基于ISO 9001与CMM的软件质量管理体系分析比较与协调实施

通过分析ISO 9001：2000与CMM的相互关系,论述了二者之间的相关性和互补性,并对二者有机结合的理论基础进行了阐述,最后对ISO 9001和CMM在以软件开发为主要业务的组织中的协调实施进行了探讨.     

Selection of sampling points for accurate evaluation of flatness error using coordinate measuring machine

Dimensional inspection, in integrated manufacturing environments, requires accurate inspection while minimizing the cost and time of inspection. The selection of sampling plan—sample size and sample point locations, the method of evaluating the form error and the nature of the manufactured surfaces will play an important role in deciding the best inspection strategy to be adopted. This paper deals with the strategy for evaluation of flatness error which is one of the most commonly used form tolerances for control of manufactured surfaces. Investigations have been carried out to ascertain the influence of surface quality (surface roughness) in determining the sampling strategy for accurate determination of flatness error while inspecting on a coordinate measuring machine (CMM). The sampling plan utilizes the Hammersley sequence for point location and the flatness error is evaluated using the minimum zone method (MZM) based on computational geometry techniques. Results indicate that the surface roughness influences the accuracy of inspection and can be used as a parameter for determining an initial sample size for the determination of flatness error.     

利用弹性网络算法求解大型三坐标测量机几何误差的方法

为提高大型三坐标测量机(CMM)的精度,修正空间几何误差,研究利用激光追踪仪多站位测量技术取代实物基准,提出了基于弹性网络算法求解CMM几何误差的方法。基于激光追踪仪多站位测量技术,结合L-M算法,实现CMM空间规划点体积误差的高精度测量,有效提高测量效率。利用弹性网络算法解算CMM准刚体模型,解决模型求解存在多重共线的难题,实现CMM几何误差的求解;将方程组中部分系数为0的项结合体积误差与单轴几何误差的关系模型来求解几何误差。实验搭建了激光追踪多站位测量系统,测量了CMM的空间待测点体积误差。实验结果表明,提出的方法可以有效求解大型CMM的几何误差。     

Results of the NIST National Ball Plate Round Robin

This report examines the results of the ball plate round robin administered by NIST. The round robin was part of an effort to assess the current state of industry practices for measurements made using coordinate measuring machines. Measurements of a two-dimensional ball plate (240 mm by 240 mm) on 41 coordinate measuring machines were collected and analyzed. Typically, the deviations of the reported X and Y coordinates from the calibrated values were within ± 5 μm, with some coordinate deviations exceeding 20.0 μm. One of the most significant observations from these data was that over 75 % of the participants failed to correctly estimate their measurement error on one or more of the ball plate spheres.     

ISO 9001:2000与成熟度模型的比较研究

本文对ISO 9001:2000质量体系与成熟度模型(CMM)进行了比较研究,分析了两者之间的相似之处和差异,并得出结论:对软件企业而言,这两种用于质量保证的模式都是可行的,但两者应相互结合、互为补充.根据ISO 9001:2000质量体系与CMM模型的特点,提出了基于ISO 9001:2000与CMM的软件开发流程模型.     

淮南矿区煤矿煤层气抽采技术

根据淮南矿区实际，提出并研究了复杂特困条件下煤与煤层气共采技术。应用数值模拟、相似材料试验、工业性试验等方法，研究了开采煤层顶板煤层气抽采技术、开采保护层卸压增透抽采煤层气技术、地面钻井抽采采动影响区域煤层气技术等采动煤岩移动卸压抽采煤层气技术。以及原始煤层强化抽采煤层气技术的关键参数，全面考察了现场应用效果。     

基于UG二次开发的整体叶轮测量路径规划

分析了整体叶轮模型特点,通过对UG进行二次开发。整合了整体叶轮三坐标测量规划的全过程,构造了叶面测量点,并利用碰撞检测等方法建立了无干涉测量路径,对测量路径的规划与修正进行了阐述,并对测量过程进行了实时仿真,以验证路径的可行性。     

基于UGCAD模型的CMM自动测量路径规划

针对三坐标测量机床(CMM)对复杂曲面测量的特点,借助UG NX软件自身提供的平而截取功能和二次开发工具,对已知叶片的CAD模型,首先采用截平面法截取各档所需型线,然后通过系统的人机交互界面,将各档型线依次离散成点集,再运用本文提出的曲率差值淘汰算法进行点的筛选,保留一定数量的测量点,再提取出这些测量点的信息,最后再根...     

Fast genetic algorithm for roundness evaluation by the minimum zone tolerance (MZT) method

According to ISO 1101, “A geometrical tolerance applied to a feature defines the tolerance zone within which that feature shall be contained”.The main goal of the minimum zone tolerance (MZT) method is to achieve the best estimation of the roundness error, but it is computationally intensive. This paper describes the application of a genetic algorithm (GA) to minimize the computation time in the evaluation of CMM roundness errors of a large cloud of sampled points.Computational experiments have shown that by selecting the optimal GA parameters, namely a combination of the five genetic parameters related to population size, crossover, mutation, stop condition, and search space, the computation time can be reduced by up to one order of magnitude, allowing real-time operation.Optimization has been tested using seven CMM samples, obtained from different machining features. The performance of the optimized algorithm has been validated using four benchmark samples from the literature and with certified samples.     

浅谈提高汽车白车身三座标合格率的工作过程

为了提高白车身尺寸制造精度,对白车身制造过程中存在的问题进行了分析,提出了从供应商质量控制、主机厂拼台定位改进、料架改进等几个关键环节进行监控,为提高白车身的制造精度提供了较为系统的见解和具体的操作方法。