面向ID&E感性认知协同的机床外观造型设计研究

目的 为了解决机床防护外观设计过程中工业设计与工程的感性认知协同问题,更好地寻求和增强双方对机床外观的认知共识,提高设计的效率和明确性,进而提高我国机床产业的整体竞争力。方法 将扎根理论的定性研究与感性工学的定量研究相结合,首先通过扎根理论聚类并提炼工业设计与工程领域存在共识的感性意向词汇;然后,使用语义差异法对代表性样本进行影响因子和造型特征元素分析,明确双方可协同的机床设计元素与感性认知的映射关系;最后,基于相应具体案例需求进行设计实践。结论 明确了机床外观设计过程中关于工业设计和工程双方存在协同认知的若干影响因子及其对应的典型感性词汇,构建了面向机床防护外观设计流程的ID&E感性认知协同系统,为机床外观设计领域提供有效的方法参考和优化思路。     

桥式龙门铣床横梁结构设计与优化

横梁作为桥式龙门铣床的主要运动部件，其结构设计的优劣直接影响机床整机的工作性能。为此，提出了一种基于正交试验设计、改进模糊综合评价和尺寸灵敏度分析的横梁结构设计与优化方法。针对横梁多因素多水平的结构设计特点，采用正交试验设计挑选出8种具有代表性的参数组合作为横梁结构设计方案。运用改进模糊综合评价法对有限元仿真数据进行处理，确定参数组合为"箱中箱式-井型-20 mm-线轨"的横梁优选方案，并对其关键设计尺寸进行灵敏度分析与优化，得到横梁结构具体的设计尺寸。优化后，横梁的静力学性能和抗振性能得到明显改善，并实现了轻量化设计，对机床横梁的实际制造起到了指导作用。研究结果表明，所提出的横梁结构设计与优化方法具有较强的工程实用性，为数控机床其它关键零部件的设计提供了新思路。     

CO2角焊中手工与角焊机作业方式的对比研究

利用工作研究的技术和方法对船厂焊接操作中常用的两种CO2角焊工作方式进行了研究,建立了标准化的操作程序,并为两种工作方式建立了评价指标及评价函数,从而得出适用于两种作业方式的选择条件,为合理选择手工焊作业与角焊机作业,提高焊接作业生产效率提供了依据。     

UG集成环境下数控机床虚拟样机的实现

数控机床是一种重要的技术装备。为提高数控机床的设计水平和能力,在数控机床的设计开发过程中需要引入新的技术和设计手段。为把虚拟样机技术应用到数控机床设计开发的工程实践中,基于虚拟样机的概念讨论了数控机床虚拟样机的具体实现过程,分析比较了实现该过程的分布式软件平台和UG集成软件平台的特点。以数控铣床新产品开发为例,研究了UG集成环境下数控机床虚拟样机的构建与仿真过程,包括数字模型与装配、运动仿真、结构分析以及在虚拟样机上的加工仿真,给出了相应的示例。研究表明,应用UG的各功能模块可以有效地构建数控机床的虚拟样机并对其进行全面的仿真,使所设计的数控机床得到全面优化,为数控机床的开发设计提供了一种可行的先进方法。     

螺栓拧紧设备机器能力指数的测试评价

介绍了机器能力指数的概念.针对螺栓拧紧设备,提出一种机器能力指数的测试评价方法,包括测试评价装置和新设备及在用设备的测试评价过程,并通过应用实例对测试结果进行数据和图形分析验证.     

工程塑料在烟机配件中的应用

工程塑料的选材是烟机配件成型的基础，加工方法的选择则是烟机配件成型的保证。试验研究了三种成型方法所能达到的精度，对比了它们的材料利用率，为合理选择成型方法提供了依据。综合考虑以上因素，我们决定选用PVDF粒料混合加工成型三轮盒模，且成型配件通过组装在烟机设备中运行情况良好。本文的研究成果对工程塑料在烟机配件中的应用具有实际意义。     

基于多源融合理论的机床圆度误差测量不确定度评定

圆度误差是评价机床加工精度的重要指标.为实现机床圆度误差测量不确定度的评定,对基于球杆仪测量的机床圆度误差的贡献因素及不确定度评定方法进行研究.首先,采用最小二乘法(least sqaure method,LSM)对圆度误差进行评定.然后,基于黑箱理论提出了多源融合误差测量不确定度评定方法.接着,根据球杆仪测量机床圆度...     

力标准机独立加码与逆程交换研究

静重式力标准机在施加递增或递减负荷过程中，当砝码进行逆程交换时会出现逆负荷现象。为此，提出了力标准机独立加码的概念与方法，建立并讨论了独立加码方法的驱动方式、砝码加卸过程的运动规律、加卸过程中吊挂受力变化、加载稳定性和工作效率问题。研究了通过少量砝码的合理组合与交换，实现多力级等力值间隔加载的技术方法。当砝码进行逆程交换时，为减小以至消除逆负荷现象进行了理论分析和实验验证。结果表明，提出的方法是可行的和有效的。为力基、标准机的技术发展和提高提供了一种新的理论方法和试验依据，对力值计量检测技术的进步具有重要意义。     

机械系统人机界面匹配优度的研究

文章运用多层次模糊综合评判的方法，提出了一种用于评价机械系统人机界面匹配合理程度的评价指标——匹配优度。在该评价指标中包含有机械系统的基本参数，即机械部件的重要性和操作频率、人体生物力学数据和人体参数的统计数据。在运用它对系统进行评价时，除能够得到系统的整体评价外，还能够分别给出手操作类、脚操作类、仪表类和座椅类等组成部分的评价结果。同时，运用匹配优度可以较好地构造系统的评价模型，使之能够完整地体现评价过程中的主、客观因素所起的作用     

基于感性工学的手电钻设计

目的以感性工学的基本理论和方法为指导,完成手电钻的形态设计。方法应用层次分析法确定手电钻感性词汇;应用语意区分法建立语意区分量表;应用形态分析法将手电钻的形态设计要素进行分解;应用排队评价法完成方案的筛选。结果通过感性分析、感性工学的实现、感性评价实现了手电钻的形态设计。结论以感性工学为指导,有效地将产品形态中的感性与理性结合起来,可以让产品形态设计的过程更为科学化和系统化。     

Design model generation for reverse engineering using multi-sensors

Reverse engineering is the process of creating a design model and a manufacturing database for an existing part or prototype. The applications of reverse engineering are in redesigning of existing partstools or prototype parts where the CAD model of the part is not available. Reverse engineering, for the most part, is performed as an interactive process where the designer identifies the surface features from digitized data and then models the surfaces accordingly. This paper presents the algorithms and implementation results for a reverse engineering system which is intended to automatically create CAD representations of part prototypes. An integrated sensory system combining contact and non-contact sensors has been developed to digitize parts surfaces. The sensory system fuses data from machine vision and a coordinate measuring machine (CMM) in order to automatically digitize the part surface. Machine vision is used to capture the orthographic views of the part. The images of these orthographic views are processed and vectorized to create five views of the part in the form of an engineering drawing. The system utilizes the generated orthographic projections to automatically drive the CMM to capture a grid of point coordinates from the part surface. The CMM digitization process is guided by the segmentation provided from the orthographic views. The segmented data from the part surface is input to the surface modeling module of the system where parametric surfaces are fitted through the digitized points. The surfaces are then extended and intersected using the Hermite approximation method to develop the 3-D CAD model of the part. Accuracy and automation is achieved by combining global shape information obtained from part images with the accurate point data acquired by a CMM. Algorithms for surface segmentation, part digitization, surface extension, and surface intersection modeling are described in this paper.     

机床直线轴重复定位精度三维评价方法研究

重复定位精度是机床的一个重要性能指标，会直接影响加工产品的质量一致性。现有以直线轴运动方向的位置偏差作为评价指标的一维评价方法已经不适用于精密机床重复定位精度的评价。为了更全面地评价机床直线轴重复定位精度，提出了机床直线轴重复定位精度的三维评价方法，以球概率误差半径作为评价指标，将一维定位评价扩展到三维空间评价。首先，以卧式加工机床为例，通过齐次坐标变换建立了运动件单轴和机床的重复定位精度的数学模型，对现有一维评价方法的局限性进行分析。其次，基于卡方分布的性质，对球概率误差半径的计算过程进行简化。最后，通过简化的球概率误差半径计算方法对机床直线轴重复定位精度进行评价。以精密卧式机床的工作台为研究对象，通过实验对一维评价方法和三维评价方法进行了对比，结果表明，以球概率误差半径为评价指标的三维评价结果与定位点空间分布的离散程度基本一致。采用三维评价方法可以使机床重复定位精度的评价更加全面，可为机床整体性能的提升提供更可靠的理论指导。     

A manufacturing resource allocation method with knowledge-based fuzzy comprehensive evaluation for aircraft structural parts

Manufacturing of aircraft structural parts has the characteristics of multiple varieties, complex structures and small batches, which make the manufacturing resource allocation highly difficult. This paper proposes a manufacturing resource allocation method with knowledge-based fuzzy comprehensive evaluation, considering multiple manufacturing resources including process planners, machine tools and cutting tools, as well as manufacturing process schemes of aircraft structural parts. Knowledge in terms of experts’ experience and historical data is used for fuzzy comprehensive evaluation. A manufacturing resource allocation model is proposed based on the analysis of manufacturing processes of aircraft structural parts. The capability of planners, the complexity of structural parts, the reliability of machine tools, the reliability of cutting tools and the correlations between manufacturing resources and structural parts are evaluated using the fuzzy comprehensive evaluation method. Multiple manufacturing resources are allocated based on the fuzzy comprehensive evaluation results. A prototype system has been implemented and a case study is used to validate the proposed approach.     

Load spectra of CNC machine tools

Load spectra of CNC machine tools are described in this paper; 112 CNC machine tools have been traced for 3 years. Data including machining parameters and conditions, drawings and NC programs of parts, process cards and specifications of each individual CNC machine tool are gathered. A database containing this information is designed. The loads of CNC machine tools are calculated and the distribution parameters of loads are estimated. A fuzzy multicriteria comprehensive evaluation method is applied to evaluate the fitness of the distribution model. This methodology lays a foundation for the reliability designs of CNC machine tools. Copyright © 2000 John Wiley & Sons, Ltd.     

The efficiency and economics of small heterogeneous labour limited queueing systems

This paper presents an evaluation of heterogeneous labour patterns in small, labour limited queueing systems. Three heterogeneous labour patterns, a homogeneous labour force and two labour assignment rules are examined. The experimental systems consist of three machine centres in parallel, each with its own queue. The arrival process is Poisson, and the queue priority rule is first-come-first-served. Each machine centre contains one machine, and the service times are exponentially distributed. The number of labourers is two. The experimental model is a GERTS QR stochastic network simulator. The evaluation focuses upon the relative merits of the various labourer efficiency patterns and offers an economic interpretation of the experimental results.     

Application of power law model in reliability evaluation of machine tools by considering working condition difference

The influence of working condition difference has not been considered in the traditional reliability modeling of numerical control (NC) machine tools. To solve the problem, a reliability evaluation method based on mixture variable parameter power law model (MVPPLM) is proposed in this study. First, the scale parameter of the PLM is obtained by multi‐dimensional exponential distribution. Second, a proportional relation of failure rate function between each working condition and reference working condition is established. The proportion coefficient is solved using the partial likelihood function. Working condition factors with a significant influence on reliability levels are selected through the chi‐squared test. Third, reliability evaluation models under different working condition levels are established through mixture distributions. The mixture weight coefficient is calculated by the standard deviation of working condition covariates. The maximum likelihood estimation method is used to estimate parameters. Finally, results of a case analysis based on the data of NC machine tools in the user field tracing test show that the MVPPLM has higher precision than the traditional method. Therefore, reliability evaluation that considers working condition difference is valuable for engineering application.     

基于层次分析法和感性工学的工程车造型设计评价

目的 为了客观评价工程车造型中人为感性情感带来的模糊和不确定性因素,寻求一种科学的工程车造型设计评价方法,并对工程车造型设计各方案进行有效评价。方法 提出以层次分析法（Analytic Hierarchy Process）和感性工学（Kansei Engineering）相结合的评价方法,并将其应用于工程车设计的造型意象评价中。通过感性工学量化造型意象词汇,并确定目标意象词汇,采用层次分析方法建立造型特征与意象词汇之间的关系模型,构建影响造型意象评价的指标体系,建立模糊综合评价矩阵,计算各评价指标权重并进行综合排名。结论 将该评价方法应用于四款水泥搅拌工程车造型设计方案评价中,运用模糊隶属度函数,建立了模糊综合评价矩阵,并对各个指标的评价结果进行了量化处理,筛选出最佳造型设计方案,为项目开发提供有效参考。     

基于IAF组合法的工程项目全寿命周期风险评价

阐述和分析了组合评价法之后,指出目前组合评价法研究的不足,认为针对系统评价过程不同阶段的特点,选择相对最为有效的方法进行分阶段的串行评价更加具有实用价值.在归结了ISM、AHP、FE等方法的特点的基础上,提出IAF分阶段串行组合评价法,并归纳其特点.运用IAF组合评价法建立了工程项目全寿命周期的风险综合评价指标体系,并以两个工程项目风险为评价对象,全程阐述了IAF组合评价法的具体应用,得出了具有可比性的评价结果.     

Key performance indicators for assessing inherent energy performance of machine tools in industries

Increasing attention has been paid toward enhancing energy retrofitting in machine tools due to its enormous energy consumption and high energy-saving potential. Developing energy-efficient machine tools and selecting appropriate machine tools in procurement processes are two effective approaches for saving energy. However, existing studies on the evaluation of energy performance to support the design and selection of machine tools, rarely consider various process controls, which have considerable impact on the energy performance of machine tools. This study proposes a group of key performance indicators, which are referred to as ‘inherent energy performance’ (IEP) indexes, to support the design and selection of machine tools with the consideration of the main process controls in the usage phase and their interaction. A systematic method is introduced to acquire the IEP indexes. The method involves a simplified measurement of basic data and the calculation of the indexes from the data. A case study indicates that the proposed indicators succeed in obtaining the energy demand information of almost all machine system activities and can be used to provide basic data for developing energy information labels, selecting matching machine tools, and designing energy-efficient machine tools.     

A Two-stage Tuning Method of Servo Parameters for Feed Drives in Machine Tools

Based on the evaluation of dynamic performance for feed drives in machine tools, this paper presents a two-stage tuning method of servo parameters. In the first stage, the evaluation of dynamic performance, parameter tuning and optimization on a mechatronic integrated system simulation platform of feed drives are performed. As a result, a servo parameter combination is acquired. In the second stage, the servo parameter combination from the first stage is set and tuned further in a real machine tool whose dynamic performance is measured and evaluated using the cross grid encoder developed by Heidenhain GmbH. A case study shows that this method simplifies the test process effectively and results in a good dynamic performance in a real machine tool.