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STUDY ON THE COMPENSATION TECHNIQUE OF POSITIONING ERRORS FOR NC MACHINE TOOLS
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作者 章青 张海根 +1 位作者 张志飞 刘又午 《Transactions of Tianjin University》 EI CAS 1998年第2期76-79,共4页
Through analysis of the basic transformation of a typical body,the error transformations of the position vector and the displacement vector are employed,a general model for positioning errors of NC machine tools by us... Through analysis of the basic transformation of a typical body,the error transformations of the position vector and the displacement vector are employed,a general model for positioning errors of NC machine tools by using kinematics of the multi body system is discussed.By means of 8031 single chip system,intelligent error compensation controller has been developed.The results of experiments on XH714 machining center show that the positioning accuracy is enhanced effectively by more than 50%. 展开更多
关键词 nc machine tools multi body system ERROR transformation matrix
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Algorithm for Detecting Volumetric Geometric Accuracy of NC Machine Tool by Laser Tracker 被引量:13
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作者 WANG Jindong GUO Junjie 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第1期166-175,共10页
Quick and accurate detecting the error of NC machine tool and performing the error compensation are important to improve the machining accuracy of NC machine tool. Currently, there are many methods for detecting the g... Quick and accurate detecting the error of NC machine tool and performing the error compensation are important to improve the machining accuracy of NC machine tool. Currently, there are many methods for detecting the geometric accuracy of NC machine tool. However, these methods have deficiencies in detection efficiency and accuracy as well as in versatility. In the paper, a method with laser tracker based on the multi-station and time-sharing measurement principle is proposed, and this method can rapidly and accurately detect the geometric accuracy of NC machine tool. The machine tool is controlled to move in the preset path in a 3D space or 2D plane, and a laser tracker is used to measure the same motion trajectory of the machine tool successively at different base stations. The original algorithm for multi-station and time-sharing measurement is improved. The space coordinates of the measuring point obtained by the laser tracker are taken as parameter values, and the initial position of each base point can be determined. The redundant equation concerning the base point calibration can be established by the distance information of the laser tracker, and the position of each base point is further determined by solving the equation with least squares method, then the space coordinates of each measuring point can be calibrated. The singular matrix does not occur in calculation with the improved algorithm, which overcomes the limitations of the original algorithm, that the motion trajectory of machine tool is in a 3D space and there exits height difference between the base stations. Adopting the improved algorithm can expand the application of multi-station and time-sharing measurement, and can meet the quick and accurate detecting requirements for different types of NC machine tool. 展开更多
关键词 laser tracker nc machine tool geometric accuracy redundant equation singular matrix least square method
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Bayesian Reliability Modeling and Assessment Solution for NC Machine Tools under Small-sample Data 被引量:16
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作者 YANG Zhaojun KAN Yingnan +3 位作者 CHEN Fei XU Binbin CHEN Chuanhai YANG Chuangui 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第6期1229-1239,共11页
Although Markov chain Monte Carlo(MCMC) algorithms are accurate, many factors may cause instability when they are utilized in reliability analysis; such instability makes these algorithms unsuitable for widespread e... Although Markov chain Monte Carlo(MCMC) algorithms are accurate, many factors may cause instability when they are utilized in reliability analysis; such instability makes these algorithms unsuitable for widespread engineering applications. Thus, a reliability modeling and assessment solution aimed at small-sample data of numerical control(NC) machine tools is proposed on the basis of Bayes theories. An expert-judgment process of fusing multi-source prior information is developed to obtain the Weibull parameters' prior distributions and reduce the subjective bias of usual expert-judgment methods. The grid approximation method is applied to two-parameter Weibull distribution to derive the formulas for the parameters' posterior distributions and solve the calculation difficulty of high-dimensional integration. The method is then applied to the real data of a type of NC machine tool to implement a reliability assessment and obtain the mean time between failures(MTBF). The relative error of the proposed method is 5.8020×10-4 compared with the MTBF obtained by the MCMC algorithm. This result indicates that the proposed method is as accurate as MCMC. The newly developed solution for reliability modeling and assessment of NC machine tools under small-sample data is easy, practical, and highly suitable for widespread application in the engineering field; in addition, the solution does not reduce accuracy. 展开更多
关键词 nc machine tools reliability BAYES mean time between failures(MTBF) grid approximation Markov chain Monte Carlo(MCMC)
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STUDY ON NEW METHOD OF IDENTIFYING GEOMETRIC ERROR PARAMETERS FOR NC MACHINE TOOLS 被引量:1
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作者 Yun Jintian,Wang Shuxin,Liu Libing,Liu Youwu (College of Mechanical Engineering, Tianjin University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2001年第3期198-202,206,共6页
The methods of identifying geometric error parameters for NC machine tools are introduced. According to analyzing and comparing the different methods, a new method-displacement method with 9 lines is developed based o... The methods of identifying geometric error parameters for NC machine tools are introduced. According to analyzing and comparing the different methods, a new method-displacement method with 9 lines is developed based on the theories of the movement errors of multibody system (MBS). A lot of experiments are also made to obtain 21 terms geometric error parameters by using the error identification software based on the new method. 展开更多
关键词 nc machine tools Geometric error Parameter identification Multibody system
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Assessment Method of Heavy NC Machine Reliability Based on Bayes Theory 被引量:1
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作者 张雷 王太勇 胡占齐 《Transactions of Tianjin University》 EI CAS 2016年第2期105-109,共5页
It is difficult to collect the prior information for small-sample machinery products when their reliability is assessed by using Bayes method. In this study, an improved Bayes method with gradient reliability(GR) resu... It is difficult to collect the prior information for small-sample machinery products when their reliability is assessed by using Bayes method. In this study, an improved Bayes method with gradient reliability(GR) results as prior information was proposed to solve the problem. A certain type of heavy NC boring and milling machine was considered as the research subject, and its reliability model was established on the basis of its functional and structural characteristics and working principle. According to the stress-intensity interference theory and the reliability model theory, the GR results of the host machine and its key components were obtained. Then the GR results were deemed as prior information to estimate the probabilistic reliability(PR) of the spindle box, the column and the host machine in the present method. The comparative studies demonstrated that the improved Bayes method was applicable in the reliability assessment of heavy NC machine tools. 展开更多
关键词 heavy nc machine reliability assessment Bayes method prior information
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The Application of the GM(1,1) Metabolism Model to Error Data Processing of NC Machine Tools 被引量:1
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作者 LIAODe-gang XIONGXiao-hong 《International Journal of Plant Engineering and Management》 2003年第2期103-107,共5页
This paper applied the gray system theory to error data processing of NCmachine tools according to the characteristic. It presented the gray metabolism model of error dataprocessing. The test method for the model need... This paper applied the gray system theory to error data processing of NCmachine tools according to the characteristic. It presented the gray metabolism model of error dataprocessing. The test method for the model needs less capacity. Practice proved that the method issimple, calculation is easy, and results are exact. 展开更多
关键词 nc machine tools gray system ERROR data processing
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Research on virtual dynamic optimization design for NC machine tools
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作者 胡如夫 崔仲华 +1 位作者 陈晓平 孙庆鸿 《Journal of Coal Science & Engineering(China)》 2006年第2期100-103,共4页
Virtual dynamic optimization design can avoid the repeated process from de-sign to trial-manufacture and test.The designer can analyze and optimize the productstructures in virtual visualization environment.The design... Virtual dynamic optimization design can avoid the repeated process from de-sign to trial-manufacture and test.The designer can analyze and optimize the productstructures in virtual visualization environment.The design cycle is shortened and the costis reduced.The paper analyzed the peculiarity of virtual optimization design,and put for-wards the thought and flow to implement virtual optimization design.The example to opti-mize the internal grinder was studied via establishing precise finite element model,modi-fying the layout of Stiffened Plates and designing parameters of the worktable,and usingthe technology of modal frequency revision and the technology of multiple tuned damper.The result of optimization design compared the new grinder with the original grinder showsthat the entire machine's first orders natural frequency is enhanced by 17%,and the re-sponse displacement of the grinding-head has dropped by 28% under the first order natu-ral frequency and by 41% under second order natural frequency.Finally,the dynamic per-formance of the internal grinder was optimized. 展开更多
关键词 nc machine tools virtual design dynamic design optimization design
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Series Design of Large-Scale NC Machine Tool
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作者 TANG Zhi 《Journal of China University of Mining and Technology》 EI 2007年第2期272-276,共5页
Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product s... Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product system de-sign in China. Therefore,in terms of a concept of product generation and product interaction we are in a weak position compared with the requirements of global markets. Today,the idea of serial product design has attracted much attention in the design field and the definition of product generation as well as its parameters has already become the standard in serial product designs. Although the design of a large-scale NC machine tool is complicated,it can be further optimized by the precise exercise of object design by placing the concept of platform establishment firmly into serial product de-sign. The essence of a serial product design has been demonstrated by the design process of a large-scale NC machine tool. 展开更多
关键词 large-scale nc machine tool series product design optimized design
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METHOD OF ENHANCING THE POSITIONING ACCURACY FOR NC MACHINE TOOLS 被引量:3
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作者 Zhang Qing Liu Youwu +3 位作者 Fan Jinwei Wang Shuxin Wang Xiaoshong Wu Jianhua (Tianjin University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1996年第4期292-299,共2页
Based on the kinematics of the multi-body system , a general model for the positioning errors of NC machine tools by means of the lower numbered body array and the geometric constraint is presented. The parameters ide... Based on the kinematics of the multi-body system , a general model for the positioning errors of NC machine tools by means of the lower numbered body array and the geometric constraint is presented. The parameters identification of geometric errors by an improved 22-line method is discussed. Moreover , an intelligent error compensation controller has been developed. All these are verified by a series of experiments on XH714 machining center. The results show that the prosition- ing errors with compensation have been reduced to ±7 μm from 50 μm. 展开更多
关键词 nc machine tool Multi-body system Parameter identification
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Research on Visual Virtual Design Platform for NC Machine Tools
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作者 HU Rufu 1,2 ,CHEN Xiaoping1,SUN Qinghong2 (1.School of Transportation and Traffic,Ningbo University of Technology,Ningbo 315016,China 2.Department of Mechanical Engineering,Southeast University,Nanjing 210096,China) 《武汉理工大学学报》 CAS CSCD 北大核心 2006年第S1期196-200,共5页
The fundamental ideas on building the collaborative design platform of virtual visualization for NC machine tools are introduced. The platform is based on the globally shared product model conforming to the STEP Stand... The fundamental ideas on building the collaborative design platform of virtual visualization for NC machine tools are introduced. The platform is based on the globally shared product model conforming to the STEP Standard,and used PDM system to integrate and encapsulate CAD/CAE and other application software for the product development. The platform also integrated the expert system of NC machine tools design,analysis and estimation. This expert system utilized fuzzy estimation principle to evaluate the design and simulation analysis results and make decisions. The platform provides the collaborative intelligent environment for the design of virtual NC machine tools prototype aiming at integrated product design team. It also supports the customized development of NC machine tools. 展开更多
关键词 VIRTUAL design nc machine TOOLS PDM STEP EXPERT system
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An Universal Modeling Method for Enhancing the Volumetric Accuracy of CNC Machine Tools 被引量:3
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作者 FAN Jin-wei, GUAN Jia-liang, WANG Wen-chao, LUO Qi, ZHANG Xiao-long, WANG Ling-yu (Department of Mechanical and Applied Electronic Engineering, Beijing Polytechnic University, Beijing 100022, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期148-149,共2页
Volumetric error modeling method is an important te ch nique for enhancement the accuracy of CNC machine tools by error compensation. I n the research field, the main question is how to find an universal kinematics m ... Volumetric error modeling method is an important te ch nique for enhancement the accuracy of CNC machine tools by error compensation. I n the research field, the main question is how to find an universal kinematics m odeling method for different kinds of NC machine tools. Multi-body system theor y is always used to solve the dynamics problem of complex physical system. But t ill now, the error factors that always exist in practice system is still not con sidered. In this paper, the accuracy kinematics of MBS (multi-body system) are developed by adding the movement error items and the positioning error items for every couple of adjacent bodies. After make an analysis for different kinds of NC machine tools we can find that NC machine tools can be looked as a kind of sp ecial MBS. It’s main construction only contains two movement branch. the one is from base part to workpiece and the other is from base part to cutter. So an u niversal volumetric error modeling method and the error analysis method for NC m achine tools can be built in this paper based on MBS theory. The essential condi tion for precision machining is derived through mathematics equations and the co ncept of ICCP (inverse changed cutter path ) and ICNI (inverse changed NC instru ction ) are presented in this paper. The numerical solution methods for ICCP and ICNI are also given in this paper which can be directly used to enhance the mac hining accuracy of NC machine tools. In order to verifying the above works, the double frequency laser interface detecting instrument of RENISHAW is used to mea sure the error parameters of the MAKINO 3-axis NC machine tools and the softwar es are developed using C++ developing language to simulate the cutte r trail under different kind conditions in the computer. Latterly the standard w ork parts are selected to be machined on the MAKINO 3-axis NC machine tools bef ore and after use the above mentioned error compensation method respectively. Th e simulation and experiment results show that the volumetric error modeling meth od is effective and the machining accuracy of CNC machine tools can be improved more than 60% after using the compensation method presented in this paper. 展开更多
关键词 error compensation nc machine multi-body syste m
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Bayesian zero-failure reliability modeling and assessment method for multiple numerical control(NC) machine tools 被引量:2
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作者 阚英男 杨兆军 +3 位作者 李国发 何佳龙 王彦鹍 李洪洲 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第11期2858-2866,共9页
A new problem that classical statistical methods are incapable of solving is reliability modeling and assessment when multiple numerical control machine tools(NCMTs) reveal zero failures after a reliability test. Thus... A new problem that classical statistical methods are incapable of solving is reliability modeling and assessment when multiple numerical control machine tools(NCMTs) reveal zero failures after a reliability test. Thus, the zero-failure data form and corresponding Bayesian model are developed to solve the zero-failure problem of NCMTs, for which no previous suitable statistical model has been developed. An expert-judgment process that incorporates prior information is presented to solve the difficulty in obtaining reliable prior distributions of Weibull parameters. The equations for the posterior distribution of the parameter vector and the Markov chain Monte Carlo(MCMC) algorithm are derived to solve the difficulty of calculating high-dimensional integration and to obtain parameter estimators. The proposed method is applied to a real case; a corresponding programming code and trick are developed to implement an MCMC simulation in Win BUGS, and a mean time between failures(MTBF) of 1057.9 h is obtained. Given its ability to combine expert judgment, prior information, and data, the proposed reliability modeling and assessment method under the zero failure of NCMTs is validated. 展开更多
关键词 Weibull distribution reliability modeling BAYES zero failure numerical control(nc) machine tools Markov chain Monte Carlo(MCMC) algorithm
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YKJ3180H Economy NC Gear Hobbing Machine
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作者 China Association of Machine ToolsIndustry 《China's Foreign Trade》 1996年第10期40-40,共1页
The YKJ3180H Economy NC GearHobbing Machine is a new variety,developed recently by the ChongqingMachine Tools Works to meet clients’demands. Its most prominent feature is its highproduction efficiency ( able to compl... The YKJ3180H Economy NC GearHobbing Machine is a new variety,developed recently by the ChongqingMachine Tools Works to meet clients’demands. Its most prominent feature is its highproduction efficiency ( able to complete awork cycle automatically), high processingprecision (Grade 7 or higher according to theGB 10095) and its cost competitiveness. This product is used in the machinetool and machinery industries at automobiles,tractors, gears and gear box factories. It canbe used for processing spur gears and helicalgears, automatic radial feed wormwheels,tapered gears and crowning gears; so it isespecially applicable in factories usingcrowning gear couplings, such as metallurgy,mining, lifting transport and the chemicalmachinery. 展开更多
关键词 nc YKJ3180H Economy nc Gear Hobbing machine
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Error Analysis and Its Offset on the NC Lathe Machine in Cutting a Semi-Sphere Surface
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作者 ZHENG Yu-cai LI Cheng-zhi LIU Chang-rong LIU Tao GUO Xiu-hua 《International Journal of Plant Engineering and Management》 2007年第4期221-226,共6页
This paper analyzed the errors that occurred by leaving the shape of the cutting edge out of consideration on a NC lathe machine in cutting a semi-sphere surface and brought forward a method to offset these errors and... This paper analyzed the errors that occurred by leaving the shape of the cutting edge out of consideration on a NC lathe machine in cutting a semi-sphere surface and brought forward a method to offset these errors and the correct calculated formula for some parameters on the basis of experiments. It has increased the manufacturing accuracy of the semi-sphere surface on the NC lathe machine. 展开更多
关键词 nc lathe machine semi-sphere error analysis
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一种基于PC-NC的免编程数控系统的CAM处理方法
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作者 甘玉轩 莫海杰 +2 位作者 张锦源 万军杨 钟文浩 《工业控制计算机》 2024年第9期67-69,72,共4页
基于PC-NC的新型数控系统平台,既能保证数控系统必需的稳定可靠性,又能充分利用PC机的应用普及优势,是为满足快速增长的无需编程数控系统市场需求而进行的数控技术应用创新。来源于国内各行众多小微规模工厂的各类材料的零配件、磨具数... 基于PC-NC的新型数控系统平台,既能保证数控系统必需的稳定可靠性,又能充分利用PC机的应用普及优势,是为满足快速增长的无需编程数控系统市场需求而进行的数控技术应用创新。来源于国内各行众多小微规模工厂的各类材料的零配件、磨具数控深加工需求量巨大,针对这类需求介绍一种免数控编程的CAM处理方法,在PC端直接画图或导入异形工件图形,经过识别统一抽象解析为简单的直线和圆弧,结合用户工艺设置信息封装形成链表数据结构,经过数据分类转换、刀具路径偏移处理、工艺类型处理形成G代码,再下发到数控系统NC运行,整个处理过程用户只需选图做工艺设置,无需数控编程,提升了生产加工效率,降低了数控系统使用门槛和成本。 展开更多
关键词 PC-nc 免数控编程 G68.2倾斜面加工 基础数据 点数据
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Identification of the key thermal points on machine tools by grouping and optimizing variables 被引量:1
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作者 梁睿君 叶文华 +2 位作者 罗文 俞辉 杨琪 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第4期87-93,共7页
The grouping and optimization approach to identify the key thermal points on machine tools is studied.To solve the difficulty in grouping because of the high correlated variables from distinct groups,the variables gro... The grouping and optimization approach to identify the key thermal points on machine tools is studied.To solve the difficulty in grouping because of the high correlated variables from distinct groups,the variables grouping technique is improved.Temperature variables are sorted according to their relativities with the thermal errors.The representative temperature variables are determined by analyzing the variable correlation in sort order and removing the other variables in the same group.Considering the diverse effect of importing the different variables on thermal error model,the method of variable combination optimization is improved.Regression models made up of different combination of representative temperature variables are evaluated by the index of both the determined coefficient and the average residual squares to select the combination of the temperature variables.For the machine tools with complicated structures which need more initial temperature measuring points the improvement is demanded.The improved approach is applied to a precision horizontal machining center to identify the key thermal points.Experimental results show that the proposed approach is capable of avoiding the high correlation among the different groups' variables,effectively reducing the number of the key thermal points without depressing the prediction accuracy of the thermal error model for machine tools. 展开更多
关键词 nc machine tools error compensation thermal error key thermal points fitting accuracy
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Machining Line Planner输出STEP-NC数控程序的研究 被引量:1
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作者 樊留群 刘玉平 《制造技术与机床》 CSCD 北大核心 2010年第7期88-91,共4页
介绍了STEP-NC的概念、数据模型及其结构特点,然后通过对比MLP(Machining Line Planner)和STEP-NC数控程序对特征和操作的不同定义方法,分析了在MLP中特征及加工工艺与STEP-NC的对应关系,探讨了在MLP中实现输出STEP-NC格式的零件加工程... 介绍了STEP-NC的概念、数据模型及其结构特点,然后通过对比MLP(Machining Line Planner)和STEP-NC数控程序对特征和操作的不同定义方法,分析了在MLP中特征及加工工艺与STEP-NC的对应关系,探讨了在MLP中实现输出STEP-NC格式的零件加工程序的方法。 展开更多
关键词 STEP-nc数据模型 数控程序 machinING LINE PLANNER
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PLANNING METHOD OF TOOL ORIENTATION IN FIVE-AXIS NC MACHINING
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作者 姬俊锋 周来水 +1 位作者 安鲁陵 张森棠 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2009年第2期83-88,共6页
The planning method of tool orientation in the five-axis NC machining is studied. The problem of the existing method is analyzed and a new method for generating the global smoothing tool orientation is proposed by int... The planning method of tool orientation in the five-axis NC machining is studied. The problem of the existing method is analyzed and a new method for generating the global smoothing tool orientation is proposed by introducing the key frame idea in the animation-making. According to the feature of the part, several key tool orientations are set without interference between the tool and the part. Then, these key tool orientations are inter- polated by the spline function. By mapping the surface parameter to the spline parameter, the spline function value is obtained and taken as the tool orientation when generating the CL file. The machining result shows that the proposed method realizes the global smoothing of the tool orientation and the continuity of the rotational speed and the rotational acceleration. It also avoids the shake of the machine tool and improves the machining quality. 展开更多
关键词 computer aided mamufacturing nc machining TOOLS FIVE-AXIS
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基于修改NC程序的加工中心软件误差补偿技术 被引量:1
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作者 于长有 张丽 《安徽水利水电职业技术学院学报》 2023年第1期52-56,共5页
文章采用水平分割法确定误差补偿点,对3种运动指令修改算法,实现定位指令、直线插补指令和圆弧插补指令的算法修改。在FANUC Series oi-mate系统VMC-850立式加工中心上运行基于修改NC程序的误差补偿软件,进行对比验证,结果表明补偿后加... 文章采用水平分割法确定误差补偿点,对3种运动指令修改算法,实现定位指令、直线插补指令和圆弧插补指令的算法修改。在FANUC Series oi-mate系统VMC-850立式加工中心上运行基于修改NC程序的误差补偿软件,进行对比验证,结果表明补偿后加工精度提高30%左右。 展开更多
关键词 加工中心 nc程序 软件 误差补偿
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基于MachineWorks的复杂数控加工环境仿真的研究 被引量:1
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作者 翁孝波 吴文江 王品 《组合机床与自动化加工技术》 北大核心 2015年第9期114-117,121,共5页
当前存在的一些商品化数控加工仿真系统通常作为一个独立于数控系统的程序而很难集成入当前数控系统中,为此有些情况下需要依据数控系统的实际情况开发数控加工仿真系统,但是当前存在的一些开发方案都或多或少存在一些问题,如开发周期... 当前存在的一些商品化数控加工仿真系统通常作为一个独立于数控系统的程序而很难集成入当前数控系统中,为此有些情况下需要依据数控系统的实际情况开发数控加工仿真系统,但是当前存在的一些开发方案都或多或少存在一些问题,如开发周期长、灵活性差。本文仔细研究了数控加工仿真系统的几个关键技术和几类常用开发方案,采用了基于专用的数控加工仿真系统库——MachineWorks的开发方案,结果显示这种方案对开发量过大和灵活性不足的问题做出相应折衷,能方便的集成入当前的数控系统中,同时能够减少开发工作量。并且本文针对一般CAM或加工仿真软件只进行零件刀具轨迹或中间文件的模拟,无法满足复杂加工环境下的加工仿真需求的问题,在此开发方案基础上对复杂数控加工环境仿真的开发思路、过程及相关关键技术做了阐述。 展开更多
关键词 machineWorks 数控加工仿真 加工环境
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