无线振动传感器网络节点设计

介绍了一种适用于振动测试的传感器网络节点,通过该节点搭建的传感器网络可以检测材料是否存在缺陷.该节点的硬件电路以cyclone Ⅲ系列FPGA为核心,包括3维振动信号调理采集单元、1个外部SD卡存储器、1个2.4G频段的无线收发单元、1个传感器单元和USB - SPI电路以实现无线、有线两种传输方式.实验结果表明设计系统是可行且有效的,将会为MEMS技术应用于振动检测领域奠定基础.     

反应堆周期监测装置的研制

本文比较详细介绍了反应堆周期装置的原理以及一种新型的电路的设计方法。经过在清华大学核能技术设计研究院屏蔽试验反应上两年的考验。证明该装置设计合理,性能稳定。     

基于CAV424的电容式压力传感器测量电路设计

随着差动式硅电容传感器广泛应用于各行各业中,对差动电容信号的检测至关重要.文中提出基于CAV424电容检测芯片作为前置检测单元,实现了电容压力传感器测量电路.该电路具有稳定性好,抗干扰性强,且通过非线性补偿有良好的线性.实验结果表明,实际电路与理论分析具有良好的一致性.     

光纤电压传感器信号处理电路的设计

介绍了光纤电压传感器的工作原理,研究了光纤电压传感器的信号接收与处理电路部分,设计并测试了放大滤波电路、模数转换及单片机的信号处理电路,对高压测量中的误差来源进行了分析。     

换能器驱动电路的设计及实验研究

换能器作为加工系统中的能量转换元件,其驱动电路的设计性能的好坏,将直接影响光整加工的加工效率及加工质量。为此进行了一种换能器驱动电路的设计,包括滤波电路、逆变电路、信号发生电路以及驱动电源主电路,可以有效且高效地驱动换能器工作。     

高压输电线路红外防鸟报警系统研制

本文介绍用于高压输电线路上防止鸟害的电子防鸟报警系统，本设计以热释电红外传感器作为检测部件，检测外界信息，并转换输出微弱的电信号，经运算放大器、A/D采样、单片机处理，滤去干扰，最后所得信号触发报警电路。     

智能电容式液位计系统设计

讨论电容式传感器的原理、电容频率转换电路、宽范围精确测量频率量的多周期测量法，及利用DS1820测量温度和用单片机进行温度补偿的方法。     

基于振筒式传感器某型压力检测系统关键电路的设计

设计了基于振筒式压力传感器的检测系统测量显示组件电路及相关软件，实现了传感器的配套集成电路。仿真与实际测试表明：各电路设计可靠、运行稳定、实用性强。检测电路及配套电路的实现对自动检测仪表中提高传感器系统测量精度提供了一条有效的途径。     

基于FPGA的光栅莫尔信号正弦性误差补偿电路研制

针对光栅莫尔信号正弦性误差对细分结果造成影响问题,对基于粒子群算法(PSO)的光栅莫尔信号正弦性误差补偿方法展开研究。在量化分析信号正弦性误差引入的细分误差的基础上,对基于PSO算法的正弦性误差补偿方法进行阐述。设计基于FPGA的补偿算法实现电路,对实现过程中的关键问题进行分析并提出解决方案。最终在FPGA电路板上对实际信号进行算法电路有效性验证,结果表明,应用该电路能有效地补偿信号正弦性误差,将信号的细分误差峰峰值由0.7″降低到0.14″。     

Evaluation of errors of temperature measurements with the aid of a thin-layer transducer in concentrated contacts

Error analysis results from temperature measurements taken with a thin-layer transducer are presented in this paper. Errors resulting from the influence of the time constant, contact pressure and isolating layer of the transducer have been determined. The formulae which permit the calculation of temperature corrections resulting from the influence of the isolating layer of the transducer are presented. The influence of some other sources that disturb the measurements has also been evaluated. It has been found that the maximum values of the total measurement error may be high but not high enough to question the justification of the application of this measurement method.     

基于水下超声成像分时复用数据采集系统的设计

利用压阻式水声传感器采集超声回波信号,通过行共用电源线,列共用信号线的方式将水声传感器组成成像阵列.使用MAX4617八选一高速模拟开关控制每个传感器与采集电路的通断,从而实现采集电路的分时复用功能.利用AD6655采集数据,FPGA作为模拟开关和采集电路的时序控制器,异步FIFO作为采集数据传送给EZ-USB的缓冲器,EZ-USB单片机负责任务的协调,并把数据打包上传给计算机.初步测试了传感器与采集通道的开关时延特性,以及分时采集样本与原始声信号吻合程度,实验结果证明系统能够完成水声传感阵列的实时数据采集任务.     

Analysis of damping resistor’s effects on pulse response of self-integrating Rogowski coil with magnetic core

A self-integrating Rogowski coil with magnetic core is investigated for accurate measurement of high-impulse current in this paper. Usually, the distributed parameters of Rogowski coil generate deleterious high-frequency resonant signal parasitizing in the useful signal of the coil circuit. Damping resistors can be used to eliminate the parasitic resonant component of the signal. In this paper, damping effects of the damping resistors on the output signal of Rogowski coil are studied in detail. According to circuit theory, approximate circuit equations of Rogowski coil with lumped parameters in simplification are put forward. Response signal of coil is analyzed and a reasonable method for choosing damping resistance is also presented. When the 50 Ω damping resistance is used, the amplitude of parasitic resonant signal has been damped by 5.7 times in contrast to the situation without any damping resistance. Result of Pspice circuit simulation corresponds to the theoretical calculation result. A standard 10 ns square pulse has been used to calibrate the coil signal before and after the damping resistors soldering on the coil, respectively. Experimental results show that the response time of the coil with magnetic core is 1.1 ns and the parasitic resonance in the coil signal is almost eliminated. The coil can accurately detect high-pulse current at kA range.     

振弦式传感器信号采集卡的研制

介绍振弦式传感器的数学模型及工作原理,给出了该传感器信号采集卡的设计方案。分析了激振与拾振电路的设计,传感器信号频率的等精度测量电路设计,以及采用CAN总线实现与主控卡相互通信的智能节点设计。该采集卡作为一个嵌入式智能单元,可实现根据不同应用需要与其他传感器采集卡自由组合,构成一个灵活的集成数据采集系统硬件平台。     

A low cost design and development of a reluctance type pressure transducer

Transmission of Bourdon gauge reading to a remote location is very important in industry. This requires a conversion of Bourdon tube displacement into an electrical signal with the help of a suitable transducer. In the present paper, a simple low cost reluctance type pressure transducer has been developed. Its theoretical analysis has been presented in the paper. The transducer has been developed and tested in the laboratory and has been found to follow the theoretical equations. The experimental results of the observed characteristics of the transducer are reported in the paper. A very good linearity and repeatability of the data has been observed.     

基于 CPLD的双通道高压脉冲信号源

针对声波测井压电陶瓷换能器容性大的负载特性,采用单片机和CPLD相结合的方式设计了一种输出幅度高、驱动电流大、脉冲宽度可调的双通道高压脉冲信号源。系统利用C8051F350单片机及PWM控制芯片MM33060A,并结合自耦变压器反激式升压电路将12 V直流供电电压抬升至300 V。采用CPLD产生精确的频率可控的300 V脉冲电压,利用脉冲变压器进一步提升电压,得到了上千伏的高压激励脉冲。实验结果标明,设计的信号源在激励压电陶瓷换能器时,负载上得到了比较理想的波形,波形上升沿陡峭,无拖尾及振荡现象,满足实际应用需求。     

Evaluation of the enhanced cavitation impact energy using a PVDF transducer with an acrylic resin backing

A transducer using a PVDF (Polyvinylidene Fluoride) film as a pressure sensitive material has been developed and applied to evaluate the cavitation impact energy. However, enhanced cavitation impact used for peening destroys the PVDF film, which is directly exposed to the cavitation impact through a polyimide tape. In the present paper, a newly developed PVDF transducer is proposed, in which a PVDF film with an acrylic resin, which attenuates the burst signal, is put on the backside of a metallic base, where the front surface of the metallic base is exposed to the cavitation impact.     

电容式压力传感器的厚膜集成化研究

采用厚膜传感技术研制电容式感压元件,并通过厚膜混合集成技术将信号处理电路集成在感压元件上成为一体,进行电容式压力传感器的厚膜集成化研究。结果表明：研制成的新型厚膜电容式集成压力传感器,线性达到0．5％,迟滞小于0．5％,具有重复性好,受分布电容,寄生电容影响小,精度高,抗过载,耐腐蚀等特点,对厚膜感压元件,信号处理电路的设计与平面化加工以及集成化等进行了介绍,并对集成化中相关工艺,兼容性及性能进行了讨论。     

超声波远距离振动信号检测系统的设计

在机械设备状态监测与故障诊断中,振动信号是一个重要的状态参量。本文针对压电式、电涡流传感器等常规的振动测量方法和仪器在特殊环境中的局限性,提出了基于超声波的非接触式检测方法,研究并设计了系统检测装置。该检测装置主要由超声波发生模块、超声波接收模块和基于LabVIEW的数据采集/处理3个部分组成,利用该装置对振动对象进行远距离测量,并同时用传统测量仪器(电涡流位移传感器)作对照实验,得到较理想的检测结果,验证了该超声波振动检测装置的有效性和可行性。     

一体化涡街流量变送器

介绍了气体涡街流量变送器的原理和方法,变送器由信号获取单元和信号处理单元组成,集成了信号变换、信号处理和信号显示与输出等功能。实际应用表明变送器性能指标达到了设计要求。     

平面加工精度的自动检测及其计算机数据处理系统研究

利用电容传感器原理组建的测量电路,将机械加工平面误差转变成电信号,读取RC电路中的电压值来获得平面测量点误差值.利用空间解析几何原理建立数学模型,将所获得的误差值输入计算机进行数据计算和处理,最后输出平面度误差值,从而实现机械加工过程中平面度检测的自动化.