基于Matlab闭环直流调速系统的分析与仿真

论文通过对单闭环直流调速系统的介绍,阐述和分析了自动控制系统的一般步骤与方法,并给予解决采用常规比例调节器为电压放大和电压比较环节时存在的问题的控制方案,同时通过软件MATLAB进行了实验验证,结果表明控制方案可行,效果良好.     

两液相生物反应器研究进展

介绍了两液相反应器的进展及存在问题，两液相反应器仍处于试验阶段，其主要问题是生物催化剂在界面的聚集损失活性等。     

Controller design for nonlinear systems using the Contoured Robust Controller Bode plot

In this paper, we develop the Contoured Robust Controller Bode (CRCBode) plot and demonstrate its use in the design of robust controllers for nonlinear single‐input single‐output (SISO) systems. The CRCBode plot shows contours (level sets) of a robust performance quantity on the Bode magnitude and phase plots of the controller. An iterative frequency domain loop‐shaping design approach is employed to eliminate all intersections of the controller frequency response with certain ‘forbidden regions,’ indicating that a standard SISO robust stability and performance criterion is satisfied. Nonlinearities are accounted for by avoiding the maximum forbidden regions over a structured uncertainty set consisting of linearizations of the system dynamics about several operating points. We demonstrate this technique by designing and experimentally verifying a flow‐rate controller for a butterfly‐valve based liquid cooling system, which is robust to valve nonlinearities and flow disturbances. Finally, we compare this compensator with one generated using an automated H _∞ synthesis algorithm and discuss the advantages of the CRCBode approach. Copyright © 2013 John Wiley & Sons, Ltd.     

一种改进的VI CFAR检测器

为得到不同杂波背景下的良好检测性能,给出了一种改进的VI CFAR检测器.该检测器主要利用均值类可变性指示（MLVI）CFAR检测器和有序统计类可变性指示（OSVI）CFAR检测器的各自优点以及VI CFAR的以背景均匀程度自动选择不同检测器思想.理论分析和仿真结果表明：该检测器在均匀背景下性能基本与MLVI CFAR重合;多目标背景下具有较强的抗多目标能力;杂波边缘背景下有较好的虚警概率控制能力且运算量小,是一种稳健的检测器.     

Cycling hardening and serration yielding of Fe-Ni-Cr alloy at high temperature under out-phase TMF

Behaviour of hardening and serration yield of a Fe-Ni-Cr alloy under isothermal cycling (ISC) and out-phase TMF was studied on the basis of varied hysteresis loops. Cycling hardening and serrated yielding for ISC depend on the temperature and the total strain range, stronger hardening with serrated yielding at higher strain range under ISC at 600 °C, but no hardening and serrated yielding occurred under ISC at 800 °C. Stronger hardening with stress serration occurred at the thermal path going to the lowest temperature, no stress serration occurred at the highest temperature under the out-phase. The hardening also depends on the total strain range, higher total strain range with lower cycling temperature resulted in a stronger hardening and remarkable serration yielding behavior. Weaker hardening without serrated yielding occurred at near 800 °C may due to an obvious cycling stress drop under out-phase TMF. Change in the shape of the hysteresis loops also expresses the degree of the damage of the tested alloy under out-phase and ISC.     

新型钢铅组合耗能器性能试验及参数优选

为了考察新型钢铅组合耗能器(NCSLD)的力学性能和提高其耗能能力,利用电液伺服压剪试验机对NCSLD耗能器进行力学性能试验,采用ANSYS实体建模的方法对耗能器进行大量的数值分析,并对性能试验和数值分析的结果进行对比,研究耗能器的滞回特征参数与其6个几何参数之间的关系,回归出二者之间的公式.提出评价耗能器性能优劣的标准及其附加条件,并以此标准为依据,利用均匀设计法和遗传算法分别对耗能器的6个几何参数进行优选.结果表明遗传算法的选优效果要好于均匀设计法,同时得到一系列性能良好的NCSLD耗能器.     

高速机车车辆的车轴数字化超声波探伤系统

针对高速机车车辆车轴的超声波探伤提出一种新的超声波探伤方案．将组合探头装置安装在车轴的端面上,用机油作耦合剂,准确定位,保证探头在扫查时超声波主声束始终穿过车轴的中心线,使主声束与裂纹相交,便可对车轴进行探伤．该系统检测机车车轴具有准确度高,精度高,效率快的特点．     

停车诱导信息系统信息采集技术研究

信息采集是停车诱导信息系统的重要组成部分,准确可靠的信息是停车诱导信息系统实现诱导功能的重要前提,文章对停车诱导信息系统的采集技术进行了综合比较和分析,总结了各种采集技术的优缺点和适用范围,并提出了采集技术的选择流程。     

简易人体穴位识别治疗仪

为了解决非专业人群寻找穴位难、不准确、不易操作等难题,设计了一种以SPCE061A为核心MCU（Micro Control Unit）的简易人体穴位识别治疗仪。给出了系统结构和实现流程,提出了一种基于层次分析原理的新型穴位检测方法,并讨论了环境因素对穴位识别结果的影响。通过人体穴位检测实验表明,本系统的穴位与非穴位正确识别率可分别达到95%和98%以上,且输出频率可调、波形可变的脉冲电压可达到模拟中医针灸治疗的作用。与传统找穴位方法相比,该方案具有操作简单、功耗低、性价比高等优点。     

湿度对CR-39固体核径迹探测器测量^220Rn／^222Rn水平的影响研究

在可调控温度、湿度及氡浓度的南华大学氡实验室对不同的湿度条件下CR-39固体核径迹探测器测量^220Rn、^222Rn的探测效率进行了测定,分析了湿度对CR-39固体核径迹探测器测量^220Rn、^222Rn探测效率的影响．实验结果表明：相对湿度在35％-95％范围内,当湿度为50％左右时,CR-39固体核径迹探测器测^222Rn,探测效率最高,标准偏差为2．0％;相对湿度在30％-100％范围内,当湿度为75％时,CR-39固体核径迹探测器测^220Rn的探测效率最低,标准偏差达到78．4％．