Industrial automation based on cyber-physical systems technologies: Prototype implementations and challenges

Cyber-Physical Systems (CPS) is an emergent approach that focuses on the integration of computational applications with physical devices, being designed as a network of interacting cyber and physical elements. CPS control and monitor real-world physical infrastructures and thus is starting having a high impact in industrial automation. As such design, implementation and operation of CPS and management of the resulting automation infrastructure is of key importance for the industry. In this work, an overview of key aspects of industrial CPS, their technologies and emerging directions, as well as challenges for their implementation is presented. Based on the hands-on experiences gathered from four European innovation projects over the last decade (i.e. SOCRADES, IMC-AESOP, GRACE and ARUM), a key challenges have been identified and a prioritization and timeline are pointed out with the aim to increase Technology Readiness Levels and lead to their usage in industrial automation environments.The authors would like to thank for their support the European Commission, and the partners of the EU FP6 SOCRADES (www.socrades.net), EU FP7 GRACE (www.grace-project.org), EU FP7 IMC-AESOP (www.imc-aesop.eu) and EU FP7 ARUM (www.arum-project.eu) projects, for their fruitful support and discussions.info:eu-repo/semantics/publishedVersio

An approach to the formal specification of holonic control systems

In the manufacturing world, globalisation leads to a trend towards the reduction of batches and product life cycle, and the increase of part diversity, which are in conflict with other requirements, such as the cost reduction achieved with higher productivity. Thus, the challenge is to develop flexible, agile and intelligent management and control architectures that satisfy the referred requirements. The holonic manufacturing and the agent-based manufacturing approaches allow a new approach to the manufacturing problem, through concepts such as modularity, decentralisation, autonomy and re-use of control software components. ADACOR, one of the holonic architectures recently proposed, defines a set of autonomous and intelligent holons aiming to improve the performance of control system in industrial scenarios characterised by the frequent occurrence of unexpected disturbances. The formal modeling and validation of the specifications of the ADACOR-holons and of the interactions between these holons to implement the manufacturing control functions is of critical importance. In this paper, a formal methodology is introduced and applied to model the dynamic behaviour of the ADACOR-holon classes

Petri net-based approach for web service automation resource coordination

In industrial automation, control systems and mechatronic devices are from diverse nature, supplied by different manufacturers and made of different technologies. The adoption of web services principles in an automated production system satisfies some requirements, namely the interoperability of such heterogeneous and distributed environments and the basis for flexibility and reconfigurability. Manufacturing processes require to access resources at different precedence levels and time instances, but in the other way resources may also be shared by different processes. A major challenge is then how individual services may interact, coordinating their activities. Petri nets may be used to describe complex system behaviour and therefore also applied to coordinate such systems. The paper introduces a Petri net based approach for the design, analysis and coordination of systems developed using web services to represent individual and autonomous resources. For this purpose, it is presented a Petri nets computational tool to support the design, validation and coordination of web service based automation systems.info:eu-repo/semantics/publishedVersio

Service-oriented control architecture for reconfigurable production systems

Evolvable and collaborative production systems are becoming an emergent paradigm towards flexibility and automatic re-configurability. The reconfiguration of those systems requires the existence of distributed and modular control components that interact in order to accomplish control activities. This paper focuses on service-oriented production systems, which behavior is regulated by the coordination of services that are provided and required by control components with different roles. Internally, these components are independent of the implementations, but an internal modular and event based structure is presented. Individual control and interaction is achieved by using embedded or inter-service control processes for which High-Level Petri Nets are proposed. Supporting the predefined control, decision support systems are used to provide conflict resolution and other decision-making functions

Energy aware knowledge extraction from Petri nets supporting decision-making in service-oriented automation

This paper introduces an approach to decision support systems in service-oriented automation control systems, which considers the knowledge extracted from the Petri nets models used to describe and execute the process behavior. Such solution optimizes the decision-making taking into account multi-criteria, namely productive parameters and also energy parameters. In fact, being manufacturing processes typically energy-intensive, this allows contributing for a clean and saving environment (i.e. a better and efficient use of energy). The preliminary experimental results, using a real laboratorial case study, demonstrate the applicability of the knowledge extracted from the Petri nets models to support real-time decision-making systems in service-oriented automation systems, considering some energy efficiency criteria

Process optimization of service-oriented automation devices based on Petri nets

Best paper award.This paper introduces a novel method for the specification and selection of criteria-weighted operation modes for the orchestration of services in industrial automation using Petri nets. The objective is to provide to the internal decision support system of a service-oriented automation device or of another applicable computational system the capability to select the best path in a Petri net orchestration model considering different criteria to evaluate the quality of services, such as the time, energy efficiency and reliability. The transition-invariants obtained from the Petri net represent the set of possible modi operandi and these are then weighted with decision criteria. The result will be afterwards evaluated in order to select the optimal modus operandi to be executed by the device. Based on the experiments, this method permits the dynamic optimization of processes in real-time, considering available parameters from devices and other resources.The authors would like to thank the European Commission and the partners of the EU FP6 project “Service-Oriented Cross-layer infrastructure for Distributed smart Embedded devices” (SOCRADES) and the EU FP7 project “Cooperating Objects Network of Excellence” (CONET) for their support

Service-oriented SCADA and MES supporting petri nets based orchestrated automation systems

The fusion of mechatronics, communication, control and information technologies has allowed the introduction of new automation paradigms into the production environment. The virtualization of the production environment facilitated by the application of the service-oriented architecture paradigm is one of major outcomes of that fusion. On one side, service-oriented automation works based on exposition, subscription and use of automation functions represented by e.g. web services. On the other side, the evolution of traditional industrial systems, particularly in the production area, as a response to architectural and behavioural (functional) viewpoints of the ISA95 enterprise architecture, where a close inter-relation between SCADA, DCS and MES systems facilitate the management and control of the production environment. Automation functions are increasingly performed by the composition and orchestration of services. Among other methods, the application of formal Petri net based orchestration approaches is being industrially established. This paper presents the major characteristics that such a Petri net based orchestration presents when it is developed, implemented and deployed in an industrial environmentThe research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 258682 (IMC-AESOP: ArchitecturE for Service-Oriented Process - Monitoring and Control) and 224053 (CONET: Cooperating Objects NETwork of excellence)

Composition of Petri nets models in service-oriented industrial automation

In service-oriented systems, composition of services is required to build new, distributed and more complex services, based on the logic behavior of individual ones. This paper discusses the formal composition of Petri nets models used for the process description and control in service-oriented automation systems. The proposed approach considers two forms for the composition of services, notably the offline composition, applied during the design phase, and the online composition, related to the synchronization of Petri nets models on the fly. An experimental case study is used to illustrate the proposed composition approach.The authors would like to thank the European Commission and the partners of the EU FP6 project “Service-Oriented Cross-layer infrastructure for Distributed smart Embedded devices” (SOCRADES) and the EU FP7 project “Cooperating Objects Network of Excellence” (CONET) for their support

Service-oriented process control using high-level petri nets

Service-oriented systems constitute a suitable approach for the development of modular, flexible and reconfigurable production systems, addressing the current requirements imposed by global markets. This paper focuses on the process control of Service-oriented production systems, whose behavior is regulated by the coordination of services that are available from distributed modular and collaborative control components. The proposed control is based on a kind of High-level Petri Nets tailored for the description, connection and synchronization of different concurrent processes. Several features can be distinguished by this approach, since its modularity, control reusability, flexibility and other valuable inherited characteristics from the proposed High-Level Petri Nets

Customizable service-oriented Petri net controllers

In industrial automation, service-orientation is a relatively new and ascending concept and thus, concrete integrated methodologies are missing to accomplish the required development tasks. A suitable approach is to use the powerful set of features that Petri nets formalism provides for such dynamic systems. This paper presents a token game template that is part of the open methodology for the development of customized Petri nets controllers, targeting the engineering of service-oriented industrial automation. This template is based on a state machine specification for the life-cycle of transitions that leaves several options open for extending it with features depending on the application. The practical use and implementation should bring, among others, featured-full and integrated modeling, analysis and control capabilities, which is required by service-oriented ecosystems. This core structure was used and validated in the development of control applications for an industrial automation system.The authors would like to thank the European Commission and the partners of the EU IST FP6 project “Service-Oriented Cross-layer infrastructure for Distributed smart Embedded devices” (SOCRADES), the EU FP6 “Network of Excellence for Innovative Production Machines and Systems” (I*PROMS), and the European ICT FP7 project “Cooperating Objects Network of Excellence” (CONET) for their support