In this paper, general requirements of next generation manufacturing systems are discussed, and the strategies to meet these requirements are considered. The production paradigms which apply these strategies are also classified. Particular emphasis is put on the paradigm of Reconfigurable Manufacturing System (RMS). Some key issues of the RMS design are discussed, and a critical review is presented concerning the developments of RMSs. Finally, suggestions of the RMS research are made and future research directions are identified.

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Reconfigurable manufacturing systems: the state of the art

Multi-functional machine tool

This paper summarizes our survey on the development of reconfigurable machines (RMs). The goals of this survey were to (i) clarify the needs and drivers to develop the RMs, (ii) define the academic and practical issues involved in the development of RMs, (iii) learn the state of the art of the RD while RMs are essential components to implement an RMS. RMs should be designed to meet a variety of task requirements via its reconfigurability. It has been found that few existing RMs can achieve this objective. The survey has concluded that the obstacles of the development of RMs include (i) the difficulties to identify and generalize design requirements since an RM is application-oriented and the design requirements have to be defined from an actual application; and in fact, some requirements are very difficult to be quantified; (ii) the lacking of efficient automated robot programming tools despite that the robots are essential components for most of the RMs; (iii) the lack of effective technologies that can be used to support system reconfigurations; (iv) no international organization that serves for standardizing the modular components for manufacturing and assembly processes; (v) the lack of the effort in implementing a heterogeneous system consisting of different types of RMs. The survey has suggested some future research works to overcome these obstacles.

Development of reconfigurable machines

This paper is concerned with object-oriented design and aims to describe an object-oriented approach [called design-with-objects (DwO)] that encompasses both the fundamentals of object-oriented design and the use of object-oriented design in the development of design process models. The major design objects are described, together with their main structure, the message passing and inheritance involved, and the computability and exchangeability of the approach. The main potential advantages of such an approach are computability, in that a design process model obtained using DwO is not just a descriptive model but a computable model; reusability, in that once a design object in DwO has been established, it can be used repeatedly; and exchangeability, in that objects with similar interfaces can be readily exchanged in a modular manner. This paper reviews the background to design process models and object-oriented design and then describes the basis of DwO. Design models, DwO methods and an architecture for DwO are described together with an example design process model formalism that uses DwO. The implementation of this example DwO design process model formalism for the problem of electronics assemblies components selection is overviewed.

Design with objects: an approach to object-oriented design

The purpose of this paper is to synthesize all possible structural configurations of three-, four- and five-axis machining centres and to investigate the geometrical characteristics of five-axis machining centres. Based on the definition of coordinate systems and the configuration code of machine tools, it was found that there are 24, 96 and 288 feasible configurations for three-, four- and five-axis machining centres respectively. The geometric characteristics of five-axis machining centres were analysed and summarized by using the method of coordinate transformation. The results of this paper are beneficial to engineers in the design and evaluation of machining centres.

On the structural configuration synthesis and geometry of machining centres

This paper deals with an object-oriented intelligent design support system which is intended to assist in the basic design of machine tools, in particular machining centres. The machine tools design process is analysed through interviews with experienced designers, and an object-oriented model is established to represent the design process. Software modules named design objects are proposed, which are basic components for the implementation of an intelligent design support system for machine tools. A prototype of the design support system for machining centres is developed based on the design objects, and some case studies are carried out to verify the effectiveness of the methods proposed.

Object-oriented design support system for machine tools

This paper presents an object-oriented model of design process and an object-oriented design support system which assists the basic design of machine tools. The process of the basic design of machine tools is analyzed in the case of machining centers. The design process is represented by a series of phases, each of which consists of two steps. The first step is to select the design parameters and the second step is to determine the values of the design parameters. The "design object" is defined here as encapsulated information which is dealt with through phases of the design process. The model of the design process is represented by trees and their relations. A tree represents the generalization-specification relation of design objects which are nodes of the tree. The relations among the trees constitute the whole-part relation. A design support system is developed based on the object-oriented model of the design process.

Masayuki Nunobiki

Papers

Object-oriented design support system for machine tools

Object-Oriented Design Support System for Machine Tools.

A study of knowledge based approach to basic design of machine tools