Harald Richter

A component-based specification approach for embedded systems using FDTs

This paper presents a framework for specification and testing of component-based embedded systems using formal description techniques (FDTs). We deal with embedded systems from the point of view of communication and thus we propose a communication model for them. We further explain the meaning of component-based embedded systems and how these can be specified using FDTs. FDTs such as Estelle and SDL are based on EFSMs (Extended finite State Machines) and have been widely used in the automation of the development process of protocols and communicating systems, i.e. for specification, analysis and validation purposes. The main goal of this work is to demonstrate the reusability of FDTs for component-based systems.

ASDEX-Upgrade Discharge Control and Shot Management

ASDEX Upgrades fully digital control system is described. Discharge control consists of 6 real time computers for discharge and system monitoring, position and shape control and extended plasma control, all synchronized by a supervisor for discharge phase switching. The timing system is integrated giving absolute time for discharge control and diagnostics. Event-dependent operation is supported. Hierarchically organized protection systems are closely coupled with the discharge and machine control systems. All systems run under a software platform for automated experiment operation.

Protection Strategy in the ASDEX Upgrade Control System

The global protection strategy of ASDEX Upgrade has three goals: protection of personnel, protection of the machine and termination of potentially dangerous discharges The new discharge termination system reacts to deviations from the discharge schedule before machine limits are violated. Its integration into the discharge control system allows for smooth termination under central control.

The timing system for the ASDEX Upgrade experiment control

For the adaptive control system of the ASDEX Upgrade tokamak experiment a new digital timing system was developed. Its structure is centralized and distributed. The timing system defines a systemwide 100-ns absolute timescale by central generation of clock and time zero information. Distributed processes are synchronized by time events and state events generated centrally. The timing system supports preprogrammed operation and adaptive operation in close collaboration with the central control computers. A summary is presented of the ASDEX Upgrade timing system design and implementation and of aspects of the integration into the control system. >

Control of a tokamak fusion experiment by a set of MULTITOP parallel computers

An overview is presented of the parallel computers developed for the last control system of the ASDEX-Upgrade tokamak. The system consists of six transputer-based computers with fixed or variable processor topology. Up to 29 transputers per computer are used together with a transputer control bus and a fifth-link concept to fully utilize the benefits of parallel processing using only two types of boards as building blocks. The transputer control bus, the fifth links, the variable interconnection network, and the modular and hierarchical structure have proven to be valuable hardware support for the software. >

Robust partitioning for reliable real-time systems

Summary form only given. Mechatronic systems request for high reliability, especially in the context of time where mostly hard real-time capabilities are mandatory. May be even stronger requirements regard the robustness against software failures and interdependences from erroneous tasks to others. We propose the concept of robust partitioning for reliable real-time embedded systems. The concept consists of two parts, memory space protection and time protection. Memory protection is realized by already existing hardware and software mechanisms. For realizing temporal protection, a two-step timer interrupt system realizing an imprecise computation concept is proposed: if the execution of a module exceeds a certain time limit before the deadline, the first timer interrupt is triggered and a backup routine is started to produce an imprecise result in the remaining time until the second timer expires. This time protection concept shows significant advantages as compared to classical approaches for single, parallel and distributed systems. We give an extended introduction into the concept and discussed first attempts for its realization.

Definition of a Configurable Architecture for Implementation of Global Cellular Automaton

The realisation of Global Cellular Automaton (GCA) using a comparatively high number of communicating finite state machines (FSM) leads to high communication effort. Inside configurable architectures, fixed numbers of FSM and fixed bus widths result in a granularity that makes mapping of larger GCA to these architectures even more difficult. This approach presents a configurable architecture to support mapping of GCA into a single Boolean network to omit increasing communication effort and to receive scalability as well as high efficiency.

AUGUSTUS at MediGRID: Adaption of a bioinformatics application to grid computing for efficient genome analysis

In past years, researchers from many domains have discovered Grid technology which opens up new possibilities in solving problems that are difficult to handle with traditional cluster computing. With the rapidly increasing number of partially or completely sequenced genomes, computational genome annotation is a particularly challenging task in computational biology. In this paper, we describe how we adapted the gene-finding tool AUGUSTUS to Grid computing in the context of the German MediGRID project. The gridification process starts with providing security requirements and running the application manually using Grid middleware. Afterwards, the application is described as a workflow of successive program executions, which are automatically distributed to appropriate Grid resources by a workflow engine. Finally, we show how a convenient graphical user interface for end users is created by means of a portal framework.

Completion of Assembly and Start of Technical Operation of ASDEX Upgrade

The last important steps of the tokamak machine assembly are described. A survey of precision and tolerances is given achieved for the vacuum vessel, the toroidal field (TF) magnet and the poloidal field (PF) coils. The first commissioning tests of vacuum vessel, TF magnet and PF coils are described together with certain features of the control and technical supervisory system. Remarks on improvements of the electric power supply system and the fast plasma control system follow. Finally the programme of the next future is briefly outlined.

A static analysis approach to data race detection in SystemC designs

One of the common methods for system behavior verification and performance estimation is high-level modeling using SystemC. A SystemC design represents parallel components of the system and their interconnections, so it is important to ensure that the design does not have synchronization errors: deadlocks, livelocks, and data races. In this paper we propose a novel approach to data races detection in SystemC designs. Our approach is based on static analysis methods and allows to detect data race errors automatically. The approach provides sound results. It includes special approximations and heuristics for a good balance between scalability and precision.We show the efficiency of our approach by evaluating it on basis of artificial and real-world SystemC designs.