Integrating multivariate engineering process control and multivariate statistical process control

Multivariate engineering process control (MEPC) and multivariate statistical process control (MSPC) are two strategies for quality improvement that have developed independently. MEPC aims to minimize variability by adjusting process variables to keep the process output on target. On the other hand, MSPC aims to reduce variability by monitoring and eliminating assignable causes of variation. In this paper, the use of MEPC alone is compared to using the MEPC coupled with MSPC. We use simulations to evaluate the average run lengths (ARL) and the averages of the performance measure. The simulation results show that the use of both MEPC and MSPC can always outperform the use of either alone. To detect small sustained shifts of the mean vector, combing MEPC with a multivariate generally weighted moving average (MGWMA) chart (MEPC/MGWMA) is more sensitive than the MEPC/multivariate exponentially weighted moving average (MEWMA) chart and MEPC/Hotelling’s χ² chart. An example of the application, based on the proposed method, is also given.     

工序能力分析在工序控制中的应用

阐述工序能力分析的原理与意义,讨论如何通过工序能力指数判断工序能力的好坏以及通过提高Cp值来提高产品质量,从而提高企业的竞争力.     

活塞质量检测与生产过程控制系统的开发

在阐述质量检测发展的趋势以及国内活塞生产企业活塞质量检测方面存在的不足的基础上，介绍了统计过程控制的概念及其实施方法。开发了活塞质量检测与生产过程控制系统。该系统的使用，可以极大地减轻检测人员的工作强度，提高工作效率，同时使质量检测过程更科学化。     

MScomm控件在过程控制系统中的应用

介绍了GK-02微机过程控制系统,MSComm控件的主要属性,主要事件,详细论述如何利用MSComn控件在过程控制系统中发送和接收数据．     

基于过程控制的设计更改控制系统研究

针对航空制造企业的特点,利用工作流技术,提出了一种基于过程控制的设计更改控制系统的体系结构,采用面向对象的Rational统一过程方法对业务过程进行分解和离散化,从中抽取基于业务角色的、粒度合适的过程元模型,将其开发成符合工作流管理联盟接口规范的软件组件,并以此构建相应的工作流模型。用该体系结构所开发的飞机制造设计更改控制系统,实现了信息集成、过程集成、过程控制、过程分析和系统柔性。     

基于Internet的网络化控制系统设计及控制研究

对于基于Internet的网络化控制系统,由于其网络延时具有随机、长时滞特性,使得控制系统稳定性和动态性能很差。本文基于离散的状态反馈网络化控制系统,提出了一种基于对象模型的多步预测补偿方法,通过在执行器端设置消息缓冲的办法实现时滞补偿的策略。基于Socket技术,应用LabWindows/CVI,采用以上时滞补偿方法设计了基于Internet的液位过程控制系统。实时跟踪控制实验和抗外部扰动实验结果结果表明,本文所提时滞补偿策略有效可行,能够很好地提高网络控制系统的动态性能。     

质量控制图及其工序质量控制

简要介绍了质量控制图的基本特点,论述了质量控制图的选择方法,对比分析了四种计量值质量控制图的应用特点,以实例详细分析了应用控制图进行工序质量控制的方法.     

智能统计工序质量控制的体系研究

针对统计工序质量控制的要求,提出了智能控制体系的基本框架,论述了控制图模式的分类及其表达。对智能统计工序质量控制的控制图模式识别、控制图异常模式的参数估计和诊断分析专家系统3个主要方面进行了分析,并提出了解决方案和系统模型。在模型构造中,采用小波概率神经网络进行控制图的模式识别和控制图异常模式的参数估计。模拟仿真和实际应用结果表明：该方法结构简单、收敛速度快、识别准确率高,能够满足控制图在线检测和分析的需要。     

Intent-based process control configuration models

Process control application engineering would be substantially less expensive if supported with readable self-documentation. An important advance would be models and languages designed to more clearly represent application Intent (as formalized herein), without the usual implementation obscurity. This paper analyzes how Intent, in the sense later defined, can be usefully defined and expressed. Process control has traditionally been defined in terms of a number of automation levels. This supports the intended Intent concept in one way, defining the implementation of higher application goals in terms of lower level ones. But a different, even more useful model is the leveling of physical sciences where each level of problem is best addressed by an appropriate kind of theory, itself dependent on lower level theories. Each theory must be proved by more fundamental theories even though those theories are much too complex to address the higher level problem directly. But more than leveling is needed. At each application level, the associated language should support concepts that make its normal usages clear. It should ensure that appropriate application practices can be expressed transparently in terms of their Intent. It should allow the engineer to clearly relate the result to the expected implementation, allowing him full control over the application. The paper will expand on prior papers to show more generally how these concepts can be developed.     

Burr control in meso-punching process

The shearing process for the sheet metal is normally used in the precision elements such as semi-conductor components. In these precision elements, the burr formation brings a bad effect on the system assembly and demands the additional de-burring process, so this imposes high cost on manufacturing. In this paper, we have developed the in-situ auto-aligning precision meso-punching system to investigate the burr formation mechanism and ultimately minimize burr. Firstly, we introduced the punch-die contact sensing method to align the punch and the die at initial state prior to the punching process. Secondly, by using the low-price semi-conductor laser, burr formed on the edges is measured intermittently during the punching process. We could, finally, make burr on the sheet metal uniformized and minimized by controlling of the precision X-Y table, 1 un resolution, and measuring burr height by semiconductor laser. Experimental results show the validity of our system for pursuing the burr-free punched elements.     

Improved process control alarm operation

Alarms are the main connection from the automation to the operator, when addressing process operation outside of its normal function. They are often as much a source of operator overload and consternation as help. Better engineering of the relative role of the operator and automation would materially help overcome the difficulties. Expert systems have been proposed as a solution. But Expert systems are really another form of automation. There remains that aspect of the alarms, which must address our inability to cover and understand a possibly larger domain of the operation not appropriate to traditional controls or present-day automation. Appropriate tools for this domain must support operator discretion and initiative. The paper suggests a set of such general, computer science based, tools requiring only the most basic configuration. They are viewed as implemented on top of those properly detailed alarm displays and interlocks, which reflect the more formal plant operating policies. They include: (a) Various forms of alarm logging and trending; (b) Short, automatically generated, word summaries of alarm activity, which allow low level data to propagate to the highest levels, including: one word and priority summaries; (c) Causal alarm pattern analyses that help the operator to predict or diagnose alarm behavior; (d) Automatic adaptation of alarms and alarm limits to varying process situations; (e) Uniform use of alarm policies to simplify alarm configuration.     

工序质量控制系统的研究

对工序质量控制系统的实现进行了研究.系统可生成质量控制图表对工序质量进行控制.     

The fifth generation process control architecture

The “fifth generation” architecture for process control systems will be based on the use of a “field bus” as being defined by the ISA SP50 standards committee. While a name has not yet been given to this architecture, this paper will call it “Network Control” to distinguish it from the fourth generation “Distributed Control”. While all previous generations worked to increase the operator's span of control, this new architecture will achieve most of its benefits through increased functionality and performance and decreased installed cost. One major driving force for this architecture should be the rapid segmentation of the process control market where parts of a total system would be supplied by the vendors most able to meet the user's needs at the lowest price. The effect of this will be a restructuring of the process control market, to the benefit of those users who can take advantage of the changed product offerings. While it is expected that all of the traditional process control system vendors will participate with their total product lines, they will no longer be able to control the market. The new functionality may also be the final blow to second generation pneumatic and electronic analog control systems.     

CMP process run-to-run control to adjust margin in control limit

This paper describes a run-to-run control method based on within-wafer distribution of film-thickness and removal rate. The main feature of this method incorporates adjusting the lower and upper margin of the film-thickness after CMP. The margins represent the differences of the minimum and maximum film-thickness values from the lower and upper control limits, respectively. In order to realize this concept, (1) the removal-rate within-wafer distribution is modeled as a polygonal line profile using the results of blanket-wafer polishing, (2) the removal rate at measurement sites of the product wafer is derived from the profile to adjust for differences between product types, (3) the profile is updated with the results of product wafer polishing in the work sequence, and (4) polishing time is calculated so that it satisfies the condition wherein the margin on the upper side equals the margin on the lower side within control limits to prevent film-thickness failure due to run-to-run variations. A capability index based on the margins is suggested and actual production results are shown using this index, which indicates a 71.6% improvement in accuracy and precision.     

智能控制在模具温控成形中的应用

模具的温度控制和调节是高效而经济地生产高质量成形零件的必不可少的条件.介绍了智能控制在模具温控成形过程中的应用现状,指出数值模拟对温控成形过程温度场的研究有助于控制成形过程,实现对模具温度的智能控制,使零件的质量得到充分保证.     

基于容错技术的过程控制系统的可靠性研究

对过程控制中的容错技术进行了研究,介绍了容错过程控制的基本思想,从控制系统的硬件和软件2个方面,分析,利用容错技术提高控制系统的可靠性的措施和方法,最后深度挖掘了容错设计中的关键技术。研究结果表明,容错技术可有效地保障过程控制系统的安全性和可靠性。     

Micro-burr formation and minimization through process control

This paper presents an investigation on micro-burr formation in machining. Micro-cutting is compared with conventional cutting in terms of cutting process characteristic and cutting conditions. In this paper, tungsten–carbide micro-mills were used to cut holes (in a drilling-like process) to investigate top burr formation. The size and type of burr created in stainless steel 304 are studied as a function of machining variables, which are feed, cutting speed and cutting edge radius, to help illuminate the micro-burr formation mechanisms. A series of experiments was conducted to study tool life as a function of cutting conditions. Tool life, here, is defined as the number of holes created before a significant increase in burr height. Based on experimental results, contour charts for predicting burr formation as well as tool life are developed to minimize burr formation and to improve tool life. The model, which includes the effect of feed, cutting speed, and the interaction between the two, predicted the burr height and tool life values with an accuracy of about ±15%.     

过程质量控制模型研究

在分析现有质量控制方法特点和总结传统机械加工过程质量控制模式存在的不足基础上,提出了一种以机械加工工序为控制对象、以保证与改进产品加工质量为目标的机械加工过程质量控制集成模型。该模型实现了机械加工过程的质量数据采集、处理与识别、分析与统计、决策与改进的集成。同时,介绍了基于机械加工过程质量控制集成模型的系统框架及其实现。     

可重构的工业过程远程监控系统

提出了一种以数据为中心的监控系统的逻辑结构。开发了一个监控系统重构平台,包括工程管理器、界面开发器和系统重构器等。论述了利用重构平台定制出符合不同应用要求的监控系统的步骤,描述了监控系统的重构过程及其运行的原理。     

A rule-based process control method with feedback

This paper describes a method for developing a rule-based control algorithm for process control that includes feedback and modification of the rule base from samples of the process output. The rules are used to guide the process toward the desired goal, or goals, and as the process operates new data samples allow the inference of new rules so that the process is automatically optimized and the rules for controlling the process are automatically generated.