Managing complexity of control software through concurrency

In this thesis, we are concerned with the development of concurrent software for embedded systems. The emphasis is on the development of control software. Embedded systems are concurrent systems whereby hardware and software communicate with the concurrent world. Concurrency is essential, which cannot be ignored. It requires a proper handling to avoid pathological problems (e.g. deadlock and livelock) and performance penalties (e.g. starvation and priority conflicts). Multithreading, as such, leads to sources of complexity in concurrent software. This complexity is considered frightening, because it complicates the software designs and the resulting code. Moreover, this paradigm complicates the understanding of the behaviour of concurrent software. A paradigm with a precise understanding of concurrency is essential. In this thesis, a methodology is proposed that comprises a paradigm of fundamental aspects of concurrency

A distributed Real-Time Java system based on CSP

CSP is a fundamental concept for developing software for distributed real time systems. The CSP paradigm constitutes a natural addition to object orientation and offers higher order multithreading constructs. The CSP channel concept that has been implemented in Java deals with single- and multi-processor environments and also takes care of the real time priority scheduling requirements. For this, the notion of priority and scheduling has been carefully examined and as a result it was reasoned that priority scheduling should be attached to the communicating channels rather than to the processes. In association with channels, a priority based parallel construct is developed for composing processes: hiding threads and priority indexing from the user. This approach simplifies the use of priorities for the object oriented paradigm. Moreover, in the proposed system, the notion of scheduling is no longer connected to the operating system but has become part of the application instead

Embedded Software Design for Mechatronic Systems

This research project is motivated by the fact that nowadays it is impossible to separate control engineering from software engineering. Besides that both of them can be found in definitions of mechatronics, this project deals with exploitation and improvement of their strong natural interdependency. In all modern reactive systems, what all mechatronics systems are, one will always find one or more embedded computers. The functionality of these computers, and in turn controlled systems, is powered by embedded software [1]

Integrated Design Tools for Embedded Control Systems

Currently, computer-based control systems are still being implemented using the same techniques as 10 years ago. The purpose of this project is the development of a design framework, consisting of tools and libraries, which allows the designer to build high reliable heterogeneous real-time embedded systems in a very short time at a fraction of the present day costs. The ultimate focus of current research is on transformation control laws to efficient concurrent algorithms, with concerns about important non-functional real-time control systems demands, such as fault-tolerance, safety,\ud reliability, etc.\ud The approach is based on software implementation of CSP process algebra, in a modern way (pure objectoriented design in Java). Furthermore, it is intended that the tool will support the desirable system-engineering stepwise refinement design approach, relying on past research achievements ¿ the mechatronics design trajectory based on the building-blocks approach, covering all complex (mechatronics) engineering phases: physical system modeling, control law design, embedded control system implementation and real-life realization. Therefore, we expect that this project will result in an\ud adequate tool, with results applicable in a wide range of target hardware platforms, based on common (off-theshelf) distributed heterogeneous (cheap) processing units

Software for Embedded Control Systems

The research of our team deals with the realization of control schemes on digital computers. As such the emphasis is on embedded control software implementation. Applications are in the field of mechatronic devices, using a mechatronic design approach (the integrated and optimal design of a mechanical system and its embedded control system). The ultimate goal is to support the application developer (i.e. mechatronic design engineer) such that implementing control software according to ðo it the first time right¿ becomes business as usual

A new Java Thread model for concurrent programming of real-time systems

The Java ™ Virtual Machine (JVM) provides a high degree of platform independence, but being an interpreter, Java has a poor system performance. New compiler techniques and Java processors will gradually improve the performance of Java, but despite these developments, Java is still far from real-time. We propose the Communicating Java Threads (CJT) model, which eliminates several shortcomings, such as Java's non-deterministic behavior, Java's monitor weakness, and lack of reactiveness for real-time and embedded systems. CJT is based on CSP providing channels, composition constructs, and scheduling of processes. The CJT Java class library, which provides all necessary classes on top of Java, is readily available to interested users. The main power of the method is that it integrates these features in a natural way and in no way conflicts with other paradigms, such as PersonalJava ™, EmbeddedJava ™, JavaBeans ™, CORBA, and PVM. All activities, reported in this paper, are carried out as part of the JavaPP project

Conceptual design for controller software of mechatronic systems

The method and software tool presented here, aims at supporting the development of control software for mechatronic systems. Heterogeneous distributed embedded processors are considered as target hardware. Principles of the method are that the implementation process is a stepwise refinement from control laws to efficient computer code and that all phases are verified by simulation. Simulation is also used as verification tool during physical-system modelling and control law development. Data flow diagrams are used as description language for controller implementations, whereas the physical-system models are expressed in bond graphs. Future work comprises the building of the complete tool, although individual parts are ready