A Lagrangian heuristic for minimising risk using multiple heterogeneous metrology tools

Motivated by the high investment and operational metrology cost, and subsequently the limited metrology capacity, in modern semiconductor manufacturing facilities, we model and solve the problem of optimally assigning the capacity of several imperfect metrology tools to minimise the risk in terms of expected product loss on heterogeneous production machines. In this paper, metrology tools can differ in terms of reliability and speed. The resulting problem can be reduced to a variant of the Generalized Assignment Problem (GAP), the Multiple Choice, Multiple Knapsack Problem (MCMKP). A Lagrangian heuristic, including multiple feasibility heuristics, is proposed to solve the problem that are tested on randomly generated instances.     

Configuration design of scalable reconfigurable manufacturing systems for part family

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 responsiveness could be achieved through new paradigms such as Reconfigurable manufacturing systems (RMS). In this paper, the problem of configuration design for a scalable reconfigurable RMS that produces different products of a part family is addressed. In order to handle demand fluctuations of products throughout their lifecycles with minimum cost, RMS configurations must change as well. Two different approaches are developed for addressing the system configuration design in different periods. Both approaches make use of modular reconfigurable machine tools (RMTs), and adjust the production capacity of the system, with minimum cost, by adding/removing modules to/from specific RMTs. In the first approach, each production period is designed separately, while in the second approach, future information of products’ demands in all production periods is available in the beginning of system configuration design. Two new mixed integer linear programming (MILP) and integer linear programming (ILP) formulations are presented in the first and the second approaches respectively. The results of these approaches are compared with respect to many different aspects, such as total system design costs, unused capacity, and total number of reconfigurations. Analyses of the results show the superiority of both approaches in terms of exploitation and reconfiguration cost.     

In-line monitoring of advanced microelectronic processes using combined X-ray techniques

Accurate and reliable in-line monitoring of the different films thickness that occur throughout the integrated circuit manufacturing process is mandatory to develop and produce advanced microelectronic devices. X-ray reflectivity (XRR) is a fundamental and suitable metrology technique to precisely determine the thickness of both transparent and metallic thin films. Furthermore, XRR is very sensitive to surface and interface roughness, and also provides information about the film density. X-ray fluorescence (XRF) is currently used as a metrology technique to control the thickness and the elemental composition of relatively thick films. The performance of a new in-line metrology tool, which gathers XRR and XRF data to monitor film thickness, has been assessed. Results on the monitoring of high κ thin films, low κ materials, copper barrier and copper seed layers are presented.     

Ultrasonic on-machine measurement for internal topographies

The integration of metrology into the manufacturing process is becoming increasingly important for production technology. The measurement directly on machine tools is especially improving manufacturing strategies. So far, optical or tactile measuring systems are the state-of-the-art for dimensional measurements in process metrology. However, the wall thickness of structures with inner cavities cannot be measured with these systems. Owing to these deficits, an ultrasonic system was integrated into the peripheral equipment of a machine tool. Both the extensive signal processing of the acoustic echoes and the developed software tool ' w -sonic' are discussed. The aim is to show the potential of the ultrasonic in-line measurement. A practical application for the individual machining of gas cylinders and initial results are also presented.     

Matheuristic approaches for Q-coverage problem versions in wireless sensor networks

This article deals with sensor coverage scheduling in wireless sensor networks subject to Q-coverage constraints. The main concern is to maximize the network lifetime, while ensuring that each target is covered by a given number of sensors. Three different variations of this problem are considered. Column generation based exact approaches are developed for those problems where the auxiliary problem is solved by a two-level approach comprising a genetic algorithm and an integer linear programming formulation. The genetic algorithm takes advantage of the auxiliary problem structure and appears to be very efficient at providing the master problem with attractive columns. The auxiliary problem integer linear programming (ILP) formulation is then mostly used for proving the optimality status of the current master problem solution. The proposed approaches are shown to be significantly faster than column generation approaches relying only on the auxiliary problem ILP formulation.     

基于"层次计量架构"的通用计量软件研究

针对日益复杂的程控仪器设备计量的自动化控制问题,提出了一种基于“层次计量架构”思想的软件开发构想,并定义了约束条件。由于程控仪器越来越专业化、集成化,使专业计量工程师要花费很大精力用于程控软件的研发。即使是本专业的人员对自己不熟悉的仪器设备,对此往往有很大隔阂。对“层次计量架构”关于专用程控仪器设备的程控软件的通用性和扩展性问题进行了分析,为快速开发出对特定计量任务的程控软件提出了一种新的构想。采用这种思想设计并实现了通用微波功率计量软件系统,并考虑了系统的扩展性和移植性的问题。     

基于数字化设计制造协同的飞机计量保障体系架构探讨

在国家科技创新,数字化设计制造高速发展的背景下,先进的数字化制造与传统的"先制造后检测再校准"的计量保障模式的矛盾愈发突出。以几何参数的数字化计量保障能力为例,通过分析对比国内外航空数字化设计制造工程中的几何参数计量保障工作现状,提出在飞机全生命周期内要保证产品数字化制造的几何尺寸精度,应依据新的产品几何规范,从产品的数字模型定义出发,面向数字化设计制造协同的关键过程和关键参数的测量溯源性要求,研究架构新的数字化计量保障技术体系,并就体系架构展开探讨。     

Selecting the nozzle assortment for a Gantry-type placement machine

Electronics manufacturing systems employ increasingly multi-head gantry machines, where several vacuum nozzles are used simultaneously in pick-and-place operations to insert components on bare PCBs. Their use includes several options that have an impact on the overall manufacturing speed of the machine. In the present paper we address the problem of selecting the nozzles for this kind of a gantry machine, which is an important subproblem of the larger scheduling problem of multi-head gantry machines. Nozzles come in different types, and different types of components may require different types of nozzles in their placing. We address first a case where a single PCB type is manufactured and the only limitation on the number of nozzles is given by the capacity of the placement head. Then we discuss the case where there is a budget limitation on the total cost of the nozzles we can buy. We show that both of these problems can be solved optimally by the means of efficient greedy algorithms. We also discuss the case of selecting nozzles when manufacturing multiple different PCB types.     

工业计量中的基本问题述评

提出并讨论了工业计量中的几个基本问题；分析了其特点及解决方向；结合现状和可持续发展，讨论了工业计量的目的、体系、范围、问题等几个方面的内容及对策；提出了工业计量可持续发展的一种解决方案。     

智能制造系统AGV小车及缓冲区容量仿真优化

具有MHS(material handling system)的智能制造系统AGV(automated guided vehicle)小车及缓冲区最大容量配置优化,属于典型的非线性整数规划问题。由于约束无法用封闭形式表达,因此较难获得问题的精确解。为此,本文提出了仿真优化的方法以获得问题的近似解。首先,对AGV小车及缓冲区最大容量配置优化问题进行了描述;其次,基于Em plant平台建立了具有MHS的智能制造系统仿真模型;然后,基于不同的优化目标,提出了3种仿真优化方法;最后,通过仿真试验对上述3种方法进行了分析与比较。分析表明,本文提出的方法及优化结果,可为企业配置AGV小车及缓冲区最大容量提供决策支持。     

支撑光学制造的几何量计量技术(英文)

几何量计量技术大量应用于光学制造业以检测零件质量和控制生产过程,是光学制造业的核心技术,涉及微纳米结构的几何量计量以及平面、球面、非球面、直纹曲面及自由曲面的面形计量.本文综述了德国联邦物理技术研究院支撑光学制造的部分计量技术.介绍了一种测量范围为25 mm×25 mm×5 mm的计量型大范围原子力显微镜(AFM),可灵活多样地测量各种微纳结构.介绍了一种新颖的AFM探针(ACP),可实现微纳结构侧壁形貌的直接、无损测量.介绍了一种应用Flared AFM探针的真三维AFM及其用于减少针尖磨损的矢量探测技术,可应用于各种纳米结构的真三维测量.介绍了可用于平面和中等曲面面形绝对测量的两种方法:差分型激光束偏转法和可溯源多路传感器法(TMS).讨论了面形测量中存在的挑战性难题.介绍了可用于面形测量的高精度三坐标测量机.     

DISCRETE-TIME MINIMAX PRODUCTION PLANNING FOR MANUFACTURING SYSTEMS

This paper deals with the production planning problem for discrete-time manufacturing systems with deteriorating items. A minimax approach is presented throughout the paper for the case where the demand is unknown. Both the cases of finite horizon and infinite horizon are discussed. Moreover, the case of production planning for manufacturing systems with failure-prone machines is also considered. For this case, a stochastic approach is used in which the states of the machines are represented by a two-state Markov process with transition rates determined by the availability of the machines. Finally, a robust control policy to take care of plant uncertainties is developed. Simulation results are also presented to show the usefulness of the approaches.     

Survey of Industrial,Agricultural, and Medical Applications of Radiometric Gauging and Process Control

Photon and particle radiations (gamma rays, x rays, brems-strahlung, electrons and other charged particles, and neutrons) from radioactive isotopes, x-ray tubes, and accelerators are now widely used in gauging, production control, and other monitoring and metrology devices where avoidance of mechanical contact is desirable. The general principles of radiation gauges, which rely on detection of radiation transmitted by the sample, or on detection of scattered or other secondary radiations produced in the sample, are discussed. Examples of such devices currently used or at least shown to be feasible in industrial, transportation, building, mining, agricultural, medical, and other metrology situations are presented, drawing from a total of 146 selected technical and review paper reference sources here cited.     

Robot selection using a fuzzy regression-based decision-making approach

Industrial robots, which enable manufacturing firms to produce high-quality products in a cost-effective manner, are important components of advanced manufacturing technologies. The performance of industrial robots is determined by multiple and conflicting criteria that have to be simultaneously considered in a robust selection study. In this study, a decision model based on fuzzy linear regression is presented for industrial robot selection. Fuzzy linear regression provides an alternative approach to statistical regression for modelling situations where the relationships are vague or the data set cannot satisfy the assumptions of statistical regression. The results obtained by employing fuzzy linear regression are compared with those of earlier studies applying different analytical methods to a previously reported robot selection problem.     

Simultaneous resource scheduling with batching to minimize weighted flow times

This paper examines scheduling problems in which individual tasks require several resources concurrently. We analyze the situation where, in addition to the need to schedule resources concurrently, it is possible to choose the batch sizes of the tasks. Although such situations arise in both manufacturing and service firms, the likely application of these results will be to repetitive batch manufacturing situations. Several formulations for this problem are presented. Both a lagrangian relaxation and a surrogate relaxation are developed. Heuristics based on these relaxations as well as extensive computational experiments are discussed. The simultaneous resource scheduling problem without batching is quite difficult because jobs need to be synchronized so that individual jobs can capture their required simultaneous resources. Nevertheless, if batch size is introduced as an additional variable, we show that the resulting problem is in some sense easier because of the added flexibility provided by the ability to adjust production batch sizes, which allows us to eliminate 'gaps' in the schedule.     

Maximizing supply chain profits with effective order management: integration of activity-based costing and theory of constraints with mixed-integer modelling

The development of a profitable-to-promise order management model in a make-to-order manufacturing environment is presented. The primary objective is to maximize profitability while ensuring that the firm has adequate resources to satisfy demand. The effectiveness of Activity-Based Costing and Theory of Constraints-based approaches is compared to assess order profitability. This order management model uses a mixed-integer program to consider simultaneously capacity, the relevant costs of supply chain resources and profitability. The results suggest that a close examination of cost structures is necessary for choosing an effective framework for a profitable-to-promise application. In manufacturing environments where direct manufacturing costs constitute a relatively small percentage of the total manufacturing cost, it would be beneficial to consider an Activity-Based Costing approach. On the other hand, in environments where direct costs are large, a Theory of Constraints-based approach would suffice.     

基于蚁群算法的中小手工制造企业人员调度

根据多品种、变批量的插单式生产的复杂特性,利用集群智能这种复杂系统建模手段研究中小企业生产线组建和人力资源调度过程。在将离散的生产单元运行特点与蚁群劳动分工模型进行对比分析的基础上,根据生产任务的要求和各个生产单元的负载不同重新设计工人的属性特征和员工间调配方案,实现了由计算机自动控制的自适应劳动分工模型。实验表明数字仿真结果大致与实际情况吻合。运行结果体现了非流水线手工作业生产中的劳动力分配的自组织自适应特征。     

Lot sizing with bounded inventory and lost sales

In production planning, there can be situations where the ability to meet customer demands is constrained by inventory capacity rather than production capacity. This situation often happens in petrochemical manufacturing, food processing, and glass manufacturing. Only a few studies can be found in the literature for this situation, and among these lost sales usually are not considered. In this paper, we consider the lot sizing problem with bounded inventory. We further consider that (1) lost sales are allowed; (2) production cost functions are non-increasing with respect to the time period; and (3) inventory capacity is non-decreasing with respect to the time period. With these considerations, we present a model as well as an algorithm which has a polynomial time complexity. An illustration is given to demonstrate both the application of our model and the algorithm.     

The block layout shortest loop design problem

The purpose of this article is to formulate and solve a shortest loop problem associated with the design of material flow handling systems in factories. The problem is formulated as an Integer Linear Program (ILP) initially containing a very large number of constraints. Several simplifications are proposed in order to reduce the problem to a size amenable by standard ILP solvers. Computational results confirm the efficiency and practicality of the proposed approach.     

Configuration design in scalable reconfigurable manufacturing systems (RMS); a case of single-product flow line (SPFL)

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 presented in the second phase of the method to optimise the process of selecting the best possible transformation for the existing machine configurations. Two different cases are designed and solved by implementing the established method. The results of these cases in terms of capital cost, capacity expansion cost, unused capacity and number of transformations, are compared with two hypothetical scenarios. Analyses of the obtained results indicate the efficiency of the proposed approach and offer a promising outlook for further research.