Ramon R. H. Schiffelers

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The hybrid χ (Chi) formalism integrates concepts from dynamics and control theory with con-<lb>cepts from computer science, in particular from process algebra and hybrid automata. It inte-<lb>grates ease of modeling with a straightforward, structured operational semantics. Its ‘consistent<lb>equation semantics’ enforces state changes to be consistent with(More)
The verification formalism / modeling and simulation language hybrid Chi is defined. The semantics of hybrid Chi is formally specified using Structured Operational Semantics (SOS) and a number of associated functions. The χ syntax and semantics can also deal with local scoping of variables and/or channels, implicit differential algebraic equations, such as(More)
A compositional interchange format for hybrid systems is defined in terms of an interchange automaton, allowing arbitrary differential algebraic equations, including fully implicit or switched DAEs, discrete, continuous and algebraic variables, that can be internal or external, urgency conditions, and operators for parallel composition, action hiding,(More)
ASML is the world's leading provider of complex lithography systems for the semiconductor industry. Such systems consist of numerous servo control systems. To design such control systems, a multi-disciplinary model-based development environment has been developed. It is based on a set of domain specific languages (DSLs) describing A) the transducers and(More)
Latest trends in embedded platform architectures show a steady shift from high frequency single core platforms to lower-frequency but highly-parallel execution platforms. Scheduling applications with stringent latency requirements on such multiprocessor platforms is challenging. Our work is motivated by the scheduling challenges faced by ASML, the world's(More)
Hybrid Chi is a process algebra for the modeling and analysis of hybrid systems. It enables modular specification of hybrid systems by means of a large set of atomic statements and operators for combining these. For the efficient implementation of simulators and the verification of properties of hybrid systems it is convenient to have a model that uses a(More)
A hybrid automaton is one of the most popular formal models for hybrid system specification. The Chi language is a hybrid formalism for modeling, simulation and verification. It consists of a number of operators that operate on all process terms, including differential algebraic equations. This paper relates the two formalisms by means of a formal(More)
In this paper, we present a case-study on application of Ramadge-Wonham supervisory control theory (abbreviated by SCT in the sequel) to a patient support system of a magnetic resonance imaging (MRI) scanner. We discuss the whole developmental cycle, starting from the mathematical models of the uncontrolled system and of the control requirements, and ending(More)
Domain-specific languages (DSLs) allow users to model systems using concepts from a specific domain. Evolution of DSLs triggers co-evolution of models developed in these languages. When the number of models that needs to co-evolve increases, so does the required effort to do so. This is called the co-evolution problem. We have investigated the extent of the(More)