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基于知识的动态调度决策机制研究 总被引:2,自引:0,他引:2
针对基于知识的调度系统在实际应用中存在的知识源具有主观倾向性、决策依赖部分属性等缺陷,提出了一种新的基于知识的动态调度决策方法。在此基础上设计了调度决策系统。以合同网协议为协调机制,构建了基于多Agent的动态调度框架;由调度专家经验知识获取调度规则知识,并采用投票表决法解决规则知识的冲突,在实现知识融合的同时获得规则知识的可信度;对资源的调度历史记录进行学习,获取资源的条件属性可信度;利用粗糙集中定义的奈件属性重要度,计算调度规则知识中各条件属性重要度,并对其进行归一化处理,获取条件属性权值;提出了基于模糊Petri网的知识决策模型,以条件属性可信度为托肯、条件属性权值为输入强度、规则知识可信度为输出强度进行推理,得到决策属性可信度,形成决策结果。描述了动态调度系统的知识决策过程,完成了系统分析设计。 相似文献
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一、前言在工、农业各类机械的制造和维修中,要装配或更换许多回转体零件,如皮带轮、拖拉机支重轮、轴承等。这些零件由于多为过盈配合,装拆均很困难,为解决这一问题,我们研制了一种多功能液压油缸装拆机构,该机构通过更换不同的简单部件,可迅速而有效地完成各种不同零件的拆或装,同时又可配以其它支架而成铆接装置和挤压装置。二、液压系统的结构和工作原理 相似文献
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在制造装备的维修决策中维修需求的正确识别决定了维修资源配置的合理性.在制造装备的功能部件层面上,将基于Rough集的连续值多属性决策模型运用到维修需求识别中.以关键部件单元的具有连续值特征的运行状态信息作为维修决策的条件属性,以维修级别的确认决策作为系统的决策属性,实现装备制造系统的维修需求识别知识的表示、挖掘和决策知识的应用.该方法能较好地解决维修决策知识的获取及知识应用的问题.最后给出了某数控机床关键减速箱维修需求识别的实例,验证了该方法的可行性和有效性. 相似文献
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基于实例推理的可倾瓦推力轴承方案设计 总被引:3,自引:0,他引:3
可倾瓦推力轴承的传统设计方法存在过程复杂、过分依赖设计者经验,以及缺乏积累和继承设计知识的问题,为此,提出了基于实例推理的设计方法,为进一步提高基于实例推理系统的实例榆索效率和质量,对系统中实例表示、相似实例匹配和实例重用三个关键技术环节进行了改进,引入相似理论和相似系统理论的基本原理,分别提出了以相似准则作为重要属性的实例表示方法,基于敏感性分析的属性权重配置算法,以及基于属性差异度的相似性度量方法.在实例莺用方面,提出了将最相似实例按照结构特性生成初始方案后再对其进行评价和修改的方法,以降低方案修改的难度和复杂性.最后,通过一个可倾瓦推力轴承的设计案例,验证了所提方法的可行性和有效性. 相似文献
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提出了制造系统的八面体总体决策框架模型.以成本、时间、质量、柔性、环境性和安全性作为制造系统总体优化的决策属性目标,通过恰当地选取决策变量和建立技术经济模型,完成从各个决策变量到六大决策属性的映射,使整个决策过程建立在科学根据和科学分析的基础上,从而实现各个制造决策属性的总体优化. 相似文献
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Chulho Chung Qingjin Peng 《The International Journal of Advanced Manufacturing Technology》2006,31(1-2):125-134
A product assembly or disassembly is completed by means of proper tools. The selection of feasible tools is an important process in planning a complete assembly or disassembly sequence. A key tooling consideration in assembly or disassembly planning is to reason the available space for a tool application during the assembly or disassembly of a product. Currently, assembly tool reasoning about space mainly depends on simulation-based or user-interactive approaches because of its computational complexity. These approaches are inappropriate in dealing with various what-if scenarios regarding assembly or disassembly planning in a rapid product development. They also depend on users’ expertise or experience in assembly or disassembly. This paper presents a novel approach to the geometric feasibility analysis for fast assembly tool reasoning. Techniques described in this paper are advantageous not only in the aid of generating a complete assembly or disassembly plan but also in the efficient support of such systems as computer-aided assembly planning (CAAP), design for manufacturing (DFM), design for assembly (DFA), design for disassembly (DFD), and computer-aided tool selection (CATS). 相似文献
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Disassembly modeling, planning, and leveling for a cam-operated rotary switch assembly: a case study
S. Vinodh R. Praveen Kumar N. Nachiappan 《The International Journal of Advanced Manufacturing Technology》2012,62(5-8):789-800
The manufacturing organizations have been witnessing a paradigm shift on designing products and services from manufacturing to sustainability. Product disassembly is a vital strategy for industrial recycling and remanufacturing which generates the desired parts and/or subassemblies by means of separation of a product into its elements. This article presents the appropriate methods for modeling planning and leveling the disassembly process of a cam-operated rotary switch assembly. The methodology involves disassembly modeling using a graphical approach. Disassembly process planning has been done using reverse assembly approach. Disassembly leveling has been done to maintain profitability and environmental features at a desired level. An optimal disassembly sequence has been derived using disassembly leveling. The resultant cost of disassembly for reusable components has been computed. The article presents a unique contribution to the field of designing for disassembly from the perspective of rotary switches. 相似文献
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针对报废汽车拆解前的成本评估问题,建立了一种基于拆解难度和模糊聚类的一般性综合成本评价模型。提出了影响报废汽车拆解难度的因素,通过模糊聚类分析确定不同车型在拆解过程中具有相同拆解难度的零组件;给出了聚类模型的拆解成本误差评价方法。以4台3类报废实验车型(轿车、运动型多用途汽车(SUV)、多用途汽车(MPV))的物理拆解实验数据为例,量化评价了基于模糊聚类的泛化拆解成本模型,结果表明,该模型具备各类车型的共性聚类特征,拆解成本最大误差低于28%。建立的拆解成本预测模型为报废汽车拆解企业关于拆解内容的决策问题提供了方法依据。 相似文献
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RESEARCH ON PROCESS AND PLAN OF DISASSEMBLY 总被引:2,自引:0,他引:2
Hu Junjun Multimedia Research Division Guangdong Telecommunication Academy of Science Technology Li Chenggang Hu Yujin Cai Xueyuan Zhou Ji Huazhong University of Science Technology 《机械工程学报(英文版)》2001,(1)
0 INTRODUCTIONProductdisassemblyisabasic problemintheareaoflifecycle ,thishasbeen provenbythreeaspectsasfollowing :(1)Disassemblyfortransport Someproductmustproperlybedisassemblyforeasetotransport,suchastofitthesizeofcontainer (2 )Disassemblyforservice Disass… 相似文献
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Diana Popescu Robert Iacob 《The International Journal of Advanced Manufacturing Technology》2013,69(5-8):1511-1525
The impact of the disassembly process on the design of a product is a recognized fact, influencing recycling, maintenance, repair, and component/material re-using—essential aspects for a sustainable development. For simplifying and improving their work, as well as for designing proper and efficient disassembly plans, it is important for engineers to benefit from a disassembly method, for automatically generating dismounting sequences, incorporated in a software solution for providing rapid disassembly information that can be further used for real-time immersive simulations. The disassembly method proposed in this paper is based on two innovative elements: the connection interface concept and the mobility operator that integrates information on geometrical constraints, contact surface relative position and common area, neighboring components, and relative mobilities of the assembly components. All these data are corroborated with knowledge-based criteria and are used to generate a set of connection interfaces for a product to define mechanical joints, automating the identification of fasteners in the assembly and determining the components’ mobility within assembly. As a consequence, it is possible to calculate and realistically simulate components’ disassembly paths. In the proposed method, valid disassembly trajectories of a component relative to its surrounding ones are modeled based on the mobility operator, the swept volume approach is used to evaluate collisions between components, and finally, the disassembly sequences are determined through an improved layer peeling technique. 相似文献
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通过基于网络的维修向导系统的支持 ,让用户方便、正确地自己进行维护维修 ,将有助于企业服务水平的提高 ,而维修工艺的自动生成则是实现网络化维修服务的关键问题之一。现对面向维修的产品结构描述、拆 /装顺序关系描述和维修工艺的自动生成方法进行了讨论与分析 相似文献
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为了解决装配结构复杂的产品拆卸序列规划中因数据组合爆炸而导致运算量剧增的问题,首先分析了典型装配体的拆卸特点,以零件自由度交集的运算结果作为拆卸方向的判断依据,提出了约束消除的概念,进而通过启发式算法实现了拆卸序列的自动生成;为了提高拆卸序列规划的运算效率和计算结果的实用性,引入了以装配关系为基础的层次化结构模型,通过逐层分解的方法降低了装配结构深度,避免了从整个复杂装配体上求单一零件的拆卸序列,达到了减少运算的目的;最后以简化的汽车为例,阐述了基于结构模型的拆卸序列规划过程。研究结果表明,以层次化结构模型为基础、以约束消除为原则的拆卸序列规划能有效降低运算量,从而控制复杂产品的数据组合爆炸问题。 相似文献
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简要介绍了VRML语言定义、特点,阐述了机械零部件虚拟建模方法。对虚拟装配流程进行分析,并对产品装/拆运动的表示形式、虚拟装配路径规划及逻辑控制、虚拟装配过程中的碰撞检测方法等关键技术进行了研究,提出了产品装/拆运动12元组表示形式。最后,通过对机械产品交互式虚拟装配进行实例仿真,验证了该技术的可行性和合理性。 相似文献
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为了提高机械产品在装配设计、结构设计和培训等方面的效率,介绍一种以Unity3D引擎为工具,基于虚拟现实技术,可在智能手机上流畅运行的机械产品拆装系统。首先,将三维模型从专业设计软件导入到3DMax中,简化零件模型的面数,构建场景模型; 其次,在Unity3D中设计World Space交互菜单,提供简洁友好的虚拟交互方式,通过C#语言,在智能手机上实现双目立体视觉、陀螺仪头部跟踪、交互外设适配及控制和角色控制器; 最后,以二级减速器为例,在智能手机上实现拆装展示。实验结果表明,该系统人机交互性能良好,具有高度的沉浸感,可以满足机械产品虚拟拆装的需求。 相似文献
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针对传统装配序列规划方法解空间大、模型简单的问题,提出了应用虚拟现实技术解决船舶装配序列规划问题的方法。该方法分为虚拟拆卸和方案评价两个阶段,分析了虚拟装配平台上进行虚拟拆卸的基本流程和关键技术——虚拟环境下的实体模型表达和基于装配约束的运动导航。建立了船舶装配序列评价模型,确定了零件重量、装配时间、装配稳定性和装配过程难度等面向手工装配的评价指标。最后,用某船舶机舱区域的规划实例进行了验证,结果表明该方法生成的装配序列对实际船舶装配生产具有指导作用。 相似文献