDRA has also facilities to detect and handle conflict situations during the dynamic process of simulation.

The principles and architecture of the system is based on the results of two decades of internationally acknowledged results of research in simulation methodology and development of earlier simulation systems utilized successfully in R&D, higher education in CAD, both in Hungary and abroad.

Some possible fields of applications:

  • Flexible Manufacturing Systems
  • Traffic simulation
  • Logistics
  • Information processing systems
  • Environmental, ecological problems
  • Micro- and macroeconomy, management
  • Biology, medical problems
  • Some examples of applications:

    QUALITY CONTROLLED MANUFACTURING

    ( A work undertaken in the framework of an EUREKA project )

    In figure a model of a factory located in Germany can be seen . The manufacturing can be divided into several processes. The different colors represent different types of processes in the manufacturing. The blue rectangles represent the input of the manufacturing. The raw materials enter into the system in these places. The boxes with S capital represent the storages. The yellow rectangles are the working places, where different robots execute their work. The green boxes are the assembly places, and the main assembling place is light blue.
    The red rectangles are the quality control sites, where the parts are examined. The examination method is the following: The work-pieces are coming in bathes. In every batch one item is checked. If this element is found to be faultless, the rest of the group will not be examined. If the element is fault, the whole group is examined one by one. The bad item will be discarded.
    Examination increases the costs of whole manufacturing, but without checking by removing faulty parts from futher processing and the assembly with faultless parts the costs may be reduced. The optimum could be found between of the 2 extreme cases. The iterative process for finding the optimal solutions has been undertaken by intelligent demons of the CASSANDRA system that monitored the process and tried various configurations of inserting and removing the sampling quality checks. Also problems of situations of the production and recycling has been investigated

    TRAFFIC SIMULATION

    ( The work has been performed in the framework of a COPERNICUS project.)



    In this figure as an illustration a highly simplyfical traffic model of the center of Budapest is shown. The model has been built from roads and crossings, which can be found in the junctions of the roads. (These elements are based on Knowledge Attributed Petri Nets by CASSANDRA simulation system.)
    In more detailed model 517 roads and 266 crossings have been implemented. The tokens represent various types of the vehicles. Different types of vehicles are signed by different colors. The buses are blue, lorries are green, 2 stroke-cars are dark red, 4 stroke-cars are light red, and the purple ones are the diesel cars. The vehicles have given destination, which is built in their knowledge bases.
    The model provides detailed air pollution emissions data continously during the dynamic simulation depending on the number and speed of the various types of vehicle on the sections. The simulator has been connected to the immission simulating model, of our partner GMD First in Germany, via internet.

    Demonstrations of applications:

    In the following simple examples the applicability of our approach is provided. (for more detailed description of the problems solved we refer to our publications)


    Simulation of an FMS system with a conveyor belt

    Simulation of an ambulance station

    Demon controlled producer-consumer system

    Problem of the dining chinese phylosophers

    Investigation an information processing system