On-machine measurement using a noncontact sensor based on a CAD model

Once a machining process is finished, an inspection process is carried out to check whether the part is within dimensional tolerances. A coordinate measuring machine (CMM) is a general metrological device for assessment of dimensions on the shop floor. It cannot be ignored, however, that CMM measurements require significant resources in operating time and cost, which has led to many studies into on-machine measurement (OMM) systems. This study aims to develop an OMM system with a noncontacting laser displacement sensing apparatus and a computer-aided design (CAD) model for ease of operation, improved operating speed, and free form profiling. The system is composed of two software modules, one for sensor alignment with the machine tool and the other for measurement based on CAD/CAM (computer-aided machining). Consequently, the system was verified on the shop floor at a numerical control (NC) machining center.     

产品数据管理(PDM)技术及其应用

文章简单介绍了产品数据管理 (PDM )技术的概念和基本功能 ,强调PDM是实施企业信息化的重要技术 ,能有效地提高企业的市场竞争能力。     

基于以太网的DNC系统的应用研究

数控系统的多样性，导致DNC系统多为专用系统。通过研究DNC结构及其运行模式，提出了一种基于以太网和RS232的混合式网络结构的集成DNC控制系统和具体的实施方案，并介绍了DNC与CAD／CAPP／CAM系统的应用集成。本系统解决了不同数控系统的互联，并且在企业中已取得了不错的效果。     

SS－CADAM微机零件CAD／CAM集成化系统

以二辊矫直机矫直辊和轴类零件为对象，在实现ＣＡＤ／ＣＡＭ集成化过程中，着重探讨：零件的形体描述和信息输入，零件数据结构，数控自动编程，数控加工过程的计算机模拟等问题。其中以ＡｎｔｏＣＡＤ图形交换文件（·ＤＸＦ文件）为基础建立的独特的零件数据结构，有效地实现了ＣＡＤ和ＣＡＭ集成中，零件几何信息和工艺信息的交换问题，对建立微机ＣＡＤ／ＣＡＭ集成化系统有普遍意义。     

硬质合金刀片锥形铣刀的CAD/CAM系统

介绍一种硬质合金刀片推形铣刀的CAD／CAM系统．本设计关键在于选择刀片在圆锥面上的位置以保证加工误差限制在允许的范围内，以及刀刃以外部分避免与被加工表面产生干涉．本系统可自动产生加工刀具所需要的数控数据。     

制造业信息化内涵及其在我国发展的现状

随着全球化竞争加剧和市场变化的加快，制造业信息化已经成为企业保持优势的必然选择，对于加入WTO后的中国来说更是意义重大。本文综合介绍了制造业中普遍应用的一些信息化技术：CAD/CAM、ERP/MRPⅡ、CIMS和电子商务的内容和应用现状、并对企业信息化的实施作了说明。     

Further investigation on the modified hyperbolic function in the CAM16 color appearance model

In the International Commission on Illumination (CIE) color appearance model CIECAM02, a modified hyperbolic function is used to represent luminance adaptation. The same nonlinear function is also used in the new color appearance model CAM16 [Color Res Appl., 2017;42:703‐718]. Although the modified hyperbolic function seems reasonable based on physiological evidence, it has an infinite slope at the origin, which causes instability for both the forward and inverse modes of the CIECAM02/CAM16 models. In this article, various possible extensions to the nonlinear luminance adaptation function in CIECAM02/CAM16 are reviewed and evaluated. Based on these investigations, the Gill extension to the hyperbolic function that is used to represent luminance adaptation [Proceedings of 16th Color and Imaging Conference, pp. 327‐331, 2008], is recommended at both the lower end (q < q_L ) and the upper end (q > q_U ), where q is the appropriate R_c , G_c , B_c (or R_wc , G_wc , B_wc ) response. In addition, the new recommended function can be readily inverted for use in the appropriate inverse appearance model. From an extensive analysis using available experimental data sets, we also propose that, for the lower and upper limits of the luminance range in the extended model, the values q_L = 0.26 and q_U = 150 be used, respectively.     

A cutting sequence optimization algorithm to reduce the workpiece deformation in thin-wall machining

A thin-wall part of lower stiffness can be subject to significant deformation during its cutting process. This study proposes a cutting process optimization algorithm to reduce the workpiece deformation. First, the volume to be removed is divided into a set of blocks. The proposed algorithm starts from the finished workpiece shape, with all the blocks removed. The objective of the proposed algorithm is to find a sequence of adding the blocks, such that the workpiece deformation is always smaller than the given threshold value when the cutting forces is imposed at each step. The workpiece deformation at each step is simulated by using the FEM (finite element method) simulation. By inverting the sequence of adding the blocks, the optimized sequence to remove the blocks can be obtained. Additionally, the block size can be modified to reduce the axial depth of cut to further reduce the workpiece deformation, or to increase the radial depth of cut to enhance the efficiency. Experiments are conducted to confirm the effectiveness of the algorithm to reduce the maximum workpiece deformation during the entire cutting process.     

An investigation of colour appearance for unrelated colours under photopic and mesopic vision

Data were obtained for the colour appearance of unrelated colours under photopic and mesopic conditions. The effects of changes in luminance level and stimulus size were investigated. The method used was magnitude scaling of brightness, colourfulness, and hue. Two stimulus sizes (10° and 0.5°) and four starting luminance levels (60, 5, 1, and 0.1, cd/m²) were used. The results at 0.1 cd/m² had large variations, so data were obtained for two additional stimulus sizes (1° and 2°) at this luminance level. Ten observers judged 50 unrelated colours. A total of 17,820 estimations were made. The observations were carried out in a completely darkened room, after 20 min adaptation; each test colour was presented on its own. Brightness and colourfulness were found to decrease with decreases of both luminance level and stimulus size. The CAM97u model predicted brightness more accurately than CIECAM02 but gave worse performance in predicting colorfulness. For hue, CAM97u and CIECAM02 both gave satisfactory predictions. Using the brightness correlate from CAM97u, a new colour‐appearance model based on CIECAM02 was developed specifically for unrelated colours under photopic and mesopic conditions, with parameters to allow for the effects of luminance level and stimulus size. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011;     

Design,refinement, implementation and prototype testing of a reconfigurable lathe-mill

This article documents the design, refinement, and implementation of a reconfigurable machine tool that provides a flexible platform for turning and milling. Advances in the design and capabilities of machine tools drive modern industry. In fact, the expanding capabilities of the machines permit novel and economic changes in the manufacturing and design of products. After the flexible manufacturing (FMS) boom, a more recent, but no less significant, area of machine development involves the reconfiguration of milling machines. This reconfigurability can also be applied to lathe-mills. The present work demonstrates satisfactorily the reconfiguration characteristics of modularity, integrability, and convertibility. We prototype and test a completely functional bench top reconfigurable lathe mill machine implemented using a $10,000 USD budget and developed following a synthesized machine tool product development methodology that begins with concept design and cutting forces to end in prototyping. In addition to reasonable results in runout, positioning, and surface roughness, the machine demonstrates the capability to produce parts with a Cpk of 1.009, thereby demonstrating the ability to fabricate this type of machine in Mexico for the local jewelry industry.