Multidomain Simulation Model for Analysis of Geometric Variation and Productivity in Multi-Stage Assembly Systems

Nowadays, the new era of industry 4.0 is forcing manufacturers to develop models and methods for managing the geometric variation of a final product in complex manufacturing environments, such as multistage manufacturing systems. The stream of variation model has been successfully applied to manage product geometric variation in these systems, but there is a lack of research studying its application together with the material and order flow in the system. In this work, which is focused on the production quality paradigm in a model-based system engineering context, a digital prototype is proposed to integrate productivity and part quality based on the stream of variation analysis in multistage assembly systems. The prototype was modelled and simulated with OpenModelica tool exploiting the Modelica language capabilities for multidomain simulations and its synergy with SysML. A case study is presented to validate the potential applicability of the approach. The proposed model and the results show a promising potential for future developments aligned with the production quality paradigm

Specifying, Analyzing, Integrating Mobile Apps and Location Sensors as part of Cyber-Physical Systems in the Classroom Environment

Cyber-Physical Systems (CPS) are characterized as complex systems usually networked, composed of several heterogeneous components that make the connection between events in the physical environment with computation. We can observe that this kind of systems is increasingly used in different areas such as automotive facilities, construction (civil engineering), health care and energy industry, providing a service or activity which depends on the interaction with users and the physical environment in which they are installed. Nowadays, in the educational context, the process of control and monitor of evaluation activities is conducted in a non-automated way by lecturers. This control is performed before, during and after the beginning of the evaluation activity, and include logistical processes such as classroom reservation, distribution of students per classroom, attendance record or fraud control. However, in an environment involving a large number of students, the execution of these tasks becomes difficult to perform efficiently and safely, requiring innovative techniques or assistance tools. In this work, the creation/design of a cyber-physical system through a modeling approach is proposed, aiming to help teachers to control and monitor evaluation activities. Based on a systematic literature study, we claim that there are no studies presenting the modeling of cyber-physical systems in an educational context, enhancing the interest of the proposed case study. In this document, we show how we used a framework named ModelicaML to model this system during the design phase. Also, this framework will offer a simulation component to simulate the behavior of the prescribed system. On the side of the hardware architecture, for the purpose of identifying the valid seats for the specific students inclass during the examination period, an indoor location system will be used, allowing to blueprint the physical layout of the room and globally manage the activity workflow. We finish this work by showing with empirical studies the gains of our solution when compared to the traditional method

Integrating AADL and FMI to Extend Virtual Integration Capability

Virtual Integration Capability is paramount to perform early validation of Cyber Physical Systems. The objective is to guide the systems engineer so as to ensure that the system under design meets multiple criteria through high-fidelity simulation. In this paper, we present an integration scheme that leverages the FMI (Functional Mock-Up interface) standard and the AADL architecture description language. Their combination allows for validation of systems combining embedded platform captured by the AADL, and FMI components that represent physical elements, either mechanical parts, or the environment. We present one approach, and demonstrator case studies

Design, modelling, simulation and integration of cyber physical systems: Methods and applications

The main drivers for the development and evolution of Cyber Physical Systems (CPS) are the reduction of development costs and time along with the enhancement of the designed products. The aim of this survey paper is to provide an overview of different types of system and the associated transition process from mechatronics to CPS and cloud-based (IoT) systems. It will further consider the requirement that methodologies for CPS-design should be part of a multi-disciplinary development process within which designers should focus not only on the separate physical and computational components, but also on their integration and interaction. Challenges related to CPS-design are therefore considered in the paper from the perspectives of the physical processes, computation and integration respectively. Illustrative case studies are selected from different system levels starting with the description of the overlaying concept of Cyber Physical Production Systems (CPPSs). The analysis and evaluation of the specific properties of a sub-system using a condition monitoring system, important for the maintenance purposes, is then given for a wind turbine

Contracts and Behavioral Patterns for SoS: The EU IP DANSE approach

This paper presents some of the results of the first year of DANSE, one of the first EU IP projects dedicated to SoS. Concretely, we offer a tool chain that allows to specify SoS and SoS requirements at high level, and analyse them using powerful toolsets coming from the formal verification area. At the high level, we use UPDM, the system model provided by the british army as well as a new type of contract based on behavioral patterns. At low level, we rely on a powerful simulation toolset combined with recent advances from the area of statistical model checking. The approach has been applied to a case study developed at EADS Innovation Works.Comment: In Proceedings AiSoS 2013, arXiv:1311.319

Systems engineering languages for modeling and analyzing supervisory control structures in cyber-physical systems

In today’s world, a new generation of high-tech cyber-physical systems are becoming an integral part of our societies and their impact is only going to increase within the next years. Because of their importance, the companies that develop these systems use proper systems engineering modeling tools to help with the design and development of these types of systems and to accelerate the whole development process. In this thesis, 4 very popular modeling tools/languages are being tested and evaluated in terms of their capabilities for model-based systems engineering. These tools are Simulink&Stateflow from MATLAB, Modelica, MechatronicUML and SysML. In order to do that, a proper introduction of the systems engineering process is presented to set the criteria in which the different tools/lan- guages will be evaluated. To support the evaluation process, a case study is presented with the CIF3 language that will be attempted with all the other languages/tools. Each modeling lan- guage/tool has been evaluated individually at first and then together with the others in the end. In addition to the first evaluation, a proper basic introduction of all the modeling concepts that each tool uses for modeling cyber-physical systems is provided and the building of the case study as well. After that, in the second evaluation, the languages are extensively compared against each other in terms of all the criteria set previously to see exactly the scope of capabilities that each tools has. As a result from the two evaluations, a definitive review for each language/tool is presented addressing their overall scope of capabilities, main strong features, main uses, possible ways of improving and future development.Outgoin

Integrated tool chain for model-based design of Cyber-Physical Systems : The INTO-CPS project

We describe INTO-CPS, a project that aims to realise the goal of integrated tool chains for the collaborative and multidisciplinary engineering of dependable Cyber-Physical Systems (CPSs). Challenges facing model-based CPS engineering are described, focussing on the semantic diversity of models, management of the large space of models and artefacts produced in CPS engineering, and the need to evaluate effectiveness in industrial settings. We outline the approach taken to each of these issues, particularly on the use of semantically integrated multi-models, links to architectural modelling, code generation and testing, and evaluation via industry-led studies. We describe progress on the development of a prototype tool chain from baseline tools, and discuss ongoing challenges and open research questions in this area

Features of integrated model-based co-modelling and co-simulation technology

Given the considerable ongoing research interest in collaborative multidisciplinary modelling and co-simulation, it is worth considering the features of model-based techniques and tools that deliver benefits to cyber-physical systems developers. The European project “Integrated Tool Chain for Model-based Design of Cyber-Physical Systems” (INTO-CPS) has developed a well-founded tool chain for CPS design, based on the Functional Mock-up Interface standard, and supported by methodological guidance. The focus of the project has been on the delivery of a sound foundation, an open chain of compatible and usable tools, and a set of accessible guidelines that help users adapt the technology to their development needs

Storage-Centric Wireless Sensor Networks for Smart Buildings

In the first part of the dissertation, we propose a model-based systems design framework, called WSNDesign, to facilitate the design and implementation of wireless sensor networks for Smart Buildings. We apply model-based systems engineering principles to enhance model reusability and collaboration among multiple engineering domains. Specifically, we describe a hierarchy of model libraries to model various behaviors and structures of sensor networks in the context of Smart Buildings, and introduce a system design flow to compose both continuous-time and event-triggered modules to develop applications with support for performance evaluation. WSNDesign can obtain early feedback and high-confidence evaluation of a design without requiring any intrusive and costly deployment. In addition, we develop a graphical tool that exposes a sequence of design choices to system designers, and provides instant feedback about the influence of a design decision on the complexity of system analysis. Our tool can facilitate comprehensive analysis and bring competitive advantage to the systems design workflow by reducing costly unanticipated behaviors. One of the main challenges to design efficient sensor networks is to collect and process the data generated by various sensor motes in Smart Buildings efficiently. To make this task easier, we provide an abstraction for data collection and retrieval in the second part of the dissertation. Specifically, we design and implement a distributed database system, called HybridDB, for application development. HybridDB enables sensors to store large-scale datasets in situ on local NAND flash using a novel resource-aware data storage system, and can process typical queries in sensor networks extremely efficiently. In addition, HybridDB supports incremental $\epsilon$-approximate querying that enables clients to retrieve a just-sufficient set of sensor data by issuing refinement and zoom-in sub-queries to search events and analyze sensor data efficiently. HybridDB can always return an approximate dataset with guaranteed maximum absolute ($L_\infty$-norm) error bound, after applying temporal approximate locally on each sensor, and spatial approximate in the neighborhood on the proxy. Furthermore, HybridDB exploits an adaptive error distribution mechanism between temporal approximate and spatial approximate for trade-offs of energy consumption between sensors and the proxy, and response times between the current sub-query and the following sub-queries. The implementation of HybridDB in TinyOS 2.1 is transformed and imported to WSNDesign as a part of the model libraries