Modular machine tools: Design and barriers to industrial implementation

The Reconfigurable Manufacturing System (RMS) paradigm has been developed to address challenges in the design of manufacturing systems and equipment that will meet the demands of modern manufacturing. This research involved the development of Modular Reconfigurable Machines (MRMs); as an emerging technology in reconfigurable manufacturing. MRMs are mechanically modular machines. The modularity permits the kinematic architecture and processing functions of the machine to be reconfigured to meet changing production requirements. This paper will focus on aspects of the mechanical design and the development of a control system that supported the modularity and reconfigurability of the mechanical platform. A modular electronic system is presented that is characterized by a plug and play approach to control scalability. This is complemented by a software architecture that has been developed with a focus on hardware abstraction for the management of an augmented mechanical and electronic architecture. The implications of MRMs for RMSs are discussed and key inhibitors to industrial implementation are identified.     

RMS design methodology for automotive framing systems BIW

Today, markets increasingly require more customized products, with shorter life cycles. In response, manufacturing systems have evolved from mass production techniques, through flexible automation and mass customization, to produce at mass production costs. Manufacturing facilities must incorporate more flexibility and intelligence, evolving toward reconfigurable manufacturing systems (RMS). RMS are amid to posses such flexibility and responsiveness and said to be the next generation of world class systems. RMS are designed for rapid change in structure and for a quickly adjustable production capacity. This paper proposes a new methodology (high level process) of framework using flexible and reconfigurable manufacturing systems principles for automotive framing systems as well as to provide a guideline to support the structure of different stages of the design methodology. The proposed methodology is presented through a case study using data based on actual production systems of three different styles; (process and design data) which supports the hypothesis of the research.     

Reconfigurability of behavioural specifications for manufacturing systems

Reconfigurable manufacturing systems (RMS) support flexibility in the product variety and the configuration of the manufacturing system itself in order to enable quick adjustments to new products and production requirements. As a consequence, an essential feature of RMS is their ability to rapidly modify the control strategy during run-time. In this paper, the particular problem of changing the specified operation of a RMS, whose logical behaviour is modelled as a finite state automaton, is addressed. The notion of reconfigurability of specifications (RoS) is introduced and it is shown that the stated reconfiguration problem can be formulated as a controlled language convergence problem. In addition, algorithms for the verification of RoS and the construction of a reconfiguration supervisor are proposed. The supervisor is realised in a modular way which facilitates the extension by new configurations. Finally, it is shown that a supremal nonblocking and controllable strict subautomaton of the plant automaton that fulfils RoS exists in case RoS is violated for the plant automaton itself and an algorithm for the computation of this strict subautomaton is presented. The developed concepts and results are illustrated by a manufacturing cell example.     

可重构制造系统监督控制器的自动重构

提出了基于改进的网重写系统(Improved net rewriting system, INRS)的可重构制造系统(Reconfigurable manufacturing systems, RMS) Petri网监督控制器的自动重构方法, 以快速适应由市场需求变化所引起的制造系统构形的频繁变化. INRS解决了网重写系统存在的问题, 可动态调整给定Petri网模型的结构而不改变其行为属性. 以集合和图的组合形式定义了RMS的构形, 并提出了基于INRS的一类模块化、可重构的Petri网控制器的设计方法. 针对这类Petri网控制器, 提出了基于INRS的自动重构方法. 方法可将RMS构形的变化转变为INRS的图重写规则, 并作用于当前Petri网控制器, 使其快速、自动地重构为所求的新控制器. 所提出的Petri网控制器的设计与重构方法, 均从理论上保证了结果的正确性, 免校验. 仿真研究验证了方法的有效性.     

Industry 4.0 smart reconfigurable manufacturing machines

This paper provides a fundamental research review of Reconfigurable Manufacturing Systems (RMS), which uniquely explores the state-of-the-art in distributed and decentralized machine control and machine intelligence. The aim of this review is to draw objective answers to two proposed research questions, relating to: (1) reconfigurable design and industry adoption; and (2) enabling present and future state technology. Key areas reviewed include: (a) RMS – fundamentals, design rational, economic benefits, needs and challenges; (b) Machine Control – modern operational technology, vertical and horizontal system integration, advanced distributed and decentralized control; (c) Machine Intelligence – distributed and decentralized paradigms, technology landscape, smart machine modelling, simulation, and smart reconfigurable synergy. Uniquely, this paper establishes a vision for next-generation Industry 4.0 manufacturing machines, which will exhibit extraordinary Smart and Reconfigurable (SR*) capabilities.     

A process-driven computing model for reconfigurable semiconductor manufacturing

Reconfigurability is essential for semiconductor manufacturing systems to remain competitive. Reconfigurable systems avoid costly modifications required to change and adapt to changes in product, production and services. A fully automated, collaborative, and integrated while reconfigurable manufacturing system proves cost-effective in the long term and is a promising strategy for the semiconductor manufacturing industry. However, there is a lack of computing models to facilitate the design and development of control and management systems in a truly reconfigurable manner. This paper presents an innovative computing model for reconfigurable systems and controlled manufacturing processes while allowing for the integration of modern technologies to facilitate reconfiguration, such as radio frequency identification (RFID) and reconfigurable field programmable gate array (FPGA). Shop floor manufacturing activities are modeled as processes from a business perspective. A process-driven formal method that builds on prior research on virtual production lines is proposed for the formation of a reconfigurable cross-facility manufacturing system. The trajectory of the controlled manufacturing systems is optimized for on-demand production services. Reconfigurable process controllers are introduced in support of the essential system reconfigurability of future semiconductor manufacturing systems. Implementation of this approach is also presented.     

Part design using manufacturing features

This paper presents a methodology by which manufacturability data is used to drive the design process. The system allows a designer to determine the features to be considered. He provides the basic geometric parameters for each feature and passes them to the modeling system for instantiations. Tolerances and surface finish allow the system to derive manufacturing implications used by the designer to review the design. The physical parameters, in addition to the processing information, lead to an integrated model which may be used by both the designer and the manufacturing personnel. This procedure may be invoked at any level of the design process and contribute to a final manufacturable design. The philosophy employed in the development of this work is to define manufacturing features as instances of generic ones with specific properties and processing methods. The design features obtain their geometric superclasses from a commercially available package of solid primitives thus allowing for the part to be graphically displayed.     

可重构制造系统可重构逻辑控制器设计与实现

针对可重构制造系统的逻辑控制问题,提出一种可重构逻辑控制器的解决方案．该逻辑控制器具有递阶分布式的控制体系结构,并根据模块化的设计思想设计成多个分离的功能模块．然后给出基于CORBA组件模型(CCM)的可重构逻辑控制器软件的开发过程．由递阶分布式体系、模块化设计和软件组件开发技术实现的可重构逻辑控制器具有快速动态重构的能力,能满足可重构制造系统逻辑控制的要求．     

A distributed architecture for reconfigurable control of continuous process operations

This paper considers a new distributed approach to reconfigurable control of continuous process operations such as in chemical plants. The research is set on a premise that emerging business pressures of product customization and industrial globalization will lead to increased need for reconfigurability in process plants. The ability of processes to support dynamic and smooth reorganization of process schemes in tandem with the changing requirements of supply chains will become important in future. Conventional control approaches based on hierarchical architectures are limited in dealing with such emerging requirements due to their inflexible structures and operating rules. Instead, more distributed approaches are required which can support increased level of reconfigurability in control systems, especially at the lower levels in hierarchy where the visibility to disturbances remains high. In this paper, one such distributed approach is considered based on the concepts of holonic manufacturing and supply chain management. The proposed approach distributes the functionality of process control into several reconfigurable process elements. These elements, while having a stand-alone capability for making their own control decisions, are also able to reconfigure themselves into alternative process schemes which evolve with the changing requirements of production. An analogy between process plants and so-called dynamic supply networks or virtual enterprises is used in this paper to define the composition of reconfigurable process elements and their operations. The proposed approach is shown to offer improved process control system reconfigurability and a control architecture which is compatible with the supply chain management needs at the next higher level. The purpose of this paper is qualitative and motivational. It is aimed to propose a new research direction in the field of reconfigurable process control.     

Trends and perspectives in flexible and reconfigurable manufacturing systems

To better understand future needs in manufacturing and their enabling technologies, a survey of experts in manufacturing has been conducted. The survey instrument (i.e., questionnaire) tries to assess the experience to date with the use of flexible manufacturing systems (FMS) and to examine the potential roles and enabling technologies for reconfigurable manufacturing systems (RMS). The results show that two-thirds of respondents stated that FMSs are not living up to their full potential, and well over half reported purchasing FMS with excess capacity (which was eventually used) and excess features (which in many cases were not eventually used). They identified a variety of problems associated with FMS, including training, reconfigurability, reliability and maintenance, software and communications, and initial cost. However, despite these issues, nearly 75% of respondent expressed their desire to purchase additional, or expand existing FMSs. The experts agreed that RMS (which can provide exactly the capacity and functionality needed, exactly when needed) is a desirable next step in the evolution of production systems. The key enabling technologies for RMS were identified as modular machines, open-architecture controls, high-speed machining, and methods, training and education for the operation of manufacturing systems.     

Reconfigurable Control Structure for Robots in Assembly

The increased use of changeable characteristics in modern manufacturing and robotic systems and applications call for improved system control design that offers some degree of reconfigurability. The need for control reconfiguration of robotic systems arises due to some inherent characteristics of the robotic system, variations of robot parameters due to environmental changes, major task changes typical in production changeover or manufacturing system reconfiguration, or geometry changes due to the reconfiguration of modular manipulators. In this paper, a reconfigurable controller, the Supervisory Control Switching System (SCSS), is proposed to meet the new on-line demands for changeability in robotic systems. The SCSS is capable of selecting the most suitable controller for a particular task or situation, from separate controllers designed a priori. The applicability and effectiveness of the developed switching control scheme have been illustrated through computer simulations of an AdeptOne SCARA manipulators carrying out assembly tasks.     

Development of holonic manufacturing execution systems

Rapid changes of market demands and pressures of competition require manufacturers to maintain highly flexible manufacturing systems to cope with a complex manufacturing environment. To meet these requirements, this work adopts the concepts of holon and holarchy to design manufacturing systems. Holon and holarchy are derived from the studies of social organizations and living organisms and possess the properties of intelligence, autonomy, cooperation, reconfigurability, and extensibility. Moreover, advanced manufacturing systems also require the properties of security certification and failure recovery. Based on the requirements of these properties, a systematic approach is proposed to develop a holonic manufacturing execution system (HMES) for the semiconductor industry. This systematic approach starts with a system analysis by collecting domain requirements and analyzing domain knowledge. The HMES Holarchy is designed by the procedure of constructing an abstract object model based on domain knowledge, partitioning application domain into functional holons, identifying generic parts among functional holons, developing the Generic Holon, defining holarchy messages and the holarchy framework of HMES, and finally designing functional holons based on the Generic Holon. It is believed that this proposed systematic approach provides a novel and efficient way to design HMES.     

A systematic approach for product families formation in Reconfigurable Manufacturing Systems

The aim of this work is to establish a methodology for an effective working of Reconfigurable Manufacturing Systems (RMSs). These systems are the next step in manufacturing, allowing the production of any quantity of highly customised and complex products together with the benefits of mass production. In RMSs, products are grouped into families, each of which requires a system configuration. The system is configured to produce the first family of products. Once it is finished, the system is reconfigured in order to produce the second family, and so forth. Therefore, the effectiveness of a RMS depends on the formation of the best set of product families. Therefore, a methodology for grouping products into families, which takes into account the requirements of products in RMSs, is an issue of core importance. These requirements are modularity, commonality, compatibility, reusability, and product demand. The methodology starts by calculating, for each product requirement, a matrix that summarises the similarity between pairs of products. Then, through the use of the AHP methodology, a unique matrix that comprises the similarity values between products is obtained. The Average Linkage Clustering algorithm is applied to this matrix in order to obtain a dendogram that shows the diverse sets of product families that may be formed.     

A non-dominated sorting genetic algorithm based approach for optimal machines selection in reconfigurable manufacturing environment

This paper deals with a problem of reconfigurable manufacturing systems (RMSs) design based on products specifications and reconfigurable machines capabilities. A reconfigurable manufacturing environment includes machines, tools, system layout, etc. Moreover, the machine can be reconfigured to meet the changing needs in terms of capacity and functionality, which means that the same machine can be modified in order to perform different tasks depending on the offered axes of motion in each configuration and the availability of tools. This problem is related to the selection of candidate reconfigurable machines among an available set, which will be then used to carry out a certain product based on the product characteristics. The selection of the machines considers two main objectives respectively the minimization of the total cost (production cost, reconfiguration cost, tool changing cost and tool using cost) and the total completion time. An adapted version of the non- dominated sorting genetic algorithm (NSGA-II) is proposed to solve the problem. To demonstrate the effectiveness of the proposed approach on RMS design problem, a numerical example is presented and the obtained results are discussed with suggested future research.     

Cloud-based design and manufacturing: A new paradigm in digital manufacturing and design innovation

Cloud-based design manufacturing (CBDM) refers to a service-oriented networked product development model in which service consumers are enabled to configure, select, and utilize customized product realization resources and services ranging from computer-aided engineering software to reconfigurable manufacturing systems. An ongoing debate on CBDM in the research community revolves around several aspects such as definitions, key characteristics, computing architectures, communication and collaboration processes, crowdsourcing processes, information and communication infrastructure, programming models, data storage, and new business models pertaining to CBDM. One question, in particular, has often been raised: is cloud-based design and manufacturing actually a new paradigm, or is it just “old wine in new bottles”? To answer this question, we discuss and compare the existing definitions for CBDM, identify the essential characteristics of CBDM, define a systematic requirements checklist that an idealized CBDM system should satisfy, and compare CBDM to other relevant but more traditional collaborative design and distributed manufacturing systems such as web- and agent-based design and manufacturing systems. To justify the conclusion that CBDM can be considered as a new paradigm that is anticipated to drive digital manufacturing and design innovation, we present the development of a smart delivery drone as an idealized CBDM example scenario and propose a corresponding CBDM system architecture that incorporates CBDM-based design processes, integrated manufacturing services, information and supply chain management in a holistic sense.     

A multiagent-based control system applied to an educational shop floor

This paper addresses the design and implementation of a multiagent-based control architecture to support modular reconfigurable production systems. The requirements for plugability of modules (manufacturing components) and product changes were considered and tested against an educational platform based on Fischertechnik, which resembles a production system composed of several workstations connected by a crane and conveyors.     

可重构制造系统的关键技术

可重构制造系统是一种新型的制造模式 .本文中详细阐述了可重构制造系统的特点以及研究内容 ,并提出了拟开展的一些研究工作     

Design and planning problems in flexible manufacturing systems: a critical review

This review paper describes the state-of-the-art research on flexible manufacturing systems (FMS) design and planning issues. The emphasis is on presenting research results coming out of the current FMS literature that help the FMS manager in setting up a highly efficient manufacturing system. In addition to that, it discusses relevant research contributions after 1986, that were not part of any of the previous survey papers on operations research models for FMSs. Also, applications of combinatorial optimization approaches to FMS planning problems are adequately exposed in the paper.     

Modeling of reconfigurable manufacturing systems based on colored timed object-oriented Petri nets

To cope with the rapid change in manufacturing market requirements, reconfigurable manufacturing systems (RMSs) with the feature of reconfigurability, have to be developed. A model that describes the reconfiguring process of a manufacturing system is developed by applying colored timed object-oriented Petri nets. Based on the main difference between configurations of RMSs and flexible manufacturing systems (FMSs), a modular hierarchical structure of RMS is developed. By the object-oriented method, all the object classes in the RMS model are identified. A macro-place is used to model the aggregation of many processes and a macro-transition is used to link all the related macro-places. Macro-places and macro-transitions are connected with arcs to form a Petri net named a macro-level Petri net so that the control logic of RMS is represented. The macro-level Petri net is refined by hierarchical steps, each step describing these macro-places by more detailed sub macro-places until all the macro-places cannot be divided. Then the characteristics of material flow and time constraints in RMS are modeled by applying colored tokens and associated time-delay attributes. This model integrates object-oriented methods, stepwise refinement ideas and Petri nets together. The RMS activities can be encapsulated and modularized by the proposed method, so that RMS can be easily constructed and investigated by the system developers.     

Digital twins-based flexible operating of open architecture production line for individualized manufacturing

Individualized manufacturing implies high flexibility of both the hardware and software of the production lines based on a fast physical and logical system (de)commissioning. This paper proposes an open architecture production line (OAPL) design together with a digital twins-based flexible operating approach for individualized manufacturing. Firstly, an OAPL is designed and implemented with physical reconfigurability by orchestrating different open architectural platforms together with open architecture machine tools (OAMTs). Secondly, an open architectural style modeling and configuration method is presented to enable the software reconfigurability of the controls of the OAPL. Thirdly, a digital twin-based online process emulating and multi-physics simulation is integrated to aid the comprehensive characterizing of the operation status of the OAPL. Based on the system reconfigurability and digital twins system, a triple-layer Learning-Optimization-Reacting approach together with an ensemble algorithm for flexible operating of the OAPL is proposed. The digital twins are formed with the ability to flexibly operate the OAPL for catering to different individualized requirements. A demonstrative implementation of a stepping-motor assembly OAPL is presented finally.