Ensuring human safety is of paramount importance in warehouse environments that feature mixed traffic of human workers and autonomous mobile robots (AMRs). Current approaches often treat humans as generic dynamic obstacles, leading to conservative AMR behaviors like slowing down or detouring, even when workers are fully aware and capable of safely sharing space. This paper presents a real-time vision-based method to estimate human awareness of an AMR using a single RGB camera. We integrate state-of-the-art 3D human pose lifting with head orientation estimation to ascertain a human’s position relative to the AMR and their viewing cone, thereby determining if the human is aware of the AMR. The entire pipeline is validated using synthetically generated data within NVIDIA Isaac Sim, a robust physics-accurate robotics simulation environment. Experimental results confirm that our system reliably detects human positions and their attention in real time, enabling AMRs to safely adapt their motion based on human awareness. This enhancement is crucial for improving both safety and operational efficiency in industrial and factory automation settings.

In Industrial Control Systems (ICSs), security is not a fancy add-on feature but a core requirement for functionality, safe operation, and organization business. To keep up with the ever-growing threat landscape and numerous security standards and regulations, leveraging Artificial Intelligence (AI) capabilities, especially Large Language Models (LLMs), seems essential. However, AI systems built using LLMs can introduce new challenges such as data leakage, generating bias and misinformation, and even new security threats. In this paper, we analyze an AI system that leverages LLMs and knowledge graphs to support security decisions in the design of ICSs, ensuring compliance with the IEC 62443-3-3 standard while aligning with the European AI Act to guarantee trustworthiness and meet legal requirements for use in Europe.

Integrating renewables into the grid introduces price fluctuations that stem from their inherent volatility. To mitigate this, adopting an energy-aware production planning strategy benefits factories and the grid. By aligning production processes with periods of abundant renewable energy and lower costs, factories can actively reduce their energy expenditures while simultaneously smoothing grid strain. However, such a transition requires expensive retrofitting of production planning systems. This paper proposes an approach to transparently integrating energy awareness into an existing Manufacturing Execution System (MES), resulting in a cost reduction without the need to retrofit the MES.

Building-integrated photovoltaics are crucial in urban areas to meet rising energy demands. Combining PV with sunshades offers energy generation and overheating prevention, necessitating intelligent control. This paper explores the use of indoor lighting sensor data as a proxy for user comfort in AI-based control of PV-integrated sunshades, addressing the conflict between PV optimization and user well-being. A living lab field test with user diaries and sensor data shows promising alignment, suggesting that sensors can effectively capture relevant aspects of user comfort. This approach offers a pathway to integrate user needs into the intelligent control of these dual-purpose building elements.

In condition monitoring, early detection of process signal drifts indicating, e.g., equipment degradation is crucial. exponentially weighted moving average (EWMA), cumulative sum (CUSUM), and discrete average block (DAB)-based drift detectors are statistical and commonly used methods. Each has benefits and limitations, suited to different data types. However, EWMA and CUSUM are fixed mean drift detectors, limiting their applicability and adaptability. This article explores adding dynamic behavior to drift detection methods. We use a wide range of synthetic data based on a real-world manufacturing process. The investigated parameter space includes standard deviation, drift rates, and outliers. Besides, each algorithm has some tuning parameters that define its behavior. Two metrics validate experiments against labeled data. Based on our observations, EWMA performs better for drift detection on average, but CUSUM is superior in detecting very small drifts. Furthermore, we derive guidelines for the choice and application of drift detection in practice.

Ensuring cybersecurity in Industrial Control Systems (ICSs) is essential, as cyber-attacks can lead to substantial economic losses and serious safety hazards. Addressing security early in the product and system life cycle is crucial to preventing expensive fixes and severe consequences later. Since requirements engineering and system architecture design are early activities in system development and are interconnected in nature, it is essential to begin integrating security into these activities. IEC 62443 is a widely used ICS cybersecurity standard that provides security requirements and architectural guidance; however, it relies heavily on human experts and manual effort, making the implementation of the standard costly and time-consuming. This article proposes an ontological framework that supports the integrated engineering of security requirements and system architectures, aiming to achieve security by design and conformance with IEC 62443 with reduced reliance on human experts. To evaluate the quality and usability of the proposed ontology, we examine a use case for requirements elicitation and validation scenarios. The findings highlight the potential of ontological approaches in improving ICS cybersecurity, particularly in terms of standard compliance.

Industrial Control Systems (ICSs) are critical in automating and controlling industrial processes. Human errors within ICSs can significantly impact the system’s underlying processes and users’ safety. Thus, it is essential to understand the factors contributing to human errors and implement targeted interventions. Various factors that influence and mitigate human errors must be explored, including organizational, supervisory, personal, and technical factors. In parallel, the impact of a security incident also needs consideration. The paper presents a Bayesian Belief Network (BBN) model developed to model these factors comprehensively and demonstrate their impact, especially in the context of security incidents. Probability distributions are employed with practical assumptions to overcome data limitations, emphasizing the model’s utility in risk assessment. The model’s complexity is addressed using multiple interconnected sub-models, enhancing accuracy and avoiding unnecessary intricacies. Despite challenges in identifying all relevant factors, a sincere effort is made to incorporate diverse research findings. This paper highlights the essential role of BBN models in understanding and mitigating human errors, contributing to the resilience of ICS processes. The use of BBN and probabilistic distributions enables quantitative and probabilistic analysis of the impact of human errors, aiding in developing more robust risk management strategies to improve system resilience in ICSs.

The convergence of Information Technology (IT) and Operational Technology (OT) in Industry 4.0 poses fresh challenges, demanding innovative strategies to ensure the safe execution of production processes. With the increasing significance of production system integrity, any security breaches can lead to severe consequences like production downtime, equipment damage, or human harm. Our prior research on Austrian industrial automation stakeholders highlighted the necessity for a cost-effective, all-encompassing approach to the integrated safety and security. We introduced an extensive ontology for safety, security, and operational requirements in IT/OT convergence. This paper presents an approach of Model-Based Systems Engineering (MBSE) for the integrated safety and security by design of industrial systems. We employ the Systems Modeling Language (SysML) 2.0 for precise modeling. We define metadata information that are used as tags for SysML 2.0 model instances. Afterwards, we create a graph-based model of the system. These graphs are used to validate safety and security standards and requirements. Finally, we automatically generate artifacts, such as code or documentation, which adhere to the standards. Our approach is extensible and supports reusability already after covering two standards. Having provided support for the standards IEC 62443-3-3 and IEC 61508, we reuse our approach to validate the standard ISO 13850:2015.

In the contemporary landscape of convergence between Information Technology (IT) and Operational Technology (OT), maintaining asset visibility within the Industrial Control Systems (ICS) infrastructure is paramount. Yet, the escalating targeting of legacy systems and air-gapped networks by cyber threats underscores the need for robust security measures and solutions to counter unauthorized access and malicious activities. This paper presents an analysis aimed at identifying gaps and opportunities in integrating IT Security Solutions with OT environments. These solutions offer comprehensive features such as real-time threat detection, asset identification, network monitoring, and incident response capabilities tailored specifically for the unique challenges posed by industrial control networks. Leveraging the Festo MPS 403–1 system as a case study, we delve into the intricacies of IT/ OT integration and highlight areas necessitating improvement to achieve seamless convergence and harness the advantages of unified systems across industries.

In the rapidly expanding landscape of Internet of Things (IoT), sensors have emerged as pivotal components, playing a critical role in sensing and data collection. However, this crucial function also renders them susceptible to potential threats such as unauthorized access and security breaches. This paper investigates the vulnerabilities that lead to these threats and offers a comprehensive set of best practices aimed at fortifying the security of IoT devices. We highlight key measures such as secure device design, robust authentication mechanisms, encrypted communication protocols, regular updates, and emphasize the importance of collaborative efforts among stakeholders using an ontological approach. An Ontology provides a structured framework for organizing knowledge, facilitating clearer communication, efficient data management, and enhanced decision-making. Thus, this paper contributes to the development of a more secure and resilient IoT ecosystem.

Integrated risk assessment is important to identify, evaluate, and mitigate potential risks in Industrial Control Systems (ICS). It is necessary for safety and security within the organization. The safety and security data necessary for integrated risk assessment are obtained from various data sources that structure and manage information. In this paper, we look into information models as a potential single source of data. We compare different information models: Asset Administration Shell (AAS) and Automation Markup Language (AML). The comparison highlights the strengths and weaknesses, commonalities and differences of each data source in terms of data integration, real-time capability, standardization, design capability, automation possibility, and practical application in risk assessment processes. The findings underscore the importance of selecting appropriate data sources to enhance the accuracy, provide the possibility of updates, and enhance the efficiency of risk assessments in ICS.

The introduction of Industry 4.0 and the integration of Information Technology (IT) with Operational Technology (OT) have brought significant advancements to Industrial Control Systems (ICS). With the convergence of IT/OT, ICS not only have to counteract against faults for safety reasons, but also have to encounter new challenges stemming from the security realm with an impact on safety issues. Ensuring the security of ICS has gained importance as any breach can cause disruption in industrial processes, leading to system downtime, production loss, and endangering human lives. Vulnerability assessment has become a crucial aspect of security research in ICS. The MITRE ATT&CK framework is one of the knowledge bases used for vulnerability management. It can be used to map identified vulnerabilities to a specific tactic provided by the framework. This mapping provides organizations with a structured approach focusing on identifying potential entry points for attackers and their progression through the system. The attacker's control of ICS could lead to a safety impact on people, processes, and the environment. This paper uses the mapping as a tool to prioritize the vulnerabilities and attacker's propagation through the network and thus help in building an effective risk propagation network using the Bayesian Belief Network (BBN). The implementation of the methodology is done using a Modular Production System (MPS) as a use case.

HVAC systems are characterized by rigid and complex internal behaviour that limits the options for efficiency optimization. KI4HVACs project aims to apply machine learning to improve office building HVAC operation and maintenance efficiency. Reinforcement learning is used for energy use optimization and supervised learning for preventive maintenance. The models are wrapped into an MPC based and a decision tree algorithm for preventive maintenance. The system uses the TRNSYS18 simulation environment that matches an actual office building with multiple zones.

The growing emphasis on environmental sustainability, driven by regulations such as Europe's Carbon Border Adjustment Mechanism (CBAM) and increased consumer awareness, is a notable trend. It is estimated that manufacturing energy consumption accounts for 24 % of global greenhouse gas emissions. As demand for renewable energy rises, current market mechanisms are unable to guarantee a carbon-free energy supply. This paper presents an approach that integrates energy availability and product carbon footprint (PCF) into production planning. The necessity for factories and energy suppliers to adapt their operations is highlighted. To ensure the optimal utilization of available energy resources, it is essential that factories implement production schedules that are responsive to fluctuations in supply. Energy suppliers must provide accurate long-term production profiles and employ anomaly detection for short-term adjustments. The proposed solution is designed to align energy consumption with renewable energy availability and PCF.

Considering security when designing a system is of utmost importance. Integrating security attributes during the design phase provides effective means. However, this process necessitates the collection and utilization of various types of data related to each asset, which should be collected from different sources, such as data sheets. Developing Industrial Control System (ICS) architecture, as an important activity during design time, enhances security by identifying threats, enforcing controls, enabling compliance, resilience, and monitoring through structured, layered design. Thus, this paper explores the incorporation of a Digital Twin into system architecture to improve the security of ICSs. In particular, we investigate the role of the Asset Administration Shell (AAS) as a standardized meta-model in providing necessary information for the development of secure system architectures. After identifying the information required for specific security activities, the current state of AAS and its capability to provide that information is assessed.

Industrial Control Systems (ICS) are increasingly becoming targets for cybercriminals seeking ransom or aiming to cause disruptive chaos because of the potentially devastating impact of ICS malfunction. Following the security-by-design principle, security measures should be integrated into ICS system design as early as possible. System architecture design is one of the earliest activities in the system development life cycle that can play a key role in enhancing security. Hence, this paper proposes an architectural security framework based on IEC 42010, a standard for system architecture description, aiming at integrating security into system architecture. As part of this framework, an ontology is designed to formalize the system architecture described in SysML v2 (Systems Modelling Language version 2) to facilitate automatic reasoning about system design against specified security requirements and rules. To this end, the transformation rules from the textual notation of SysML v2 to OWL (Web Ontology Language) are specified. A use case is presented and analyzed that demonstrates the practicality of the proposed approach in adding security to the system architecture.

In response to the growing need for compliance with diverse safety and security regulations, crucial for safeguarding both humans and machines in the era of Industry 4.0 (I4.0), it has also become increasingly crucial for industries to ensure adherence to safety and security standards. However, navigating the complexities of regulations and standards can be daunting, often leading to inefficiencies in compliance processes. Our goal is to foster a comprehensive understanding of an effective approach to meeting compliance requirements in these related fields. Therefore, this paper introduces a semi-automated method for ensuring compliance with unified safety and security standards within the context of I4.0. This approach empowers management teams to thoroughly analyze the specific requirements necessary to maintain a protected environment. Compliance can be achieved at both the asset component and system levels, aligning with the relevant standards. Additionally, we present a detailed analysis of a use case and its output, demonstrating the practical application and efficacy of our approach.

To make a management decision for the Operational Technology (OT) environment, obtaining OT asset information from a plant is essential. Key Performance Indicators (KPIs) can play a crucial role in evaluating the performance of the manufacturing process, minimizing production costs, assessing process effectiveness, and investigating various settings to improve performance, operations, and quality in OT. This paper aims to provide a detailed examination of how Asset Information Mining Sources (AIMSs) support the process for acquiring both static and runtime OT asset information. Once we have obtained accurate OT asset information, we can calculate the KPIs and incorporate them into a knowledge representation using an ontology-based model. This model can assist the management team in making informed decisions and provide a roadmap for exploring further automation possibilities.

The increasing complexity and interconnectedness of Industrial Control Systems (ICSs) necessitate the integration of safety and security measures. Ensuring the protection of both personnel and critical assets has become a necessity. As a result, an integrated risk assessment approach is essential to comprehensively identify and address potential hazards and vulnerabilities. However, the data sources needed for an integrated risk assessment comes in many forms. In this context, Automation Markup Language (AutomationML or AML) emerges as a valuable solution to facilitate data exchange and integration in the risk assessment process. The benefits of utilizing AML include improved interoperability, enhanced documentation, and seamless collaboration between stakeholders. A model, filled with information relevant to integrated risk assessment, is developed to illustrate the effectiveness of AML. Ultimately, this paper showcases how AML serves as a valuable information model in meeting the growing need for comprehensive safety and security risk assessment in ICSs.

Industrial control systems (ICSs) are critical to the operation of industrial processes and critical infrastructure. Safety and security are crucial in any system or process, particularly in ICSs where failures can lead to severe consequences such as injury, loss of life, and damage to equipment and infrastructure. However, safety and security are often considered separately during the concept and design stages. An integrated risk assessment approach can combine safety and security considerations and provide a holistic evaluation of the overall risk to ICSs. Ontology-based approaches provide a systematic and structured method for representing knowledge and concepts related to risk assessment in industry. The aim of this paper is to develop an ontology based approach and generate a concept for integrating safety and security risk assessment. A case study is analysed using the ontology with a SPARQL query example.

The convergence of Information Technology (IT) and Operational Technology (OT) increases the interdependencies of operation, safety, and security requirements of OT systems. Cyber attacks may interfere with safety functionality which may lead to severe injuries. A possible conflict between safety and security is the usage of authentication. A safety requirement for machinery is violated if a safety function is not accessible at all times (e.g., due to the usage of authentication). There is a variety of standards and best practices on how to implement security or safety from an isolated viewpoint. Some standards even consider safety and security or link at least to other standards when the other domain has to be considered. However, there is no integrated approach to address conflicts between safety and security. Other relevant domains needed for risk or site managers (e.g., operation, product quality, risk evaluation, and risk treatment) are not addressed in a single holistic standard or approach. Without holistic guidance, risk managers are forced to solve this issue manually on best effort or include knowledge of domain experts who provide their expertise which is typically bound to a single domain in scope of the manager’s interest. Due to the complex interdisciplinary interplay of these domains, knowledge representation using ontologies may be key to model all relations and constraints needed for risk or state managers to consider in their risk managing business process. Therefore, this work presents the results of a literature survey analyzing several ontologies considering at least one relevant domain to address when performing risk management at OT systems.

With the advent of Industry 4.0 (I4.0) systems, ensuring the safety and security of these systems' design has become a paramount concern for stakeholders. One concern is the increased costs of fixing errors in later phases, such as integration and operation compared to the design phase. Formal verification techniques offer a rigorous approach to verifying the correctness of system behaviours and properties. This paper explains the fundamental principles of formal verification in safety and security domains. We use a SysML-based environment called AVATAR ("Automated Verification of Real Time Software"). It allows for a formal description and verification of safety and security properties. Specifically, we demonstrate the application of AVATAR in verifying the safety and security properties of a Cobot system architecture upon requirements. Moreover, we evaluate the challenges, opportunities, and limitations of using AVATAR in industrial settings and provide recommendations for its enhancement or designing a new methodology for I4.0 application verification. The results show that formal verification techniques can be enhanced to address safety and security concerns in I4.0 complex and critical systems.

Industrial control systems (ICSs) are complex networked systems that enable automation of large-scale processes. Depending on the application domain, the risk of the failure of components can have catastrophic repercussions. Up to now, a safety risk assessment is carried out to identify and narrow down possible failures. However, with the recent increase of cybersecurity attacks, a need of an integrated safety and security risk assessment is rising. This encompasses a comprehensive approach to assess the risks associated with ICSs and develop strategies for mitigating those risks. This paper proposes Bayesian Belief Network (BBN) as a representative of a probabilistic method and show its suitability for an integrated safety and security risk assessment. The method is evaluated by means of a use case. It provides risk propagation of functional safety, human safety and shows a propagation path from security to functional safety. The assessment is based on practical vulnerability assessments, technical documentations, manual observation and expert opinions.

The convergence of Information Technology (IT) and Operational Technology (OT) leads to an increasing interdependence between the protection goals of security and safety. A cyber-attack targeting safety functions may in turn lead to hazards endangering people and the environment. Furthermore, misusing safety functions may impact availability by causing a machine or production line to stop working. This work analyzes how Austrian stakeholders of industrial automation enterprises address security and safety risks to mitigate undesired situations. The stakeholder analysis performed considers vendors of products or components, integrators, and asset owners of industrial systems. Secure infrastructures, system architectures, and risk management are subject areas of this analysis. The analysis was conducted in two phases. First, an online survey was created where the involved stakeholder offered their answer simultaneously. Considering the results of the survey, individual stakeholder workshops were carried out to obtain additional, more specific perceptions about the stakeholder’s OT system and components with respect to security and safety considerations. The obtained results provide insights into the current practices in the industry regarding safety and security.

Most of the sensor nodes in the Internet of Things (IoT) and home automation systems (HAS) applications are designed to be low-cost and energy efficient. These devices are expected to be lightweight, and flexible with low maintenance. These criteria limit the computational and communications capabilities of such systems whereas system protection and data authentication have always been limitation factors due to security cost complexity.In this paper, we investigate and propose a simple, lightweight, and cost-effective watermark security method for Wireless sensor networks (WSNs). It is an improved version of our previous research on the metadata-enhanced cross-watermarking approach. The original watermark generator has been extended to achieve cipher block chaining integrating with side-channel watermarking. The watermark bits are hidden in the transmitting channel properties. The experimental results and security analysis prove this scheme, provide data authenticity and transmission integrity without additional security payload.

The IEC 62061:2021 standard requires production owners to ensure both functional safety and information security for their industrial applications. Unfortunately, traditional models of functional safety and information security have been designed in isolation and are difficult to combine. This paper introduces the Safety & Security Combination (SafeSecCombi) approach to combine models for functional safety and security concerns in automating digital production. SafeSecCombi (i) validates causes for desired and undesired effects regarding safety in an industrial production process by linking these causes to products, production processes, and production resources; (ii) identifies Industrial Internet of Things (IIoT) assets that can cause unsafe behavior in case of a successful security attack; and (iii) analyzes risks of security attacks to these IIoT assets. Therefore, SafeSecCombi provides a model for the combined analysis of safety and security concerns regarding a Cyber-Physical Production System (CPPS). In a feasibility study on an industrial work cell for metal processing with a collaborative robot, we evaluated the effectiveness and efficiency of the SafeSecCombi approach. Results indicate that the SafeSecCombi approach is feasible and effective, and provides safety and security experts with actionable, context-specific causes for security-related safety issues and countermeasures that are well grounded in engineering models, as a foundation to address the IEC 62061:2021 requirements.

The current industry has to adapt to rapidly changing customers' needs. Reconfigurable manufacturing, therefore, provides capacity and functionality on demand which is essential for competitiveness in fast-changing markets. Furthermore, Industry 4.0 or even more so, Industry 5.0 emphasizes human-centred production with collaborative robots, Cobots, to create human-robot interactions. In such scenarios, safety and security are difficult to address due to the intrinsic features of reconfigurable manufacturing, like exposure to numerous requirements changes in a short period. As safety and security can conflict in different phases of the system life-cycle, one of the earliest activities to avoid conflicts is requirements engineering which can significantly diminish the cost and time of fixing issues compared to later phases like operation. This paper proposes a methodology for safety and security requirements interaction management, including conflict detection and resolution, and shows its applicability through a reconfigurable collaborative human-robot use case. Based on the proposed methodology, we detected and resolved two safety and security requirement conflicts.

The Digital Twin (DT) paradigm has received attention for its potential in diverse industrial sectors like manufacturing, automotive, healthcare, electric grid, and transportation. The Asset Administration Shell (AAS) as an instantiation of the DT paradigm is proposed by Plattform Industrie 4.0, aiming to exchange asset-related data and services from when the asset is produced to its disposal in an interoperable way involving the key stakeholders. In Industrial Control Systems (ICS), AAS integration can bring about new safety and security concerns. Although there are standards covering safety and security separately, no finalised standard supports safety and security in a combined way. The increase in safety and security concerns because of AAS integration and recent cyber attacks that showed security and safety are interconnected, encourage us to explore one of the earliest activities in system development, requirement specification. Therefore, this paper investigates the impact of AAS integration into a use case on safety and security requirements specification according to IEC 62443 and 61511. The results highlight the interconnection of safety and security requirements in the proposed use case due to AAS integration and illustrate security requirements that potentially can affect safety.

Cyber-physical systems (CPSs) have attracted increasing attention in recent years due to their promise for substantial and long-term benefits to society, economy, environment, and citizens. In addition, the rapid advances in computing, communication, and storage technologies have resulted in a revolution in the information communication technology domain and domination in the industry context. The utilization of CPSs in industrial settings has led to industrial cyber-physical systems (ICPSs), which, in conjunction with the information-driven interactions, enables large-scale cooperation in industrial facilities and among all the stakeholders of the value chain. Hence, the research on ICPSs is essential, especially with respect to the engineering of such systems for industrial applications. This article presents an overview of recent developments in ICPSs. We first introduce the architecture of ICPSs. Then, we review the developments of ICPSs in relevant research domains. Finally, this article concludes by presenting some potential future research directions on ICPSs.

Information Technology (IT) and Operational Technology (OT) are converging further, which increases the number of interdependencies of safety and security risks arising in industrial architectures. Cyber attacks interfering safety functionality may lead to serious injuries as a consequence. Intentionally triggering a safety function may introduce a security vulnerability during the emergency procedure, e.g., by opening emergency exit doors leading to enabling unauthorized physical access. This paper introduces a risk evaluation methodology to prioritize and manage identified threats considering security, safety, and their interdepedencies. The presented methodology uses metrics commonly used in the industry to increase its applicability and enable the combination with other risk assessment approaches. These metrics are Common Vulnerability Scoring System (CVSS), Security Level (SL) from the standard IEC 62443 and Safety Integrity Level (SIL) from the standard IEC 61508. Conceptional similarities of those metrics are considered during the risk calculation, including an identified relation between CVSS and SL. Besides this relation, the skill level and resources of threat actors, threats enabling multiple identified attacks, the SIL of safety-relevant components affected, business criticality of the targeted asset, and the SL-T of the zone targeted by the attack are considered for risk evaluation. The industrial architecture to be analyzed is separated into zones and conduits according to IEC 62443, enabling the analyzed system to be compliant with its requirements.

Today’s industrial control systems consist of tightly coupled components allowing adversaries to exploit security attack surfaces from the information technology side, and, thus, also get access to automation devices residing at the operational technology level to compromise their safety functions. To identify these concerns, we propose a model-based testing approach which we consider a promising way to analyze the safety and security behavior of a system under test providing means to protect its components and to increase the quality and efficiency of the overall system. The structure of the underlying framework is divided into four parts, according to the critical factors in testing of operational technology environments. As a first step, this paper describes the ingredients of the envisioned framework. A system model allows to overview possible attack surfaces, while the foundations of testing and the recommendation of mitigation strategies will be based on process-specific safety and security standard procedures with the combination of existing vulnerability databases.

Currently, risk assessment of industrial control systems is static and performed manually. With the increased convergence of operational technology and information technology, risk assessment has to incorporate a combined safety and security analysis along with their interdependency. This paper investigates the data inputs required for safety and security assessments, also if the collection and utilisation of such data can be automated. A particular focus is put on integrated assessment methods which have the potential for automation. In case the overall process to identify potential hazards and threats and analyze what could happen if they occur can be automated, manual efforts and cost of operation can be reduced, thus also increasing the overall performance of risk assessment.

Production planning is not normally concerned with energy costs, but with the increasing share of volatile renewable energy, energy prices are becoming volatile, too. Production planning will ultimately have to take this into account. The problem here is in the uncertainly of price predictions and the associated risk. The present work investigates how to integrate dynamic energy price prediction uncertainty into the optimization of energy consumption in an industrial production setting. To that end, we incorporate the cost of prediction errors into the predicted energy prices up to the planning horizon. Such risk-adjusted prices are then used as the basis for energy-aware production planning. First results show that this concept can handle different error distributions and can be assumed feasible.

Modernizing street lighting is a logical reaction to dynamic economic changes and energy prices. The idea for intelligent street lighting is simple, complete control over the street lights depending on the conditions. At the same time, the main objective of this system is to lower energy consumption and, consequently, less CO2 emission. The number of cities which have established new lighting systems is growing fast because it is environment-friendly and economical. Modern lighting systems have different levels of intelligence and apply different strategies for changing energy consumption patterns. The impact of changing the lighting logic is much less than using intelligent street lighting or switching from conventional lights to LEDs. However, the total energy consumption for public lighting is too high that it is worth investigating any possible way for energy efficiency improvement, even for a fraction of one percent. This research explains a simulation-based approach in three real-world implementations for energy efficiency improvement using Street Lighting Simulation. In our studies, smart street lighting provides %25 to %60 energy savings, and optimizing the lighting strategy brings up to %5 more energy efficiency.

Securing smart sensors in IoT or more general in automation applications is mostly seen and addressed from a networking viewpoint. While there is much research on how to make communication in sensor networks secure and prevent data manipulation during transmission, less attention is paid to the sensor itself that provides the actual measurement data. However, manipulation of the sensor can lead to serious malfunction of an automation system. Protection of the hardware side of a sensor is therefore desirable, but faces constraints related to cost or technical feasibility. In this paper, we investigate a simple watermarking scheme applied to the analog readout of a resistive sensor. Based on the example of a outside temperature sensor in a heating control, we analyze various attack scenarios involving voltage injection and determine the level of protection that can be achieved.

Voice assistants, and in particular smart speakers, have become very popular in the recent past. Their growing ability to interact with users in natural language makes them a convenient interface for control of entertainment systems, appliances, smart homes, IoT applications, and many Internet applications. Nevertheless, they are controversial devices, not only because of the obvious challenges for security and privacy of their users. This paper investigates the concerns and motivations of users of voice assistants, but also those of non-users who are a group that is often disregarded in an engineering context. Following a theoretical model of non-usage, a representative nationwide survey was conducted in Austria to obtain quantitative insight into the groups of users and non-users of voice assistants. While the results confirm several former works regarding the sociodemographic characteristics of the groups, we find that only 75% of the non-users actively resist against the technology, whereas 20% rather feel excluded from using it. One of the surprising results also was that users and non-users share the same security and privacy concerns.

The interconnection of automation technology with IT systems, also referred to as Industry 4.0, enables cyber attacks to impact safety (e.g., TRITON malware). Conversely, installed safety functions and requirements may also affect security requirements (e.g., the emergency stop function has to be avail-able without prior authentication and authorization). Therefore, threat modeling (TM) methods considering security, safety, and their interdependence are needed to get a comprehensive view of potential flaws of an industrial architecture. This paper presents a case study of the TM methods STRIDE-LM and Failure-Attack-CounTermeasure (FACT) graph w.r.t. the identification of safety and security flaws and their interdependence, with the aim to provide an impression of possible solutions to the described problem. The study was applied to a use case derived from a stakeholder analysis showing common characteristics and requirements of industrial automation systems. As STRIDE-LM was designed only to consider security flaws, it was extended to cover safety aspects as well. Preliminary results of the application of the TM methods show differences in efficiency, precision, and the granularity of information provided.

With the introduction of Industry 4.0 (I4.0), man-ufacturing systems are moving towards digitalization which is one of the principal visions of I4.0. In industrial automation systems, safety and security are fundamental aspects that will gain even more importance in the future, even more so as systems become more interconnected in I4.0. The Asset Administration Shell (AAS) is one of the key enabling concepts towards the realization of I4.0, and its generic approach ensures applicability in different areas. Nevertheless, the lack of a reference for developing such applications has led to a diverse collection of implementation efforts. This is an interoperability issue that may increase safety and security concerns in future I4.0 applications. This paper proposes a safety and security reference architecture to provide a firm ground for developing safe and secure AAS-based applications in the context of I4.0. It breaks down critical aspects of AAS development into understandable elements to facilitate decision-making for the key stakeholders, from vendors to system integrators to operators who aim to move towards I4.0 realization.

Low-power wide-area networks (LPWANs) enable a vast number of sensors to be connected in a low-maintenance, low-cost, and easily deploy-able way. Conventional cryptogra-phy measures used to provide secure communication in such networks, often result in a higher on-air time, which directly increases the energy consumption. Also the additional message size needed may exceed the actual payload. This paper combines the concept of sensor data watermarking together with side-channel utilization to satisfy integrity protection of sensor data without the need to sacrifice payload size for message authen-tication codes (MACs). Practical experiments using LoRaWAN over The Things Network (TTN) show that watermarks can be embedded in a side-channel without significantly changing the channel characteristics thus making the security fully transparent to the original data transmission both in terms of payload and timing characteristics.

Indoor localization is a core technology for many position-aware applications. This is often based on the mea-surement of the signal strength at the receiver end, which is available for many commercial radio protocols without additional costs, e.g., for WiFi, Bluetooth or Zigbee. However, a major limitation with received signal strength (RSS)-based methods are high inaccuracies resulting mainly from physical propagation effects. But these effects are not the only cause for erroneous position estimates. In this paper we first present a RSS measure-ment system and localization setup based on Software Defined Radio (SDR)s, which reduces protocol-specific influences such as transmit power management. In addition, the RSS value can be measured with a much higher resolution and sampling rate, which gives more headroom to analyze its statistical and temporal properties. The measurement data is then evaluated to get an insight on the errors and disturbances commonly associated with RSS localization schemes. This allows us to identify a problem in the basic way RSS-based localization methods process the measurement data, which could be partially responsible for the high variance typically associated with RSS measurements and the elusive fast fading effect. The goal of this work is to investigate some fundamental aspects of RSS localization to better understand the limitations of the technology.

Modern cars are characterized by a growing number of sensors, actuators, and advanced driver assistance systems that require a synchronized view of the time. These devices are typically interconnected by CAN, which is still the most important in-vehicle network. Precise clock synchronization over CAN is difficult due to the properties of the bus, and current approaches often use dedicated hardware or proprietary software solutions. A few years ago, however, the AUTomotive Open System ARchitecture (AUTOSAR) development alliance published a standardized synchronization method. In this article, we investigate what synchronization precision can be realistically achieved in a real-world automotive hardware and software environment. This involves pure software timestamping, standard CAN controllers without hardware modifications, and a typical automotive real-time operating system. We evaluate several approaches to reduce the synchronization jitter using filtering and optimizing the timestamping procedure. Experiments show that, ultimately, a precision better than 50$\mu$s can be achieved with a fully AUTOSAR-compliant software implementation.

Advanced industrial communication systems are fundamental pillars of the ongoing digital transformation of industrial systems. Initiatives like the Industry 4.0 and the Industrial Internet Consortium aim at increasing the overall production efficiency leveraging on fast, reliable, and deterministic communication technologies. The improvements of information and communication technologies (ICT), driven by the tremendous influence of the consumer market, result in positive relapse for the industrial ICT, allowing an ever-increasing amount of data and information to be gathered from systems, machines, and devices. On the other hand, the availability of low-cost computational capabilities permitted to easily process these “Big Data,” generating on-the-fly trend forecasts for the management systems, which, in turn, allow to issue actions for controlling the manufacturing processes in real time. The ensemble of all these technologies is generally addressed with the term industrial Internet of Things (IIoT).

The application of Industry 4.0 (I4.0) architectures to the conservative nature of present Industrial Control System (ICS) has brought along many challenges. The ever-changing and dynamically altering threat landscape has led to many hazards and risks w.r.t. safe and secure operation of underlying assets. To understand and manage such risks, organizations perform assessments. Risk assessments performed today are typically handled in a centralized manner on a higher layer of the automation pyramid. The concept of the Asset Administration Shell (AAS) for I4.0 component might provide means to access and process data at the component level throughout the lifecycle, thus taking the assessment from a strictly centralized to a distributed manner. This paper, thus, focuses on the possibility of risk assessment either performed centrally or in a distributed manner aiming at highlighting data sources, acquisition, and processing mechanisms for the same relying on the AAS.

Energy consideration in production planning is becoming more important due to concerns over the climate change. However, the uncertainty of energy availability hinders the optimisation of production. The proposed concept uses an iterative approach of adjusting production scheduling in respect to the available energy using a multi-criteria optimisation that not only includes factory utilisation but also the likelihood of the predicted energy availability.

In the course of the energy transition novel solutions are needed to solve challenges that arise. Many customer owned energy resources become connected and shall contribute to the demand-supply balancing process, eventually. Small size suggest to solve related volatility issues also locally. Flexibilities of customer appliances provide the means to mitigate/manage the impact of volatile energy production close to the source. This paper presents an approach to rate appliance specific flexibility offers. Provider and user needs are addressed independently via the metrics benefit and quality. Introducing the problem and the proposed 2D-rating, we sketch exemplarily how PV and electric room heating flexibility can be predicted, offered, and used.

We present a watermarking scheme for sensor data, which accurately detects sensor voltage manipulation attacks. Due to a low complexity implementation running locally on a microcontroller, the proposed technique is well suited for home automation systems but also IoT systems where lightweight sensor nodes with restricted communication capabilities are commonly applied. The watermarking technique is based on modulating the sensor supply voltage, which embeds the watermark signal into the sensor output voltage. Hence, invasive voltage tampering attempts including ADC grounding and voltage injection attacks can be efficiently detected. According to the performed characterization results, our method is able to distinguish normal operation and an attack condition with approx. 98% accuracy for the entire ADC input voltage range. In a real-world demonstration involving a thermistor based temperature sensor all attack attempts were successfully detected.

With technological revolutions like the Internet of Things and Industry 4.0 on the doorstep, localization of network nodes is more important than ever. Indoor localization systems mostly work with omnidirectional antennas for simplicity reasons. Using directional antennas has advantages, though, and devices with such antennas will be included in IoT systems someday. In this paper, the focus is on dynamic changes in the configuration of localization systems. Adding an antenna must be handled fast and efficiently. Frequent recalculations of the configuration could be necessary, and limited resources make a reduction of the computational effort desirable. In this work we look at possible methods to cut the computational effort while minimizing the penalty on accuracy. Since accuracy is of utmost importance for indoor localization, there is a fine line which is important to find.

In Industry 4.0, Information Technology (IT) and Operational Technology (OT) tend to converge further with an increasing interdependence of safety and security issues to be considered. On one hand, cyber attacks are possible which can alter implemented safety functionality leading to situations where people are harmed, serious injuries may occur or the environment gets damaged. On the other side, safety can also impact security. For instance, the misuse of a Safety Instrumented System (SIS) may force a machine or a production line to shut down resulting in a denial of service. To prevent or mitigate risks from such scenarios, this paper proposes a threat modeling technique which addresses an integrated view on safety and security. The approach is tailored to the industrial automation domain considering plausible attacks and evaluating risks based on three different metrics. The metrics selected consist of Common Vulnerability Scoring System (CVSS) used as an international standard for rating cyber security vulnerabilities, Security Level (SL) from IEC 62443 to rate cyber security risks in OT environments w.r.t. the underlying architecture, and Safety Integrity Level (SIL) from IEC 61508 to rate safety risks. Due to the variety of use cases involving the chosen metrics, the approach is also feasible for followup analyses, such as integrated safety and security assessments or audits.

Industry 4.0 (I4.0) intends to make manufacturing agile, more efficient, and more customer-oriented. Considerable efforts have been made to enhance the safety and security aspects of I4.0 systems. However, the lack of a standard model has prevented the convergence toward safety and security. Plattform Industrie 4.0 has introduced the Asset Administration Shell (AAS) with the Reference Architectural Model Industry (RAMI 4.0) to integrate assets into the world of information. This paper draws the potential capabilities of AAS in bringing safety and security to I4.0 systems. For this goal, a safety and security model is proposed based on RAMI 4.0 to be used as a reference for developing the AAS model. A level control system is used as an illustrative example of an Industrial Control System (ICS) to demonstrate how to respond to I4.0 safety and security challenges using the AAS model.

Despite its age and even though Ethernet is becoming popular, CAN is still widely used in distributed automotive systems. In such applications, a network-wide notion of time is often a prerequisite. However, precision clock synchronization over CAN is difficult to attain, and current approaches use dedicated hardware or proprietary software solutions. On the other hand, there is a standardized synchronization method which was defined by the AUTOSAR development alliance. This paper investigates the achievable precision using a purely software-based implementation of the AUTOSAR method using standard CAN controllers in a typical automotive real-time operating system. Preliminary results show that a precision of around 400 microseconds can be achieved with a fully AUTOSAR-compliant software implementation, and that there are options for further improvement.

Low-data rate networks typically cannot afford the overhead entailed with security measures because of lack of bandwidth. In this paper we propose a method for embedding digital watermarks in LoRaWAN based sensor systems. With the presented approach, the transmitted messages themselves do not need to be modified. Rather, the inter-packet interval between individual packets is used as a side-channel to carry the security-relevant information. We first examine the specific characteristics of LoRaWAN which are typical also for similar low-data rate wireless networks and then present a feasible, lightweight approach for the generation of the digital watermarks. Subsequently, we analyze first simulation results of two different differential methods for the watermark implementation.

Knowledge about temperature conditions in industrial processes is a key factor for process efficiency and control. This paper specifically investigates the measurement of temperature distributions along pipes in furnaces to monitor the status of deposit growth inside the pipes. Contrary to common spot measurements, we propose fiber optical sensors (so-called fiber in metal tubes) allowing a high spatial resolution. As the measurement is only indirect, taking the pipe wall temperature as approximation for the fluid temperature inside the pipe, we present a model-based approach taking into account the thermal characteristics of the deposit layer. 2D simulations show the temperature distribution around the pipes and are used to derive first indications regarding the optimal placement of the sensors.

The ambitious climate goals of the European Union to complete the transition toward an entirely renewable energy supply request new balancing concepts to better cope with the required increase of distributed and volatile energy sources. Energy Communities could be an enabler thereto, the idea being that the community management coordinates heterogeneous energy assets, owned and operated by community members, to jointly utilize their resources internally and thereby reduce external grid load. In this paper we present an analysis of functional requirements to initiate a new technical framework for Energy Communities. This first functional description of Energy Community management aiming on community internal energy balancing is provided as a starting point for integration profiles development according to the Integrating the Energy System (IES) approach.

The increasing use of renewable energy sources, together with an ever-increasing energy demand, puts the electrical grid under heavy pressure. Grid extensions mitigate these factors, but are very costly. Other methods enabling an economically viable energy transition towards more renewable energy sources should be explored. We present a preliminary assessment of the impact of different mixes of prosumers on the energy balance and self-consumption of a rural community. We quantify unused potential regarding demand-side management, the extension of photovoltaic peak power, as well as battery storage. We implement models for electric production and consumption profiles and simulate scenarios with varied prosumer compositions. The results show that demand-side management does not change the self-consumption of photovoltaic energy significantly, whereas installation of more battery storage together with increased photovoltaic production promises better results for the rural community studied.

With increasing deployment of wireless devices also localization gets a consequential boost in industrial and other IoT environments. Localization so far in most cases assumes omnidirectional antennas. This paper investigates a generalized Received Signal Strength (RSS) fingerprinting localization algorithm for antennas with arbitrary radiation patterns in order to include IoT devices with directional antennas in localization.Focus is set on the recursive algorithm which improves performance of the traditional fingerprinting methods. First a machine-learning aided analysis of the overlapping reception areas of the antennas is conducted for quickly determining possible initial positions of the nodes to be localized. Then, for reaching higher resolution, different up-scaling techniques and gradient search is applied. In particular, the localization accuracy vs. computational efficiency is investigated which is an important trade-off for many applications.

In smart manufacturing, the demand increases to be able to monitor and adjust process execution during production. It has led to a shift towards distributed, modular automation. A solution seems to be to use a cognitive architecture. It turns out that their generality often makes them unsuitable for specific industrial problems. In this paper, we propose a cognition-inspired architecture design for health monitoring tasks. The problem class is represented by a conveyor belt use case. We then discuss to what extent this architecture matches common implementations of cognitive theories by following a generalized cognitive process.

Common localization approaches are usually based on omni-directional antennas. There are various algorithmic methods, all of which assume strictly uniform radiation in all directions. However, in general, the output characteristics of these (nominally omnidirectional) antennas are not completely omnidirectional or even highly directional depending on the specific design. This article investigates the use of clustering algorithms to identify different areas of joint signal parameters that can be used for an RSS-based localization method. A set of clustering algorithms is investigated, and their properties to cluster RSS maps for localization applications are compared. In particular, their score for cluster quality and their execution speed relevant for deployment in embedded systems has been evaluated.

The papers in this special section focus on emerging technologies and new trends in industrial informatics. Industrial informatics is a very dynamic and open-ended research area investigating the application of computing in different industrial domains. The international conference on Industrial Informatics (INDIN) was established by the IEEE Industrial Electronic Society in 2003 in order to bridge the significant gap between the high expectations of practice and the state-of-the-art in industry and academic research [item 1) in the Appendix]. Its intention is to provide a dynamic platform for researchers in industry and academy to present their cutting-edge results, and by doing that, form the global industrial informatics agenda.

The industrial communication market is dominated by Ethernet-based fieldbus systems. Although they share similar requirements and market segments, their implementations and ecosystems differ considerably. As a result, end customers and device manufacturers are faced with a multitude of technologies that need to be produced, run, diagnosed, maintained, and kept in stock. Although the availability of products and services is largely satisfactory, dealing with multiple solutions generates high costs and limits IoT capability. This paper introduces Open Platform Communication Unified Architecture Time-Sensitive Networking (OPC UA TSN) as a new technology and presents the current view. This time, the industrial prospects of fulfilling industrial communication requirements while leveraging the cost benefits of standard Ethernet hardware in the midterm are in reach. We anticipate that OPC UA TSN will reveal itself as a game changer in the field of industrial automation, being a candidate for establishing a holistic communication infrastructure from the sensor to the cloud.

Information is the key element in modern factory automation and process control systems, and one of the most difficult tasks is to provide, distribute, and properly process it. Information transfer and processing in this scenario depend to a large extent on appropriate communication systems, usually referred to as “industrial networks.” Significance, content, and properties of information may, of course, vary within a given application context. For instance, a distributed control system typically handles sensor and actuator information with stringent real-time requirements, whereas production planning needs to cope with huge amounts of data, such as those concerned with customer orders or bills of material, with more relaxed timing. The industrial networks deployed at the various hierarchical levels of automation systems thus have to meet different requirements, to ensure that timely and reliable data flows are maintained among the different components they connect, such as field devices, controllers, human–machine interface (HMI) systems, cloud computers, manufacturing execution systems (MES), and so on[1],[2]. According to the specific needs of the numerous application fields such as manufacturing, electrical power distribution, motion control, environmental monitoring, and chemical processes, to mention but a few[3],[4], industrial networks may have diverse architectures, traffic types, and performance.

Industrial communication systems represent one of the most important innovations of the last decades in the context of factory and process automation systems. They are networks specifically designed to cope with the tight requirements of these challenging application fields such as real time, determinism, and reliability. Moreover, industrial networks are often deployed in environments characterized by strong electromagnetic interference, mechanical stress, critical temperature, and humidity. Over the last three decades, different classes of industrial networks have been developed according to changing requirements and available communication and information technologies. In this paper, we first provide an account of the state of the art, reviewing classical fieldbuses, real-time Ethernet networks, and industrial wireless networks, along with their most relevant features, applications, and performance figures. We introduce the complex standardization framework and analyze the market status and assumptions for future development. In the second part, we address the future perspectives focusing on new technologies, standards, and fields of application. In particular, we consider the time-sensitive networking (TSN) family of standards, Industrial Internet-of-Things (IIoT) systems, high-performance wireless LANs, industrial applications of cellular networks, and Ethernet networks for automotive communication.

The main infrastructural parts of urban intersections are road marks, traffic lights, and lighting. Signaling - except for metal signs - is always realized as intelligent systems. In case of lighting systems, a trend for including intelligence into the luminaries for remote control and diagnosis applications can also be recognized. The increase in smartness comes at the cost of increased energy consumption. This paper describes a simulation first principle based system design of future intelligently managed street luminaries as smart lighting control system. Typical use cases were found and a simulation platform designed, to calculate estimated energy savings compared to regular LED-based light solutions, already reducing considerable lighting infrastructure costs. The paper presents a unique approach of mapping light area comparisons to simplified percentages and a promising simulation results of soon to be tested overall system energy efficiency increases by more than 20 % and CO2reductions without compromising traffic safety while maintaining and even increasing smart features of tomorrows critical infrastructure.

Monitoring is an important aspect of operation and maintenance in virtually every industrial system. However, the extent and methods of monitoring vastly vary in different systems, from fully automated to fully manual. One of the challenges of automated monitoring is the tediousness of, and the extent of engineering time and effort required to develop necessary models or machine learning algorithms for the units to be monitored. Model-free monitoring, on the other hand, can save resources and efforts substantially. However, more often than not they have a very limited scope and application. Such a system is needed, for example, to monitor entire Heating, Ventilation and Air Conditioning (HVAC) systems, consisting of different types of sensors such as temperature, pressure, humidity or flow sensors. Recently, we proposed the Context-Aware Health Monitoring (CAH) system for model-free monitoring of any injective-function black-box, and it was tested successfully on an AC motor. In this paper, we evaluate the CAH system for an entirely different industrial use-case, that is, a hydraulic circuit. The results show the potential for considerable benefits in monitoring HVAC systems. Moreover, in the light of applying CAH to different use-cases which may potentially need a different setup of parameters, we performed a sensitivity analysis on the values of different parameters in the system. The results show the robustness of CAH with regard to the values of these parameters.

On one hand, the worlds rising electricity demand can lead to increased renewable, clean, environmentally friendly generation. On the other hand, this increase of volatility poses many new challenges for today's power supply system to integrate this hard to predict generation. One direction many efforts are undertaken, is the introduction and increase of flexibility on the consumer side, leading to more smartness and communication need between power consumption and production. In the customer premises, home energy management systems are being developed to increase own consumption for users, but also offer an access point for other stakeholders, to receive market or grid signals, to accomplish timing and coordination. To be able to analyze, e.g. the energy flows and to gain a better understanding of scaling effects; there is a need for simulation frameworks like RAPSim. This paper describes the implemented extension of RAPSim with an additional consumer component, which allows integrating selected functions of home energy management into the simulation. The simulation allows the new consumer component to closely approximate the behavior of home energy management systems that have a photovoltaic system and a battery storage installed. Further possibilities to extend the components and features in the future are also pointed out.

Heating, ventilation, and air conditioning systems contribute significantly to the overall energy consumption of buildings. In order to operate these systems more efficiently, the airflow distribution must be known for the entire facility. This information can be obtained by installing wirelessly connected sensor nodes. Power supply for such distributed data acquisition systems is a challenge because it is difficult and costly to install cables. Therefore, in this paper, energy harvesting strategies are investigated to supply these sensor nodes with energy, with the objective of reducing installation and maintenance effort. The main challenges are the relatively high energy of 2 Ws needed per measurement and the fast measurement interval of one minute. The investigated energy forms are airflow, thermal and solar energy. The aim of this study is to determine which energy forms are suitable under typical operating conditions in HV AC systems and how they can be used. As the same measurement procedure is used for each energy form, an objective comparison can be drawn. It is concluded that solar as well as airflow energy are promising to harvest from, while thermal energy is less suitable in most cases.

For distributed measurements to be consistently aligned a global notion of time within the network is necessary. Clock synchronization performance is hampered by delays and jitter accumulated not only in the network, but also in the timestamping procedures of the devices being synchronized. The resources available on such sensors are often constrained, both by cost and power consumption. Software solutions on single processor systems are common. While the synchronization process is critical, it usually has a supporting role and therefore cannot be assumed to have the highest priority. This paper analyzes the influence of periodic, non-interruptable tasks (e.g. measurements) on the timestamping process, presents mathematical models for simulation and a modified median filter to efficiently deal with these errors.

Since the release of Bitcoins as crypto currency, Bitcoin has played a prominent part in the media. However, not Bitcoin but the underlying technology blockchain offers the possibility to innovatively change industries. The decentralized structure of the blockchain is particularly suitable for implementing control and business processes in microgrids, using smart contracts and decentralized applications. This paper provides a state of the art survey overview of current blockchain technology based projects with the potential to revolutionize microgrids and provides a first attempt to technically characterize different start-up approaches. The most promising use case from the microgrid perspective is peer-to-peer trading, where energy is exchanged and traded locally between consumers and prosumers. An application concept for distributed PV generation is provided in this promising area.

Robotics is a surprisingly old discipline, and robots have shaped industry and the various industrial revolutions for many decades. This paper covers topics relevant to the IES Technical Committee on Factory Automation, focusing in particular on the evolution of industrial robotics. After providing a historical perspective on the topic, the paper addresses current and future trends, revealing the close link between the progress in industrial robotics and the parallel evolution of industrial communication systems, which represent an enabling technology for modern industrial robotics.

In the context of Industry 4.0, constantly evolving shop floors generate the need for a highly adaptive and autonomous automation system with lean maintenance, minimum downtime, maximum reliability, and resilience. Future Manufacturing Execution Systems (MESs) will be more complex and dynamic as well as distributed physically and logically. This makes it very difficult, if not impossible, for the conventional centralized architectures to effectively control these vibrant Cyber-Physical Production Systems (CPPSs). To address these issues, we propose Self-Aware health Monitoring and Bio-inspired coordination for distributed Automation systems (SAMBA), an architecture which tackles these challenges. SAMBA increases the ability of the system to intelligently adapt to rapidly changing environment and conditions of future CPPSs.

To enable highly efficient operation of large scaled ventilation systems a continuous measured and well located air flow monitoring for control purposes and energy management is needed. The air flow monitoring solution is targeting low manufacturing cost as well as sufficient accuracy when operating near complex duct flows like pipe bends and tees. Therefore, a novel, low-cost, thermal air flow sensor, which takes non-uniform velocity profiles into account, is presented and characterized due to its application in heating, ventilation and air conditioning systems. Extensive numerical simulations and experimental investigations in an operating ventilation system show reasonable results and prove basic feasibility of the suggested novel sensor concept.

The papers in this special section focus on telecommunication services in automation applicaitons. The evolution of automation systems has always been the result of continuous improvements to state-of-the-art systems, occasionally punctuated with significant paradigm and architectural changes that acted as innovation drivers. This happened with the industrial revolutions, which had in their origin the appearance of disruptive technologies, such as the steam engine and machine tools (first industrial revolution); electrification, mass production, and assembly lines (second industrial revolution); use of microprocessors and software (third industrial revolution).

Wireless communication is widely used for node localization in various automation domains. Schemes based on time difference of arrival (TDOA) are a good compromise of achievable accuracy and implementation effort. Due to restrictions on possible reference sensor positions in industrial environments, the geometric conditions between reference and mobile nodes locations are often difficult. Consequently, iterative algorithms can fail or result in high computational effort. Exact direct methods introduce no additional errors, but can result in a valid pair of solutions. Existing direct methods thus either rely on a priori information to sort out one of those two solutions, or revert to nonexact linearization approaches of the underlying hyperbolic equations. In this work, we present a direct approach that applies exact direct methods, and resolves the ambiguous pairs of solutions without a priori information. Its divide and conquer structure and the high computational efficiency of the available exact direct methods makes it a very good candidate for fast parallel computing in distributed sensor networks. The performance is compared to the Cramer-Rao lower bound, to the iterative Gauss-Newton method and to another direct method. The new method is presented for the TDOA scheme, but can also be applied to time of arrival, or any other range-based scheme.

The lack of provisioning of synchronized timing support from known timing standards in IEEE 802.11 wireless networks has been overcome in IEEE 802.11-2012 through the timing advertisement (TA) mechanism. The scheme, however, presents a synchronization architecture of a cascade of four clocks. It provides no information on how the external time will be synchronized with the built-in clock of the access point (AP) and when the timestamping is performed on the wireless link, which can lead to a loss in synchronization accuracy. To this end, this work analyzes the quantitative performance of the TA mechanism with a non-IEEE802.11 mechanism, SyncTSF, which also uses the same four clocks as in the TA mechanism and compares their performance with the help of simulations. Both schemes offer similar accuracy and precision if the offset corrections involved in both schemes are carried out properly. Nevertheless, SyncTSF is more flexible, as it can be easily implemented using commercial off-the-shelf hardware using only software support. For the implementation of TA mechanism, additional guidelines from the IEEE 802.11 Standard along with dedicated hardware support is required.

Just like Ethernet before, IEEE 802.11 is now transcending the borders of its usage from the office environment toward real-time communication on the factory floor. However, similar to Ethernet, the availability of synchronized clocks to coordinate and control communication and distributed real-time services is not a built-in feature in WLAN. Over the years, this has led to the design and use of a wide variety of customized protocols with varying complexity and precision, both for wired and wireless networks, in accordance with the increasingly demanding requirements from real-time applications. This survey looks into the details of synchronization over IEEE 802.11 with a particular focus on the infrastructure mode which is most relevant for industrial use cases. It highlights the different parameters which affect the performance of clock synchronization over WLAN and compares the performance of existing synchronization methods to analyze their shortcomings. Finally, it identifies new trends and directions for future research as well as features for wireless clock synchronization which will be required by the applications in the near future.

The shift towards massively distributed energy generation demands more decentralized flexibility to meet strict power quality constraints of the electric grid. A cyber-physical system such as a smart grid can provide increased flexibility by utilizing additional information and communication technologies to better monitor the medium and low voltage distribution networks and to actively control grid-connected resources, ranging from loads to distributed generation, to electric mobility but at the cost of increased complexity. Essential future functionalities such as dynamic management of line use, fault detection and fast service restoration are only possible with appropriate sensors and actuators in place. These missing sensors and actuators on the distribution level are being developed today. This paper presents a standards based, low cost, open source, ICT emulation platform setup to test necessary networking concepts of these smart grid component prototypes already in various stages of development. Preliminary development results of the first example applications chosen: Customer Energy Management System, Smart Breaker, and Smart Meter, are shown in this work in progress paper.

Due to their increasing complexity, the implementation of automation systems faces more challenges. Cognitive architectures have been designed to deal exactly with that. The purpose of a cognitive architecture is to find an action to every possible sensor data to move the system closer to a defined goal. The method is to utilize stored knowledge to reason about the best solution. The challenge for the implementation of such an architecture is to manage the overwhelming complexity of functionality and data. This paper presents the Agent-based Cognitive Architecture (ACONA) Framework, which aims at providing a general infrastructure, allowing the implementation of various cognitive architectures. It considers the encapsulation of functionality and provides a flexible composition of building blocks by applying a multi-agent approach.

Localization of wireless nodes is widely used in automation. Time difference of arrival (TDOA)-based schemes have a good trade-off between implementation effort and attainable precision. Calculating the position of the mobile nodes is challenging due to a hyperbolic multilateration problem where the geometry between reference and mobile nodes is often degenerate. For unsuitable initial positions, iterative algorithms can fail, which favors direct methods. Exact direct methods are computationally efficient, but due to geometric ambiguities they can give a valid pair of solutions. In this work, we present a generally applicable divide and conquer approach which resolves these ambiguities and does not require an initial position.

In recent years, the Internet Protocol (IP) has become a common basis for communication in several automation domains. For smart grids, it is even more beneficial because it brings a unification aspect into a field characterized by a variety of heterogeneous communication protocols which are in use today for various functions and services inside a smart grid. Besides, IP offers a convenient approach to implement security in the communication infrastructure by using its native security extension, IPsec. Nevertheless, IPsec was originally devised for IT environments and not for automation networks. This article therefore analyses the performance impact of IPv6 and IPsec on the end-to-end communication in resource-limited devices using Intel and ARM architectures, respectively. Based on standard Linux as an operating system, we employ a lean measurement setup which can be used even on devices with limited processing power without influencing the measurement results too much. The experimental results show that the influence of security features on the processing time of IPv6 packets is below one millisecond, which should be feasible for many smart grid applications.

This paper introduces a concept for bringing dependability into the area of building automation. The proposed approach is able to extend existing building automation networks with dependability features. For this purpose, the communication stack of a particular system is extended by adding an intermediate layer. This so-called dependability layer is transparent to allow seamless integration. Thereby, reliability is addressed in terms of fault tolerance by offering redundant network topologies. A heartbeat mechanism and an acknowledgment procedure as well as a specific message format satisfy the safety requirements. Moreover, the dependability layer offers security mechanisms that establish a secured channel among communicating nodes.

The increasing presence of wireless communication in factories has encouraged the introduction of novel applications on the factory floor. Highly accurate clock synchronization of wireless devices is necessary for timely communication between these devices and in some cases such as time-based localization, a major pre-requisite. One critical factor affecting synchronization performance is propagation delay variations suffered by a packet when it moves from its source to the destination. In this preliminary study, a set of measurements have been carried out to find out the extent of these variations. A highly accurate timestamping unit is used to detect the departure and arrival of a packet on the wireless channel, as the timestamping unit undergoes relative motion in an office environment. The results indicate that propagation delay variations are less affected by mobility than by reflections of signals from surrounding surfaces and objects. Future work will investigate whether the above observation is correct by employing higher speed mobility.

IEEE 802.11 Wireless Local Area Networks are an appealing complement, if not an alternative, to Ethernet-based industrial solutions because it not only can match Ethernet's high throughput but also leads to reduced costs and more system-design flexibility. However, like in Ethernet, clock synchronization service for applications has not been inherently present in IEEE 802.11. This paper analyzes the clock synchronization mechanisms of IEEE 802.11, which has become a major communication technology to establish the Internet of Things in industries, and how they can be used to provide high precision clock synchronization. In doing so, this work discusses the different parameters which can affect the performance of clock synchronization over the wireless channel, such as timestamping quality, clock adjustment, and synchronization overhead. An outlook to the future includes the new trends for synchronization for wired-wireless hybrid and fully wireless mesh networks where the IEEE 802.1AS audio video bridging networks and IEEE 802.11s mesh networks are leading the line, respectively.

In order to support very small cycle times, Profinet isochronous real-time (IRT) was improved by implementing the dynamic frame packing (DFP) mechanism. It turned out that DFP is relatively efficient, but it still has two crucial drawbacks. The complex scheduling has to be recalculated every time the network structure is modified. Furthermore, DFP only operates efficiently in line topology. This study presents a proposal for further improvements of Profinet IRT by implementing an automatic packing mechanism (APM). The main advantage of APM lies in the fact that a dedicated scheduling algorithm is not required. Furthermore, APM achieves approximately the same performance as DFP in line topology, but it has a distinctive advance in star or tree topologies. This paper also presents experimental validation results that prove the functionality of the approach. APM could be implemented with only minor modifications of the media access control (MAC) and physical layer (PHY) hardware to improve the flexibility of Profinet IRT.

Automation systems are composed of tightly integrated mechanical, electronic, and computer equipment being designed to reduce or even eliminate the need for human intervention in the realization of many different tasks. Also, the automation of systems and processes is often characterized by some interesting features, such as reduced exploration costs and intrinsically higher efficiency, safety, and quality. The papers in this special focus on the use of automation in communication systems.

The prime goal in automation systems is to increase productivity while at the same time save production costs. Nevertheless, in recent years there is increasing concern about the ecological footprint of production systems and a growing demand for energy optimization. Heating, ventilating and air conditioning (HVAC) systems in large industrial buildings consume a substantial amount of energy and typically run independently of the actual production processes. Integrating the two systems, however, can be beneficial in terms of overall energy optimization. This paper proposes a modular modelling of the building thermal load with the aim of connecting this model with the typical architecture of Manufacturing Execution Systems (MES). As the building automation system is distributed, the idea is to bind it with a set of generic cells that encapsulate a thermal model of the physical surrounding as well. With this approach the cell thermal load behaviour can be predicted for energy optimization. To allow implementation on the existing embedded devices and controllers with limited computational resources, a reduced complexity model is developed. As the model is to be used for model predictive control (MPC), also the first steps towards the development of the control algorithm are introduced and the benefits compared to traditional approaches are shown.

Air conditioning systems need permanent monitoring of the mass and energy flows in the air ducts to assess their proper operation and detect and correct changes that may occur with time. This is a prerequisite for energy efficiency and demanded by recent legislation such as the Energy Performance of Buildings Directive issued by the European Union. Such distributed monitoring systems require low-cost and robust flow sensors that need not be extremely precise, but give a good indication of the flow distribution within the air conditioning system. In this paper we present a technology feasibility study to implement flow sensors based on thick-film thermopiles printed by silk screen printing on a plastic carrier film. Finite element simulation studies using Cu-Ni thermopiles prove the viability of the sensor concept. Within the scope of a thorough analysis of the sensor design space, an optimized layout could be found which together with a feedback control operating mode allows for a substantially enlarged dynamic range of the sensor.

The residual error rate of a safety critical system gives the residual risk of a system failing, considering the mitigation mechanisms that are in place to prevent incidents. This calculation has to be based on a model that describes the error rate of the system without mitigation mechanisms in place. For industrial communication protocols, a simple error model is given in IEC 61784-3 [1, B.3]. This simple model is an abstraction of reality, trying to model just those properties of reality needed to calculate the residual error rate for an industrial communication system. Unfortunately, the model has two problems that will be addressed in this paper: burst-errors are not properly modelled and the Bit Error Rate (BER) of the model is under heavy discussion in the standardization committees. Therefore this paper proposes another approach for an error model that does not rely on a BER, but is based on the standards used for electromagnetic compatibility (EMC) testing, and tends to deliver a more realistic distribution of errors for industrial environments.

The absence of built-in clock synchronization support for IEEE 802.11 networks has been a concern for industrial applications which are seeking to use wireless networking on the factory floor. In IEEE 802.11-2012, the timing advertisement (TA) mechanism is proposed which provides guidelines for the application synchronization. It involves calculating and maintaining the time offset with respect to the timing synchronization function (TSF) timer of the access point. In the wireless stations, the TSF-based synchronization mechanism and the offset are combined to establish synchronization to an external timebase. With respect to the lack of implementation guidelines and support for the TA scheme, this paper compares and discusses the TA scheme and the software-based SyncTSF scheme previously proposed by the authors, which employs the TSF timer as the timing source in the network. The initial simulation results show that both schemes can provide similar performance, depending upon the controller design and the timestamping technique.

Profinet IRT makes use of dynamic frame packing (DFP) in order to support very short cycle times. The applied packing order is highly dependent on the network topology, and thus the scheduling must be recalculated offline every time the network structure is changed. This study presents a proposal for an automatic packing mechanism (APM) that is based on subframes with delimiters using control characters. As a consequence the subframe positions can be recognized by each device, which makes a scheduling dispensable. Furthermore, APM achieves better performance than DFP, especially in star or tree topology. The paper also presents experimental validation results.

The papers in this special section focus on the deployment of distributed data processing in industrial applications. The main objective is both bringing together ideas of the worldwide research community about one common platform and presenting the latest advances and developments in design, modeling, programming, management, and innovative implementations of distributed information systems, including the latest works related to industrial communication technologies to be used in the future.

We present a development study of a robust inter-ferometric transducer for elastic deformations excited by mechanical vibrations. In contrast to known methods using piezoelectric, fiber Bragg grating and Fabry-Perot interferometer sensors, we deal with pronounced spatially distributed transduction based on arbitrary shaped fiber segments like fiber optic coils. This approach allows, e.g., an omnidirectional sensitivity characteristic in case of circular shaped fiber segments, and offers a high immunity against electromagnetic interferences. Omnidirectional transducer characteristics are beneficial for vibration detection on complex shaped bodies. A finite element model simulation (FEM) is used to demonstrate the detection capacity for Lamb waves propagating in a carbon fiber reinforced polymer (CFRP) matrix.

For a distributed embedded system (DES) to operate continuously in a dynamic environment, it must be flexible and highly reliable. This applies in particular to its communication subsystem. The Flexible Time-Triggered Replicated Star for Ethernet (FTTRS) aims at providing such a subsystem by means of a highly-reliable switched-Ethernet architecture based on the Flexible Time-Triggered paradigm (FTT), a master/slave communication paradigm where the master periodically polls the slaves using so-called trigger messages (TMs). In particular, FTTRS interconnects nodes by redundant communication paths provided by two switches, each embedding an FTT master that manages the communication. This allows FTTRS to tolerate the failure of one switch without interrupting the communication as long as the masters are replica determinate, i.e., provide identical service to the slaves. The master replica determinism entails the masters broadcasting their TMs in a lockstep fashion: when one master broadcasts a TM, the other should do the same quasi-simultaneously. In this paper we present a solution inspired by the Precision Time Protocol (PTP) for achieving this lockstep transmission and preliminary results showing the precision with which we can synchronize the masters on a software prototype.

The characterization and optimization of a low-cost thermal flow sensor optimized for the use in heating ventilating and air conditioning (HVAC) systems is presented. The fabrication of the transducer is exclusively based on printed circuit board technology to keep costs low and allow for easy handling and replacement. The measurement principle utilizes a calorimetric principle with thermoresistive heat transfer. The thermistors form a Wheatstone bridge while the heating element is supplied with a constant current. The AC bridge output voltage is a function of the flow offering adequate sensitivity and a suitable measurement range for HVAC systems. The main experiments focus on flow measurements with a Lock-In amplifier technique to evaluate the measurement range and sensitivity. Based on prior results for time constants, output voltage, sensitivity, etc., the sensor design has been optimized.

Network-based clock synchronization is an important prerequisite for many application areas and more and more required for the factory floor for network arbitration, control, and monitoring. Limitations of existing clock synchronization protocols are that they either support high redundancy and robustness or high precision. This paper presents an approach to integrate slave-side robustness into high precision clock synchronization. To achieve this goal, a system design facilitating the IEEE 1588 Precision Time Protocol (PTP) is proposed, which supports multiple masters in parallel and provides highly reliable and robust clock synchronization, while at the same time demanding no changes to the network and timing infrastructure. The slave-side robustness can be further enhanced to provide improved monitoring support for IEEE 1588. This makes the solution especially appealing for large-scale networks where retrofitting must be done efficiently and the network infrastructure is not under the control of the end device operator.

Two recent trends in industrial robotic applications demand for a new generation of control platforms. The first one is the paradigm shift from separating robots and human workers with fences and light curtains towards a work environment in which humans and machines work together very closely. The second one is the preference of commercial off-the-shelf hardware (COTS) over dedicated hardware for economical and performance reasons. Applying COTS hardware into safety critical systems is a trend that is already in wide use in areas like public transportation or public safety, assuming the possibility for designing lower priced systems as well as less hardware dependency to specific manufacturers. Increasing computational power implicating less need for specialized hardware, as well as ongoing development of virtualization technologies implying new possibilities dealing with redundancy press this development. Up to now, this approach is only used for non-safety relevant parts in the area of industrial automation. Increasing complexity of state of the art automation systems leads towards the use of more powerful CPUs, ideally standard industrial PCs. This work identifies and analyzes possible exclusion criteria for a COTS solution with respect to IEC 61508 safety integrity level (SIL) 3 on behalf of a proposed system concept. The concept is theoretically analyzed with respect to the performance of state of the art hardware. In addition an estimation of the order of magnitude for the performance impact of the calculation using arithmetic codes over the native execution is given.

Vibration and displacement sensors need to be compact for many applications in automation or consumer electronics, and microelectromechanical structures are a convenient way to implement such sensors. For these MEMS devices, optical readout methods have proven to be superior to capacitive or piezoresistive strategies in terms of sensitivity as well as noise and interference immunity, however the integration of light sources and detectors is not easily possible. This paper presents an approach to use organic optoelectronic devices for the readout. OLED and OPD (organic photo detector) are structured on the glass substrate and cover encapsulating the MEMS devices, allowing for a tightly integrated sensor based on vertical light flux modulation by a horizontally moving proof mass. The paper describes the principle sensor structure as well as the fabrication of suitable organic devices. First test results show that the approach is feasible.

Real-Time Ethernet networks increasingly gain importance for the employment in industrial applications. Certain Real-Time Ethernet networks were optimized to reach very small cycle times well below 100 μs by modifying the Ethernet hardware. Two important and wide-spread systems of this class are EtherCAT and Profinet IRT. VABS is a newer high-performance system which is still under development. This study presents an objective performance comparison of the three systems. It turns out that both Profinet IRT and the summation frame based systems EtherCAT and VABS exhibit distinctive strengths and weaknesses. Profinet IRT gains the advantage with asymmetric inbound and outbound data payloads, but it runs behind EtherCAT and VABS for very small data-payloads.

In distributed systems, clock synchronization performance is hampered by delays and jitter accumulated not only in the network, but also in the timestamping procedures of the devices being synchronized. This is particularly critical in software timestamp-based synchronization where both software- and hardware-related sources contribute to this behavior. Usually, these synchronization impairments are collapsed into a black-box performance figure without quantifying the impact of each individual source, which obscures the picture and reduces the possibility to find optimized remedies. In this study, for the first time, the individual sources of delay and jitter are investigated for an IEEE 802.11 wireless local area network (WLAN) synchronization system using the IEEE 1588 protocol and software timestamps. Novel measurement techniques are proposed to quantify the hardware- and software-related delay and jitter mechanisms. It is shown that the delays and their associated jitter originate from both the WLAN chipset and the host computer. Moreover, the delay from the chipset cannot be considered symmetric and any such assumption inevitably leads to a residual offset, and thus to synchronization inaccuracy. Therefore, a calibration-based approach is proposed to compensate for these delays and to improve the performance of WLAN synchronization. Experimental results show that with optimal error compensation, a similar synchronization performance as software-based synchronization in Ethernet networks can be achieved.

We present a study devoted to the utilization of elastic Lamb waves in structural heath monitoring for damage detection in composite material. We pay attention to the detection of these high dispersive and multimode waves in large range specimen. In contrast to known methods using piezoelectric, fiber Bragg grating and Fabry-Perot interferometer sensors, we deal with spatially distributed transduction based on a fiber optic coil. This method offers an omnidirectional sensitivity characteristic end high immunity against electromagnetic interferences. Comsol finite element method (FEM) is used to demonstrate the detection capacity of Lamb waves along large ranges using the omnidirectional fiber optic sensor.

Up to now, production systems only concern was to minimize production costs or to optimize the utilization of production resources. But with the increasing energy prices and the growing concern over the environmental impact of production systems (industrial systems consume a quarter of all energy), efficient use of energy in manufacturing environment cannot be ignored any longer. MANUbuilding concept brings together the manufacturing systems requirements with the building automaton concerns over the efficient energy use and develops the local decision making based on dynamically expanding clusters to optimize the energy consumption in a factory.

A concept of a flow sensor optimized for the use in HVAC (Heating Ventilating Air Conditioning) systems is presented. The fabrication of the transducer is based on PCB (Printed Circuit Board) technology to keep costs low and allow for easy handling and replacement. The complete sensor device consists of a quantizer, a conversion circuitry, and a network link. Through interaction with the streaming fluid, the transducer generates an electrically measurable signal which allows determination of the total flow of the fluid. The measurement principle is based on a modification of the calorimetric principle. Hence, miniaturized heat sources and nearby temperature detectors have to be implemented. The behavior and performance of the sensor concept has been studied by means of finite element simulations. The quasistatic and transient simulations reveal the temperature allocation inside the sensor and the surrounding fluid and therefore allow a further optimization of the sensor for different applications.

The function block standard IEC 61499 is gaining popularity as a solution for distributed automation systems. Its event-based concept suggests the use of packet-based networks such as conventional Ethernet as underlying communication infrastructure. For such networks, however, proper Quality of Service (QoS) mechanisms are required to ensure adequate network performance. Ideally, these mechanisms must be configured and controlled from the IEC 61499 system both during engineering and normal operation. This paper addresses the problem of fully integrating Ethernet switches into an IEC 61499 system rather than treating them as transparent network components. An analysis of existing QoS support in available devices reveals a large degree of heterogeneity in the implementations that calls for an abstraction layer. This abstraction is introduced by means of a dedicated QoS function block attached to the device which makes the QoS parameters accessible from the function block application layer thus making the device-specific implementation transparent to the IEC 61499 system developer.

With the evolving technologies smart metering, or generalized the smart grid, it becomes reasonable to think about integrating household devices into a Demand Side Management (DSM) network. This paper gives an overview about the state of the art in the area of DSM. Subsequently, it is shown what is needed to convert a standard, commercial-off-the-shelf refrigerator into a networked smart fridge. Following this, a simulation model and a basic algorithm for load control of a refrigerator is presented and analyzed. Finally, possible improvements of hardware and the algorithms are proposed.

Manufacturing Execution Systems are essential elements for vertical integration in modern automation systems because they provide the link between the centralized enterprise level and the distributed shop floor. Existing centralized MES implementations can however not properly cope with an unpredictable order flow, changes on the shop floor, or the increasing complexity of both. Distribution of the MES functionalities would allow shifting the decision making process from the enterprise down to the field level, resulting in a more flexible manufacturing system. This paper investigates how and to which extent MES functionalities can actually be distributed in different approaches with varying degree of organization and shows what affects system behavior with respect to flexibility and optimization.

Information transfer is an essential factor in automation systems. For reasons of practicability, the development of industrial communication networks focused on horizontal aspects, i.e., the provision of suitable automation networks on the various levels. Conversely, vertical integration has become a topic of interest only in the recent past and mostly concerns the interconnection of field-level networks and IP-based office-type networks. Such interconnection can reasonably be achieved via gateways. This survey paper reviews concepts and defines a set of criteria that are relevant for the design of such gateways. Furthermore, it compares the applicability of common Internet communication standards like SNMP, LDAP, SQL, native web technologies, OPC XML-DA, and OPC UA as higher-level access protocols to field-level data, thus providing a basis for vertical integration on an application level. For comparison, a dedicated proprietary protocol is discussed as well.

Modern trends in manufacturing demand vertical integration between the enterprise and the field control level. Existing Manufacturing Execution System solutions fail to satisfy the requirements of unpredictable order flow and dynamic shop floor; neither can they deal with the increasing complexity of both. Distribution of the MES functionalities would allow shifting the decision making process from the enterprise down to the field level and providing concurrency of execution that results in a flexible system covering all three levels of the automation pyramid. This paper investigates how and to which extent MES function can actually be decentralized and describes a possible implementation based on software agents.

The very popular Precision Time Protocol (PTP or IEEE 1588) is widely used to synchronize distributed systems with high precision. The underlying principle is a master/slave concept based on the regular exchange of synchronization messages. This paper investigates an approach to enhance PTP with fault tolerance and to overcome the transient deterioration of synchronization accuracy during a recovery from a master failure. To this end, a concept is proposed where a group of masters negotiates a fault-tolerant agreement on the system-wide time and transparently synchronizes the associated IEEE 1588 slaves. Experimental verification on the basis of an Ethernet implementation shows that the approach is feasible and indeed improves the overall synchronization accuracy in terms of fault tolerance.

In factory communication systems, wireless networks are likely to complement wired automation networks, rather than replacing them. There is therefore an increasing interest in the way wireless and wired systems will interact and form a hybrid network. The hybrid network architecture proposed in this paper specifically addresses WLAN infrastructures in industrial environments. The paper discusses design challenges and describes the proposed system architecture and its main components.

Wireless technologies in industrial automation increase flexibility, but pose challenges to the design of security strategies. The typical requirements regarding integrity protection, authentication, and availability need to be transferred from the traditional wired network domain to wireless networks without impairing the benefits of wireless communication. This article presents results of the security concept for flexible wireless automation in real-time environments devised in theflexWARE project. It includes the results of the security requirement analysis, a description of the procedural design approach towards security, and describes innovative communication protection mechanisms for wireless domains including seamless handover and novel location-based security services.

The distribution of real-time tasks in a networked environment in principle has several advantages, above all a high degree of flexibility easing system extension and replacement of devices and components. Component-oriented system design concepts and suitable networks such as Ethernet additionally facilitate distributed automation applications. Yet, really distributed systems are problematic to apply in practice as debugging capabilities are limited. One essential prerequisite is that network traffic can be monitored in real-time with respect to its timing within the entire system, so that events can be ordered and their interplay analysed. This paper proposes a novel distributed measurement and debugging concept for embedded systems where tracing facilities are directly integrated into the network nodes so as to enable and ease failure analysis and detection on all protocol layers.

Many applications such as distributed measurements or real-time networks benefit from a common notion of time. Protocols providing high precision and simple clock synchronization are necessary to achieve such a common time base. However, most of the available protocols are lacking with regard to fault tolerance and performance in case of a fault. The project IMAGINE (introduction of master group based industrial Ethernet) overcomes these limitations by introducing a fault-tolerant IEEE 1588 master group. A proof of concept for a large-or even medium-scale network is, however, very difficult to obtain under laboratory conditions. Therefore, a simulation framework has been developed, which is presented in this paper.

Information transfer is an essential factor in automation systems. For reasons of practicability, the development of industrial communication networks focused on horizontal aspects, i.e., the provision of suitable automation networks on the various levels. Conversely, vertical integration has become a topic of interest only in the recent past and mostly concerns the interconnection of fieldbus systems and IP-based networks. This paper reviews gateway concepts and compares the applicability of the SNMP, LDAP, and OPC (OLE for process control) as higher-level access protocols based on a set of criteria that are relevant for fieldbus/IP gateways. It appears that after years of development, OPC has finally reached a promising state.

In modern communication networks the task of synchronizing the system clock of nodes is of growing interest. Especially in sensor networks synchronized applications are of crucial importance, but a global view of the system status can only be examined if the individual data acquisitions are exactly related to each other. This imposes constraints on the implementation that are rarely discussed. The present work proposes a driver and protocol stack architecture which allows each node to participate in different clock synchronization mechanisms at a time. Further the important problem of hard real-time requirements within the software environment is addressed, including the critical task of detecting missed events and the continuous amortisation of system clock deviations. An insight to realisation is given with a discussion about the implementation study used in the REMPLI (real-time energy management via powerlines and Internet)

Distributed control systems (DCS) have gained huge interest in the automation business. Several approaches have been made which aim at the design and application of DCS to improve system flexibility and robustness. Important approaches are (among others) the holonic manufacturing systems (HMS) and the plant automation based on distributed systems (PABADIS) approach. PABADIS deals with plant automation systems in a distributed way using generic mobile and stationary agents and plug and participate facilities within a flat structure as key points of the developed control architecture. HMS deals with a similar structure, but aims more at a control hierarchy of special agents. This paper gives a description of the PABADIS project and makes comparisons between the two concepts, showing advantages and disadvantages of both systems. Based on this paper, it will be possible to observe the abilities and drawbacks of distributed agent-based control systems.

This paper presents a smart capacitive angle sensor suited for automotive and industrial use. To comply with tough constraints of such applications in terms of environmental conditions, unit costs, and physical size, a fully integrated solution is mandatory. However, the limitations and capabilities of a single mixed-signal integrated circuit have considerable impact not only on the hardware architecture of the digital and analog system components, but also on the feasible measurement algorithm. A thorough investigation of all major nonlinear effects leads to an accurate system-level model of the sensor which is used to design a robust and reliable fully integrated sensor system capable of handling signal offset and amplitude variations. In addition, the proposed system recognizes and reacts on electromagnetic disturbances. Measurements taken from a final prototype comply with the simulation results.

Web-enabled devices are a synonym for smartness and intelligence in automation. Remote access for configuration and maintenance, total quality management, and enhanced user interfaces are only a few benefits. However, the efforts needed to equip a conventional device with a Web interface are often underrated. The goal of this paper is to show the hard- and software requirements for a Web-enabled refrigerator. The case study is based on an embedded controller with built-in Web server. Internet protocol stack, and 10 Mbit Ethernet controllers. The paper discusses hard- and software architecture and gives a detailed overview of the resource consumption of the individual components. We find that even a rudimentary implementation of a Web interface needs a substantial amount of program and data memory.

This article describes the architecture and implementation of two systems on a chip, which support high accuracy clock synchronization over Ethernet networks. The synchronization is based on the SynUTC technology and on the novel IEEE 1588 standard for a precision clock synchronization protocol for networked measurement and control systems. The network interface node on one hand provides all necessary hardware support to be flexibly used in a broad range of applications. The switch add-on on the other hand accounts for the packet delay uncertainties of Ethernet switches and is crucial for high accuracy clock synchronization.

Automated meter reading, energy billing and energy management are applications that are based on and require remote access to control networks. Such applications are intrinsically linked to power-lines and as such suggest using the power distribution grid not only for energy transport but also as the communication medium. This paper describes a data acquisition and control system for energy distribution and consumption using power-lines and IP-based networks for communications. The primary application is meter reading with fine-grained resolution both in time and location of consumption. The paper describes the communication architecture and the services provided by the system and show how the peculiarities of especially the power-line communication influence the design of the interconnection between the two network types. Security aspects of the system are also discussed.

Today's smart sensors allow for the implementation of ample computing resources to improve their performance without increasing chip area and thus production costs significantly. What makes them more complex and at first sight less robust is in fact also a chance to improve their fault tolerance. In this paper we present a fault analysis for a capacitive angular sensor designed for automotive applications. Based on the assessment of potential faults and effects degrading the performance, we discuss constructive and operative measures and design decisions that have been taken to enhance the robustness of the system. A key component is a self-calibrating carrier frequency measurement principle, which is used to compensate common drift effects as well as to filter out electromagnetic disturbances. Electrical faults can be detected and lead to a fail stop behavior of the system. It is shown how these fault tolerance mechanisms are implemented in both a passive (i.e., by virtue of system design) and active way through appropriate data processing algorithms. The results of the case study are considered typical for capacitive sensors, but seem applicable also to similar problems.

Much work is in progress in order to improve acceptability, effectiveness and service of modern production systems. This is particularly true when ecology and the new e-business constraints are considered. Within this framework, the use of software agents in factory automation is a rather new topic. We present the EC-funded PABADIS project, which aims at employing partially mobile software agents to facilitate production planning and eliminate constraints of the traditional centralized approach. To this end, actual production units need to be equipped with appropriate agent platforms, which in turn must have access to a control device to allow for vertical integration. We discuss design options for these interconnections, which effectively have gateway functionality. The still ongoing project is expected to contribute to meeting the requirements of the next generation of production systems.

Gateway interconnections between fieldbus systems and IP-based LANs are becoming increasingly popular, which raises security questions. We discuss methods to secure a gateway and present two different ways to apply appropriate authentication and encryption mechanisms. Furthermore, we propose an organizational concept that is suitable for the management of authorization keys. The favored means to store and distribute the keys is smart cards; however, a scheme based on user-names and passwords is also presented as a fall-back solution with restricted access rights. Performance measurements confirm that the smart card approach is more time-consuming, but acceptable for small data packets.

Reliable real time data transmission ought to be able to tolerate both transient faults and line failures. The former are readily dealt with by employing appropriate error control coding, whereas the latter require multiple transmission lines. The conventional approach is to use one active and several standby channels. However, utilizing all available channels through multiple feeding and implementing active redundant receivers allows instantaneous recovery from line failures. We investigate such receiver structures for a data transmission system based on a double-error correcting BCH-code with underlying Manchester line coding and three parallel data links. Different approaches for implementing majority voting strategies are compared with respect to overall error handling capabilities. As a result we will propose an optimal structure called majority Manchester decoder requiring only moderate implementation overhead.