Selected Publications

Efficient manufacturing of products have become more important than ever in our global society. Have you ever thought about how these systems themselves are designed? Manufacturing systems that produce these products are becoming increasingly complex. They need to be flexible, in order to quickly adapt to changing market demands. Products need to be produced faster, while ensuring their quality. All these constraints make the design of present-day manufacturing systems a true challenge. Achieving the economic and quality goals of manufacturing requires the use of a sophisticated controller that directs the scheduling of operations in the system and handles on-line changes in the production process. The controller in a sense functions as the brains of the system, and controls its behavior. In this article, we describe how these controllers can be automatically generated from domain-specific models that specify the system and its requirements.
In Magazine of e.t.s.v. Thor and the department of Electrical Engineering at Eindhoven University of Technology.

This paper introduces a formal modeling approach for compositional specification of both functionality and timing of manufacturing systems. Functionality aspects can be considered orthogonally to timing aspects. The functional aspects are specified using two abstraction levels; high-level activities and lower level actions. Design of a functionally correct controller is possible by looking only at the activity level, abstracting from the different execution orders of actions and their timing. As a result, controller design can be performed on a much smaller state space compared to an explicit model where timing and actions are present. The performance of the controller can be analyzed and optimized by taking into account the timing characteristics. Since formal semantics are given in terms of a (max,+) state space, various existing performance analysis techniques can be used. We illustrate the approach, including performance analysis, on an example manufacturing system.
In Proceedings of the 2016 Forum on specification and Design Languages, FDL 2016, Bremen, Germany, September 14-16, 2016.

This paper presents an industrial case study on modular design of a supervisory controller for wafer logistics in lithography machines. The uncontrolled system and control requirements are modeled independently in a modular way, using small, loosely coupled and minimally restrictive extended finite automata. The multiparty synchronization mechanism that is part of the specification formalism provides clear advantages in terms of modularity, traceability, and adaptability of the model. We show that being able to refer to variables and states of automata in guard expressions and state-based requirements, enabled by the use of extended finite automata, provides concise models. Additionally, we show how modular synthesis allows construction of local supervisors that ensure safety of parts of the system, since monolithic synthesis is not feasible for our industrial case.
In 18th ACM/IEEE International Conference on Model Driven Engineering Languages and Systems, MoDELS 2015, Ottawa, ON, Canada, September 30 - October 2, 2015.

Recent Publications

Recent Posts

On September 16th 2016, I presented the paper “Compositional Specification of Functionality and Timing of Manufacturing Systems” during the Forum on specification and Design Languages, held in Bremen, Germany. The paper introduces a formal modeling approach for compositional specification of both functionality and timing of manufacturing systems. Functionality aspects can be considered orthogonally to timing aspects. The functional aspects are specified using two abstraction levels; high-level activities and lower level actions.

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In the last decade there has been a lot of interest in generalized parsing techniques. These techniques can be used to generate a working parser for any context-free grammar. This means that we no longer have to massage our grammar to fit into restricted classes such as LL(k) or LR(k). Supporting all context-free grammars means that grammars can be written in a natural way, and grammars can be combined, since the class of context-free grammars is closed under composition.

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Projects

  • xCPS group @ Eindhoven University of Technology

    The xCPS group is part of the Electronic Systems group at Eindhoven University of Technology. In our research, we look at cyber-physical systems where we look at scheduling and optimization problems that arise in these type of systems.

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