基于VC++6.0的双盘式渐开线测试仪齿廓偏差测量控制系统设计

双盘式渐开线测试仪是测量标准齿轮渐开线齿廓的高精度仪器之一.简要介绍了双盘式渐开线测试仪的测量原理和基于VC 6.0的测量控制系统设计.系统由测量软件控制研华数据采集卡PCL-818L采集测量值,通过串口将采集数据传给计算机,最后由软件进行数据处理得到被测齿轮的齿廓偏差并绘制出齿廓偏差曲线.     

基于偏差分析的航空装备软件费用控制方法

针对航空装备软件费用控制与管理问题,提出了一种基于偏差分析的费用控制策略,给出了重大偏差标准设定方法,将挣值管理引入到航空装备软件费用监控中,解决了软件费用与进度的控制问题。研究结果表明,基于挣值管理的方法可准确掌握项目费用和进度的实施情况,当费用或进度偏离计划时,能够及时发现项目研发中存在的问题并采取策略进行调整,有效实现了软件费用和进度的监控与管理。     

一种基于CAD技术的渐开线齿轮齿廓构建方法

本文分析了目前常用的渐开线齿轮齿廓创建方法的不足之处。根据渐开线的形成原理,运用ADAMS软件,采用小步长、多迭代和多控制点的方法,创建出高质量、高精度的渐开线齿廓线。通过ADAMS与其他CAD造型软件的接口,可以进行渐开线齿轮的实体设计。     

基于ISO 13849-1标准的安全继电器

EN 954-1标准概括了控制系统与安全相关部分设计的一般性原则。但是,随着电子和可编程电子系统在机械设备应用领域的广泛应用,系统变得越来越复杂,控制系统以及其相关子系统的设计有了更新、更高的要求,因此需要一种新标准来适应系统这种新的要求,ISO 13849-1正是基于此原因而产生。     

渐开线直齿圆柱齿轮创建方法的探讨

本文作者介绍了两种分别以Pro／ENGINEER和CAXA软件为平台的渐开线直齿圆柱齿轮三维实体造型方法,利用这两种方法可提高直齿圆柱齿轮的三维造型速度和设计效率。     

基于形式化方法的测试驱动开发研究

对测试驱动开发中测试用例的自动生成和管理问题进行了研究,并时现有方法进行了分析和比较.给出了一种基于形式化方法的测试用例生成和管理方案.该方案通过形式化语言描述软件规约,并通过相应工具生成和管理测试用例,从而提高了测试驱动开发的效率.最后给出了该方案在极限编程各个开发阶段的应用.     

基于电子齿轮功能的齿轮轴-轴跟踪测量法

研究了伺服驱动器的电子齿轮功能和渐开线直齿圆柱齿轮齿廓偏差的测量原理,提出了一种基于电子齿轮功能的轴-轴跟踪测量齿廓偏差的方法,降低了数控系统的跟踪误差使仪器的测量精度得以提高,解决了标准轨迹法对控制系统本身性能及坐标轴之间的协调性要求较高,以及测头跟踪测量法自动循环测量实现困难的弊端。     

基于0-1属性矩阵的矩阵压缩存贮方法研究

在矩阵压缩存贮中引入0-1属性矩阵的概念,并在0-1矩阵的基础上给出了利用一维动态数组以及二维动态数组和一维动态数组混合存贮稀疏矩阵的寻址公式,该存贮方法为快速有效的存贮方法,节约了内存空间。     

基于SVM的0-1序列生成器

提出一种0-1序列生成器的设计方法。该方法通过Logistic映射得到一组对初始值具有敏感性、快速衰减的自相关性、长期不可预测性和伪随机性的随机序列;利用SVM对随机序列进行粗粒化,由于SVM的确定性和不改变随机序列的时序性,生成0-1随机序列。理论研究和数值模拟表明,该序列发生器具有良好的随机性,并且易于实现。     

基于蚁群算法的多维0-1背包问题的研究

系统地阐述了蚁群算法,并对它进行改进、优化。将蚁群算法应用于求解多维0-1背包问题,提出一种求解多维0-1背包问题的算法——多维0-1背包问题蚁群算法。它大大减少了蚁群算法的搜索时间,有效改善了蚁群算法易于过早地收敛于非最优解的缺陷。仿真实验取得了较好的结果。     

CAN标准中的时钟容差修正建议

在CAN标识符的仲裁阶段,由于传输延时的存在,发送显位的节点无法看见快节点迟到的隐位/显位跳变沿,因此发送节点间无法建立同步。在最坏情况下,快的发送节点在最后一位退出,它可能一直没有与胜出的慢节点同步,直至ID后的第1个隐位/显位跳变沿。这就使正确同步所需的时钟容差大幅度减小,这是原CAN标准ISO11898-1：2003以及一致性测试标准ISO16845：2004未考虑到的。本文分析了这种情况,提出了修正建议。     

PROCESSUS – Integration of SEI CMM and ISO quality models

Integration of the two best-known quality management models for software production and maintenance, the Capability Maturity Model and the ISO 9001 Model (including ISO 9000-3) is of great interest for both the European and the American software market. The definition of a quality management model which would conform to the requirements of both models and use the advantages of each was a key goal of our research work within the project PROCESSUS.1 Research work was conducted in two steps: first, the detailed comparison of both models was made in order to define their common issues and specifics of each model, and secondly, the integrated model based on the results of the comparison was defined. In this paper the comparison method and results are described. Further, a method for the integration and a framework of the integrated model are presented. The core of our work is actually the content of the integrated model. Due to extensive content of the integrated model examples of some parts only are given in the appendix. The integrated model presented in this paper has already been successfully used in organizations which are cooperating in the project PROCESSUS o these organizations achieved the needed maturity for certification to the ISO 9001 standard and a maturity level near level 3 of CMM.     

Whole-body vibration exposure experienced by motorcycle riders – An evaluation according to ISO 2631-1 and ISO 2631-5 standards

Riders of twelve motorcycles, comprising 6 full-scale motorbikes and 6 motor-scooters, and 5 sedan vehicles, performed test runs on a 20.6 km paved road composed of 5 km, 5 km, and 10.6 km of rural, provincial and urban routes, respectively. Each test run of motorcycle was separately performed under speed limits of 55 km/h and 40 km/h. Tri-axial accelerations of whole-body vibration (WBV) were obtained by using a seat pad and a portable data logger, and the driver's view was videotaped with a portable media recorder. Root mean square (RMS) acceleration, 8-h estimated vibration dose value (VDV₍₈₎) and 8-h estimated daily dose of static compression dose (S_ed) were determined from the collected data in accordance with ISO 2631-1 and ISO 2631-5 standards. Experimental results indicate that the WBV values of the sedan vehicle drivers have low RMS, VDV₍₈₎ and S_ed values (RMS 0.27–0.32 m/s²; VDV₍₈₎ 6.3–8.3 m/s^1.75; S_ed 0.21–0.26 MPa). However, over 90% of the motorcycle riders had VDV₍₈₎ (mean 23.5 m/s^1.75) exceeding the upper boundary of health guidance caution zone (17 m/s^1.75) recommended by ISO 2631-1, or had S_ed (mean 1.17 MPa) exceeding the value associated with a high probability of adverse health effects (0.8 MPa) recommended by ISO 2631-5. Over 50% of the motorcycle riders reached these boundary values for VDV and S_e in less than 2 h. The WBV exposure levels of the full-scale motorbikes riders and motor-scooter riders were not significantly different. However, the RMS and VDV₍₈₎ values of motorcycle riders indicate significant roadway effect (p < 0.001), while their S_ed values indicate significant speed limit effect (p < 0.05). This study concludes that the WBV exposure levels of common motorcycle riders are distinctively higher than those of sedans, even on a regular paved road. The impact on health of WBV exposure in motorcycle riders should be carefully addressed with reference to ISO 2631-1 and ISO 2631-5.

Relevance to industry

This study compares the predicted health risks of motorcycle riders according to ISO 2631-1 and ISO 2631-5 standards. Experimental data suggest that the vibration dose value of ISO 2631-1 and daily dose of equivalent static compression stress of ISO 2631-5 have roughly equivalent boundaries for probable health effects.     

The W-Process for Software Product Evaluation: A Method for Goal-Oriented Implementation of the ISO 14598 Standard

The importance of software product evaluations will grow with the awareness of the need for better software quality. The process to conduct such evaluations is crucial to get evaluation results that can be applied and meet customers' expectations. This paper reviews a well-known evaluation process: the ISO 14598 standard. The review focuses on the difficulties in selecting and evaluating the appropriate evaluation techniques. The review shows that the standard has problems in applying evaluation processes in practice due to insufficient attention to goal definition and to relationships between activities being implicit. Also, the standard ignores the trade-off between goals and resources and pays insufficient attention to feedback. To address these deficiencies, the W-process is proposed. It extends the standard through an improved process structure and additional guidelines.     

程序执行时间的静态预估与可视化分析方法

软件时间性能分析与评估技术是实时软件开发中的一个重要课题.提出了一种基于控制流程图的程序执行时间的可视化分析框架,研究了中间代码段与源程序中语句的对应关系的自动分析、源程序语句行的CPU周期数的提取和计算方法、基于控制流程图的点到点最大时间分析算法和CPU周期的绝对时间估计方法.设计并实现了一个实用的基于控制流程图的程序执行时间静态分析与评估工具.最后,对研究工作进行了相关比较和总结.     

A critical look at ISO 9000 for software quality management

A considerable number of software suppliers report improvements in product and service quality, development costs and time to market achieved with the help of the ISO 9000 standards. Nevertheless, the ISO 9000 family has received unfavourable criticism in journals, textbooks and at software quality conferences. The paper summarizes, discusses and reviews eleven of the most popular arguments against the ISO 9000 standards. The review of the criticism is based on findings of two empirical surveys among European software suppliers that have implemented an ISO 9000 quality system. The paper concludes with suggestions and guidelines for advances in software quality management concepts, such as the ISO 9000 family, CMM, BOOTSTRAP and the emerging SPICE standard.     

Usability Meanings and Interpretations in ISO Standards

The usability of a software product has recently become a key software quality factor. The International Organization for Standardization (ISO) has developed a variety of models to specify and measure software usability but these individual models do not support all usability aspects. Furthermore, they are not yet well integrated into current software engineering practices and lack tool support. The aim of this research is to survey the actual representation (meanings and interpretations) of usability in ISO standards, indicate some of existing limitations and address them by proposing an enhanced, normative model for the evaluation of software usability.     

一种航空机载嵌入式软件安全性评价方法研究

机载嵌入式软件是航空电子系统的重要组成部分,其安全性直接关系到飞行安全。由于软件安全性包含的范围较广,对安全性的评价往往周期长、结果不明确。针对嵌入式软件安全性评价的难题,在软件的整个生命周期采用分类模糊综合评价方法,建立了评价模型,提出了一种嵌入式软件安全性评价方法,在软件生命周期的5个阶段提出了59种评价元素,每种评价元素均反应出软件在每个阶段的关键活动。在各个阶段选择相关项目人员对每个元素进行评价,并依据计算公式得出软件安全分值。通过工程实践证明,该方法切实可用,评价过程相比传统的方法节约了时间,评价结果准确、直观,为航空机载嵌入式软件尤其是型号软件的安全性评价提供了一种新方法,为软件总体质量的评价和软件安全性的改进方向提供支撑。     

航空机载软件测试质量评价方法研究

软件测试是提高软件产品质量和降低软件维护成本的重要手段。针对高安全关键航空机载软件测试质量评价难题,结合航空机载设备研制生存周期、航空机载软件研制生存周期和航空机载软件测试阶段,提出一种全生存周期航空机载软件测试质量评价方法,并建立了基于软件研制过程测试、三方测评、定型/鉴定测评和用户使用四个阶段的质量评价模型,包括测试需求分析和策划质量、测试设计和实现质量、测试执行质量和测试总结质量4项活动和18种度量元。通过工程实践证明,该方法技术实现上可行,具有评价要素更完整、评价模型更合理、评价结果更客观的特点,为解决航空机载软件测试质量评价提供了一种新方法,最终能达到降低软件维护成本和提高软件测试质量的目的。