电磁耦合式位移传感器的直接数字解调电路设计

针对电磁耦合式位移传感器轴角位置的测量,采用了由旋转变压器AD2S80A构成的测角系统,介绍了其工作原理、硬件构成及相关参数的选择。研究了系统与DSP的接口设计,并提出了利用锁存器解决在读取AD2S80A时出现的延时问题,从而提高了伺服控制系统的实时性。     

A space search optimization algorithm with accelerated convergence strategies

Evolutionary algorithms (EAs), which have been widely used to solve various scientific and engineering optimization problems, are essentially stochastic search algorithms operating in the overall solution space. However, such random search mechanism may lead to some disadvantages such as a long computing time and premature convergence. In this study, we propose a space search optimization algorithm (SSOA) with accelerated convergence strategies to alleviate the drawbacks of the purely random search mechanism. The overall framework of the SSOA involves three main search mechanisms: local space search, global space search, and opposition-based search. The local space search that aims to form new solutions approaching the local optimum is realized based on the concept of augmented simplex method, which exhibits significant search abilities realized in some local space. The global space search is completed by Cauchy searching, where the approach itself is based on the Cauchy mutation. This operation can help the method avoid of being trapped in local optima and in this way alleviate premature convergence. An opposition-based search is exploited to accelerate the convergence of space search. This operator can effectively reduce a substantial computational overhead encountered in evolutionary algorithms (EAs). With the use of them SSOA realizes an effective search process. To evaluate the performance of the method, the proposed SSOA is contrasted with a method of differential evolution (DE), which is a well-known space concept-based evolutionary algorithm. When tested against benchmark functions, the SSOA exhibits a competitive performance vis-a-vis performance of some other competitive schemes of differential evolution in terms of accuracy and speed of convergence, especially in case of high-dimensional continuous optimization problems.     

中点箝位型三电平变换器系统安全工作区的刻画及应用

为了提高中点箝位型三电平变换器的可靠性,基于器件的安全工作区,综合考虑了变换器的拓扑结构、直流母线杂散参数、控制系统的延迟以及温度等因素,推导出了变换器系统安全工作区(SSOA)的数学模型。定量分析了结温和风速对SSOA边界的影响,并分别刻画了结温和风速影响下SSOA的三维立体图形。应用该方法对55 kW/380 V的变换器样机进行保护设计,通过实验验证了基于SSOA所设定的保护边界的有效性,表明SSOA可以保障变换器的可靠稳定运行,提高变换器的可持续运行能力。     

CDMA蜂窝系统定位技术的发展与展望

本文首先介绍了蜂窝移动通信系统定位技术的概念，阐述了定位技术研究的重要性及其在国内外的发展状况，然后对常用的定位方法进行了分析比较，指出CDMA系统定位误差的主要来源并提出解决这些问题的基本思路与方法，最后对定位技术在CDMA和GSM系统中的应用进行了简单介绍。     

面向语义服务结构的模型研究

针对SOA在构建业务处理、信息转换和消息通讯方面存在诸多弊端的现状，主张融合语义Web和Web服务的技术优势，提出一种新的面向语义服务的结构，该结构用WSDL-S作为Web服务间交互的纽带，使服务之间能完成基于语义的互操作、共享和集成；用任务驱动的消息机制将其各个构件联系起来并协同工作，这便于其在Web上异构、分布的部署。并探讨了SSOA的工作机理——动态执行语义，并通过实例证实其可行性。