三维机械装配误差的建模方法

提出了一种基于等价替换思想的三维装配误差的建模方法,该方法从分析三维装配中各种误差因素对装配性能的影响机理入手,首先基于等价替换思想对各种误差因素所产生的影响逐类逐个予以建模,然后将等价模型在三维装配的尺寸链中集成,最终得到全面考虑各种误差因素影响的三维装配等价模型。     

工业机器人位姿误差的计算

机器人连杆的加工误差、温度变化以及机械传动误差等诸多因素会导致机器人抓手的位置和姿态产生误差。本文以机器人运动学及误差理论为基础 ,推导出了在各种位姿描述情况下机器人位置和姿态误差的计算公式。该方法可以作为对各种工业机器人的位姿精度进行分析的基础     

机器人手臂误差分析及误差补偿

本文对机器人手臂的误差和影响误差的因素作了分析,建立起机器人夹持器(手)的运动误差与各种原始误差的函数式,文章着重于推导作为误差传递函数的各种偏导数矩阵,得到了统一的表达式。这种形式特别适合电子计算机计算。文章最后讨论了误差补偿方法和导出了补偿计算的公式。     

钢管自动测长的误差分析及解决

分析了钢管自动化车间精整区自动测长设备的两种基本原理：推钢测长和在线测长,并推导了钢管长度的运算公式。根据各种影响因素,以及误差的性质和特点,分别从系统误差、随机误差和临界粗大误差方面,分析了误差的产生来源和误差大小。最后从工程实际应用的角度,提出了解决或缩小各种误差的方法。     

非球面镜片面形检测技术综述

非球面镜片的应用越来越广泛,面形误差是影响非球面质量的重要指标,所采用的面形检测方法非常重要。介绍了非球面镜片面形误差的各种检测方法,并对各种检测方法进行了比较。最后,对非球面镜片面形检测技术的发展趋势作出了预测。     

关于齿轮周节误差的测量问题

本文用数学模式给出了各种周节误差的定义及其相互之间的关系。举出实际例子说明周节误差的各种测量方法。作者对周节测量中的一些问题,诸如周期分量的次数与周节误差测量的放大率、周节测量中的不稳定误差、测量值的处理方法等等,都提出了自已的看法。     

传动误差比相测量方法的分析与比较

对传动链误差的比相测量方法进行了归纳，分析了各种方法的测量特性、误差因素及适用的传动比范围，阐明了传动误差测量技术的发展趋势。     

平面度误差各种评定方法的比较

介绍了平面度误差各种评定方法的原理,并对各种评定方法对同一被测平面的平面度误差评定结果及数据处理难度进行了比较。结果表明,最小二乘法的评定结果比较接近最小区域法,且数据处理简便,对测量采样点的布置无特殊要求。     

Stewart平台机构标定的鸡尾酒法

针对Stewart平台机构的标定提出了一种方便、实用的方法——鸡尾酒法,该方法采用正解方式自动构造结构误差雅可比矩阵,并采用了与测量方式相一致的广义坐标。通过该方法可以利用各种普通的测量工具或者各种测量工具的组合使用对Stewart机构进行标定,避免了利用专门工具进行空间多维坐标测量的复杂性。同时还对标定过程中所涉及的误差雅可比矩阵的建立及求解方法、结构误差耦合情况、不同误差项的加权以及新增测量项的处理等问题进行了详细介绍。     

内径表定中心装置误差分析

分析了内径表定中心装置误差产生的原因，对生产中如何减小定心误差提出了相应的控制方法，给出了检测定心误差出现各种情况时的对策。     

三坐标测量机动态误差的建模方法

为了提高三坐标测量机的测量速度,缩短测量周期,分析了影响给定的三坐标测量机动态误差的因素。对三坐标测量机的具体和了分析,用电感测微仪进行了动态偏转角的测量,并推导出由动态偏转误差得到测头处的动态位移误差的方法。同时,对由导轨的直线度造成的误差进行了讨论。指出动态误差主要是由各构件绕气浮导轨连接处的偏转和各运动构件本身的弯曲变形造成挫理论上可以证明,在气浮导轨力矩刚度和横梁弯曲刚度已知的情况下,只要     

Geometric error measurement and compensation for the rotary table of five-axis machine tool with double ballbar

This paper proposes a novel measuring method for geometric error identification of the rotary table on five-axis machine tools by using double ballbar (DBB) as the measuring instrument. This measuring method greatly simplifies the measurement setup, for only a DBB system and a height-adjustable fixture are needed to evaluate simultaneously five errors including one axial error, two radial errors, and two tilt errors caused by the rotary table. Two DBB-measuring paths are designed in different horizontal planes so as to decouple the linear and angular errors. The theoretical measuring patterns caused by different errors are simulated on the basis of the error model. Finally, the proposed method is applied to a vertical five-axis machining center for error measurement and compensation. The experimental results show that this measuring method is quite convenient and effective to identify geometric errors caused by the rotary table on five-axis machine tools.     

激光调阻机多档测量误差的软件自适应校正

为了减小激光调阻机测量系统的多档测量误差对阻值修调精度的影响,提出了一种基于有源单臂电桥测量原理自适应地校正激光调阻机多档测量误差的方法.通过测量和标定高精度标准电阻的测量误差,自适应地获取校正激光调阻机多档测量误差的系列修正值,进而用系列修正值对所有待修调电阻的阻值测量误差进行校正,达到进一步减小系统测量误差的目的.实践证明,在测量硬件电路保证高稳定性、微小波动性测量的前提下,应用该方法可使测量系统的精度指标达到:低阻区(R<100Ω)为±0.5‰;中阻区为±0.2‰;高阻区(R≥1MΩ)为±2‰.     

套装式双片簧三维模拟测头的研制

本文介绍了三维模拟测头的套装式双片簧结构，结构尺寸设计及影响精度的因素，并对测头的精度进行了分析，还介绍了它的测量电路。该测头采用套装式双片簧结构较三层楼式双片簧结构精度高、结构紧凑、体积小巧。它可用于三坐标测量机上作发讯测头，又可作三维测微测头     

Automated measurement and compensation of thermally induced error maps in machine tools

In this paper, a direct method of machine tool calibration is adopted to model and predict thermally induced errors in machine tools. This method uses a laser ball bar (LBB) as the calibration instrument and is implemented on a two-axis computerized numerical control turning center (CNC). Rather than individually measuring the parametric errors to build the error model of the machine, the total positioning errors at the cutting tool and spindle thermal drifts are rapidly measured using the LBB within the same experimental setup. Unlike conventional approaches, the spindle thermal drifts are derived from the true spindle position and orientation measured by the LBB. A neural network is used to build a machine model in an incremental fashion by correlating the measured errors with temperature gradients of the various heat sources during a regular thermal duty cycle. The machine model developed by the neural network is further tested using random thermal duty cycles. The performance of the system is also evaluated through cutting tests under various thermal conditions. A substantial improvement in the overall accuracy was obtained.     

Error Analysis of Indirect Broadband Monitoring of Multilayer Optical Coatings using Computer Simulations

Results of studying the errors of indirect monitoring by means of computer simulations are reported. The monitoring method is based on measuring spectra of reflection from additional monitoring substrates in a wide spectral range. Special software (Deposition Control Simulator) is developed, which allows one to estimate the influence of the monitoring system parameters (noise of the photodetector array, operating spectral range of the spectrometer and errors of its calibration in terms of wavelengths, drift of the radiation source intensity, and errors in the refractive index of deposited materials) on the random and systematic errors of deposited layer thickness measurements. The direct and inverse problems of multilayer coatings are solved using the OptiReOpt library. Curves of the random and systematic errors of measurements of the deposited layer thickness as functions of the layer thickness are presented for various values of the system parameters. Recommendations are given on using the indirect monitoring method for the purpose of reducing the layer thickness measurement error.     

A Hole-Plate Artifact Design for the Volumetric Error Calibration of CMM

To measure the volumetric error of coordinate measuring machines (CMMs), a hole-plate artifact method was studied. Example designs of the hole-plate are shown using titanium and ceramic materials. The deflection by its own weight of the designed hole-plate is analysed using the finite element method. The hole distances moved by the deflection are shown in different hole-plate set-up cases, for vertical and horizontal positions. The influence of inside hole roundness as a measuring standard is also studied. Eccentric errors for different hole roundness are simulated. The hole-plate set-up errors are also discussed. A method for obtaining the parametric errors of a CMM is shown using the hole-plate as a measuring artifact for CMM positioning error. In addition, a method for measuring 2D and 3D length errors using the hole-plate data is introduced.     

微机综合测量系统的误差因素分析

分析了采用微机综合测量系统检测机械零件尺寸及形位误差时的主要误差因素,并提出了消除或减小误差的方法。     

多相流分相含率检测

介绍了基于双能射线对油气水多相流分相含率的测量机理及系统构成 ,通过对射线穿过原油的透射计数 ,并对各种误差进行补偿、修正 ,从而实现对多相流分相含率的在线测量     

Simulation of the errors transfer in an articulation-type coordinate measuring machine

It is necessary to study the transferring effect of every error resource of a coordinate measuring system. This paper gives quantitative analysis of the transferring effects of parameter errors in a non-perpendicular coordinate measuring system. A typical articulation-type coordinate measuring system is analyzed which combines six angle encoders and three measuring arms and one stylus. The measuring equation of this system is given and the error-transferring model is derived from this equation. As the systematic errors of the parameters of the system are given beforehand, simulated computation is carried out on the error-transferring model of this articulation-type coordinate measuring system. The effects of parameter errors on the position of the stylus of the coordinate measuring system are clearly seen from the simulation results. These make the software error correction of the coordinate measuring system possible and will also provide the base for error correction of the system.