基于状态空间的制造网络输出预测与扰动因素分析

针对复杂多变的制造网络为一随机动态系统,在分析内外扰动因素对制造网络状态影响的基础上,从订单流的角度建立网络中订单概率转移矩阵;定义制造网络中制造单元的状态变量;从系统动态分析的角度选定在制品订单量作为制造网络全局最优控制的反馈状态变量,进而构建制造网络的状态空间动态模型。通过分析扰动因素对订单概率转移矩阵的影响,建立扰动状态转移方程,更新扰动因素作用下的订单概率转移矩阵,简化制造网络状态空间的求解复杂度;从控制论的角度出发,利用建立的状态空间输出方程预测制造网络扰动因素影响下的订单输出量,并采用典型输入信号分析制造单元对扰动因素的动态响应。以某结构件数控加工厂的制造网络为例,验证该模型与扰动分析方法的有效性。     

基于MAS的制造系统监控技术研究

为了提高制造系统的敏捷性和可控性,研究了基于多代理系统(MAS)的制造系统控制结构,提出一种具有监控功能的制造资源Agent模型及其信息采集模块实时信息处理的标准化流程。对制造资源Agent的功能和结构进行了详细分析,并论述了实现过程。通过该模型实现了对现场信息的采集、匹配、融合和传输,从而保证了制造系统现场信息的及时反馈。最后通过建立实验系统证明了模型的可行性。     

基于STEP的制造资源能力建模及其应用研究

分析了并行工程对制造资源的需求特点,基于ＳＴＥＰ建立了制造资源能力模型,采用面向对象技术,建立了制造资源库和制造知识库;基于制造资源和制造知识,进行零件可制造性评价与反馈,从而指导产品设计。     

An integrated object-oriented approach for design and analysis of an agile manufacturing control system

The agile manufacturing paradigm has emerged as an important concept in the development of manufacturing systems. The control software, developed based on the object-oriented technology, leads to reusability, reconfigurability, and scalability; and the agility of a manufacturing control system can be achieved. In this research, an efficient and systematic methodology for developing an object-oriented agile manufacturing control system is proposed. The proposed development process is divided into four stages: functional analysis, static structural analysis, behavior analysis and verification, and system implementation. The Integration Definition for Function Modeling (IDEF0), Object-Oriented Petri Net (OPN), and Unified Modeling Language (UML) are integrated into the corresponding stages based on their characteristics. In order to develop the system rapidly and efficiently, the transformation rules between the IDEF0 and OPN, and between the OPN and sequence diagram are conducted. In addition, the attributes and operations for each object are also defined directly from the OPN model. The result of the integrated IDEF0/OPN/UML systematically leads to object-oriented control software design for manufacturing systems. Finally, an assembly and packaging system is given to illustrate how the integrated object-oriented approach is implemented for developing the manufacturing control system.     

基于GO法的制造系统可靠性分析

可靠性是衡量制造系统性能的一个重要指标,传统方法在分析复杂系统可靠性的过程中存在很大的局限性。针对这一问题,提出了一种基于GO法的制造系统可靠性分析方法。设计了车间制造系统控制模型,该模型通过系统分析直接建立GO图,在此基础上运用状态组合算法对该模型进行了可靠性分析。分析过程证明,GO法在理论上符合严格的逻辑推导,为制造系统的可靠性分析提供了一种新的方法。     

Detecting re-design area for increasing manufacturability of drilling and three-axis pocketing operations

The intensive competition has forced the manufacturing industry to improve product quality and production efficiency, and meanwhile reduce production cost. Detecting potential manufacturability problems in early design stages would prevent unnecessary cost involved in re-work and/or re-design activities at later manufacturing stages. This paper presents an algorithm for determining re-design areas to feedback the designer when the design model involves machining holes and pockets using a three-axis computer numerical control machine. The algorithm takes into account the various sizes of tools and tool holders, and therefore allows a designer to test the manufacturability of their available cutters on their design models. A color-based obstacle-detecting method, based on layer-slicing of re-design areas, helps a designer to re-evaluate a design model for increasing manufacturability. Practical examples are provided as the output of the process.     

An integrated methodology for operations analysis of computer integrated manufacturing systems: Application to an FMS for manufacture of medical instruments

This paper contributes a novel methodology for operations analysis of computer integrated manufacturing systems. The methodology employs an integrated set of personal computer-based manufacturing systems modelling software, and is conducted in three stages. The methodology is illustrated in detail for analysis of materials flow and staffing for a flexible manufacturing system (FMS) installed at a medical instruments manufacturing plant. First, a rough-cut capacity and materials flow analysis was performed using a queueing model. Second, a detailed analysis of FMS system characteristics was conducted by creating and analysing a discrete-event simulation model. Finally, a graphical animation package was used to verify previous results and provide visual feedback on FMS system performance. Analysis results were obtained rapidly and conveniently, and were used to advise manufacturing managers regarding FMS operating policy. This analysis methodology can be applied to a wide range of computer integrated manufacturing systems and manufacturing cells.     

基于MAS的制造系统监控技术研究

为了提高制造系统的敏捷性和可控性,研究了基于MAS的制造系统控制结构,提出一种具有监控功能的制造资源Agent模型及其信息采集模块实时信息处理的标准化流程。对制造资源Agent的功能和结构进行了详细分析,并论述了实现过程。通过该模型实现了对现场信息的采集、匹配、融合和传输,从而保证制造系统现场信息的及时反馈。最后通过建立实验系统证明了该模型的可行性。     

基于LCL滤波器的谐波抑制型能量回馈器的研究

针对LCL滤波器存在谐振尖锋的问题,在电流单环控制的基础上加入了有源阻尼电流环,讨论分析了逆变器侧电流环和有源阻尼电流环的电流双闭环控制方法.在电网电压具有较高的谐波干扰下,电流双环控制不能完全抑制因扰动引起的电流谐波,故提出了重复控制器与电流双闭环结合的复合控制技术.分别从系统的稳定性、扰动抑制性、收敛性和稳态误差特性几个方面对复合控制技术进行了讨论和分析.基于Matlab/Simulink平台建立了LCL型能量回馈器逆变系统的仿真模型,进行了关键参数的调试,并对输出电流谐波含量和电网电压有谐波干扰时输出电流波形的谐波含量进行了对比.研究结果表明,基于重复控制和电流双环控制的复合控制技术的能量回馈器输出的电流谐波含量更低,对外部干扰的抑制能力更好.     

云制造环境下基于离散Markov跳变系统的机床装备资源动态优选方法

针对云制造环境下加工任务执行过程中机床装备资源易受紧急插单、加工质量异常、设备运行故障等高频随机扰动影响,致使产品加工服务质量(QoS)不能满足客户个性化需求的问题,提出一种基于离散Markov跳变系统的机床装备资源动态优化选择方法.首先,结合云制造服务运行特点,构建了云制造环境下面向加工任务执行过程的服务质量动态演化...     

一种基于Petri网的顺序共享资源AMS＊s

Ｐｅｔｒｉ网控制器自动设计及控制程序自动生成方法的研究是自动制造系统ＡＭＳｓ和柔性制造系统ＦＭＳｓ领域研究的热点问题之一〔２～６〕。本文以ＡＭＳｓ计划和调度产生的生产序列ＰＳ和资源需求序列ＲＲＳ为基础，为顺序共资源ＡＭＳｓ设计了一种规格说明语言，以自动生成ＡＭＳｓＰｅｔｒｉ网模型的矩阵形式，并给出了转换步骤。由于引入了资源状态反馈，故生成的Ｐｅｔｒｉ网模型是无死锁的。最后，用一个实例说明了设计过程。     

车间现场信息采集技术研究与系统开发

为了提高制造系统的运行效率和透明度,探讨了具有反馈功能的制造系统控制模型和数控设备运行状态信息的采集原理。采用总线型以太网和串行通信接口相结合的结构实现了针对串口设备的车间现场信息采集网络, 并且提出一种基于PLC的DNC接口开发方法。该方法通过获取PLC中I／O端口的状态达到信息采集的目的,并将这些原始信息映射为管理层和数据库系统易于识别的格式。在以上研究基础上建立的车间现场信息采集系统应用B／S架构的软件开发模式,设计了基于网络的公共数据库,各部门以数据视图的形式共享信息,由此实现了灵活的信息采集与管理,并通过试运行证明了该系统的有效性和实用性。     

SLIDING MODE CONTROL FOR ACTIVE AUTOMOBILE SUSPENSIONS

ＳＬＩＤＩＮＧＭＯＤＥＣＯＮＴＲＯＬＦＯＲＡＣＴＩＶＥＡＵＴＯＭＯＢＩＬＥＳＵＳＰＥＮＳＩＯＮＳ①ＺｈａｎｇＪｉａｎｗｕＬｉｕＸｉｎｌｉａｎｇＳｈａｎｇｈａｉＪｉａｏｔｏｎｇＵｎｉｖｅｒｓｉｔｙＡｂｓｔｒａｃｔＮｏｎｌｉｎｅａｒｃｏｎｔｒｏｌｍｅｔｈ...     

基于滑动平均订单预测的半导体生产库存模型

为满足变化莫测的市场需求与半导体制造企业复杂的制造过程,针对半导体生产企业的生产时间不确定性和订单到达不确定性,分别使用滑动平均法与指数平滑法建立客户订单预测模型,提出了基于这两种客户需求预测模型的离散反馈状态生产库存控制系统模型;讨论了这两种模型系统有界输入有界输出的稳定性,并给出了基于这两种模型的系统达到有界输入有界输出稳定的参数限制条件。使用某半导体制造企业的订单生产数据,对两种预测模型进行仿真运算,比较了这两种模型下系统生产库存控制的具体效果。仿真结果显示,两种模型都可以满足客户订单的需求。通过检验表明,滑动平均法预测模型能使半导体企业生产库存控制获得小于3%的牛鞭效应,优于指数平滑法预测模型的结果。     

Self-improving process control for molecular beam epitaxy

This paper addresses manufacturing research involving advances in material process control. The research objective has been to develop intelligent, self-directed and self-improving control systems which enablein situ (real-time) control path generation based on both product (material behaviour) and processing (control agent) feedback. A product-process control philosophy which emphasises product quality is described together with a generic architecture for representing product and process knowledge.Specific details are presented involving the development and application of a self-directed and self-improving material processing system for molecular beam epitaxy of gallium arsenide wafers. Special emphasis is given to the development of a neural model for self-improving control as well as future research directions.     

知识化制造系统中模式选择的风险评价

为解决知识化制造系统中模式选择的风险评价问题,提出了基于网络分析法和熵权系数法的风险决策方法。根据知识化制造系统的特点,对实施知识化制造模式所具有的风险因素进行了详细分析,建立了制造模式选择的网络分析法模型;考虑到风险各因素之间的依赖与反馈关系,以及避免主观判断的不确定性和随意性,提出了将主观判断与客观情况相结合的集成网络分析法和熵权系数法的新风险决策方法。实例研究表明,该方法在模式选择的风险评价中减小了人为因素的影响,提高了评价结果的科学性和公平性。     

柔性制造工作站控制模型及控制逻辑的自动生成研究

针对柔性制造工作站的特点提出的工作站控制器模型,为了实现工作站控制器控制代码的自动生成,提出了规范化Ｐｅｔｒｉ网的概念,并建立了工作站控制的ＳＰＮ模型与对象模型、ＳＰＮ模型与ＰＬＣ的梯形图代码之间的映射规划与方法,从而较好地解决了工作控制器控制代码的自动生成问题。     

柔性制造系统中OPN模型的建立

针对敏捷制造单元的特点 ,提出了一种面向对象的知识Petri网的建模方法。一方面 ,此方法建立的实时控制模型可采用数学分析手段进行模型的死锁分析 ;另一方面 ,此方法将控制 /决策知识融入到面向对象Petri网中 ,使控制系统具有一定的智能性     

Developing a location–inventory model under fuzzy environment

Process analytical technology encourages the industry to adopt innovative technologies to increase quality. The key components of this approach are better understanding the product manufacturing process, data analysis, process analytical tools, process monitoring, and continuous feedback during the manufacturing process. Remote process analytical technology over public IP networks can significantly reduce the cost of maintenances and technical support, and simplify the classical OPC-like architecture based on multiple server gateways. The requirements for using remote process analytical technology for high-speed processes are mainly concerned with cyber security and high data refresh rate on the remote monitoring machine. This work intends to evaluate a new, open application protocol named CyberOPC dedicated to CNC machines. The CyberOPC version presented in this paper supersedes the first version presented in previous papers, which had no streaming features. The CyberOPC technology is not only an open alternative to other data exchange protocols, but it also introduces streaming capabilities to gain high refresh rate on remote control stations. It is based on the Client/Server Model, where a software layer is introduced between CNC and the remote monitoring station, on the Server side of CyberOPC. Even if the case study adopts a tunneling Schema that includes server gateways, the requirements to develop protocols in embedded devices and modern CNC are fulfilled by several devices that include a TCP/IP stack.     

面向网络化制造的企业集成控制模型研究

在分析企业网络化集成控制的基础上,提出了基于CORBA与MAS的企业内部各异构系统的集成控制模型,构建了基于CORBA的MAS通信与协作模型和企业内部的集成控制体系结构,论述了内部通信的实现机制,并通过联网加工试验,验证了所构建的集成控制模型中的若干理论和实现技术。