数控机床运动误差检测技术

该方案中 ,“工件即基准”是整个检测过程的核心。其特点柔性高 ,可集成 ,且检测精度随会传感器精度的提高而提高。6　基于虚拟基准的ＮＣ机床运动误差检测新方案　　由于一般ＮＣ机床常常是按ＮＣ指令通过双轴联动的圆插补运动实现圆周进给的 ,相应的圆轨迹误差图像反应了从指令发布 -机电耦合伺服系统 -驱动件-执行件 -检测件直至终端的情况的丰富完整的信息 ,通过从拾取误差源信号 ,建立数控机床运动误差检测的虚拟基准 ,利用算法 ,分离出各个误差分量 ,并且分析出产生误差的机床功能部件[2 1] 。根据测量结果 ,还可以优化传感器的位置 ,…     

提高轮廓加工误差联机检测精度的研究

在数控机床或加工中心上采用联机检测轮廓加工误差的方法，不用价格昂贵的坐标测量机，具有简单、省时、经济的特点。文章分析了数控机床或加工中心的直线运动误差对联机检测轮廓加工误差精度的影响，并测量出了加工中心的几何运动误差，提出了消除机床几何运动误差影响，提高轮廓加工误差联机检测精度的方法。实验结果表明，所采用的方法可以明显提高轮廓加工误差联机检测精度。     

基于球杆仪的PRS-XY型混联数控机床关键结构参数误差快速检测技术

对PRS-XY型混联数控机床的关键结构参数误差的快速检测技术进行了研究.提出了影响机床运动精度的关键结构参数,并建立了误差计算模型,进而提出了能够反映机床运动性能的球杆仪测试方案.通过仿真计算,得到了关键结构参数误差对检测结果的影响,并通过实验进行了验证.最终建立了PRS-XY型混联数控机床关键参数误差与检测相关结果的对应关系,为快速误差诊断提供了依据.     

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。     

虚拟数控加工过程的建模与仿真

本文介绍了虚拟数控加工过程的概念,提出了虚拟数控加工过程中的关键技术的建模和仿真,包括工件建模,夹具建模、刀具建模及虚拟数控机床建模和虚拟数控机床加工过程的仿真以及机床的加工误差等。     

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。     

BF-850B立式高速数控机床精度检测及误差补偿研究

机床在加工的过程中会因为物理变形和热变形,使得加工零件的精度难以保证,因此必须对运动中的影响机床精度的误差源进行误差分析及实时补偿。利用激光干涉仪和球杆仪对数控机床定位精度进行检测,并建立了关于机床变形的检测数据的数学模型,确定了定位误差补偿方法,同时以具体的数控机床为例进行了定位精度检测与误差补偿,最后对补偿效果进行了分析。结果表明：该定位误差检测及补偿方法具有可行性与实用性,使数控机床的定位精度得到了显著的提高。     

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Renishaw的数控机床定位精度和动态性能的研究

阐述了用Renishaw激光干涉法测量误差的原理,并且通过计算机控制的误差补偿系统对数控机床的定位误差进行补偿,实验结果表明这种方法可以大幅度提高数控机床的定位精度.通过分析数控机床机械传动部件的数学模型,得出数控机床进给系统低速爬行的原因,并提出了提高数控机床低速进给运动的平稳性和运动精度的措施.     

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。     

Radial error measuring device based on auto-collimation for miniature ultra-high-speed spindles

This study has developed a radial error measuring device for miniature ultra-high-speed spindles because it is very difficult to measure the radial error motion of miniature ultra-high-speed spindles by the conventional measurement method using capacitive-type displacement sensors. The authors have proposed an optical measurement method based on auto-collimation, which evaluates the radial error motion according to the movements of a laser beam reflected from a target sphere attached to the spindle end. This optical measurement method is suitable for radial error measurements of miniature ultra-high-speed spindles because of its applicability to a small target sphere, high-speed response and minor susceptibility to electric noise. In this paper, the measurement principle, and basic characteristics of the optical measurement method in addition to an approximate analysis are shown. The radial error motion of a miniature ultra-high-speed spindle with a steel ball 1 mm in diameter are measured by an optical measuring device designed and manufactured to implement the proposed method. The measurement results show that the optical measuring device is able to measure the radial error motion of ultra-high-speed spindles with a maximum rotational speed of 200 krpm.     

An examination of the effect of variation in datum targets on part acceptance

The use of datum targets within Geometric Dimensioning and Tolerancing (GD&T) is commonplace in industry today. Datum targets are used primarily for manufacturing and inspection setups where it is not practical to have tooling that contacts the entire surface of the datum. Establishing a simulated datum from datum targets may be done physically or mathematically. In the process of establishing a simulated datum, there are several possible sources of variation. Any variation or error in establishing the datum will manifest itself as variation or error in the measurement of the distance between the feature and the datum. This paper examines the effect of variation in datum targets on part acceptance using both mathematical analysis and simulation. The focus of this examination is diametric positional tolerance of holes that reference the datum established by datum targets. A three-dimensional mathematical model of the hole position error with respect to the datum target variation is developed. Then, simulation is adopted to identify the major sources of hole position error due to errors in datum targets. It is found that the datum target variation has a profound effect on the measured location of holes referencing those datums. Explanation and validation for accepted practice are offered and some additional basic guidelines are developed for the placement of datum targets relative to hole patterns.     

An analysis of the effect of datum-establishment methods on the geometric errors of machined features

With the advent of probing systems and their integration with machining centers, coordinate metrology-based datum establishment is eliminating the need for precision hard-contact locators in many machining applications. Unfortunately, the coordinate data collected by these systems are often subject to noise in the form of random and biased errors of the workpiece datum features and measurement system. Consequently it is important to use datum-establishment algorithms that are insensitive to noise and that lead to the least measurable machined-feature error.This paper describes a simulation analysis that was carried out to evaluate the performance of three datum-establishment methods: 3–2–1, sequential least-squares (SQLS) and simultaneous least-squares (SMLS). The analysis involved the simulated drilling of three holes in a two set-up process. Simulated coordinate data were obtained from three planar, nominally orthogonal surfaces subject to perpendicularity errors and random roughness errors. Workpiece datum reference frames were fitted to this data using the three methods, the holes were drilled relative to these reference frames, and their position errors were computed relative to an ANSI-Y14.5M-defined reference frame.This analysis demonstrated that the SMLS method results in significantly less hole-position error [0.0173 mm average, 0.0146 mm standard deviation (SD)] than either the 3–2–1 method (0.0943 mm average, 0.0143 mm SD) or the SQLS method (0.0904 mm average, 0.0245 mm SD). This is despite the fact that the datum reference planes (ANSI Y14.5M) used to define these errors are defined sequentially relative to the extrema of the datum features, whereas the SMLS method defines the datum reference planes simultaneously with the purpose of minimizing fitting error.     

管道机器人超声测量轮廓重建方法的研究

针对大型管道内生物附着物状态的高精度测量需求,提出一种利用齐次变换的轮廓重建方法,通过坐标变换使偏移轮廓的坐标校正回准确轮廓的坐标,消除运动位置偏差引起的轮廓测量误差。通过建立管道超声测量实验装置进行实验验证,得到偏移重建后产生的绝对误差为9 mm、相对误差为2.36%,偏转重建后产生的绝对误差为6 mm、相对误差为1.6%,误差落在超声检测系统的厘米级分辨率之内。后续可以通过提高超声检测系统的分辨率提高轮廓检测精度。该方法可以应用于水下管道轮廓检测以及水下机器人基于轮廓的自动定心探测。     

机床误差正交光栅检测及补偿的研究

文章提出了多轴机床空间误差的平面正交光栅检测和补偿方法.建立了包含21项几何误差的数控机床误差模型,给出了应用神经网络进行空间误差识别和补偿的技术.通过试验对比,验证了该方法的可行性.     

基于随动控制的蜗杆检测系统设计

提出一种基于随动预定位技术的环面蜗杆检测方法,通过建立蜗杆运动与测头运动的对应关系的理论模型,以每个采样点测量的蜗杆实际运动坐标映射下一采样点的测头坐标,再采用时间细分技术的高精度运动控制将测头提前定位到下一采样点,从而实现环面蜗杆加工误差的在线随动测量、特定喉部半径下的实际空间螺旋线测量。通过不同喉部半径下的多条螺旋线构建出环面蜗杆的实际轮廓面形,再与理论模型比对后获得相应的加工误差,根据这种方法设计了上、下位机组成的检测系统。     

基于Matlab的平面度误差最小区域法评定

平面度是形状公差的主要项目之一,其误差的测量与评定在几何量测量中有着重要的意义.分析了常用的近似评定法(三点法、对角线法、最小二乘法等)存在的局限性,根据最小区域法的定义,给出了基准平面方程及平面度误差评定目标函数数学模型的建立方法,并举例说明了采用Matlab进行平面度误差的计算.结果证明该方法利用Matlab只需要进行简单的矩阵运算,具有简单实用的特点.     

Measurement of slide error of an ultra-precision diamond turning machine by using a rotating cylinder workpiece

Two measurement methods of using a rotating cylinder workpiece, which are referred to as the one-probe method and the two-probe method, respectively, are proposed for measurement of the horizontal error motion (X-directional error motion) of the Z-slide of an ultra-precision diamond turning machine. In the one-probe method, a displacement probe mounted on the opposite position of the turned (self-cut) cylinder workpiece with respect to the cutting tool is moved by the Z-slide to scan the workpiece being rotated by the spindle with its axis of rotation along the Z-axis. The Z-slide error can be obtained by an averaged output of the probe over one rotation without the influence of the spindle error and the surface form error of the cylinder. In the two-probe method, in addition to the displacement probe used in the one-probe method, another displacement probe is mounted at the position of the cutting tool. The rotating cylinder is scanned along the Z-direction by the two displacement probes simultaneously and the Z-slide error can be accurately measured by using the averaged output of the two probes over one rotation. Both the methods can measure not only the out-of-straightness component of the slide error but also the out-of-parallelism of the Z-slide axis with respect to the spindle axis. Experiments are carried out to verify the feasibility of the proposed methods.     

海底原位分层观测系统触底与贯入深度检测

提出在结构紧凑的海底原位分层观测系统装置上应用加速度传感器模块JY901测量触底和贯入深度,设计触底、贯入深度计算算法,在MATLAB中进行仿真计算验证算法和误差;在六自由度运动平台上进行加速度传感器测量位移的实验,测量误差在5%左右;设计使用铁棒自由下落贯入砂土模拟海底原位分层观测系统装置贯入沉积物的过程,验证了加速度检测触底的方案可行,测量贯入深度误差为10%左右。研究提供了一种不增加额外传感器的海底原位分层观测系统的运动状态检测方法。     

基于实时误差补偿的精密定位系统的研究

介绍了基于实时误差补偿的精密定位系统的组成，分析了系统的偏摆振动模型，讨论了偏摆误差检测原理。利用有限元软件ANSYS。设计了采用双层平行板弹性铰链结构、基于PZT直接驱动的微驱动补偿工作台。实验结果证明，采用实时误差补偿技术，定位系统的运动性能得到较大提高。