Technical feasibility analysis of utilizing special purpose machine tools

Special purpose machine tools (SPMs) are primarily used for performing drilling-related operations and are widely used in mass production including automotive component manufacturing. Utilization of SPM is considerably widespread; however, this technology is relatively new and expensive. The important problems facing manufacturing industries wishing to utilize this technology is feasibility analysis to decide whether a SPM can be utilised for production of the given part and if it is feasible which SPM components would be appropriate. Since the cost of utilizing SPM is high, feasibility analysis must be performed before any investment on detailed design. This paper proposes a technical feasibility analysis method which assists in deciding whether SPM is applicable for machining a given part to achieve the highest productivity. The method is based on the framework which consists of relations between the desired part properties to the characteristics of the SPM components. These relations are captured as rules and constraints in an intelligent system which is implemented in Visual Basic. Applying the proposed method to a number of industrial parts shows that it is a very useful tool in deciding when SPMs should be utilized.     

Design of a reconfigurable prognostics platform for machine tools

For decades, researchers and practitioners have been trying to develop and deploy prognostics technologies with ad hoc and trial-and-error approaches. These efforts have resulted in limited success, due to the fact that it lacks a systematic approach and platform in deploying the right prognostics tools for the right applications. This paper introduces a methodology for designing a reconfigurable prognostics platform (RPP) which can be easily and effectively used to assess and predict the performance of machine tools. RPP can be installed on the equipment and it has the prognostic capabilities to convert the data into performance-related information. The equipment performance information can then be integrated into the enterprise asset management system for maintenance decision making through the Internet. Two industrial cases are used to validate the effectiveness of applying the RPP for different prognostic applications as well as the reconfigurable capabilities of the proposed RPP.     

The application of manufacturing culture to the design of Asian region oriented machine tools

During the last years the demand for regionally and culturally harmonised machine design is increasingly on the agenda. The problem of localising products like machine tools instantly poses the question for new procedures that allow including the regional and cultural adaptations into the design processes of machine tool companies. How to transform the general insight into the necessity of culture- and region-adapted technologies and how to embed it into a design procedure comprising applicable design attributes is the crucial problem addressed. The paper shows in an exemplary way how ambiguous design attributes can eventually be embodied in a prototype design.     

实时小型GUI工具的设计

开发了一套c语言实现的小型实时图形用户界面工具,介绍了GUI系统的基本设计思路.系统已成功应用于一款继电保护机产品.     

Loading flexible manufacturing systems: a heuristic approach

In this study, heuristic algorithms are developed for loading Flexible Manufacturing Systems. The heuristic approach is an efficient way of planning the FMS with multiple nonlinear loading objectives.     

Assessment of reconfiguration schemes for Reconfigurable Manufacturing Systems based on resources and lead time

Reconfigurable manufacturing equipment is developed to meet the growing demand for more agile production. Agile manufacturing technology can improve the turnover of a company if it enables fast market introduction for volume production. Modular reconfiguration, defined as changing the structure of the machine, enables larger variation of products on a single manufacturing system; these solutions are called Reconfigurable Manufacturing Systems (RMS). The quality of RMS, and the required resources to bring it to reliable production, is largely determined by a swift execution of the reconfiguration process. This paper proposes a method to compare alternatives for the ways to implement reconfiguration. Three classes of reconfiguration are defined to distinguish the impact of the proposed alternatives. The procedure uses a recently introduced index method for development of RMS process modules, based on the Axiomatic Design methodology. Weighting factors are used to calculate the resources and lead time needed to implement the reconfiguration process. Application of the method leads to quick comparison of alternatives in the early stage of development. Successful execution of the method was demonstrated for the manufacturing process of a 3D measuring probe.     

An approach to integrating intelligentdiagnostics and supervision of machine tools

Arguments are presented for the necessity of integrating diagnostics and supervision in technological machines. An example of integrated diagnostics and supervision of the machine tool main drive, based on an expert system and neural network, is shown. Problems of intelligent thermal displacement supervision and questions related to practical supervision of machining centres are presented.     

Self-reconfigurable software architecture: Design and implementation

To respond quickly to the rapidly changing manufacturing environment, it is imperative for the system to have such capabilities as flexibility, adaptability, and reusability. The fractal manufacturing system (FrMS) is a new manufacturing paradigm designed to meet these requirements. To facilitate a dynamic reconfiguration of system elements (i.e., fractals), agents as well as software modules should be self-reconfigurable. Embodiment of a self-reconfigurable manufacturing system can be achieved by using self-reconfigurable software architecture. In this paper, therefore, self-reconfigurable software architecture is designed by conducting the following studies: (1) analysis of functional requirements of a fractal and environmental constraints, (2) design of reconfigurable software architecture especially for a reconfigurable agent, (3) selection of proper techniques to implement software modules, and realization of software architecture equipped with self-reconfigurability. To validate this approach, the designed architecture is applied to the FrMS.     

Resource partitioning for Integrated Modular Avionics: comparative study of implementation alternatives

Most current generation avionics systems are based on a federated architecture, where an electronic device runs a single software module or application that collaborates with other devices through a network. This architecture makes the software development process very simple, but the hardware system becomes very complicated and it is difficult to resolve issues of size, weight, and power efficiently. An integrated architecture can address the size, weight, and power issues and provide better software reusability, testability, and reliability by means of partitioning. Partitioning provides a framework that can transparently integrate several real‐time applications on the same computing device, allowing the isolation of the execution environment in terms of resources and faults. Several studies on partitioning software platforms have been reported; however, to the best of our knowledge, extensive comparison and analysis of design and implementation alternatives have not been conducted owing to the extreme complexity of their implementation and measurement. In this paper, we present three design alternatives for partitioning at the user, kernel, and virtual machine monitor levels, which are compared quantitatively. In particular, we target the worldwide standard software platform for avionics systems, that is, Aeronautical Radio, Incorporated Specification 653 (ARINC 653). Overall, our study provides valuable design references and demonstrates the characteristics of design alternatives. Copyright © 2013 John Wiley & Sons, Ltd.     

Error compensation in machine tools: a neural network approach

For a non-idealized machine tool, each point in the workspace is associated with a tool point positioning error vector. If this error map can be determined, then it is possible to substantially improve the positioning performance of the machine by introducing suitable compensation into the control loop. This paper explores the possibility of using an artifical neural network (ANN) to compute this mapping. The training set for the ANN is obtained by mounting a physical artifact whose dimensions are precisely known in the machine's workspace. The machine, equipped with a touch trigger probe, measures the positions of features on the artifact. The difference between the machine reading and the known dimension is the machine error at that point in the workspace. Using standard modeling techniques, the kinematic error model for a CNC turning center was developed. This model was parameterized by measurement of the parametric error functions using a laser interferometer, electronic levels and a precision square. The kinematic model was then used to simulate the artifact-measuring process and develop the ANN training set. The effect of changing artifact geometry was explored and a machining operation was simulated using the ANN output to provide compensation. The results show that the ANN is capable of learning the error map of a real machine, and that ANN-based compensation can significantly reduce part-dimensional errors.     

Feed-rate and trajectory optimization for CNC machine tools

The key task performed by CNCs is the generation of the time-sequence of set-points for driving each physical axis of the machine tool during program execution. This interpolation of axes movement must satisfy a number of constraints on axes dynamics (velocity, acceleration, and jerk), and on process outcome (smooth tool movement and precise tracking of the nominal tool-path at the desired feed-rate). This paper presents an algorithm for CNC kernels that aims at solving the axes interpolation problem by exploiting an Optimal Control Problem formulation. With respect to other solutions proposed in the literature, the approach presented here takes an original approach by assuming a predefined path tracking tolerance—to be added to the constraints listed above—and calculating the whole trajectory (path and feed-rate profile) that satisfies the given constraints. The effectiveness of the proposed solution is benchmarked against the trajectory generated by an industrial, state-of-the-art CNC, proving a significant advantage in efficiency and smoothness of axes velocity profiles.     

Design,refinement, implementation and prototype testing of a reconfigurable lathe-mill

This article documents the design, refinement, and implementation of a reconfigurable machine tool that provides a flexible platform for turning and milling. Advances in the design and capabilities of machine tools drive modern industry. In fact, the expanding capabilities of the machines permit novel and economic changes in the manufacturing and design of products. After the flexible manufacturing (FMS) boom, a more recent, but no less significant, area of machine development involves the reconfiguration of milling machines. This reconfigurability can also be applied to lathe-mills. The present work demonstrates satisfactorily the reconfiguration characteristics of modularity, integrability, and convertibility. We prototype and test a completely functional bench top reconfigurable lathe mill machine implemented using a $10,000 USD budget and developed following a synthesized machine tool product development methodology that begins with concept design and cutting forces to end in prototyping. In addition to reasonable results in runout, positioning, and surface roughness, the machine demonstrates the capability to produce parts with a Cpk of 1.009, thereby demonstrating the ability to fabricate this type of machine in Mexico for the local jewelry industry.     

Simulation and graphical animation of advanced manufacturing systems

Automated production systems, known as Flexible Manufacturing Systems (FMS), offer a promising solution for the low productivity of mid-volume, mid-variety batch production. These systems consist of integrated machine modules and material handling equipment under computer control.This paper describes a general purpose discrete-event Flexible Manufacturing Systems Simulator (FMSSIM). The package is programmed in FORTRAN and is capable of simulating different configurations, material handling systems, and topologies including bidirectional tracks. The simulator checks blockage of routes due to interference of carts and simulates random failures and repairs of the various components in the system. The simulator provides the user with a wide range of priority rules to select from, and enables the user to define his own rules if required. The simulator produces reports on various vital system performance statistics and also displays the movement of parts through the system on a refreshed CRT. This simulator is a modular, user-oriented package which allows the designer to evaluate a wide range of systems with varied design parameters and select an efficient flexible manufacturing system. Some general trends in the behaviour of the flexible manufacturing systems are identified and guidelines for their design and operation are suggested.     

A distributed scheduling and shop floor control method

We suggest a market-like framework for scheduling and shop floor control in computer-controlled manufacturing systems where each resource agent and part agent acts like an independent profit maker. A part-resource negotiation procedure is suggested including price-based bid construction and price revising mechanism. Alternative routings for each production order are considered in scheduling and shop floor control. A simulation-based scheduling method is suggested to estimate the start time and the completion time of each task. We develop a prototype soffivare which utilizes the object-oriented concept.     

基于J2EE的机床售后服务系统的设计与实现

引入J2EE架构体系,研究并实现了基于Web的机床售后服务系统.提出了在J2EE平台上应用MVC模式开发机床网络化服务系统的方法,增强了系统的健壮性和可扩展性.详细介绍了机床售后服务系统的功能,并引入了基于TBAC的动态访问权限控制策略,弥补了RBAC的不足,简化了规模较大的协同系统的访问权限的分配和管理.采用案例检索和关键字查询相结合的方法,提高了检索的效率.     

Achieving e-Manufacturing: multihead control and web technology for the implementation of a manufacturing execution system

Intelligent Manufacturing Systems requires advanced and efficient manufacturing technologies, management and procedures in order to achieve value creation in global markets. E-Manufacturing is the set of information technologies that allows companies to achieve on demand manufacturing through the integration of e-business applications. Cornerstone of this concept are Demand Flow Technology, Manufacturing Execution Systems (MES) and Digital Operational Method Sheets (OMS) which are vital to control shop floor operations where there is a need to balance manual and automated operations. Specially, Mexican companies face large diversity of products and multiple production lines, with high turnaround rotation of the workers. A low cost solution that integrates Demand Flow Technology, MES with Digital OMS is described, the system has been developed using LINUX servers, Multi-head control technology (multiple monitors to a single server) and a WEB based environment. This technological solution offers an affordable, stable, and high performance solution to transform the production into a more balanced system with shorter and faster cycles allowing a company to achieve e-Manufacturing. Received: February 2005/Accepted: January 2006     

The evolving factory of the future: Integrating manufacturing and information systems

In recent years there have been rapid developments in both manufacturing and information technologies and their systems. Advances have occured so rapidly that often the results has been “islands” of automation and information subsystems, such as CAD/CAM, robotics, group technology, and office automation. Some recent developments, however, provide capabilities for integrating these “islands” into systems which both improve manufacturing productivity and produce more meaningful management information. Integrated systems seem imminent. Suggestions that could help ensure a smooth evolution toward these systems are made and some conclusions are drawn.     

Integrating scheduling and control functions in computer integrated manufacturing using artificial intelligence

Proper integration of scheduling and control in Flexible Manufacturing Systems will make available the required level of decision-making capacity to provide a flexibly-automated, efficient, and quality manufacturing process. To achieve this level of integration, the developments in computer technology and sophisticated techniques of artificial intelligence (AI) should be applied to such FMS functions as scheduling. In this paper, we present an Intelligent Scheduling System for FMS under development that makes use of the integration of two AI technologies. These two AI technologies — Neural Networks and Expert Systems — provide the intelligence that the scheduling function requires in order to generate goodschedules within the restrictions imposed by real-time problems. Because the system has the ability to plan ahead and learn, it has a higher probability of success than conventional approaches. The adaptive behavior that will be achieved contribute to the integration of scheduling and control in FMS.