基于速度比例的伺服平台控制特性分析

针对伺服平台中非线性、多干扰的控制问题,文章采用速度比例、位置反演的控制方法对永磁伺服平台进行串行复合控制,利用电机及减速器动力学方程建立系统数学模型,通过递推Lyapunov函数的逐步演算,最终获得系统的控制量函数;经过仿真平台的俯仰及方位的阶跃控制特性分析,得到了反演比例控制策略的动态特性.     

Planning a cost-effective cellular manufacturing process—a case study

The drive key is one of the most important high-precision components of aircraft braking systems. In this paper, a cost-effective drive key manufacturing process is developed. This proposed manufacturing process makes use of near net shape manufacturing, CNC machining, and cellular manufacturing methods. To make the proposed process a reality, proper engineering changes of the parts along with group technology are applied to the product design, in conjunction with the pro posed manufacturing methods. In addition, a general spread sheet program is developed for each style of fixture module to assist in part program coding. Moreover, statistical process control (SPC) is implemented to verify product quality and accept the product at the point of manufacture. It is observed that the implementation of the proposed drive key cellular manufacturing process results in a tremendous improvement in quality, throughput and productivity as well as a drastic reduction in manufacturing operations, workholding fixtures, cutting tools, and inspection media.     

Supplier quality assessment to identify depth technical knowledge of component reliability

As a result of global competition, international companies that manufacture photocopiers, printers or car navigation systems have to purchase low-cost electronic components such as semiconductors and hard disk drives by outsourcing production. However, it is often difficult for these companies to evaluate the quality of their suppliers through interviews and technical documentations. This article proposes new measures for supplier assessment and a systematic approach to select suppliers that have in-depth knowledge of component reliability and technology. The measures for selection not only include the physical quality of components but also information disclosures provided by suppliers, which consist of failure analysis, reliability data and details of the design-manufacturing process. The proposed measures are applied to real data of photocopier manufacturing enterprises. Experiments conducted show that a systematic assessment will enable selecting appropriate suppliers with a lower failure rate.     

职业驱力、全面薪酬满意度对科研绩效的激励路径

在科技人才人力资源开发的理论研究和实务工作中,工作绩效及其激励问题一直处于核心地位。本研究利用679个本土科技工作者样本,运用结构方程模型、层次回归分析等数据分析方法,检验科技工作者职业驱力、全面薪酬满意度这两个分别反映个体特征因素与工作特征因素的变量在科技工作者科研绩效的激励机制中所发挥的效应。研究结果表明:科技工作者的科研结果绩效受到行为绩效的显著影响;行为绩效受个体特征因素与工作特征因素的协同激励,其中,事业型职业驱力起主导作用,非经济薪酬满意度居间起调节作用;经营型职业驱力则会侵蚀科研行为绩效与结果绩效。     

基于旋转变压器及TMS320F28035的伺服系统位置检测

为检测伺服系统位置信息,以旋转变压器作为位置传感器,设计了基于芯片AU6802N1的位置检测电路并在此基础上提出了一种仅利用TMS320F28035对旋转变压器转子位置直接解算的方法。该方法综合运用正弦峰值采样、CLA浮点数计算、误差校正等手段。实验表明,该方法在位置解算的速度和精度上可与AU6802N1芯片相比,节约了系统成本,具有一定的实用性。     

基于CANopen协议的数字伺服电机通信主站研究

在数控系统中利用CANopen总线协议实现对数字伺服驱动器的上位控制,硬件环境为FPGA、MCP2510、MCP2551和IDM6408EIA数字伺服驱动器。主从站之间的数据发送与接收主要以过程数据对象（PDO）和服务数据对象（SDO）的方式进行,并采用VHDL语言编程,在FPGA中实现CANopen主站的应用层功能。实验表明,CANopen通信能成功实现,数字伺服驱动器能够按照来自上位机的指令驱动伺服电机。     

基于ANSYS的增强型混合式进电动机的静转矩分析与计算

文章介绍了一种新型的增强型混合式步进电动机,该型电机在普通混合式步进电机的定子槽中加装了径向充磁永磁材料。研究中通过ANSYS软件对该型电机进行了三维电磁场有限元仿真分析。有限元分析结果与试验结果符合良好,分析结果显示：与普通混合式步进电机相比,增强型混合式步进电动机的最大静转矩幅值提高了约60%,极大地改善了电机的总体性能。     

中国体制改革的动力及其获取原则与方式

中国体制改革已进入攻坚阶段,保持和增强改革的动力成为保证改革成功的关键.要获取更加强大的改革动力,必须坚持为社会绝大多数人谋利益、长远和整体利益与眼前局部利益有机统一、公平分担改革成本和共享改革成果、正确处理效率与公平的关系、统筹兼顾和通过推进改革消除改革阻力等基本原则,必须选择政治动员、思想教育、利益协调和舆论引导等主要方式.     

基于D类放大器的外置式DBS的驱动电路设计

以DBS的治疗参数为依据,设计了外置式DBS的驱动电路。以单片机MSP430的PWM输出作为信号源,来控制D类放大器的开关,D类放大器的双端输出用以驱动初级线圈。通过实验可在模拟负载两端获得有效的单极性刺激脉冲,此脉冲会随着信号源的频率,占空比等参数的变化发生相应的变化,并且得到了3%的传输效率,证明了D类放大器用于外置式DBS的驱动电路的可行性。     

基于网络的出版社管理信息系统的设计与实现

以开发的出版社管理信息系统项目为背景,对出版社的业务流程进行全面的分析,并以此需求为出发点,探讨了出版社业务系统可行的解决方案。