数控机床误差补偿评价研究

为了提高数控机床的位置精度,保证生产质量,对数控机床位置精度误差性质的分类、辨识方法、误差补偿以及误差补偿效果评价方法进行了研究,提出使用方差分析技术分离机床位置精度误差的系统误差和随机误差,并基于F检验方法推断系统误差所占比重的相对大小、位置精度误差是否需要补偿并能够对补偿的效果做出评价,并用实例验证了该方法的有效性.     

数控机床加工精度提高技术的进展及其存在的问题

数控技术和数控机床的诞生开创了控制和生产领域的新时代,给机械制造业带来了一次新的技术革命。数控机床技术的迅速进步大大推进了精密、超精密加工技术的发展,使加工精度提高到了一个新的台阶,提高数控机床精度的研究也得到了极大的重视。从误差防止和误差补偿两个方面,介绍了国内外关于提高数控机床精度的研究现状,指出了具有广泛应用前景的误差补偿这项实用技术之所以难以在国内数控机床行业普及和使用所存在的核心问题。最后根据企业实际情况提出开展误差补偿技术应用研究的必要性和主要研究内容。     

数控机床在线检测系统的定位误差补偿实验研究

为了提高数控机床在线检测精度,研究机床各个轴的定位误差对数控机床在线检测精度的影响。针对数控机床误差补偿进行实验研究,采用激光干涉仪在数控机床上测量出各个轴的定位误差,将各个轴的定位误差依次进行补偿;并以Visual C++6. 0为工具,编写了三次样条曲线的算法程序,将测量的数据点拟合成一条曲线,达到可以预测机床任意点误差的效果;进行标准块检测实验。结果表明:在数控机床在线检测系统中实施误差补偿,效果较为明显,利用补偿软件可以实现对数控机床任意点进行补偿。     

基于多体系统理论的车铣中心空间误差模型分析

数控机床的误差建模是进行机床运动设计、精度分析和误差补偿的关键技术,也是保证机床加工精度的重要环节.本文利用多体系统理论来构建超精密数控机床的几何误差模型,该模型简便、明确,不受机床结构和运动复杂程度的限制,为计算机床误差、实现误差补偿和修正控制指令提供了理论依据.在机床实际应用中,可以利用由精密机床误差建模所推导出的几何位置误差来修正理想加工指令,控制机床的实际运动,从而实现几何误差补偿,提高机床加工精度.     

基于PMAC数控机床定位精度控制研究

数控机床定位精度和重复定位精度直接影响数控机床的加工精度。通过分析影响数控机床定位精度的原因,利用系统螺距误差补偿方法对数控机床进给系统的定位精度进行补偿。试验结果表明：该误差补偿策略显著提高了系统的位置精度和运动精度,为提高机床的加工精度奠定了基础。     

数控机床误差检测及补偿技术研究进展

随着精密制造业的发展,加工件成型难度和表面精度的要求不断提高,一般数控加工设备生产的零部件标准已经不能满足航空航天、船舶、轨道交通等高尖端行业需求。针对数控机床误差检测与误差补偿技术领域,具体阐述激光干涉仪、球杆仪、平面光栅、R-test和机器视觉等检测仪器的应用方法,分析数控机床几何误差、热变形误差和切削力误差的补偿技术,并对机器视觉技术在数控机床误差检测和补偿领域的应用进行了总结。最后结合数控机床误差检测及补偿技术中尚需解决的问题,对提高数控机床精密性进行了展望。     

基于FANUC系统的螺纹误差测量与补偿

螺距误差是影响数控机床加工精度的重要因素.根据误差产生原因,介绍数控机床螺距误差补偿的依据和原理;以某一型号数控车床为例,详细说明了利用激光干涉仪实现误差测量及补偿的具体方法.结果表明,该补偿方法能较大程度提高数控机床的加工精度.     

数控机床误差的快速标定及补偿技术

数控机床误差的快速标定及补偿是数控机床机电联调的重要内容,是实现数控机床精度升级的重要途径。本文开发了一套简便快速的数控机床误差检测、评价与补偿系统。试验结果表明,应用此系统不仅能大幅度提高了精度检测的效率,而且能显著提高数控机床精度。     

半闭环数控机床误差补偿技术研究

为提高半闭环数控机床的位置精度,建立半闭环位置控制数学模型,研究机床传动误差的补偿机理,构造半闭环误差补偿控制模型,并通过一个实例验证了该误差补偿方法的有效性。     

华中HED-21S数控实验台螺距误差补偿的研究

螺距误差是造成数控机床加工精度下降的重要原因之一.针对华中HED-21S数控实验台产生的螺距误差,通过分析螺距误差补偿原理,对z轴误差进行了补偿.实验结果表明:利用螺距误差补偿消除传动部件间隙,能够提高数控机床的定位精度和重复定位精度.     

非球面数控磨床的误差建模与补偿研究

以实验室自主研发的非球面数控磨床为研究对象,系统分析了该磨床几何误差元素,基于齐次变换原理和多体系统理论,建立了该磨床包含所有几何误差源的综合误差模型。基于双频激光干涉测量仪,应用9线误差辨识法和回转误差辨识法建立了以磨床单项误差为变量的组合方程,并求取了磨床的各误差分量。针对非球面数控磨床定位误差的特性,提出了增量式误差补偿原理。研究表明:该误差建模及补偿原理可以有效地提升非球面数控磨床的定位精度。     

精密卧式加工中心空间误差的建模、测量与补偿技术

采用空间误差补偿技术,可有效提高数控机床的空间定位精度。以一台精密卧式加工中心为对象,系统阐述其几何误差补偿中的关键问题及解决方案。通过三维误差建模与分析,得到该机床的21项几何误差中有17项需要测量和补偿,另外4项误差对机床定位精度的影响甚微。以此为依据,设计误差测量及补偿方案,并给出误差的具体测量方法和补偿结果。结果表明:经过一次系统地误差测量与补偿,精密卧式加工中心的空间定位精度可以提高50%～70%;合理规划和实施空间误差测量,可大幅提高测量效率。     

基于多体系统理论的数控机床加工精度几何误差预测模型

针对多轴联动数控机床加工精度误差补偿问题,从分析数控机床误差产生机制和建立精度误差补偿模型的角度,提出基于多体系统理论的数控机床加工精度几何误差预测模型。分析B-A摆头五轴龙门数控机床的拓扑结构关系、低序体阵列、各典型体坐标变换,推导出B-A摆头五轴龙门数控机床的精度几何误差预测函数模型。采用平动轴十二线法误差参数辨识算法,计算出B-A摆头五轴数控机床21项空间几何误差,为精度几何误差预测函数提供有效的误差参数。该精度误差参数建模方法,对不同结构和运动关系的数控机床具有通用性,为后续数控机床误差动态实时补偿提高切削加工精度提供了理论基础。     

Accuracy enhancement of five-axis machine tool based on differential motion matrix: Geometric error modeling,identification and compensation

This paper presents the precision enhancement of five-axis machine tools according to differential motion matrix, including geometric error modeling, identification and compensation. Differential motion matrix describes the relationship between transforming differential changes of coordinate frames. Firstly, differential motion matrix of each axis relative to tool is established based on homogenous transformation matrix of tool relative to each axis. Secondly, the influences of errors of each axis on accuracy of tool are calculated with error vector of each axis. The sum of these influences is integration of error components of machine tool in coordinate system of tool. It endows the error modeling clear physical meaning. Moreover, integrated error components are transformed to coordinate frame of working table for integrated error transformation matrix of machine tools. Thirdly, constructed Jacobian is established using differential motion matrix of each axis without extra calculation to compensate the integrated error components of tool. It makes compensation easy and convenient with reuse of intermediate. Fourthly, six-circle method of ballbar is developed based on differential motion matrix to identify all ten error components of each rotary axis. Finally, the experiments are carried out on SmartCNC500 five-axis machine tool to testify the effectiveness of proposed accuracy enhancement with differential motion matrix.     

立式加工中心空间误差验证及补偿

为提高某立式加工中心整机加工精度,借助旋量理论建立完备立式加工中心空间误差模型,在此基础上实现机床空间误差有效补偿.以旋量理论为基础推导并建立机床刀具运动链与工件运动链运动学正解,分析机床21项几何误差原理,在考虑21项几何误差的基础上建立该立式加工中心完备空间误差模型;利用九线法完成各项几何误差辨识;基于旋量运动学正解求解机床运动学逆解后得出运动轴实际运动路径,并通过体对角线实验对比补偿前后的效果.结果表明:所提补偿方法补偿效果显著,验证了机床空间误差模型的准确性,实现了提高机床加工精度的目的.     

A general approach for error modeling of machine tools

This paper presents a general and systematic approach for geometric error modeling of machine tools due to the geometric errors arising from manufacturing and assembly. The approach can be implemented in three steps: (1) development of a linear map between the pose error twist and source errors within machine tool kinematic chains using homogeneous transformation matrix method; (2) formulation of a linear map between the pose error twist and the error intensities of a machine tool; (3) combination of these two models for error separation. The merit of this approach lies in that it enables the source errors affecting the compensatable and uncompensatable pose accuracy of the machine tool to be explicitly separated, thereby providing designers and/or field engineers with an informative guideline for the accuracy improvement by suitable measures, i.e. component tolerancing in design, manufacturing and assembly processes, and error compensation. Two typical multi-axis machine tools are taken as examples to illustrate the generality and effectiveness of this approach.     

基于多体系统理论的矫直机几何误差的建模与补偿

针对矫直机的几何误差建模和补偿技术进行研究。将矫直机床视为一个多体系统结构,完成对矫直机的拓扑结构描述,并进行压头、夹头和跨距调整等关键运动部件的误差分析。通过其次变换矩阵体系统推导机床几何误差模型,基于建立的误差模型,采用激光干涉仪识别机床运动轴的几何位置误差。提出矫直机的几何误差补偿方法并设计与开发补偿软件,对矫直机定位精度进行补偿。通过实验进行了误差补偿效果评价,实验结果证明误差模型的正确性以及软件补偿的可行性。     

Accuracy enhancement of five-axis CNC machines through real-time error compensation

Although error modeling and compensation have given significant results for three-axis CNC machine tools, a few barriers have prevented this promising technique from being applied in five-axis CNC machine tools. One crucial barrier is the difficulty of measuring or identifying link errors in the rotary block of five-axis CNC machine tools. The error model is thus not fully known. To overcome this, the 3D probe-ball and spherical test method are successfully developed to measure and estimate these unknown link errors. Based on the identified error model, real-time error compensation methods for the five-axis CNC machine tool are investigated. The proposed model-based error compensation method is simple enough to implement in real time. Problems associated with the error compensation in singular position of the five-axis machine tool are also discussed. Experimental results show that the overall position accuracy of the five-axis CNC machine tool can be improved dramatically.