STEP-compliant NC research: the search for intelligent CAD/CAPP/CAM/CNC integration

Since the first generation of Numerically Controlled (NC) machine tools was developed in the 1950s, there have been many developments which make today's NC machines completely unrecognizable from their early ancestors. Further developments, however, are now being significantly limited by the current programming language (ISO6983 or RS274D) that has been supporting NC manufacture since day one. Today a new standard, informally known as STEP-NC, is being used as the basis for development of the next generation of Computer Numerically Controlled (CNC) controller. This new standard is ISO 14649 and ISO 10303 AP 238. This standard gives CAM and CNC vendors the opportunity to integrate the capabilities of CAD/CAM systems with a new breed of intelligent CNC controllers, which have bi-directional communication of information representing standardized geometric and manufacturing data. This paper presents a comprehensive review of STEP-NC developments for a range of CNC processes. These developments include some major projects collaborated at the international level as well as those carried out by different groups of researchers in countries such as Germany, Switzerland, UK, Korea, USA and New Zealand. This paper also tries to portray a futuristic view of STEP-NC applications for CAD, CAPP, CAM and CNC integration, identifies the issues and challenges for STEP-NC, and provides a vision of a STEP-NC-compliant process chain supported by a product and manufacturing model.     

并行工程在CAD／CAM中的应用

在CIMS中应用并行工程，可以加快新产品开发速度，本文主要介绍CAD／CAPP并行工程系统和实现它的关键技术。     

CAD／CAM在包装工业中的应用

概述国外CAD/CAM(计算机辅助设计/计算机辅助制造)技术在包装工业中的发展;并结合我国的实际情况,展示了CAD/CAM在我国包装工业的发展前景。     

Machining error compensation using radial basis function network based on CAD/CAM/CAI integration concept

This paper presents a machining error compensation methodology using an Artificial Neural Network (ANN) model trained by an inspection database of the On-Machine-Measurement (OMM) system. This is an application of the CAD/CAM/CAI integration concept. First, to improve machining and inspection accuracies, the geometric errors of a three-axis CNC machining centre and the probing errors are compensated using a closed-loop configuration. Then, a workpiece is machined using the machining centre, and the error distributions of the machined surface are inspected using OMM. In order to analyse efficiently the machining errors, two characteristic error parameters, W err and D err , are defined. Subsequently, these parameters are modelled using a Radial Basis Function (RBF) network approach as an ANN model. Based on the RBF network model, the tool path is corrected to effectively reduce the errors using an iterative algorithm. In the iterative algorithm, the changes of the cutting conditions can be identified according to the corrected tool path. In order to validate the approaches proposed in this paper, an experimental machining process is performed, and the results are evaluated. As a result, about 90% of machining error reduction can be achieved through the proposed approaches.     

基于环球网的CAD/CAM技术

提出了开发基于Ｉｎｔｅｒｎｅｔ（中文意为环球网）的ＣＡＤ／ＣＡＭ系统的思想，并利用Ｉｎｅｔｅｒｎｅｔ中应用最普遍的ＷＷＷ服务中的上应网关接口成功地开发了基于Ｉｎｔｅｒｎｅｔ的ＣＡＤ／ＣＡＭ系统。     

The OptikDent dental CAD/CAM suite

A dental CAD/CAM system is presented that includes a 3D measurement camera for contactless measurement of the shapes of prepared teeth, or from dental impressions, together with software for reconstructing the surface profile and digital simulation of the restoring crown, in which an NC machine tool is used for the automatic production of the restoring crown made of dental ceramic. __________ Translated from Izmeritel’naya Tekhnika, No. 12, pp. 58–60, December, 2006.     

Force prediction models and CAD/CAM software for helical tooth milling processes. I. Basic approach and cutting analyses

The need for reliable quantitative machining performance information for efficient and effective use of machining operations is discussed, as are the recent developments of predictive models and modular software for forces and power in practical operations based on a unified mechanics of cutting approach. The cutting action, comprehensive predictive force models and software modules for peripheral milling, end-milling and slotting operations are developed at three levels of sophistication. The first and basic or ‘ideal case’ model assumes perfectly rigid cutters with no eccentricity and includes all the important process variables, while the second or ‘eccentricity’ model also includes the inevitable eccentricity noted in practice. The third and most sophisticated ‘deflection’ model incorporates both eccentricity and cutter deflection in addition to the many process variables. The necessity to individually study each type of milling operation in order to identify, assess and verify the appropriate predictive model is highlighted in this first paper and the findings for each operation are reported in subsequent parts of this investigation.     

CAD/CAM技术在零件加工中的应用

为研究和推广CAD/CAM技术在加工中的应用,依据CAD/CAM技术基本原理,分析CAD/CAM对机床数控系统的插补功能、刀具补偿功能等的影响,以底座零件加工为例,通过对底座零件的建模和加工过程的详细描述,阐述CAD/CAM技术在零件加工中的应用过程,说明CAD/CAM技术在零件设计和制造中的先进性和优越性。     

箱体零件CAD／CAPP／CAM集成系统的研究与实践

在ＣＩＭＳ环境下，针对箱体零件ＣＡＤ、ＣＡＰＰ、ＣＡＭ信息集成的功能需求，在基于特征的箱体零件信息模型、工艺计划模型与服务于工艺设计的制造环境模型的支持下，开发出了特征造型，工艺设计及加工过程仿真与ＮＣ编程等子系统，从而完成了一个集成化的箱体零件ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统。     

汽车制造业中的CAD/CAE/CAM集成应用

以研究院所和企业的合作事例为基础,将汽车车身覆盖件拉深模具CAE分析模型的几何信息到通用CAD/CAM平台的顺畅传递,以及应用CAM系统对模具进行数控加工建模与仿真的实现过程做实例,表明了在国内汽车设计制造企业中实现CAD/CAE/CAM集成应用的可行性和有效性.     

CAD／CAM系统中几何参数公差的辅助确定

本文从机械精加工中常用的外圆磨削着手，寻求圆柱形零件的尺寸误差、圆度误差、表面粗糙度之间的内在联系；同时考虑零件的功能要求、加工方法和加工成本，建立计算机辅助确定几何参数公差的数学模型，为ＣＡＤ／ＣＡＭ系统及其它机械设计中合理选择零件几何参数公差提供依据。     

A CAD/CAM system for spatial cams

Design and manufacture of cams are complicated engineering tasks which require usually lots of time and effort. Therefore, a CAD/CAM system for cams would be very useful. Recently, there has been an increasing demand from industry for automatic machines operating with spatial cams. This paper deals with a methodology of computer-aided design and manufacture of spatial cams. The computerized procedure is described in detail with accompanying examples     

利用CAD/CAM软件确定数控编程中未知点的坐标

针对常用未知点算法繁琐易出错,提出了用CAD/CAM软件的尺寸标注、测量、目标捕捉等功能确定零件数控编程未知点坐标的方法,并通过实例介绍了这些方法的操作步骤。与常用方法相比较,该方法具有简单、准确、方便、快捷等优点。     

CAD/CAM中曲面求交技术的研究

提出了用几何特征量来描述二次曲面和相关的边界曲线的方法，并据此研究了求交算法，避免了代数法中频繁的坐标变换，减少了浮点运算误差出现的几率，简化了曲面求交算法，使曲面求交算法更加稳定可靠。     

直角式驱动装置CAC／CAD／CAM

介绍一种分度驱动装置，由专用计算机软件选型，着重对一种型号进行结构然后采用ＢＣＡＤ软件进行计算机辅助设计，并论述该软件的主要特点，采用ＣＡＤ／ＣＡＭ功能的数控机床进行计算机辅助制造对该机床的数控机械部分进行论述。     

Recent progress in CAD/CAM laser direct-writing of biomaterials

The matrix-assisted pulsed-laser evaporation direct-write (MAPLE DW) process allows for computer-controlled deposition and machining of mesoscopic voxels of material with a high degree of spatial resolution. This article provides a review of current biomedical research activities that involve patterning of three-dimensional structures using the MAPLE DW process. Recent developments in microfabrication of hydroxyapatite-osteoblast-like cell composites, laser micromachining of differentially adherent substrates, and the influence of processing parameters (e.g., laser energy density and spot size) are discussed. The MAPLE DW process may be used to fabricate free-standing cell-seeded networks with unique geometries for tissue engineering, drug discovery, and other biomedical applications.     

几种CAD/CAM齿科全瓷修复陶瓷的磨粒磨损特性

CAD/CAM全瓷修复系统因高效率、高精度、方便性等特点在口腔修复中有着广泛的应用前景。与之配套的可切削陶瓷材料是该系统得以临床推广应用的基础,因此成为了生物材料研究的一项重要课题。本论文以80目的石英砂用MM200型摩擦磨损试验机对五种常用齿科全瓷修复材料进行了磨粒磨损试验,结合材料硬度和断裂韧性分析几种材料的磨损量,并用扫描电镜观察磨损表面形貌,对材料的磨损特性进行研究。结果表明:玻璃陶瓷(LDG)由于其脆性较大而具有较最高磨损量,磨损表面有裂纹,有明显的表面损伤;预烧结材料的磨损量小于长石质瓷,且表面形貌比长石质瓷更细致平整。     

CAD/CAPP/CAM集成系统的研究与开发

文章介绍了可实用的CAD/CAPP/CAM集成系统。该系统是由机械产品设计人员,工艺人员和数控机床NC编程人员共同努力,在商品CAD/CAM软件Pro/ENGINEER平台上开发的。系统由三个子系统组成：零件信息识别子系统,CAPP子系统和自动CAM子系统。零件信息识别子系统从三维零件中提取零件信息,CAPP子系统分析零件信息,自动生成零件加工工序和工步,从刀具数据库中查询刀具及切削用量,并完成各工序的工步排序。自动CAM子系统根据CAPP的结果,自动生成Pro/ENGINEER的NC工步,经过NC仿真后     

Evaluation of subsurface damage in CAD/CAM machined dental ceramics

Commercial ceramics for dental computer aided design/computer aided manufacture (CAD/CAM) restorations suffer from surface chipping defects and microcracking. The influence of CAD/CAM machining of dental materials on the mechanical strength and extension of the damage zone was studied. Two different commercial dental ceramics, a feldspathic porcelain and a glass–ceramic, were CAD/CAM machined according to dental practice. The extension of the damage zone was analysed by a stepwise erosion of the surface, and the biaxial flexural strength was measured. To simulate the adhesive fixing of ceramic inlays, the specimens were sealed using a light-curing monomer. The different machining behaviour is dominated by the microstructure of the investigated materials. Owing to the high amount of glassy phase, the feldspathic porcelain shows extensive microcracking and chipping defects. The extent of the damage zone can be determined as 40–60 m. Sealing of the surface did not affect the flexural strength of the machined samples. The dominating response to machining of the glass–ceramic is crushing and crumbling with a major contribution of plastic deformation on a microscopic scale. The extent of the damage zone is less than 20 m. These cracks can be bridged by sealing of the surface, resulting in a substantial increase in strength. © 1998 Chapman & Hall     

工业中CAD/CAM几何造型的研究与应用

通过形状复杂的水轮机转轮叶片的几何造型研究,提出了3DCAD／CAM在工业中的应用模式。