新品

NJ-5HMC40精密五轴联动加工中心采用模块化设计结构,工作台为连续分度的回转工作台(C轴0-360°),主轴头为连续分度摆动头(B轴0-110°),可实现任意五轴五联动加工,该机床由计算机进行数字控制,具有直线、圆弧和螺旋线插补等功能,还可订货供应两工位托板工件自动交换装置(简称2PC),工件检测系统,刀具检测系统以及相应的数控系统。可对工件位置尺寸等进行自动测量,并能检测刀具的磨损或破损情况,实现刀具寿命管理。该机床在工件一次装夹后,可完成铣、镗、铰、攻丝和轮廓的粗、精加工,其定位精度和回转工作台分度精度分别达到微米级水平。广…     

θFXZ型测量机的回转轴线标定方法

回转轴线的标定技术是保证θFXZ型测量机测量精度的一项关键技术。针对该型测量机没有y方向运动的特点,分析了其内外径测量原理,讨论了回转轴线标定误差与内外径测量误差的关系,并提出了一种基于环形标准件内孔、外圆的测量结果,快速标定回转轴线的方法。试验结果表明:利用该方法进行θFXZ型测量机的回转轴线标定,标定后,测量机对其它型号环形标准件的测量误差在±0.001 mm以内。该方法实现了对回转轴线的精确标定,同时操作简单,可以制定标定软件,实现回转轴线的软件自动标定。     

θFXZ型回转体测量机回转轴线标定策略研究

为提高θFXZ型测量机的测量精度,研究回转工作台的轴线标定问题。针对该型测量机缺少Y向运动自由度,回转轴线Y向偏移直接影响测量精度的特点,提出首先利用千分表和标准球测试回转轴线的Y向偏移,并调整将其抑制甚至消除。同时还提出回转轴线的空间模型的建立方法,解决了轴线X向偏移以及Y向残余偏移,并将XZθ坐标转换成XYZ坐标,用于后续尺寸计算和处理。实验结果表明,利用该方法调整和标定回转轴线后,在不同高度测量圆柱体工件时,其直径测量重复性可达2μm,有效避免安装环节带来的误差,提高了圆柱体尺寸的测量精度。     

回转体零件的非接触自动测量

介绍了三坐标测量机与光学非接触测头组成的回转体零件表面自动测量系统,通过设计具有偏心调整机构的回转工作台和安装摄像机监测系统,实现了回转体零件的非接触自动测量.     

圆柱圆锥组合零件误差检测中的消偏

针对该检测的工作原理，检测方法进行了设计与研究；提出了一套自动消除装夹偏斜影响和误差分离的方法，并提出了通过测量后的数据处理提高检测精度以补偿硬件精度不足的方法。     

外圆磨床的上工作台最小位移量计算

设计外国磨床的上工作台回转机构时必须确定该工作台回转时的最小线性位移量。。该位移量对于保证被磨圆柱面或圆锥面达到规定磨削精度是必不可缺的。不同精度等级的外圆磨床所对应的不同。值将事先确定对回转机构各参数钢H度、电机对执行机构的传动速比，数在外圆磨床测量变换器技术性能）以及对上工作台导轨的设计要求，而回转机构和导轨的结构应能保证工作台平稳运动。为此，现研究一下上工作台的回转机理（见图1）。上工作台l上置有头架2和尾架电长度为L且被磨削而为圆柱面的工件8装夹在头角架顶尖之间。在点五上以B为半径对该工作台…     

铸件加工余量自动化三维测量技术及装备

目前通过人工划线的方式测量铸件的加工余量,其效率低且重复性差,而面结构光三维测量技术具有非接触、速度快、精度高等优势,因此广泛应用于铸造、锻造等领域。将面结构光三维测量技术与六关节机器人以及高精度电动转台相结合,设计铸件加工余量三维视觉测量系统。利用机器人和转台具有极高的重复定位精度这一特性,将不同方位的测量数据统一到同一个坐标系下,实现无标拼合;仅需5～6个标记点,通过计算标记点的坐标转化关系,实现正反面数据的自动拼合。该系统能够自动测量铸件点云数据并将其与设计图进行自动对比,自动出具检测报告,实现铸件加工余量的自动化检测。试验证明,该系统8min完成铸件的余量测量,系统精度为0.072mm,重复精度为0.065mm,能够满足铸件加工余量的检测要求。     

基于敏感度分析的曲轴综合测量机关键误差溯源

曲轴综合测量机通过一次装夹可完成对曲轴全部关键参数的精密测量,其测量精度对评定被测曲轴是否合格有着直接的影响,这使得分析该测量机各部件的几何误差对其测量精度的影响成为一个亟待解决的难题.针对上述问题,基于多体系统理论,结合曲轴综合测量机采用板式测头的结构特点,分析了测量机的拓扑结构和误差变换矩阵;基于推导的曲轴连杆颈几...     

简易回转曲面现场检测技术研究

回转曲面的几何测量一般在三坐标测量机上完成。介绍了一种简易的接触式回转曲面现场测量方法，该方法将三坐标的检测原理应用到数控车床上，利用数控车床自身的坐标系统完成回转曲面检测的数据采用，通过检测软件完成采样数据的计算。该方法的检测精度可以满足粗加工、半精加工以及中等精度刚性较好零件的精加工。     

回转体测量机高精度标定技术研究

回转体测量机由同转工件台和测量架组成,能够在工件一次装卡条件下对回转体零件的内外轮廓参数进行高精度的快速检测.根据该测量机的结构特点,分析了测量机的各项系统误差,提出了测量架运动直线与回转轴线之间平行度、测头的测量方向与同转轴线的垂直度、测头偏心等系统误差的标定方法,建立了标定数学模型,剔除了由于标准件加工、安装等不确...     

产品模型定位系统核心技术研究

模型定位一直是逆向工程领域和图像处理领域的重要技术之一,结合零件加工定位和无损检测的需要,提出了产品模型定位系统框架和问题解决方法。该系统以工业CT或CMM测量数据作为三维输入方式,构成待配准模型,以CAD模型作为理论模型。针对待配准模型与理论模型,研究并实现了粗配准技术、精确配准技术、配准定位的分析评估以及数据拼合等核心技术。该系统可以应用于无损检测、无损评估以及加工定位等领域,具有广泛的应用前景。     

NON-CONTACT MEASUREMENT OF SCULPTURED SURFACE OF ROTATION

A method for measuring the sculptured surface of rotation by using coordinate measuring machine (CMM) and rotary table is proposed. The measurement is realized during the continuous rotation of the workpiece mounted on the rotary table while the probe moves along the generatrix of the surface step by step. This method possesses lots of advantages such as simplicity of probe motion, high reliability and efficiency. Some key techniques including calibration of the effective radius of the probing system, determination of the position of axis of rotation, auto-centering of the workpiece, data processing algorithm, are discussed. Approaches for determining the coordinates on measured surface, establishing workpiece coordinate system and surface fitting are presented in detail. The method can be used with contact or non-contact probes. Some fragile ceramic and plaster parts are measured by using the system consisting of a CMM, rotary table, motorized head and non-contact laser triangulation probe. The measurin     

CMM touch trigger probes testing using a reference axis

A new method of testing of touch trigger probes for coordinate measuring machines (CMM) has been proposed. The concept is based on measurements of the distance between reference and triggering points in various directions. The reference points are established by the rotation axis of a precise rotary table. The advantage of this method relies on easy realisation with application of a commercial device for roundness error measurement. The accuracy of the presented method is much higher in comparison with the existing procedures of CMM probes calibration.The mathematical principle of the method has been presented and used for evaluation of its uncertainty. The validity of the method was experimentally confirmed by means of one- and two-stage type probes.     

颅骨点云模型的优化配准

由于颅骨的三维点云数据模型复杂且不同人的颅骨差异较小,对其配准精度要求较高。为了提高颅骨点云模型的配准精度和收敛速度,提出了一种先粗配准再细配准的配准方法。首先,对颅骨点云数据模型进行去噪、简化和归一化等预处理;然后,通过区域划分、区域配准和求解组合系数以及求解刚体变换等步骤实现区域层次上的颅骨粗配准;最后,通过引入动态迭代系数来改进基于旋转角约束的迭代最近点算法,并采用该改进的ICP算法实现颅骨的细配准,从而达到精确配准的目的。实验结果表明:与ICP算法相比,改进的ICP算法的配准精度和收敛速度分别提高了约30%和50%。证明该种先粗配准再细配准的颅骨点云模型配准方法是一种精度高、速度快的有效颅骨配准算法。     

光学扫描和CMM测量数据的配准研究

研究了光学扫描和CMM测量数据的配准问题。给出了基于配准工作台的配准方法,分析了影响配准的误差因素;以法矢准则提取了扫描数据中的标准球数据,并由基准点连接线段的中点代替原来的基准点改进了三点定位算法。实验对比了几种配准方法的误差,验证了改进方法的可行性。     

Precision tracking control of a horizontal arm coordinate measuring machine in the presence of dynamic flexibilities

One of the major sources that affect measurement accuracy and limit the use of high motion speeds in coordinate measuring machines (CMM) is the position error. In fact, static and dynamic probe errors are more direct factors in measuring machine accuracy, but are not the subject of this research. However the accuracy of acquisition of component position errors using a CMM in motion is also of importance, hence the dynamics of a CMM need to be considered. Therefore, this research aims to model the dynamics of a horizontal arm CMM by considering drive flexibility at joints and evaluates the characteristics of the system for fine motion control purposes. Design of a precision tracking controller (PTC) to perform superior tracking for enhancing the measurement accuracy and the probing speed in providing less inspection time at high motion speeds is carried out. A dynamic model for the CMM is developed including drive flexibilities represented with lumped springs at the joints. Due to the non-collocated nature of the control scheme in the flexible CMM dynamics, a non-minimum phase system is observed in the proposed CMM model. Using the derived CMM model with joint flexibilities, tracking motion control simulations are conducted at different probing speeds for the cases where a PI controller and a feedback PTC are employed. A comparison of the PI controller with the feedback PTC is also performed. Results demonstrate that the effects of joint flexibilities on the contour error and probing speeds are significant and the PI controller is not capable of providing good accuracy during challenging tasks such as corner tracking. However, the simulation results indicated that by using the proposed feedback precision tracking controller, contour errors in corner tracking that are caused by joint flexibilities can be reduced effectively .     

Influence of measured objects parameters on CMM touch trigger probe accuracy of probing

Influence of the measured objects parameters on coordinate measuring machine (CMM) touch trigger probe inaccuracy of probing is investigated. Factors such as material stiffness of measured workpiece, its surface shape and roughness are taken into consideration. The measuring method out off CMM, based on a rotary table and a reference axis is applied for tests. The concept is based on measurements of the distance between reference and triggering points in various directions. The reference points are established by the rotation of a precise rotary table. The statistical analysis of variance and regression is applied for data analysis.     

三坐标测量机驱动的摄像机标定技术

为了降低摄像机的标定费用和提高标定精度,提出了一种基于三坐标测量机平动的摄像机标定技术,对该技术的原理、数学模型、标定步骤和标定精度进行了研究。根据摄像机标定的基本原理,利用三坐标测量机沿X、Y、Z轴移动和正交精度都很高的特点,以三坐标测量机带动待标定摄像机产生和白色陶瓷标准球球心(标定特征点)在X、Y、Z轴方向上的相对平动,得到标定特征点在测头坐标系中不同位置的坐标;在每一个确定位置,摄像机拍摄标定特征点的像,经图像处理后,计算出像点在计算机帧存坐标系中的坐标。引入测头坐标系,建立了该项摄像机标定技术的数学模型,给出了标定步骤,组建了标定系统。比对标定实验结果表明,基于三坐标测量机平动的摄像机标定系统与专用标定系统的标定精度相当,数据相差在±1μm以内,满足工程实际精度要求,成本低、标定效率高。     

零件轮廓测量机安全监测系统的设计

为适应现代先进制造业质量检测自动化的需要,研究开发能够在线非接触、高精度自动检测的智能三坐标测量机已经成为制造业发展的必然趋势,其中机器视觉检测技术的应用为实现复杂自由曲面的自动化检测提供了技术支持。介绍了零件轮廓测量机的工作原理,分析了回转工作台和偏心调整机构在回转体零件测量系统中的作用。采用合理的图像处理技术,完成了包括测量工位上异常物体的检测、工件类型识别和工件位置检测等功能在内的图像识别系统的设计。     

Enhance performance of inspection process on Coordinate Measuring Machine

Coordinate Measuring Machine (CMM) has been an important inspection tool in quality control for several years owing to its high accuracy and precision. Effectiveness of inspection plan generated by CMM greatly depends on measurement cycle time. Lesser the inspection time taken by CMM to measure a given part better will be the performance of inspection process. Therefore, it has been critical to reduce measurement time for efficient performance of inspection process. In this paper, methodologies to generate most suitable measurement path resulting into minimum inspection time has been introduced. These methodologies are based on different algorithms to reduce measurement cycle time for CMM. The different algorithms have successfully been explored and compared to show their effectiveness in minimizing inspection time for stationary CMM equipped with touch trigger probe. The proposed methodologies have also been implemented and tested on real-world mechanical part with certain number of features to demonstrate their applicability.