FMS 中加工质量检测与控制技术的研究

 介绍了一种新的变携式电子仪器用以采集加工质量数据。通过鲁棒统计,提出了一个鲁棒估计算法处理测量结果和误差。应用模糊集理论提出一个新的模糊逻辑控制器并实现了加工质量模糊自动控制。     

无回油槽双列内节流液体静压轴承的研究

内节流液体静压轴承结构简单、紧凑、容易保证节流精度,而且双列内节流静压轴承润滑油泄漏少,功耗小,轴的挠曲刚度高,因此有必要对这种轴承的性能进行全面的研究。根据液体静压支承理论,利用流量平衡方程,分析了无回油槽双列曲节流体静压轴承的基本性能,即受径向载荷和承受弯矩的能力,得出了一些重要结论,从而为该轴承在实际中应用提供了理论依据。     

公差分配中零件加工难易程度的模糊综合评判

在保证产品装配精度的前提下,成本高低是优选公差分配不同方案的主要指标。但是,成本与零件的尺寸大小,结构工艺性,材料的可加工性以及制定制造环境下所选加工方法的精度等因素有关。因此在装配体中如何经济合理地健全各个零件的公差是一个非常复杂的问题。通常,设计人员根据标准和凭借经验来决定零件的公差,缺乏一致性和科学性,为此,运用模糊综合评判方法来确定设计零件在特定制造环境下的加工难易程度系数Ｃ,从而为合理分     

机器人在FMS中的应用

一、引言 FMS是一种技术密集度高,资金密集度高的项目。随着用户对产品多样化的需要,制造厂商对提高产品质量、降低成本的要求以及机器人、计算机技术的迅速发展,促使了FMS的发展。世界上出现的第一套FMS     

基于工序能力的公差统计分析方法的研究

介绍了公差分析中的工序能力和工序能力指数,分析了工艺误差为正态分布、工艺误差均值漂移分别为均匀分布和正态分布时尺寸误差的统计特性,给出了装配特性的统计公差分析结果,举例说明了该公差分析方法的应用过程.     

Automatic pipes routing based on flow loss in electromechanical product

Based on flow loss,a new automatic pipe-routing algorithm is proposed for electromechanical product in 3D space,which consists of pre-processing and optimization search.Utilizing chaos theory,a chaos grid pre-processing model (CGPM) is established to efficiently pick up the solution space and reduce the search range in the pre-processing,which simplifies the optimization search.A modified particle swarm optimization (PSO) algorithm is presented to seek for an approximate optimal trajectory in the solution space in the optimization search based on standard PSO algorithm and migration characters of people.The comparison of experiments and analysis results shows that the modified PSO algorithm is capable of preventing prematurity effectively and searching for the optimal trajectory more efficiently.Theoretical analysis proves that the modified PSO algorithm converges at global optimum.The examples show that the automatic pipe-routing algorithm based on flow loss is effective and practical for electromechanical product.     

基于ARX的三维参数化特征造型

在ＡｕｔｏＣＡＤ中实现三维参数化特征造型的方法，提出了特征和参数的面向对象表示。利用数据库技术解决了ＡｕｔｏＣＡＤ参数化特征建模数据与外界的数据交换问题。     

面向自动化装配的DFA评价技术

本文论述了开展面向自动化装配生产方式的DFA评价技术研究的必要性以及研究中必须考虑的问题,并总结了这一技术中应用的主要方法和评价准则。     

动态VaR估计模型及实证

为了准确描述金融收益率序列的波动率聚集,异方差、厚尾等特性,研究我国证券市场的时变风险,本文利用极值理论和GARCH模型在处理金融数据上的优点,构造了基于GARCH-EVT的条件VaR模型,并对沪市综合指数收益率进行实证研究,结果表明,上海股市存在ARCH效应,收益率序列具有较强的自相关性;以GARCH模型为基础的条件极值方法比GARCH-正态和GARCH-t模型更好地消除了厚尾性对估计结果的影响,能更准确地捕捉风险的时变特性.     

Objective function of cost in optimal tolerance allocation

An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coefficient is derived,which takes into account of several factors affecting the manufacturing cost,including the forming means of the blank,size,machining surface features,operator’s skills and machinability of materials. The coefficient is then converted into a weight factor used in the inversed square model representing the relationship between the cost and tolerance,and,hence,an objective function for cost is established in optimizing and allocating tolerance. The higher is the manufacturing difficulty coefficient,the higher is the relative manufacturing cost and the higher is the weight factor of the tolerance allocation,which indicates the increase of the tolerance’s effects on the total manufacturing cost and,therefore,a larger tolerance should be allocated. The computer-aided tolerance allocation utilizing this model makes it more convenient,accurate and practicable.