Anna Valente

An approach to design and develop reconfigurable control software for highly automated production systems

The current work outlines a comprehensive development approach to support the realisation of innovative reconfigurable factory control software from the preliminary design to its deployment in the shop floor. The proposed method consists of three major steps: control conceptual design, application development and evaluation of solution robustness. The innovation features of the proposed control development approach rely upon the integration of reconfiguration policies in the distributed automation infrastructures based on standard IEC 61499. The benefits of the proposed approach have been assessed with regard to an industrial application dealing with the manufacturing of personalised footwear goods.

Holistic Approach for Jointly Designing Dematerialized Machine Tools and Production Systems Enabling Flexibility-Oriented Business Models

Machine tools and production systems are traditionally designed in two separate stages, thus severely penalize the possibility to match customer production requirements. This work introduces the concept of dematerialization for machine tools and systems whose design principles answer to energy savings and cutting edge performance requirements across their lifecycles. The proposed approach consists of four main steps: new business total-life cycle services, design of dematerialized machine tools, process planning and configuration of production system solutions. The benefits coming from the adoption of machine and system dematerialization strategy have been addressed with reference to an industrial case study.

Design and implementation of a distributed part-routing algorithm for reconfigurable transportation systems

The reconfigurability feature represents an instrumental characteristic for manufacturing systems that are required to frequently adapt the architecture and functionalities to match evolving production environment where changes of product variants and demand volumes frequently occur. Transportation systems embrace a major industrial application of the reconfiguration concept. Reconfigurable transportation systems (RTSs) are conceived as multiple independent modules to implement alternative inbound logistic systems’ configurations. Together with mechatronic interfaces and distributed control solutions, the full exploitation of reconfigurability strategies for transportation systems relies upon flexible production management policies. This enables the dynamic computation of part routings in RTSs after every reconfiguration and change in the way transportation modules are exploited. The current work proposes an innovative agent-based algorithm that combines global and local optimisation criteria to manage the part flow in RTS. The proposed approach is designed as fully distributed across transportation modules; based on current RTS’ topology and status, it ensures the autonomy in selecting routing decisions while embracing global and local evolving optimisation strategies. The benefits of the approach have been investigated with reference to a set of realistic RTS topologies exhibiting different routing options, in order to assess the algorithm under different part-routing conditions.

Energy-efficient distributed part programme for highly automated production systems

Distributed part programmes (PPs) across the shop-floor resources have been identified as a possible enabler of production flexibility, while the energy assessment has been recognised as a relevant factor for the global sustainability. This article proposes a distributed PP approach, identified as network part programme (NPP), while addressing the minimisation of system energy consumption. The approach, called energy-based NPP, is based on two mathematical models. The first model generates a number of alternative pallet configurations according to the minimisation of workpiece set-ups and energy consumption. The second model grants the energy consumption threshold at system level through the selection of previously-generated and alternative workplans. The application of the approach on a real case shows a reduction of the energy consumption, the respect of the system energy consumption threshold and a substantial improvement in operational costs compared to traditional workplan design methods.

Closed-loop production and automation scheduling in RMSs

Highly reconfigurable and agile production systems are selected to operate in production contexts often characterized by changes of the production requirements or changes of the part family demand. The operational level for such system architecture is expected to manage the short term production planning while guaranteeing the automation layer enables physical devices to exploit logic control tasks within the specific time buckets. The proposed work outlines an integrated approach supporting the operational level for RMSs in which the scheduling of production jobs and the scheduling of corresponding automation tasks are dynamically coupled. Connections with consolidated constraint-based representation and solving techniques are also discussed. The integrated scheduling approach has been validated with reference to a Finishing Robotic Cell (FRC) operating in a pilot assembly line.

An AI based decision support system for preventive maintenance and production optimization in energy intensive manufacturing plants

Besides pursuing the economic goals of low costs and high profits, companies are becoming more and more aware of the environmental and social impact of their actions. Companies striving for the integrated optimization of environmental and economic perspectives within their production processes, need to be supported by tools helping to understand the effects of the decision making process. In this context, this paper describes a Decision Support System (DSS) enabling the early identification of problems occurring on manufacturing lines thus suggesting related recovery actions, together with the potential repercussions of their adoption, at economic and environmental level. The decision making process beneath the DSS starts from the aggregation of production lines sensors data in Key Performance Indicators (KPI). The data are then processed by means of an Artificial Neural Networks (ANN) based knowledge system which enables to suggest preventive maintenance interventions. The proposed maintenance activities, elaborated throughout a scheduling engine, are integrated within the weekly production schedule, according to the selected optimization policy. Preliminary tests have been carried out in manufacturing plants of IKEA industries and Brembo.

Dematerialized manufacturing systems

Machine tools are an integral part of modern manufacturing across all major industrial sectors and form the backbone of current precision engineering best practise. However, the state of the art in machine tool technology has not progressed significantly from the initial inception back at the turn of the last century through to today’s multiaxis systems. The solid cast rigid carcass construction with predominantly serial configuration has been the mainstay for the majority of currently produced machine tools. The European Union (EU) Framework Platform 7 project entitled DEMAT – Dematerialised Production Systems: A new way to design, build, use, and sell European Machine Tools – was a project that pushed the boundaries of current state-of-the-art machine tools, with the aim of providing a new vision for next generation sustainable machine tools. The goal of DEMAT is to provide a new EU vision for custom tailored combinations of extremely lightweight, mechanically non-stiff, skeletal and low-environmentalimpact machines that are integrated with total life-cycle services based on innovative win-to-win business models. The underlying concept is that European machine builders conceive machines as combinations of easily exchangeable modules that consist of ultra-light and adaptive skeletal structures. These skeletal structures are designed from a perspective that considers structure, control strategies and processes in an integral way for satisfying the functional requirements and for assuring the optimal global robustness and reliability of the machine with the minimum possible material amount. This dematerialisation approach breaks the link between production results and the material structure of machines and reduces the total life-cycle impacts and costs of machines. By integrating a number of dematerialised machines with innovative business models and total lifecycle services, machine tool builders are able to realise dematerialised manufacturing systems with customised flexibility. This holistic approach for designing, producing and using dematerialised manufacturing systems integrated with total life-cycle services will produce a new paradigm in the Europeanmanufacturing sector: the dematerialisedmanufacturing solution aims to pave the way for transforming the European small and medium sized enterprises-intensive machine-tool industry into a knowledge-based, competitive, sustainable and value-adding sector. This special issue of the International Journal of Computer Integrated Manufacturing comprises of a set of selected publications that encompasses the major research and developments from the DEMAT project attached to specific work packages and project outputs. The papers form a cohesive set of publications that portray the full extent of the DEMAT projects’ major exploitable outputs across the key domains – machine design, production system design, information sharing, holistic production planning, distributed part programmes and business models. The first paper by Bustillo et al. proposes a new methodology to overcome limitations of reducing mechanical stiffness, which involves the design of machine tools with ultra-light structural components, and the development of strategies to counteract the loss of productivity as a consequence of lightweight machines. The methodology includes use of modular boxes built with carbon-fibre trusses, calculation of the dynamic stiffness of the designs, the identification of its weaknesses in terms of its cutting processes, and the design and integration of active damping systems in the machine to soften expected vibrations under the most critical cutting conditions. The second paper by Copani et al. outlines an innovative production system design and management framework based on the concept of dematerialisation whose major purpose is to reduce the amount of material, energy and degrees of flexibilities of machine tools and systems to the minimum requirements based on user needs. The framework presents a set of methodologies related to the pallet configuration and process planning, the machine tool configuration and the system configuration, all nested together. The third paper by Dhokia et al. presents research on the design and implementation of a unique prototype information sharing platform that supports and enables the design of a DEMAT machine tool. It provides a unique approach to design and life-cycle monitoring of machines. An experimental software system has been developed using Unified Modelling Language machine tool data models implemented as Java classes, and a Structured Query Language database to store machine tool component data. The database has been populated with typical machine tool components to demonstrate the functionality of a prototype information sharing platform, when developing DEMAT machine tools. The fourth paper by Choi et al. focuses on a holistic production planning approach in a reconfigurable manufacturing system. The energy consumption and material flows that are incurred on the reconfigurable International Journal of Computer Integrated Manufacturing, 2015 Vol. 28, No. 4, 337–338, http://dx.doi.org/10.1080/0951192X.2015.1016365

Closed-loop production and automation schedule execution in RMSs under uncertain environmental conditions

Highly automated production systems are conceived to efficiently handle evolving production requirements. This concerns any level of the system from the configuration and control to the management of production. The proposed work deals with the development of an innovative platform jointly managing the production scheduling level and the automation level. The major advantage coming from the platform is the capacity of generating scheduling plans which are executed at automation level and concurrently monitored over time so that any production anomaly or system misbehavior can be dynamically interpreted and adapted by regenerating online a new schedule. The paper describes the current release of our closed loop architecture that integrated both control and automation parts.

An integrated framework for combined designing dematerialised machine tools and production systems enabling flexibility-oriented business models

The current work outlines an innovative production system design and management approach based on the concept of dematerialisation whose major purpose is to reduce the amount of material, energy and degrees of flexibilities of machine tools and systems to the minimum requirements based on the user needs. The successful introduction of this new generation of Dematerialised Machines and Systems relies on a structured design framework. It starts from an accurate identification of the business models driving the company strategy and the identification of specific markets where the dematerialisation principle is a winning leverage to compete. Based on the analysis of production demand and the reference market context, the framework presents a set of methodologies related to the pallet configuration and process planning, the machine tool configuration and the system configuration, all nested together. The benefits of the Dematerialisation framework will be investigated with regard to a set of benchmarks coming from the industrial practice.

Development and Optimization of an Innovative Double Chamber Nozzle for Highly Efficient DMD

Injection nozzles design in Direct Metal Deposition (DMD) critically affects the performances of the process in terms of powder deposition efficiency. In fact, the fluid-dynamic behavior of the powder particles falling into the molten pool strongly depends both on the internal geometry of the deposition nozzle and on the geometry of the nozzle outlet. This efficiency, for commercial nozzles, is usually under 50%, thus implying an unaffordable powder waste. SUPSI implemented an innovative nozzle concept, designed as a coaxial double chamber that enables the concurrent flow of the powder-carrier gas mixture and of the shielding gas. In this configuration, the shielding gas allows to reduce the spread of the blown powder particles, constraining the carrier gas flow and limiting its divergence. Such innovative design also enables the integration of various modules - different in shape - to be nested to the bottom end of the nozzle, in order to adapt its outlet geometry. The main objective of the design is to influence the shape of the powder flux ejected from the nozzle outlet by exploiting the shielding gas while limiting oxidation processes. In order to assess the influence of the feeding parameters on the flow geometry, different concepts and shapes of nozzle outlet have been tested and investigated against the deposition efficiency, both numerically and experimentally. The testing campaign relies upon an image analysis performed on a demonstration setup where the powder flux is tracked using a high-speed camera. Experimental results demonstrate improved deposition efficiency through a significant (up to 18%) spread reduction.