System identification of tendon reflex dynamics.

Patellar tendon reflexes were evaluated in 12 healthy adult subjects using several measures of the reflex responses and of the system input-output relationship. A hand-held instrumented hammer was used to tap the patellar tendon and to elicit the reflex response. Tendon reflex dynamics were estimated using the recorded tapping force (as input) and the quadriceps muscle electromyogram and knee joint extension torque signals (as output). A dome-shaped rubber pad was mounted onto the most sensitive spot on the patellar tendon, where it served as a tapping target, and helped to reduce the reflex variability significantly (p < 0.01). The input-output properties of the system relating the reflex torque to the tapping force were characterized using several measures: the tendon reflex gain (Gtr), contraction rate (Rc), and half-relaxation rate (Rhr). Reflex loop delay (t(d)) was estimated using the delay from the onset of tapping force to the onset of reflex torque. We determined that these system parameters provided significantly more repeatable and consistent characterization of tendon reflexes than did reflexive torque or EMG signals alone (p < 0.025). The input-output relationship relating the EMG signals of the stretched muscle to the tapping force was also identified to help characterize neuromuscular dynamics of tendon reflexes. The observed sensitivity and consistency of the reflex system measures suggest that with appropriate simplification of the instrumentation, these methods may prove useful in routine clinical practice, and may allow more precise quantification of the tendon jerk than is currently feasible with standard clinical tests.     

Development of a computed tomography algorithm for ion temperature measurement

A new algorithm for 2D ion temperature measurement was developed by including Gaussian fitting of Doppler broadened spectral lines in tomography reconstruction. A modified Bessel function model and squared cosine function model were used to satisfy both the annular boundary conditions in space and the Gaussian profile of spectral lines in wavelength. This method was found much more robust against projection signal errors than the conventional Gaussian‐fitting method at each wavelength. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 142(4): 1–8, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10114     

Development of a laser wavefront sensor for measurement of discharges in air

A laser wavefront sensor of the Shack‐Hartmann type capable of simultaneous measurement at two wavelengths was constructed. The sensor uses a single optical path, and is suited for applications such as high‐voltage discharges in air, in which large insulation distances are necessary. The sensor was used to detect optical path differences due to an impulse discharge in air across a needle–plane electrode gap of gap length 17 mm. Optical path differences were measured at laser wavelengths of 532 and 1064 nm at 1.6 µs after insulation breakdown across the gap. From the difference in optical path differences at the two wavelengths, a line‐integrated electron density distribution in the direction perpendicular to the gap was obtained near the high‐voltage electrode. The distribution had a peak value of 1.4 × 10²⁰m^?2 and a full width at half maximum of 4.4 mm. Because of the coverage of a large observation area including the entire gap, the spatial resolution was 1.4 mm, which was inadequate to obtain the precise form of the electron density distribution. However, the results show the possibility of applying laser wavefront sensing to electron density measurement. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 146(4): 10–17, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10247     

Development of a contactless measurement method for transmission line surge voltage waveform

This paper proposes a contactless method to measure a surge voltage waveform on an overhead transmission line and on a cable sheath enclosed in a corrosion‐proof layer. To measure surge voltage and current waveforms on the overhead line, the method is based on electromagnetic coupling between the overhead line and a surge sensor, composed of a closed loop which is a distributed parameter line. The surge waveform is estimated from the induced voltage to the closed loop and from a Z‐parameter theory. To measure the cable sheath voltage waveform, the method is based on electrostatic coupling between the sheath and a detecting electrode, which is portable and detachable, and is composed of quite simple components, and its potential dividing ratio is adjustable using a lumped capacitor. The proposed method is inexpensive, is easy to measure surge waveforms with reasonable accuracy, and also is applicable to surge measurement on a live line because of its contactless nature. © 2001 Scripta Technica, Electr Eng Jpn, 136(1): 9–15, 2001     

新型电缆导体直流电阻测量仪的研制

采用小电流电压比率法测量原理 ,研制了一种智能型的电缆导体直流电阻测量仪。它能够快速精密地测量导体的直流电阻 ,并能自动转换显示其 2 0°C、单位长度 (1km)的电阻和 2 0°C时的电阻率。该仪器还具有液晶汉字化显示、蓄电池供电和便于现场使用等特点。     

蓄电池析气测量仪的研制

介绍了析气测量仪的设计方案、结构、原理和使用,测量时将蓄电池析出的气体通过导气管流入特制的量筒中,气体体积在100mL以内,储存在量筒中并可直接读出气体体积,每到100mL,通过位置传感器控制放空量筒内的气体,并由计数器记录放空次数。该仪器解决了将蓄电池放在水中两个电极电解水产生气体,来测量蓄电池析出气体体积的不准确和麻烦的问题,并能观察析出气体的快慢。     

磁性薄膜噪声测量系统研制

利用惠斯通电桥和两极放大电路在磁屏蔽腔中设计开发了磁性薄膜低频噪声测量系统。通过内推法和外比法测试证明该系统测量精度高,稳定性好,能够完成加磁场环境下的低频噪声测量。利用此系统发现各向异性磁电阻元件在退火后1/f噪声明显降低。该装置对于磁性薄膜提供了一种非破坏的有效检测手段,同时也提供了检测磁性转变内在机制的一种有效途径。     

基于某型数据存储压力仪的图形用户界面开发

可重构数据存储压力仪是一种新型的爆炸冲击波超压测试仪器,为了提高该压力仪测试数据判读的速度和准确性,进一步对测试数据进行分析处理,本文通过对可重构数据存储压力仪数据存储格式的分析,应用MATLAB语言及其用户界面开发环境(GUIDE),对该压力仪自带的数据处理软件进行了二次开发,设计了界面友好、交互性强、数据处理功能强大的图形用户界面,在实地试验测试中,该软件实现了对所采集数据的快速精确的读取和分析,有较强的实际应用价值.     

Development and implementation of a laser headlight system for electro-optic characteristic measurement and comparison

In this study, a laser headlight driving controller (LHDC) using the controller area network (CAN)-bus communication system was developed and implemented for vehicle headlight applications. To observe temperature variations that influence the forward-bias voltage and optical power of laser diodes, the laser diode was placed in an ambient temperature-testing chamber to measure the electro-optic characteristics and calculate the electro-optic conversion efficiencies. The optical power and conversion efficiency values obtained at different temperatures (from negative to positive temperatures) when optical power adjustment was executed using analog and pulse-width modulation technologies were compared. Moreover, a human-machine operating interface was developed using the LabVIEW software. Therefore, the LHDC and laser optical power can be controlled using a computer through the CAN-bus communication system to control the LHDC and monitor it.     

高精度MOA测试仪标准装置研制

介绍了一种高精度氧化锌避雷器（MOA）测试仪标准装置的实现。给出了标准装置的硬件构成原理及其组成模块的功能。介绍了软件设计的程序流程。该装置提供可控标准电源,有效地模拟了MOA工作环境下的状态。向MOA测试仪注入标准源,然后将测量值与标准值对比,进而对测试仪进行科学校验。现场使用表明。该仪器具有成本低、精度高、抗干扰能力强、人机界面友好等优点。     

电动大巴双向电能计量装置的设计与实现

介绍了一种基于微处理器和专用电能计量芯片的直流双向电能计量装置,实现对电动大巴能耗的全数字化计量,详细分析了系统的硬件电路结构和主要软件设计,并提出多项抗干扰措施提高计量的电磁兼容性能。实验结果表明,该装置测量直流电能的精度为可以达到百分之一,实际装车运行稳定可靠。     

新型矫顽力精密测量仪的研制

介绍了一种新研制的矫顽力测试仪,该装置基于PC机丰富的软件资源和强大的数据处理能力,实现矫顽力的自动精确测量,测量方法上,通过气源驱动将直流剩磁转换为交流电信号以克服零漂,运用带通滤波和相关分析抑制干涉;通过线性回归分析寻找准确的过零点,应用优化算法提高测量速度。与现有同类产品相比,测量重复性和准确性有了较大的提高。     

基于80C196KC微处理机的同步电机智能化转速继电器

分析了同步电机转速信号装置的发展现状 ,介绍了智能化转速继电器的工作原理 ,软硬件结构以及抗干扰措施。现场应用实践表明 ,该转速继电器具有测速精度高 ,测速范围宽 ,操作简单 ,可靠性高 ,与上位机通信方便等优点 ,具有推广应用价值     

基于80C196KC微处理机的同步电机智能化转速继电器

分析了同步电机转速信号装置的发展现状,介绍了智能化转速继电器的工作原理,软硬件结构以及抗干扰措施.现场应用实践表明,该转速继电器具有测速精度高,测速范围宽,操作简单,可靠性高,与上位机通信方便等优点,具有推广应用价值.     

继电保护测试仪时间测量精度检测校准装置研制及性能分析

为推进智能变电站建设,针对继电保护测试仪时间测量精度缺少验证手段导致的保护测控等关键二次设备应用和推广受影响的问题,研制了一种针对继电保护测试仪时间测量精度开展检测校准的装置。首先,分析现有方法的弊端,提出继电保护测试仪时间测量精度检测校准的整体思路,明确设计方案。其次,利用输入数据精确时间标定和精准时间的输出控制技术,实现SV、GOOSE和硬接点信号的高精度采集和输出。最后,基于动作事件生成及精确时间戳实现电力系统常见动作时间的高精度、宽量程模拟,作为继电保护测试仪测量的基准误差。试验及工程验证结果表明,新研制装置的时标精度、动作时间模拟和抗干扰能力满足标准要求和应用需求,有效解决了继电保护测试仪时间测量精度无法检测校准的行业难题,提高了检测校准能力和效率。     

防振锤功率特性两种测试方法的比较

测量防振锤的功率特性按其控制条件不同分为定振幅法和定振速法 ,从理论和实验两方面论证了定振速法比定振幅法更接近防振锤在实际线路中的运行情况 ,其结果也更能反映防振锤的实际功率特性     

Development of a laser radar using LDS dye and sum frequency generation for NO2 measurement

A laser radar for measuring vertical concentration profiles of atmospheric NO₂ was developed. The laser transmitter uses an LDS765 dye laser pumped by a Nd:YAG laser. The dye laser output is converted to wavelengths 446.8 and 448.1 nm, which are used for NO₂ measurement, by sum frequency generation (SFG) using a pair of KD^*P crystals. The dependence of the LDS765 dye laser output on wavelength and dye concentration was investigated, and the performance of the laser transmitter was evaluated. Compared to the Coumarin 445 dye laser conventionally used for NO₂ measurement, this laser transmitter represents a significant improvement in output stability, as well as in maximum output energy and overall conversion efficiency. Using the newly developed laser radar, NO₂ concentrations of 20 to 40 ppb were measured for vertical range 500 to 1000 m, which were in rough agreement with values monitored on the ground. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(2): 26–33, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10231     

测量航空发动机转速的便携式系统的开发

本文详细介绍了一种测量航空发动机转速的以FPGA(XC2S100E 6PQ208C)为测量转速核心处理芯片,嵌入式单片机(S3C2410)为数据处理器的便携式系统的设计方法.详细介绍了系统的硬件组成和软件设计,并利用ISE6.2的集成开发环境编写了测量转速的软件程序,给出了系统测量的仿真波形.仿真结果表明,该设计方案符合设计要求.     

一种角位移测量仪的研制

介绍一种用于光学测量投影仪的角位移测量仪。它通过硬件电路对一个旋转编码器输出的角位移信号进行辨向和计数,再使用一个微处理器对辨向信号和计数信号进行处理,得到被测工件在Z旋转方向的位移值,最后对位移测量值进行误差修正,得到该仪器的测量分辨率为1’且测量精度为±3．9’。实验表明：所研制的角位移测量仪具有准确、可靠的特点。     

泵站水锤的波追踪计算方法

推导了波追踪法求解水泵-管道系统水锤和断流弥合水锤的方程,讨论了波追踪法和特征线法在理论、求解过程和计算精度上的异同。经计算得到的水泵过渡过程参数和断流弥合处参数的变化规律表明,两种算法的理论本质上是一致的,但波追踪法直接计算压力波（与初始值的水头差值）;不考虑管道摩阻损失时,两者的计算结果完全一致,表明文中提出的针对泵站和断流弥合处的方程和边界条件是正确的;而考虑摩阻时,由于对摩阻项处理方法的差异,导致两者计算结果略有差异,两者相对差值小于0.3%,两种算法具有相同计算精度;计算断流弥合处的瞬变参数变化时,得到的最大值和最小值相同。对于复杂管路或管网系统,波追踪法可直接依据泵站管道的边界条件计算管道内的水力过渡过程,无须采用数值算法,计算效率相较于特征线法提高。