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To provide accurate capacity and functionality needed for each demand period (DP), a reconfigurable manufacturing system (RMS) is able to change its configuration with time. For the RMS with multi-...

A reconfigurable manufacturing system (RMS) can provide a customised manufacturing process to complete changes in operational requirements or machine status. The effective development of an RMS is ...

Reconfigurable transfer lines (RTLs), which are highly responsive to demand fluctuations, have gained increasing attention. This research deals with the line configuration design and balancing prob...

Intense global competition, dynamic product variations, and rapid technological developments force manufacturing systems to adapt and respond quickly to various changes in the market. Such responsi...

The dynamic nature of today’s manufacturing industry, which is caused by the intense global competition and constant technological advancements, requires systems that are highly adaptive and responsive to demand fluctuations. Reconfigurable manufacturing systems (RMS) enable such responsiveness through their main characteristics. This paper addresses the problem of RMS configuration design, where the demand of a single product varies throughout its production life cycle, and the system configuration must change accordingly to satisfy the required demand with minimum cost. A two-phased method is developed to handle the primary system configuration design and the necessary system reconfigurations according to demand rate changes. This method takes advantage of Reconfigurable Machine Tools in RMS. In fact, by adding/removing modules to/from a specific modular reconfigurable machine, its production capability could be increased, with lower cost. A novel mixed integer linear programming formulation is presente...

A recent trend in research on reconfigurable manufacturing systems is the development of reconfigurable machine tools (RMTs). A RMT can be used as a group of machines through change of its configuration to satisfy different manufacturing requirements. A literature review is provided in this paper to demonstrate the state-of-the-art advances and challenges on research and development of RMTs from the perspectives of architecture design, configuration design and optimisation, and system integration and control. In architecture design, semi-open and open architectures based on modular design approach are often selected to allow different modules of the machine to be added and removed. In configuration design and optimisation, operations of reconfiguration processes are analysed and optimised to achieve variety of configurations with the minimum reconfiguration effort. In system integration and control, transfers of motion, energy and data among different modules of the RMT are carried out. The challenges in ...

During the expected lifetime, evolving economical and optimum reconfigurable manufacturing system (RMS) configuration in a desired period to give the exact functionality and the exact capacity needed, when it is needed, is an important optimisation problem. This paper presents RMS configuration design methodology in a desired period with optimisation of the present worth of total cost of RMS including capital cost of machine investment, reconfiguration costs, operating costs, maintenance costs and salvage value over time. The configuration decision considers flow line features such as multi-product, number of stages, and functionality blocks in each stage, etc., with various constraints satisfaction. Phase 1 aims at RMS evolution scenario and the mathematical modelling. Phase 2 evolves RMS configuration alternatives. Phase 3 aims at RMS configuration alternative optimisation using mathematical model and artificial immune system. A case study demonstrates the methodology, the effectiveness of the methodolo...

Configuration performance prediction (CPP) is critical in the whole process of configuration design for a modular product family. Its aim is to estimate the key performance parameter values in advance, thus evaluating if the product variant can satisfy the customers’ personalised requirements or not. In this paper, we propose a novel prediction approach based on the integration of rough set and neural network ensemble through discovering the knowledge from the historical configuration information table. The minimal hitting set is introduced and its equivalence relationship with the minimal attribute reduction is proven. A genetic algorithm is designed to perform the approximate reduction of the condition attributes. A neural network ensemble model used for regression prediction is constituted by means of the variant bagging method based on error clustering. This methodology can reuse the discovered configuration rules and knowledge efficiently, as well as reduce the effort of experimental measurement to s...

Product configuration design is of critical importance in design for mass customization. This paper will investigate two important issues in configuration design. The first issue is requirement configuration and a dependency analysis approach is proposed and implemented to link customer groups with clusters of product specifications. The second issue concerns the engineering configuration and it is modelled as an association relation between clusters of product specifications and configuration alternatives. A novel methodology and architecture are proposed for accomplishing the two configuration tasks and bridging the gap between them. This methodology is based on integration of popular data mining approaches (such as fuzzy clustering and association rule mining) and variable precision rough set. It focuses on the discovery of configuration rules from the purchased products according to customer groups. The proposed methodology is illustrated with a case study of an electrical bicycle.

In mass customization, web-centric knowledge-based configuration systems have become an important tool to help customers configure products that satisfy their different needs and the complex configuration constraints of a product family (PF). An effective knowledge representation scheme and the associated reasoning mechanisms are essential for the success of these systems. This paper presents an object-oriented approach that integrates the functional and structural models of a PF with design process knowledge. Invasion-based search algorithms are proposed to deal with different situations in product customization and heuristic knowledge is introduced in these algorithms to improve the search efficiency. Optimization models have been constructed in terms of customers’ preferences to provide them with the highest satisfaction in product customization. Based on the representation scheme and reasoning algorithms, a web-based configuration system prototype is developed to support product customization. An exam...

Proper fixture design is crucial to workpiece quality assurance in manufacturing. Incorrect fixture design may lead to workpiece deformation during machining. The fixture configuration design is one of the important aspects of fixture design. This paper deals with fixture layout optimization problem. The objective is to minimize the norm of all the passive contact forces satisfying Coulomb friction constraint, work-piece static equilibrium constraint and contact constraint, for the entire cutting operation. To solve this problem, the paper proposes Genetic Algorithm with Learning Automata (GALA) algorithm, which is a population based interconnected learning automata algorithm incorporating genetic operators. The algorithm enjoys the good characteristics of both GA and LA. It is validated with an example of face milling operation. The optimal layout is found to be in tune with empirical facts. Also, for the further investigation of the algorithm, it has been tested on a different problem sets and a compara...

This paper presents a fixture configuration verification methodology that takes into account dynamic machining conditions--including the effect of dynamic gravitational forces--in the verification process. The fixture verification system is modelled as a linear optimization problem with respect to minimum clamping forces. The method provides a simple and effective means for (a) verifying whether a particular fixturing configuration is valid with respect to locating stability, deterministic workpiece location, clamping stability and total restraint; (b) identifying which locator loses contact with the part for an invalid fixture configuration; (c) identifying which clamp needs to be replaced; and (d) determining the minimum clamping forces to restrain the piece during the entire machining process. Since a fixture configuration design is validated not only under a given cutting direction, but also under an inverse cutting direction, this allows designers to understand thoroughly whether the fixture configur...

Fixturing is an important manufacturing activity in the production cycle. The computer-aided fixture design (CAFD) technique has been developed and become part of CAD/CAM integration. CAFD consists of three major aspects: setup planning, fixture planning, and fixture configuration design. An automated modular fixture configuration design system has been developed and applied to industrial practice. This paper focuses on a technical problem involved in the development of automated fixture planning systems, that is, the accessibility analysis of a fixturing surface on workpiece. The fixturing surface accessibility should be correctly assessed to reflect the extent of ease to place a fixture component in contact with the fixturing surface. The objective of accessibility analysis is to help the fixture planning fulfill the optimum selection of fixturing surfaces and points on workpiece. Firstly, several basic criteria for evaluating the eligibility of a surface being a preliminary candidate fixturing surface ...