Reijo Tuokko

An IEC 61499 application generator for scan-based industrial controllers

In order to cope with todays market uncertainties, manufacturing is required to rapidly adapt and react to changes and unpredictable scenarios. These are currently among the main research and development topics in order to reveal new approaches and methodologies to achieve these goals. The Industrial Electrotechnical Commission (IEC) created the IEC 61499 (function block) standard. This standard proposes an open architecture for distributed industrial-process measurement and control systems (IPMCS). The IEC 61499 defines the basic concepts and methodology for the design of modular reusable distributable systems, and paves the way for the new reconfigurable and flexible manufacturing. This paper presents the development of a software tool (IEC 61499 application generator) that enables the deployment of IEC 61499 applications to scan-based embedded controllers. However, the IEC 61499 standard foundations rely on an event-based model. The paper describes an approach to implement an event-based architecture on a scan-based industrial controller.

Formal validation of intelligent-automated production systems: towards industrial applications

This paper introduces a framework for formal modelling and validation of automation systems destined to be used directly by control engineers. The framework is based on a modelling formalism of Net Condition/Event Systems (NCES), which is graphical, modular and typed. This allows for the modelling of realistic hierarchically organised automation systems in a closed plant-controller loop. The framework consists of methodologies and tools, which enable formal analysis of automation systems. The framework is to be used for the improvement of safety characteristics, reliability and robustness of such systems by means of prediction of potential faults and deadlocks.

Possibilities of a Microfactory in the Assembly of Small Parts and Products - First Results of the M4-project

The research in mini, micro and desktop factories originates from early 90s and has continued since then by developing the technological basis and different technological building bricks and applications in the field of high-precision manufacture and assembly of future miniaturized and micro products. This has paved the way to mini, micro and desktop factories which are seen as one potential solution for that kind of production by improving space, energy and material resource utilization and answering to the needs of design for postponement and customer-close customization and personalization. The research efforts done during these years are now increasingly leading also to commercialization and real industrial applications. The objective of this paper is to present an overview of the international microfactory research and to introduce in more detail the modular microfactory concept developed in the M4-project.

Emplacement and Blue Print – An Approach to Handle and Describe Modules for Evolvable Assembly Systems

Abstract Todays production systems have presently continuous changes like load variations, new products, faults, change of process modules, etc. which require new methods to react to them quicker, sustainable and more automatically. In order to answer these requirements, the paper presents as one corner stone of the solution, a concept called Emplacement to describe, manage and use the information of process equipment in modular and reconfigurable production systems like Evolvable Assembly Systems. First the paper introduces the concept and presents the key components. It discusses also how the concept addresses the specific requirements of systems in scope. Second the implementation of the concept is presented as two standardised, XML based file formats – Emplacement and Blue Print – were developed for electronic module description. The description delivers the virtual representation of the module including information like interfaces, skills, properties (business and technical), CAD models, datasheets, etc. The interconnection between and details of these languages are discussed. Finally a case study making use of the developed languages is briefly introduced.

Process planning based on feature recognition method

Managing and controlling very complex manufacturing systems and vast volumes of accumulate knowledge, holonic manufacturing system is developed. This paper introduces a method, which utilizes feature-based modeling for defining a pre-process plan. The pre-process plan developed can be linked in a holonic system. This paper, the generic steps for making a product are called “pre-process plan”. The pre-process plan defines the required capabilities on a high level. All the resources have some sort of capability that represents the possible candidates for the product manufacturing. The feature recognition method offers geometric and non-geometric (such as shape, type, tolerance and material) information. Using feature information a pre-process plan can be defined. The fact that the pre-process plan does not strictly define the used processing methods allows the product to be manufactured on different machines based on their availability or other criteria. This is important in dynamic, adaptive production environment.

Presenting capabilities of resources and resource combinations to support production system adaptation

Todays turbulent production environment calls for adaptive and rapidly responding production systems that can adjust to required changes both in production capacity and processing functions. This kind of adaptivity can not be reached without intelligent methods and tools supporting the adaptation planning and deployment of the systems. This paper introduces novel method to present and manage capabilities of production resources and combined capabilities of multiple co-operating resources. This modeling approach enables matching of products and resources based on their required and provided capabilities and this way supports rapid allocation of resources.

Emplacement and Blue Print – Electronic Module Description Supporting Evolvable Assembly Systems Design, Deployment and Execution

The assembly systems need to react frequently on everyday changes like introduction of new products and variants, load variations, change of process modules, etc. In order to answer these challenges more effectively, quickly, automatically and with sustainability, new methods are required. The paper proposes as one basic part of the solution a concept called Emplacement to specify, manage and use the information of process equipment in modular, reconfigurable and agile systems like Evolvable Assembly Systems. First part of the paper presents shortly the framework where the proposed concept can be applied in the phases of systems design, deployment and execution. The essential is the link between the assembled product and equipment module through the processes combining the two former. The second and main part focuses on introduction of the Emplacement concept itself. The concept has three main components – Emplacement, Blue Print and History Container – providing the electronic description of a module in XML based format. The first two are standardised and they provide the virtual representation of the production modules including essential information like mechatronics interfaces, capabilities i.e. skills, properties (both business and technical), CAD models, datasheets, etc. The interconnection between and details of these languages are discussed in the following chapters.

Application of UML in plant modeling for model-based verification: UML translation to TNCES

There do exist dozens of formal languages and formalisms that may be used for modeling different phenomena of real world. The time for industrial acceptance of a certain language is directly proportional to the complexity of the language. In our work we apply timed net condition/event systems (TNCES) formalism for modeling a closed loop system depicting interconnected controller and controlled plant. We hope to increase the method adoption by applying a Unified Modeling Language (UML) for plant modeling. UML is well-developed language supported by a number of tools. This paper gives general details on the approach to the formal validation and verification of industrial systems and presents the translation procedure of UML to TNCES.

Logistic and control aspects for flexible and reactive micro and desktop assembly at the factory level

In addition to micro assembly and micro manufacturing micro factories are currently widely studied around the world. However, the research is typically focusing on single machines and not so much on integration of single processes and machines into wider process chains and larger systems with integrated material logistics. This paper discusses issues related to realization of a larger scale integrated micro factory for assembly of multi-part products. Special attention is paid on the logistical aspects and control concepts supporting flexibility and dynamic reconfigurability of the system. A scenario of a microfactory system as a holonic manufacturing system enabling reactivity of the system to sudden changes and failure situations is also presented.

Modelling and Verification of PLC-Based Systems Programmed with Ladder Diagrams

Abstract This paper reports the results on verification of automation software systems that were developed during MOVIDA1 project. In particular, PLC-based control systems implemented in Ladder Diagrams (LD) were modelled and verified. A formalism of Net Condition/Event Systems, derived from Petri Nets, was applied to model both the behaviour of a PLC (programmed in ladder logic) and the dynamics of the controlled plant. A model-checking was applied to verify system properties. Software tools supporting model generation from the source code automate the process of model generation and verification. The paper describes the details of modelling of ladder logic structures and an example of the model-checking application for verification of programmable control systems.