Factory Automation Systems Research Articles

Synthesis of resilient fallback control system under cyber-attacks via supervisory control

Industrial control systems (ICS) require system design and operation under cyber-attacks. This study aims to design a fallback control system that can switch from normal control to fallback control and verify its superiority. The target system is a factory automation (FA) system consisting of a normal programmable logic controller (PLC) and a fallback PLC. In this system, we design a fallback logic that takes over control in the case of cyber-attacks. The design of this logic requires a system model that manages smooth state transitions between normal control and fallback control in an integrated manner under cyber-attacks. In response, we model a control program in the framework of discrete event systems (DESs) and apply supervisory control to derive a supervisor model that can manage the system in an integrated manner. To ensure the controllability of the FA system during cyber-attacks, we design a control specification that includes a detection function to enable rapid switching of the control state. As a result, we generate the fallback logic from the supervisor model with guaranteed controllability under cyber-attacks and implement it in a fallback PLC to verify the effectiveness of the proposed logic.

Adaptation of the Four Levels of Test Maturity Model Integration with Agile and Risk-Based Test Techniques

Many projects that progress with failure, processes managed erroneously, failure to deliver products and projects on time, excessive increases taking place in costs, and an inability to analyze customer requests correctly pave the way for the use of agile processes in software development methods and cause the importance of test processes to increase day by day. In particular, the inability to properly handle testing processes and risks with time and cost pressures, the differentiation of software development methods between projects, the failure to integrate risk management, and risk analysis studies, conducted within a company/institution, with software development methods also complicates this situation. It is recommended to use agile process methods and test maturity model integration (TMMI), with risk-based testing techniques and user scenario testing techniques, to eliminate such problems. In this study, agile process transformation of a company, operating in factory automation systems in the field of industry, was followed for two and a half years. This study has been prepared to close the gap in the literature on the integration of TMMI level 2, TMMI level 3, and TMMI level 4 with SAFE methodology and agile processes. Our research has been conducted upon the use of all TMMI level sub-steps with both agile process practices and some test practices (risk-based testing techniques, user scenario testing techniques). TMMI coverage percentages have been determined as 92.85% based on TMMI level 2, 92.9% based on TMMI level 3, and 100% based on TMMI level 4. In addition, agile process adaptation metrics and their measurements between project versions will be shown, and their contribution to quality will be mentioned.

Intelligent Machinery Product Service Blueprint Development and Verification: An Empirical Study of Machine Tool Industry

Integrating of products and services is regarded as an effective strategy to meet the rapidly changing needs of customers and to create more value for customers. The academic community is also paying more and more attention to the study of product and service integration. In order to verify whether the development of the product service blueprint is suitable for the machine tool industry, this study is divided into four sub-studies, namely service attributes analysis, service requirement analysis, service innovation modeling, and service establishment and validation. Through qualitative and quantitative study and design, product service blueprints of universal standard machines, customized special machines, and composite machining machines for metal deposition are constructed in this study. At the same time, the three dimensions of smart manufacturing of machine tools are constructed in this study, namely virtual factory design and automation system integration, massive data and cloud computing, and smart systems and smart devices. Furthermore, the reliability, validity and importance of the development of new services in this study have been verified.

Mathematical modeling on application of wireless networks for industrial automation-factory automation

Since traditional automation relies on wires, the machines’ versatility will be restricted. Thus maintenance is required to prevent cable wear and breakage, which would be costly and highlighted the importance of wireless connectivity in overcoming some of the limitations of conventional factory automation. Moreover, two of the most critical considerations, reliability and latency, need to be fulfilled so that a factory automation system can perform flawlessly. However, in factory automation, 0ms is the perfect condition since many machines share the same network. Furthermore, it can only reduce latency to a certain extent but not to zero. This study focuses on wireless networks for Industrial Automation Factor Automation’s system architecture, including network devices and topology, and then demonstrates one of the wireless networks’ main technologies, retransmission. This paper develops a mathematical analysis based on Negative Acknowledgement (NACK)-based retransmission mode as default retransmission for field devices to send data frames to the gateway device periodically. The results demonstrate an automatic on-demand retransmission (AODR) scheme able to provide higher efficiency of retransmission rate.

Sistem Otomatisasi Plant Factory dengan Tiga Jenis Tanaman Sayuran Berbeda Berbasis Mikrokontroler dan Android

Plant Factory is a technology concept that facilitates the formation of an environment that is suitable and good for plant growth, easy to control, does not require a large area of land, and is applied indoors so that it is not affected by outdoor weather conditions. Therefore created a system that automatically controls and monitors environmental conditions such as temperature, humidity and light. This system uses Arduino mega 2560 as a microcontroller, DHT22 temperature and humidity sensors to assess room temperature and humidity, RTC as an indicator of plant irradiation time, a micro SD module as data storage for sensors and actuators, and a Bluetooth module as a medium for data transmission. This actuator consists of a fan to control temperature, a humidifier to control humidity and an LED as a substitute for lighting plants. There are three plants as samples for testing the Plant Factory system, namely spinach, lettuce and mustard greens with each Plant Factory system for these plants. All temperature, humidity and actuator conditions can be monitored via the Android application. The plant factory automation system with three types of vegetable plants based on microcontroller and android is successfully running according to its function.

Dynamic Automobile Assembly Process using IOT

In the wake of #AtmanirbharBharat and #MakeInIndia planks, there is a huge thrust to Manufacturing. This paper focuses on the Automobile Manufacturing process, enabling a customizable product, vis-a-vis a rigid Manufacturing process developed as per Industry 4.0 principles aided by IOT (Internet of Things) tools. The solution proposes to modularize entire Automobile Production/ Assembly Process, which simulates the whole process of the delivery to every customer through to the Manufacturer facilitates highly customized products based on dynamic user choices. Seamless integration of Networked Production Components is realized by building interfaces between existing ERP systems and MES (Manufacturing Execution Systems). The system adopts M3 - Modular Manufacturing Mode, via Wireless Networks for Industrial Automation - Factory Automation (WIA-FA) and Dynamic Control System, to Manufacture and Maintain Automobile Products at Scale. Proposed approach also improved Production Equipment utilization. Another aspect of this approach is flexibility of the Production/ Assembly Processes to enable high customization in product specification

The Impact of Rate Adaptation Algorithms on Wi-Fi-Based Factory Automation Systems.

Factory automation systems based on the IEEE 802.11 Wi-Fi standard may benefit from its Multi-Rate Support (MRS) feature, which allows for dynamically selecting the most suitable transmission rate for the targeted application context. The MRS is implemented by means of rate adaptation algorithms (RAAs), which has already demonstrated to be effective to improve both timeliness and reliability, which are typically strict requirements of industrial real-time communication systems. Indeed, some of such algorithms have been specifically conceived for reliable real-time communications. However, the computational complexity of such algorithms has not been effectively investigated yet. In this paper, we address such an issue, particularly focusing on the execution times of some specific rate adaptation algorithms, as well as on their impact on the automation tasks. In this respect, after a formal description of the algorithms, we present the outcomes of an extensive experimental session, which includes practical measurements and realistic simulations. The obtained results are encouraging, since the measured execution times indicate that rate adaptation algorithms can be profitably adopted by industrial automation systems, allowing for improving their reliability and timeliness without impacting on the overall performance.

Real-time networks and protocols for factory automation and process control systems [scanning the issue

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 and Their Future Challenges: Next-Generation Ethernet, IIoT, and 5G

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.

Coexistence Standardization of Operation Technology and Information Technology

In factory automation (FA) and process control, networks and protocols of the operation technology are more and more merged with those of the information technology (IT). The requirements of operational technology (OT) and IT are different. Modern networks and protocols for communication in FA and process control systems must take care of the coexistence and convergence between the IT and OT worlds. Due to historical developments, the standards for OT were and remain defined by the International Electrical Commission. The IT, on the other hand, is the domain of the International Telecommunication Union and the International Standard Organization (ISO), which takes over most of the standards in the communication field from the IEEE Standard groups 802. This paper provides an overview of the standardization bodies involved and provides examples on how different requirements introduced by OT and IT can coexist. The merging of OT and IT on an Ethernet network with time-sensitive networking is the key technology for real-time applications in the factory floor. The adoption of the industrial protocol OPC UA provides secure connections from the factory floor to automation cloud infrastructures. IO-Link wireless, as new standard for sensors and actuators in OT, provides coexistence mechanisms toward wireless standards in IT applications such as IEEE 802.11. These examples show that there are possibilities to coexist and even to merge the standards and technologies of OT and IT in a successful way.

WIA-FA and Its Applications to Digital Factory: A Wireless Network Solution for Factory Automation

Intelligent factory automation systems strongly rely on industrial wireless control networks which have to ensure timely and reliable data exchange among their components. This paper presents a comprehensive survey on recently approved International Electrotechnical Commission standard Wireless networks for Industrial Automation–Factory Automation (WIA-FA). This paper first introduces the system architecture of WIA-FA including network device, network topology, and system management, and then illustrates WIA-FA protocol stack and key technologies. Furthermore, two WIA-FA testbeds are described to demonstrate the high performance of WIA-FA. After that, three examples of practical applications are provided in this paper. One application deploys a WIA-FA network to monitor and control industrial robots in a digital workshop. The second application adopts the deployment of WIA-FA as a real-time wireless network that connects automated guided vehicles (AGVs) in a logistic sorting system. The last application coordinates multiple cooperative AGVs via the WIA-FA network to carry large and complex components. Finally, the open issues and future directions for WIA-FA networks are presented.

Co-design of safe and efficient networked control systems in factory automation with state-dependent wireless fading channels

In factory automation, heterogeneous manufacturing processes need to be coordinated over wireless networks to achieve safety and efficiency. Wireless networks, however, are inherently unreliable due to shadow fading induced by the physical motion of the machinery. To assure both safety and efficiency, this paper proposes a state-dependent channel model that captures the interaction between the physical and communication systems. By adopting this channel model, sufficient conditions on the maximum allowable transmission interval are derived to ensure stochastic safety for a nonlinear physical system controlled over a state-dependent wireless fading channel. Under these sufficient conditions, the safety and efficiency co-design problem is formulated as a constrained cooperative game, whose equilibria represent optimal control and transmission power policies that minimize a discounted joint-cost in an infinite horizon. It is shown that the equilibria of the constrained game are solutions to a non-convex generalized geometric program, which are approximated by solving two convex programs. The optimality gap is quantified as a function of the size of the approximation region in convex programs, and asymptotically converges to zero by adopting a branch-bound algorithm. Simulation results of a networked robotic arm and a forklift truck are presented to verify the proposed co-design method.

Multiagent Gathering With Collision Avoidance and a Minimax Distance Criterion—Efficient Algorithms and Hardware Realization

Multiple autonomous agents working cooperatively have contributed to the development of robust large-scale systems. While substantial work has been done in manufacturing and domestic environments, a key consideration for small hardware agents engaged in collaborative factory automation and welfare support systems is limited area and power on-board. When the agents attempt to meet for performing a task, it is natural for them to encounter obstacles and it is desirable for each agent to optimize its resources during its navigation. In this paper, we develop efficient geometric algorithms to find a point, termed as the gathering point (and denoted by $P_G$ ), for the agents that minimizes the maximum of path lengths . In particular, we present an $O(n \log _2 n)$ time algorithm for calculation of $P_G$ for an environment with two agents and $n$ static polygonal obstacles. We then use the notion of a weighted minimax point to derive an efficient algorithm (with complexity of $O(k^2 + kn \log _2 n)$ ) for computing $P_G$ for an environment with $k$ agents and $n$ obstacles. An enhancement to a dynamic environment is then presented. We also present details of an efficient hardware realization of the algorithms. Each agent, equipped with only an ATmega328P microcontroller and no external memory, executes the algorithms. Experiments with multiple agents navigating amidst static as well as dynamic obstacles are reported.

A Group-Oriented DTLS Handshake for Secure IoT Applications

The datagram transport layer security (DTLS) is a de facto standard for the end-to-end security of the constrained application protocol (CoAP) that defines the following three security modes: preshared key (PSK), raw public key, and certificate. The pros and cons of each security mode are obvious. Even though the PSK mode is the most preferable in terms of the performance of the DTLS handshake, the in-advance distribution of a unique symmetric key for each pair of endpoints is difficult as the number of pairs increases. Alternatively, the certificate mode provides a convenient key-management functionality but its performance is very poor. The focus of most of the previous works is the reduction of the computational load for a single DTLS handshake that is induced by the certificate mode. In this paper, a group-oriented end-to-end security is considered, together with the introduction of a new security mode. Namely, a security association is established between a CoAP client and a group of CoAP servers (sensor devices); however, a fine-grained access control can be enforced so that each CoAP client can access a limited number of CoAP servers in the group. Furthermore, when each CoAP client performs several DTLS handshakes with the CoAP servers in the group, the first DTLS handshake involves a single public-key operation. A public-key operation, however, is not required for the subsequent DTLS handshakes, so the overall computational burden can be reduced. Also, a testbed was established along with the implementation of the proposed security mechanism for the conduction of a performance comparison with the other security mechanisms. Note to Practitioners —Datagram transport layer security (DTLS) is a standards-based security protocol to secure communications in an IoT environment, including home, factory, or building automation systems. However, to develop a practical security solution based on DTLS, several assumptions inherent to DTLS need to address the practical requirements of various IoT scenarios. Furthermore, some barriers associated with implementing DTLS in an IoT environment should be overcome. This paper presents an interface to extend the basic security functionalities provided by DTLS. Through the interface, a general security platform can be constructed and combined with DTLS. Hence, fine-grained access control and group security can be merged with DTLS, together with standards compliance.

A Calibrated Test-Set for Measurement of Access-Point Time Specifications in Hybrid Wired/Wireless Industrial Communication †

In factory automation and process control systems, hybrid wired/wireless networks are often deployed to connect devices of difficult reachability such as those mounted on mobile equipment. A widespread implementation of these networks makes use of Access Points (APs) to implement wireless extensions of Real-Time Ethernet (RTE) networks via the IEEE 802.11 Wireless LAN (WLAN). Unfortunately, APs may introduce random delays in frame forwarding, mainly related to their internal behavior (e.g., queue management, processing times), that clearly impact the overall worst case execution time of real-time tasks involved in industrial process control systems. As a consequence, the knowledge of such delays becomes a crucial design parameter, and their estimation is definitely of utter importance. In this scenario, the paper presents an original and effective method to measure the aforementioned delays introduced by APs, exploiting a hybrid loop-back link and a simple, yet accurate set-up with moderate instrumentation requirements. The proposed method, which requires an initial calibration phase by means of a reference AP, has been successfully tested on some commercial APs to prove its effectiveness. The proposed measurement procedure is proven to be general and, as such, can be profitably adopted in even different scenarios.

Supporting semi-automatic co-evolution of architecture and fault tree models

During the whole life-cycle of software-intensive systems in safety-critical domains, system models must consistently co-evolve with quality evaluation models like fault trees. However, performing these co-evolution steps is a cumbersome and often manual task. To understand this problem in detail, we have analyzed the evolution and mined common changes of architecture and fault tree models for a set of evolution scenarios of a part of a factory automation system called Pick and Place Unit. On the other hand, we designed a set of intra- and inter-model transformation rules which fully cover the evolution scenarios of the case study and which offer the potential to semi-automate the co-evolution process. In particular, we validated these rules with respect to completeness and evaluated them by a comparison to typical visual editor operations. Our results show a significant reduction of the amount of required user interactions in order to realize the co-evolution.

Integración Vertical en plantas industriales utilizando OPC UA e IEC-61499

Los sistemas de automatización industrial actuales tienen que hacer frente a los desafíos que surgen al tratar de solventar las necesidades generadas por un mercado altamente competitivo. Estos desafíos conducen a la utilización de una nueva generación de sistemas de automatización basado en los denominados Sistemas Ciber-físicos de Producción (CPPS – Cyber-Physical Production Systems). Los CPPSs permiten la integración de sistemas de adquisición de datos tradicionales y novedosos sistemas de procesamiento inteligente de datos, con el objetivo de extraer información y mejorar el rendimiento general del sistema productivo. Para lograrlo, es necesario cerrar la brecha existente entre los sistemas de control y los niveles superiores. Este trabajo propone una aproximación en el desarrollo de aplicaciones bajo la norma IEC-61499 para el intercambio de datos entre el nivel de planta y las capas más altas empleando el estándar industrial OPC UA. La comunicación OPC UA ofrece mecanismos de suscripción que permiten una integración eficiente y sencilla de recursos que residen en diferentes dispositivos. Además, dado que la arquitectura OPC UA permite su ejecución incluso en dispositivos empotrados, la propuesta aportada en este artículo permite adquirir información de la planta empleando arquitecturas de bajo coste, al mismo tiempo que se posibilita un diseño basado en componentes con independencia de la plataforma hardware utilizada.

設備構造およびサービス識別子の構造化による一元的な制御設備管理の効率化

It is said to be coming the era of "Internet of things" (IoT). In this field, various things connect to the network. In addition, the using of IoT is rapidly becoming the most popular concepts in the industry of Factory Automation and Control System Management. IoT concept makes a new opportunity on analyzing and intelligent component packages. However, the IoT concept caused the problem of the management for consistent identifiers. To solve this problem, we propose two techniques. The first technique is "Structured ID" that is able to define complicated structure of control systems using IDs on tree structure. The second technique is "Relational link" that is able to describe meaning for subset of structured IDs. Our proposal techniques reduced the development cost of control system manager to 1/3. Additionally, we are providing two products using these techniques.

Manufacturing System Upgrade with Wireless and Distributed Automation

This paper presents a case study of developing a distributed factory automation system model upgrade with decentralized control deployed on a network of six programmable automation controllers communicating wirelessly. The goal is to develop a distributed system which is flexible enough, and easier to reconfigure with on-the-fly online software updates in a smart factory automation environment. Our approach benefits mainly production industries which require a robust and modular software design requiring less effort for their production line. The developed solution aims at flexibility, re-configurability, ease of maintenance and reduced downtime costs.

Cloud computing as a facilitator for web service composition in factory automation

Cloud computing is an information technology paradigm enabling companies to sell computing resources more dynamically. Software and hardware are now commodities leased on demand. Because computer systems leased from a cloud service provider, virtual machines, are typically connected to internet, they can host web services, which are frequently components of service oriented architectures (SOAs). Such architectures have recently been adopted in factory automation, as they allow systems to reach high levels of decentralization and loose-coupling. SOA-based Factory automation systems combine physical production equipment with web services that belong to the information processing (cyber) domain, and they are therefore highly cyber-physical. When some of the services are deployed on cloud resources, SOA-based factory automation systems can be classified cloud-based cyber-physical systems. Each service in such a system is typically able to perform rather simple, atomic operations, whereas achievement of complex goals requires that the services be composed to collaboratively carry out workflows. This article investigates the use of cloud resources in automatic service workflow composition. To facilitate the acquisition and utilization of cloud resources, a system of two specialized web services is proposed. The system includes a web service that dynamically deploys virtual machines to carry out planning processes, thereby exhibiting artificial intelligence. Finally, this paper demonstrates the integration of the system with a previously proposed semantic web service composition framework.