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State diagram describing the discrete behavior of the oven cube

State diagram describing the discrete behavior of the oven cube

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Conference Paper
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The push for energy efficiency of industry processes is driving various efforts to analyze, simulate and optimize the underlying complex and large cyber-physical systems. While some efforts use co-simulation, we instead focus on an integrated hybrid approach that offers the ability to model hybrid components as a whole with all their aspects, based...

Contexts in source publication

Context 1
... behavior can be described semi-formally using e.g. state diagrams, see Figure 2. ...
Context 2
... production schedule plays an important role for the facility model, as it constitutes the major input vector to differentiate scenarios. Entries in the production schedule are essentially commands for state changes (see also Figure 2), and, depending on the cube, different arguments and parame- ters can be appended. Table I shows two production schedule scenarios over one day (00:00 to 24:00). ...

Citations

... The building-related cubes are further explained in Building model within the BaMa digitaltwin ecosystem; however, a detailed description of all other cube models would be beyond the scope of this study. Further information is available in Raich et al. (2016), Smolek et al. (2017), and Smolek et al. (2018). ...
... A set of use cases has been used to define building-related information exchange requirements, along with information about TBS, production processes, and logistics, needed for the hybrid simulation models. First simple prototypes were developed to test modular cubes (Raich et al., 2016;Smolek et al., 2018), which then evolved into models of real manufacturing facilities from project partners Smolek et al., 2017). For the domain of BEM inside the hybrid simulation, necessary input for the two related cube types, as described in Building model within the BaMa digital twin ecosystem and Figure 4, was identified based on traditional requirements of BEM tools assorted appropriately to the cube approach. ...
Article
Energy and resource efficiency as well as reduction of emissions are nowadays significant objectives for production companies. Industry 4.0, through extensive digitalization along the value chain, enables the achievement of these objectives not only in the construction of new facilities but also in existing facilities as well. This requires an interdisciplinary approach, extending over production and logistic processes as well as the building, technical building services, and energy supply systems, consolidated through integrated modeling and simulation-based optimization. The research question this study addresses is how to digitally couple these subsystems and optimize the overall system’s performance in terms of energy and resource efficiency, by distancing from silo-field thinking while using an integrated analysis approach. The article briefly presents a holistic modeling and simulation framework, utilizing modular digital twins (DTs) of all elements that may constitute a given industrial unit. The integration of multiple DTs of these subsystems in a hybrid (continuous and discrete) simulation forms a holistic DT ecosystem of an existing facility. The particular focus of the study is the building representation in this DT ecosystem for energy-efficient production. Based on a methodology including hybrid simulation, building information modeling (BIM), and visual programming, a semi-automated data acquisition workflow was proposed. The hybrid simulation is based on Discrete Event System Specification (DEVS) formalism, where the building is incorporated as a building energy model (BEM). Within the abstracted representation of the overall system, the article explores the possibilities of parametrizing the DT of the building, interconnected with the rest of the factory elements, by acquiring information directly from existing BIM models. Through a comparative case study, the proposed workflow is compared to a manual one in terms of integrity and benefits. The study’s contribution lies in: 1) the detection of the required building level of abstraction for a holistic DT ecosystem, 2) the definition of the interconnections between the building-related counterparts and the rest of the virtual environment as well as the data required for their parameterization, and 3) proposing a semi-automated workflow via virtual programming, for BIM-based creation of the building model within a holistic DT ecosystem.
... For these reasons, we employ a formal model description, called hyPDEVS [39] for hybrid system modelling [22]. Compared to using typical co-simulation methods, hyPDEVS offers tighter hybrid integration and improved modularity [36] by following a strict component-based paradigm that defines atomic and coupled components, which can be combined to create new application models. ...
... The components are designed for reusability and take into account entity exchange as well as energy balance equations. More details on the hybrid simulation are described in [39,42]. ...
Article
Full-text available
This paper presents the development and evaluation of a digital method for multi-criteria optimized production planning and control of production equipment in a case-study of an Austrian metal casting manufacturer. Increased energy efficiency is a major requirement for production enterprises, especially for energy intensive production sectors such as casting. Despite the significant energy-efficiency potential through optimized planning and the acknowledged application potential for sophisticated simulation-based methods, digital tools for practical planning applications are still lacking. The authors develop a planning method featuring a hybrid (discrete-continuous) simulation-based multi-criteria optimization (a multi-stage hybrid heuristic and metaheuristic method) for a metal casting manufacturer and apply it to a heat treatment process, that requires order batching and sequencing/scheduling on parallel machines, considering complex restrictions. The results show a ~10% global goal optimization potential, including traditional business goals and energy efficiency, with a ~6% energy optimization. A basic feasibility demonstration of applying the method to synchronize energy demand with fluctuating supply by considering flexible energy prices is conducted. The method is designed to be included in the planning loop of metal casting companies: receiving orders, machine availability, temperature data and (optional) current energy market price-data as input and returning an optimized plan to the production-IT systems for implementation.
... Parts of this thesis have also been published in other papers over the course of multiple research projects. The most relevant ones are [136,135,229,130,252,133,132,129,28,29,134]. 7 ...
... After evaluating both methods with regard to their capabilities to model hybrid systems in an industrial context [222], it turned out that DEV&DESS was unfit for our applications, due to its shortcomings related to Classic DEVS, and we instead had to opt for a solution based on Parallel DEVS (PDEVS), i.e. hyPDEVS. The drawback, however, is that hyPDEVS is less known in academia and is lacking off-the-shelf tool support [229]. 50 ...
... The case study is a simplified model of a real production plant of an industrial bakery that produces baked goods [229]. The conceptual model of this case study is depicted in Figure 5. 10. ...
... However, as discussed in [5], the use of transitory states leads to a delay of events regarding processing order, which in turn impedes reusability of components. Due to the reasons mentioned above and the experiences we made with applying both, DEVS [6] and PDEVS [7], we decided to revise PDEVS resulting in RPDEVS published in [8]. Basically, the changes include the support of 'true' mealy behavior and the merging of the three state transition functions δ int , δ ext , and δ con f into one generic state transition function δ . ...
... However, as discussed in [5], the use of transitory states leads to a delay of events regarding processing order, which in turn impedes reusability of components. Due to the reasons mentioned above and the experiences we made with applying both, DEVS [6] and PDEVS [7], we decided to revise PDEVS resulting in Revised Parallel DEVS (RPDEVS) published in [8]. Basically, the changes include the support of 'true' mealy behavior and the merging of the three state transition functions δ int , δ ext , and δ con f into one generic state transition function δ . ...
Conference Paper
Full-text available
The Revised Parallel DEVS (RPDEVS) model-ing formalism enhances the Parallel Discrete Event System Specication (PDEVS) by the ability to model 'real' Mealy behavior of components. The term 'real' Mealy behavior can be summarized as immediate output response to an input event without a state transition in between. Although this enhancement simplies model creation, especially of reusable components, it requires a more complex simulation algorithm. In this paper, we present an RPDEVS abstract simulator that describes the simulation execution of RPDEVS models.
... For the continuous aspects, energy balance equations model the transient dynamics of the internal temperature. A detailed explanation of the oven Cube as well as a translation of the oven model into hyPDEVS are given in Ref. [18]. ...
Article
Full-text available
An energy-efficient production is imperative and can reduce costs. Despite the acknowledged potential to increase energy efficiency in production systems through production planning and control (PPC), adequate planning methods are lacking. This article presents an interdisciplinary approach for a simulation-based multi-criteria optimization, integrating energy efficiency into PPC objectives. The method considers production equipment together with HVAC and technical building services. It features a novel integrated hybrid discrete/continuous simulation method enabling to accurately capture dynamic interactions between material and energy flows. The approach is evaluated in a case study on the food industry, indicating potential energy efficiency gains of up to 30%.
... The remainder of the paper is structured as follows: the next chapter will discuss the hybrid cube models, focusing on the building and energy systems. A more detailed description of the models of the production equipment can be found in Raich et al. [23]. Thereafter a simulation example using the discussed models is presented and the results for different scenarios are discussed. ...
... Each station is provided with electric energy, oven and freezer additionally receive thermal energy from respective energy grids. A more comprehensive description of production and logistics cube classes can be found in Raich et al. [23]. ...
Article
Full-text available
In the challenge of achieving environmental sustainability, industrial production plants, as large contributors to the overall energy demand of a country, are prime candidates for applying energy efficiency measures. A modelling approach using cubes is used to decompose a production facility into manageable modules. All aspects of the facility are considered, classified into the building, energy system, production and logistics. This approach leads to specific challenges for building performance simulations since all parts of the facility are highly interconnected. To meet this challenge, models for the building, thermal zones, energy converters and energy grids are presented and the interfaces to the production and logistics equipment are illustrated. The advantages and limitations of the chosen approach are discussed. In an example implementation, the feasibility of the approach and models is shown. Different scenarios are simulated to highlight the models and the results are compared. © 2018, International Centre for Sustainable Development of Energy, Water and Environment Systems SDEWES. All rights reserved.
... Over the last decades, Classic DEVS and its variant PDEVS have established in the scientific community, which can be verified by the numerous publications and simulation engines existing around DEVS ( Franceschini et al. (2014)). We applied both Classic DEVS (Preyser (2015)) and PDEVS ( Raich et al. (2016)) in projects and experienced modelling difficulties with both formalisms ( Preyser et al. (2016)). But also others describe similar problems (Traoré (2007), Cicirelli et al. (2007)). ...
Conference Paper
Full-text available
In this work, we present a Revised Parallel DEVS (RPDEVS) formalism. The Classic Discrete Event System Specification (DEVS) and Parallel DEVS (PDEVS) formalisms do not support modelling of ’true’ mealy behaviour, i.e. reacting to an input message immediately with an output message. Instead, such behaviour has to be modelled via transitory states and multiple state updates. This not only increases model complexity, it also impedes reusability of model components in different contexts. RPDEVS enhances PDEVS with the capability to model mealy behaviour directly. Hence, the output function λ can access the input bag. This introduces some challenges regarding the simulation algorithm which we will take a look at. Further, the terms algebraic loop and illegitimate model will be discussed in the context of RPDEVS. It is shown that RPDEVS models which are free of algebraic loops are also legitimate. Finally, it will be demonstrated that like Classic DEVS and PDEVS, also RPDEVS provides closure under coupling.
... In order to address this deficiency, this research is meant to develop a novel planning tool that increases both the energy efficiency and general performance of production systems, using a hybrid simulation-based optimization approach. The general planning concept has been published by the research team [7], so has the hybrid simulation concept [8] and the development of the optimization module [9]. The particular paper at hand focuses on the adaption of the planning method to a specific real life industrial application and on evaluating the optimization potential in an industrial use case. ...
... For testing purposes and first implementations the MATLAB-DEVS-Toolbox developed by HS Wismar [23] was used. For the purpose of the optimization, the performance of the simulation had to be tweaked, so a software implementation partner implemented the engine in C++ [8]. ...
Conference Paper
Full-text available
This presented research comprises the development of an optimization module for use in a novel production optimization tool-similar in function but not mode of operation to an Advanced Planning System-, with energy efficiency incorporated into its goal system. The optimization features a hybrid-simulation of production systems as an evaluation function. A hybrid simulation has been developed and presented in preceding publications, in order to enable a sufficient consideration of interactions between material flow and the thermal-physical behavior of the production system. The size of the search space for the complex optimization problem necessitates a customized two-phase-optimization method, which is based on a Genetic Algorithm, with the consideration of linear constraints and extended customizations. The results, obtained in a case study featuring a food production facility, show energy savings of around 20 percent together with significant productivity gains.
... In order to address this deficiency, this research is meant to develop a novel planning tool that increases both the energy efficiency and general performance of production systems, using a hybrid simulation-based optimization approach. The general planning concept has been published by the research team [7], so has the hybrid simulation concept [8] and the development of the optimization module [9]. The particular paper at hand focuses on the adaption of the planning method to a specific real life industrial application and on evaluating the optimization potential in an industrial use case. ...
... For testing purposes and first implementations the MATLAB-DEVS-Toolbox developed by HS Wismar [23] was used. For the purpose of the optimization, the performance of the simulation had to be tweaked, so a software implementation partner implemented the engine in C++ [8]. ...
Article
Full-text available
This presented research comprises the development of an optimization module for use in a novel production optimization tool – similar in function but not mode of operation to an Advanced Planning System –, with energy efficiency incorporated into its goal system. The optimization features a hybrid-simulation of production systems as an evaluation function. A hybrid simulation has been developed and presented in preceding publications, in order to enable a sufficient consideration of interactions between material flow and the thermal-physical behavior of the production system. The size of the search space for the complex optimization problem necessitates a customized two-phase-optimization method, which is based on a Genetic Algorithm, with the consideration of linear constraints and extended customizations. The results, obtained in a case study featuring a food production facility, show energy savings of around 20 percent together with significant productivity gains.