Christian SonntagINOSIM Software GmbH / INOSIM Consulting GmbH
Christian Sonntag
Dr.-Ing.
About
69
Publications
8,440
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
453
Citations
Citations since 2017
Introduction
Model-based production support, material flow simulation, optimal production scheduling, reactive production scheduling business intelligence applications, KPI extraction and visualization, modular production, modular logistics, optimal control, logic control, model-based design, debottlelecking
Publications
Publications (69)
Sequential Function Chart (SFC) is a powerful graphical formalism for the specification of logic controllers that is well recognized and very successful in industry. In this paper, a scheme for the automatic translation of SFCs into the Compositional Interchange Format (CIF) for hybrid systems is presented that enables the straightforward connectio...
This brochure presents the research and innovation agenda for the years 2016-
2025 that is proposed by the European Project CPSoS - Towards a European
Roadmap on Research and Innovation in Engineering and Management of Cyber-physical
Systems of Systems (October 1, 2013 - June 30, 2016). CPSoS has been
funded under the 7th Framework Programme of the...
The connectivity aspect of the Internet of Things (IoT) has received most of the attention over the last years and has led to mature solutions for IoT‐connected devices. This chapter focuses on the opportunities that the provision of streams of real‐time data from a large number of IoT‐connected devices with sensing capabilities provides for monito...
The complexity of modern industrial batch plants makes it nearly impossible for plant personnel and production managers to predict their future behavior accurately over longer periods of time. This contribution presents the INOSIM Foresight system for predictive decision support that employs highly accurate dynamic material flow simulation to creat...
In this work, a simulation-optimization strategy is applied to a benchmark scheduling problem from the pharmaceutical industry, as published by Kopanos, et al. (2010). The optimization is performed by a meta-heuristic using a commercial Discrete Event Simulation software as the schedule builder (simulation-optimization approach). Our work is motiva...
This chapter presents EU–US industrial drivers and societal needs that are relevant for EU–US collaboration activities in the information and communication technology sector. The contents are based on the industry interviews that were performed, complemented by the results of the desk research. The chapter presents the key recommendations from indu...
Cyber Physical Systems (CPS) are inherently complex and incorporate interacting heterogeneous subsystems. Model based design of complex CPS is a multi-scope, multi-aspect challenge. In the design process of such systems, usually many different models are built. These models describe elements of the system at different levels of detail and
under dif...
There are many examples of modern technical systems that consist of many closely integrated physical and cyber subsystems. Centralized management and control strategies may not always be the best option, or may even be infeasible, for these so-called cyber-physical systems of systems (CPSoS) due to their large complexity or due to confidentiality r...
This report describes the major results that were obtained by the PICASSO Expert Groups in the first half of the PICASSO project on the technology sectors Internet of Things (IoT) / cyber-physical systems (CPS), Big Data, and 5G, and on ICT policy relating to these technology sectors.
The major contributions of this report are:
- Technology theme...
Kurzfassung
Die vorausschauende Instandhaltung (engl. Predictive Maintenance) gewinnt für die produzierende Industrie weltweit an Bedeutung, da Produktionsmodernisierungen im Rahmen der Industrie 4.0 sowie die zunehmende Verwendung von heterogenen Sensoreinheiten die Instandhaltungsplanung immer komplexer gestalten. Darüber hinaus ist das ServiceKo...
This paper presents two hierarchical techniques for the coordination of distributed model predictive controllers and discusses and compares their robustness to the presence of local constraints and their speed of convergence. These techniques follow feasible- and infeasible-path coordination approaches. The controlled system is assumed to consist o...
To meet the quality requirements in the production of cement, samples are taken in the production process, transported to a central lab and analysed partially automatically. The measurements are used to adjust the parameters of the production process. An optimal management of the laboratory system can lead to significant throughput gains and shorte...
![Fig. 2. DANSE system engineering life cycle, from [6].](profile/Radoslav-Paulen/publication/300324158/figure/fig2/AS:599737325584384@1519999929240/DANSE-system-engineering-life-cycle-from-6_Q320.jpg)
The CPSoS project is developing a roadmap for future research and innovation in cyber-physical systems of systems. This paper presents preliminary findings and proposals that are put forward as a result of broad consultations with experts from industry and academia, and through analysis of the state of the art in cyber-physical systems of systems.
Petrochemical and chemical complexes are so-called Systems of Systems (SoS) that consist of
many subsystems that interact by exchanging energy, material and information. The individual
plants or units are managed locally, by human managers and operators or by automatic algorithms,
but the efficiency of the overall site depends on the coordinated us...
The paper deals with the optimization of the operation of so-called systems of
systems, i.e. large systems where the subsystems possess some autonomy but the system as
a whole has to be operated optimally. Speci�cally, the focus is on systems of systems that
are physically coupled, e.g. electric grids or production plants that are coupled by
ows o...
This paper proposes a modeling, simulation, and validation framework for large-scale
technical Cyber-physical Systems of Systems with distributed management architectures. The goal of the
framework, which is based on the freely available Modelica language for object-oriented heterogeneous
modeling, is to reduce the (currently very large) engineerin...
In the model-based design of complex technical systems, many design data artifacts are generated, such as models in different formalisms and design-related documents, which include specifications, test results, and design decisions. The consistent treatment and integration of these design artifacts is a challenge that is as of yet unsolved in indus...
In warehousing systems, the speed of the removal and distribution of goods often represents a bottleneck as it limits the achievable throughput and, thus, the efficiency of the complete warehousing system. Consequently, an optimal management of the distribution of goods can lead to large efficiency and financial gains. In this contribution, it is s...
The industrial model-based design of controlled processes yields a large amount of design data with complex interdependencies, which makes it difficult to detect incon-sistencies that lead to design errors which are only detected very late in the design pro-cess. In addition, a variety of models in different formalisms is often used which re-strict...
In this paper, a hierarchically structured formalism, the Hierarchical Cause-Effect Charts (HCEC), is introduced to iteratively refine and formalize complex control requirements of industrial systems, resulting in a hierarchical tree structure of small and transparent cause-effect matrices that can be translated into Boolean formulae algorithmicall...
While automatic model transformation is the preferable approach to interconnect model-based design and analysis tools since many tools require access to the model structure and to a symbolic representation of the model equations, this approach is not always feasible in industrial practice. This can be the case if there are syntactic or semantic dif...
In recent years, the object-oriented Modelica formalism for dynamic hybrid models has become a de-facto standard for the equation-based modeling, design, and analysis of complex, heterogeneous systems. It provides powerful mechanisms for model structuring and consistent model re-use, and a variety of tools are available that are based on the Modeli...
This paper proposes a work flow for the model-based design of industrial logic controllers implemented in Sequential Function Charts (SFC). The design procedure starts from informal natural-language requirements that are formalized in an iterative refinement process. The results of this tool-supported process are (1) a formal specification of the l...
The purpose of the Compositional Interchange Format for hybrid systems (CIF) is to establish inter-operability of a wide range of tools by means of model transformations to and from the CIF. Using the CIF as intermediate, the implementation of many bi-lateral translators between specific formalisms can be avoided. The main contribution of this pape...
In recent years, the object-oriented Modelica formalism for dynamic hybrid
models has become a de-facto standard for the equation-based modeling, design, and analysis of complex, heterogeneous systems. It provides powerful mechanisms for model structuring and consistent model re-use, and a variety of tools are available that are based on the Modeli...
The purpose of the Compositional Interchange Format for hybrid systems (CIF)
is to establish inter-operability of a wide range of tools by means of model transformations to and from the CIF. Using the CIF as intermediate, the implementation of many bi-lateral translators between speci�c formalisms can be avoided. The main contribution of this paper...
Ein großes Hindernis bei der Anwendung verschiedener modellbasierter Werkzeuge zur Auslegung komplexer Regelungssysteme ist die Inkompatibilität der unterliegenden Modellformalismen. Daher müssen Modellübersetzungen oft manuell vorgenommen werden, was zeitintensiv, fehleranfällig und teuer ist. In diesem Beitrag wird ein algorithmischer Ansatz für...
Subspace monitoring has recently been proposed as a condition monitoring tool that requires considerably fewer variables to be analysed compared to dynamic principal component analysis (PCA). This paper analyses subspace monitoring in identifying and isolating fault conditions, which reveals that existing work suffers from inherent limitations if c...
One of the major challenges towards a broad industrial acceptance of hybrid systems techniques and tools is the large number of distinct modeling formalisms and the resulting manual effort for the tool-based solution of many complex design or analysis tasks. A promising approach to achieve inter-operability between hybrid systems tools is to develo...
Today, many supermarket refrigeration systems are controlled by decentralized control systems that often lead to excessive starting and stopping of the compressors which drive the cooling cycle and, consequently, to a large wear of the process equipment. In our previous work, a hierarchical model-predictive control scheme was proposed for supermark...
Most industrial production systems, in particular process-ing systems, are equipped with control architectures in which continuous and discrete controls coexist. In such hybrid dynamic systems, the continuous dynamics depends on the current operating regime or logic conditions, and the (autonomous) switching between different qualitative behaviors...
The control of solar plants is challenging for several reasons, one of which is that the solar irradiation that represents the main energy source cannot be manipulated and is subject to large fluctuations due to changes of the weather conditions. For the solar air conditioning plant considered in this work, which is located at the University of Sev...
While current approaches for the safety verification (understood here as the verification that the trajectories of the system remain in a prescribed set in the state space) of hybrid systems yield rigorous proofs for system safety, their applicability is restricted to relatively small systems. In this paper, the safety properties of a logic-control...
In this paper, the task to start the operation of an evaporation system with hybrid dynamics is considered. The evaporator system was provided as a benchmark for hybrid control by a major chemical company. Rigorous modeling gives rise to a hybrid automaton with high-dimensional nonlinear DAE dynamics that describe the continuous evolution in differ...
Supermarket refrigeration systems are hybrid systems due to switching of the continuous dynamics and due to the presence of discretely switched actuators such as valves and compressors. The main control goal for these systems is to keep temperature and pressure levels within tight bounds while minimizing the wear of the compressors. In our previous...
Important skills of a control engineer are the ability to subdivide complex control design projects into smaller design steps and to solve the subproblems, taking into account the interdependencies between the subtasks as well as the overall goals and requirements. In this paper, the web-based learning environment Learn2Control is presented which h...
While current approaches for the safety verification (understood here as the verification that the trajectories of the system remain in a prescribed set in the state space) of hybrid systems yield rigorous proofs for system safety, their applicability is restricted to relatively small systems. In this paper, the safety properties of a logic-control...
In industrial practice, extensive simulations are performed in order to analyse the safety and the correct operation of controlled chemical processes. One aspect of verifying the safe operation is to prove that the states of the system stay within a safe region for a certain set of inputs or disturbances which is the main theme of this paper. Recen...
In recent years, integrated reactive separation processes (see e.g. (Agreda et al. 1990)) have attracted considerable attention in both academic research and industrial applications (see also chapter 3). In this contribution, the operation of a pilot-plant-scale reactive semi-batch distillation column at Dortmund University is studied. In previous...
Supermarket refrigeration systems are of hybrid nature due to forced and autonomous switching of the continuous dynamics and the existence of discretely switched actuators such as valves and compressors. One of the main control goals for these systems is to keep temperature and pressure levels within tight bounds while minimizing the wear of the co...
This paper deals with the systematic design of a multivariable controller for a medium-scale reactive distillation column that is operated in semi-batch mode. This is a challenging problem because of the time-varying and strongly nonlinear dynamics of the process and considerable deviations of the behaviour of the real plant from the rigorous model...
The control of solar plants is challenging for several reasons, one of which is that the solar irradiation representing the main energy source cannot be manipulated and is subject to large disturbances due to changes of the weather conditions. For the solar air conditioning plant considered in this work, additional difficulties arise from the prese...
Supermarkt-Kühlsysteme lassen sich geeignet durch hybride Modelle beschreiben, da sie sowohl diskret schaltende Aktuatoren (Ventile und Kompressoren) als auch autonomes Schalten zwischen verschiedenen kontinuierlichen Dynamiken aufweisen. Das Hauptziel der Regelung dieser Systeme ist es, die Temperaturen in den Kühlvitrinen innerhalb enger Grenzen...
Mit der in der industriellen Praxis oft angewandten simulationsbasierten Vorgehensweise zur Validierung von Regelungskonzepten kann die Sicherheit eines geregelten Prozesses nicht rigoros gezeigt werden. Dieser Beitrag beschäftigt sich mit der algorithmischen Bestimmung von Sicherheitszertifikaten (Barrier Certificates) für verfahrenstechnische Pro...
While current approaches for the safety verification of hybrid systems yield rigorous proofs for system safety, their applicability is restricted to relatively small systems. In this paper, the safety properties of a large-scale industrial processing system with hybrid dynamics are investigated using two optimization-based approaches. While the fir...
While current approaches for the safety verification of hybrid systems yield
rigorous proofs for system safety, their applicability is restricted to relatively small
systems. In this paper, the safety properties of a large-scale industrial processing system
with hybrid dynamics are investigated using two optimization-based approaches. While
the fir...
In this paper, we consider the task to start the operation of an industrial evaporation system. Rigorous modelling gives rise to a hybrid automaton with large nonlinear DAE-models that describe the continuous evolution in the discrete locations. The optimization problem is solved by a hierarchical procedure that consists of a branch-and-bound algor...
In this paper, we consider the task to start the operation of an industrial evaporation system. Rigorous modelling gives rise to a hybrid automaton with large nonlinear DAE-models that describe the continuous evolution in the discrete locations. The optimization problem is solved by a hierarchical procedure that consists of a branch-and-bound algor...
This paper deals with robust low-order controller design for a medium-scale pilot reactive distillation column. In the first step, the attainable control performance for a linear model of the column that is identified from experiments is computed. In this step, actuator limitations and model uncertainty resulting from a priori knowledge and confide...
Dieser Beitrag beschäftigt sich mit der systematischen Auslegung einer Mehrgrößenregelung für eine reaktive Rektifikationskolonne im Technikumsmaßstab. Im ersten Schritt wird auf der Grundlage eines linearen Prozessmodells, das durch experimentelle Systemidentifikation gewonnen wird, durch mathematische Optimierung die erreichbare Regelgüte bestimm...
This description presents a supermarket refrigeration system as a benchmark for the development of new ideas and a comparison of methods for the modeling and control of hybrid systems. The benchmark features switched dynamics and discrete-valued inputs which make it a hybrid system. Furthermore, the outputs are subject to a number of constraints. T...
Optimizing the operation of processes with hybrid dynamics is challeng-ing since the discrete dynamics (i.e. abrupt changes of states or inputs) introduces discontinuities with which gradient-based solvers often cannot cope very well. This contribution suggests a scheme that combines model predictive control (MPC) with genetic algorithms and embedd...
Projects
Projects (6)
In OptiProd.NRW, scientists, ICT experts from SMEs, and global industrial partners are developing a software framework to solve realistic planning and scheduling problems from the process industries. The methods employed combine state-of-the-art mathematical optimization and (meta-)heuristics with event-driven simulation that is much more detailed and accurate than in existing approaches, enabling the direct deployment of production schedules to real-world plants without modifications.