基于ATmegal6单片机光纤转速检测

针对传统采用的较为繁琐且不准确的物理方式检测电机转速的状况,将ATmega16单片机加入进行控制计数,并辅以数码显示,使用光纤式光电开关的结构进行传感接收信号,再应用单片机采用测频法对光电开关输出脉冲信号的频率进行检则。本装置在降低测速器成本,提高测速稳定性及可靠性等方面有一定价值,而且可以达到一般工业测速的测量标准,具有广泛的前景。     

基于ATmega16单片机光纤转速检测

针对传统采用的较为繁琐且不准确的物理方式检测电机转速的状况,将ATmega16单片机加入进行控制计数,并辅以数码显示,使用光纤式光电开关的结构进行传感接收信号,再应用单片机采用测频法对光电开关输出脉冲信号的频率进行检则.本装置在降低测速器成本,提高测速稳定性及可靠性等方面有一定价值,而且可以达到一般工业测速的测量标准,具有广泛的前景.     

一种简易的智能数字芯片检测装置

针对实验教学过程中数字芯片型号识别和内部故障等问题,设计了一种基于MSP430系列单片机的低功耗智能数字芯片检测装置。利用布尔函数关系式建立了故障集,并对测试芯片生成测试向量,通过单片机编写待测芯片逻辑功能的测试程序,用单片机I/O对待测芯片的逻辑功能进行检测,并将检测结果与存储的芯片逻辑功能进行对比,判断待测芯片是否存在故障。实验结果表明,该装置能够实现对双列直插式数字芯片的快速检测,并显示数字芯片型号或故障,具有体积小、检测速度快,使用方便等优点。     

一种 LCR自动测量系统

为了方便于测量电阻、电容、电感值的大小,本文设计了一种基于单片机的LCR测量系统。该系统可以将电阻、电容和电感加在对应的测量电路上转化为频率信号,将频率信号送入AT89S52的计数端,通过定时和计数可以计算出信号的频率,根据频率和待测参数的关系反演出被测参数。该系统简单、实用,具有一定现实意义。     

简易数字频率计

本设计以单片机AT89C51为核心设计了一种简易数字频率计。它主要由输入整形电路、单片机AT89C51和显示电路等组成。被测信号(以正弦波为例)通过放大、整形电路转换成同频率的方波脉冲信号作为外部事件,采用单片机内部的定时/计数器T0进行计数。其输出信号输送至89C51单片机T0计数器对其进行计数,T1定时器进行定时。然后通过软件编程转换为频率,并通过七段数码显示管显示被测信号的频率。经测试表明,本设计基本上达到了一定频率范围测试的要求。     

基于FPGA的智能高精度频率测量设计

为提高频率测试的精度和智能化程度,减少测试时间,提出一种基于FPGA的依据待测信号频率智能选择测试方案的频率测量方法。利用控制时钟和待测信号通过门电路延时产生的脉冲触发闸门信号,对待测信号频率精确测量进行理论分析、电路仿真以及FPGA硬件实现。仿真和测试结果表明:该方法能够依据待测信号自适应选择测试方案,提高测试精度,降低时间,很大程度上减少人工参与。     

基于灰度值差分的纸张计数算法设计

针对实际生产中机械式纸张计数存在成本高、噪声大的缺点,采用基于灰度差分的纸张计数算法,并且实验验证了其计数的准确性。基于灰度差分的纸张计数算法将排列整齐的纸张的图像进行灰度化后,利用Gabor滤波器进行图像边缘增强,并利用图像灰度投影后的灰度差分,得到灰度像素曲线;根据波峰与波峰之间的间隔初步判断1张纸的厚度,排除干扰峰谷点后,准确定位出波峰或者波谷的的位置;根据标记的位置,实现对纸张进行计数。实验验证结果表明:该算法能较好地实现对纸张的计数,且简单易行,准确率在97%以上。     

基于灰度投影的硬板纸计数方法研究与应用

目前基于视觉的纸张计数方法大多是做图像分割或者边缘检测,虽然简单易行,但存在分割阈值难以选取的缺点。因此,提出一种基于灰度投影的硬板纸张计数算法。首先,将排列规律整齐的硬板纸张的图像通过灰度投影后得到其灰度像素曲线,再利用高斯函数得到的离散值作为权重,判断灰度像素曲线波峰和波谷的性质,然后根据波峰与波峰和波谷与波谷之间的间隔初步判断一张纸的厚度,并排除干扰峰谷点后准确定位出波峰或者波谷的位置,同时根据标记的位置实现对硬板纸张进行计数。最后,用实验验证了所提算法的有效性,实验计数结果表明,该方法能很好地实现对硬板纸的计数,且操作简单易行,2种不同硬板纸张计数结果的准确率均在98%以上。     

飞秒激光器脉冲重复频率的锁定技术研究

介绍了光纤飞秒激光器脉冲重复频率锁定技术的应用背景及其原理,并设计了一套可快速实现重频锁定的实验装置,最终将激光器的脉冲重复频率锁定到铷原子钟上,使飞秒激光器的脉冲重复频率获得和原子钟同样的稳定度;通过计数器采集锁定后激光器的脉冲重复频率数据,使用Allan方差给出了稳定度评价,对激光器脉冲重复频率锁定前后的稳定度进行了对比。实验证明,自主设计的实验装置可以实现锁定功能,具有很好的实用价值。     

基于LabVIEW的气体继电器检测系统的研制

本文讲述基于LabVIEW软件平台的气体继电器检测系统的解决方案。将被测气体继电器安装在校验台上,采用涡轮流量传感器检测流速冲击叶片产生的脉冲信号,通过USB2821采集卡采集到计算机,应用LabVIEW软件测试系统的固有频率,并依此计算待测气体继电器的流速,最后应用实验的方法验证系统的可行性。     

Fundamental Mass Flow Measurement of Solid Particles

A generic mass flow measurement device was developed as a variation on the theme of counting. In a hypothetical infinitely sparse mass flow, the number of passing particles could be counted in a time frame and multiplied by the mean mass per particle to obtain a mass flow per time unit. In a mass flow of realistic density, however, particles travel in cluster formation and direct counting of individual particles is impossible. If a method could be available that reconstructs the original number of particles in a cluster, the mass flow can be computed for realistic clustered mass flows. This reconstruction algorithm was developed in this research; it uses the measured cluster lengths to reconstruct the total number of particles in each passing cluster. The lengths of the clusters were measured with an optoelectronic device. The reconstruction algorithm was developed using simulation, augmented by clustering theory. For identical diameter particle flow, simulation results showed that the number of particles in a cluster could be reconstructed using a very simple reconstruction formula. This formula uses only the total number of clusters per time frame and the total number of individual particles measured in the same time frame. However, identical diameter flow is not realistic, since even identical particles are measured with a certain error. Reconstruction of the realistic distributed diameter particle flow was approximated using the identical particle method. The optical mass flow sensor has major advantages over traditional methods. It is virtually insensitive to vibrations, contamination, temperature drift, and misalignment and the underlying measurement concept is well understood. But most importantly, the sensor does not require calibration. The mass flow of identical particles (4.5 mm air gun pellets) was measured with an error smaller than 3% even for high density flow rates.     

Fundamental Mass Flow Measurement of Solid Particles

A generic mass flow measurement device was developed as a variation on the theme of counting. In a hypothetical infinitely sparse mass flow, the number of passing particles could be counted in a time frame and multiplied by the mean mass per particle to obtain a mass flow per time unit. In a mass flow of realistic density, however, particles travel in cluster formation and direct counting of individual particles is impossible. If a method could be available that reconstructs the original number of particles in a cluster, the mass flow can be computed for realistic clustered mass flows. This reconstruction algorithm was developed in this research; it uses the measured cluster lengths to reconstruct the total number of particles in each passing cluster. The lengths of the clusters were measured with an optoelectronic device. The reconstruction algorithm was developed using simulation, augmented by clustering theory. For identical diameter particle flow, simulation results showed that the number of particles in a cluster could be reconstructed using a very simple reconstruction formula. This formula uses only the total number of clusters per time frame and the total number of individual particles measured in the same time frame. However, identical diameter flow is not realistic, since even identical particles are measured with a certain error. Reconstruction of the realistic distributed diameter particle flow was approximated using the identical particle method. The optical mass flow sensor has major advantages over traditional methods. It is virtually insensitive to vibrations, contamination, temperature drift, and misalignment and the underlying measurement concept is well understood. But most importantly, the sensor does not require calibration. The mass flow of identical particles (4.5 mm air gun pellets) was measured with an error smaller than 3% even for high density flow rates.     

基于荧光法生物气溶胶监测仪计数效率评价及方法研究

生物气溶胶监测仪是一类快速、实时监测空气中生物气溶胶的新兴仪器。为系统评价生物气溶胶监测仪的计数效率,开展了荧光法生物气溶胶监测仪总粒子和荧光粒子2个通道的计数效率评价。首先设计搭建了1套生物气溶胶监测仪计数效率评价装置,然后通过表面原子转移自由基聚合反应(SI-ATRP)制备了单分散、荧光性质稳定的荧光聚苯乙烯微球。采用制备的荧光微球雾化法发尘,模拟生物气溶胶环境,开展计数效率的评价,总粒子数和荧光粒子数计数效率分别为98.9%和98.1%,评价结果表明搭建的装置能满足荧光法生物气溶胶监测仪计数效率的评价需求,对生物气溶胶检测具有意义。     

焊条在线计数装置研究

目的研究设计焊条自动包装机上的焊条在线计数装置。方法在调查现有焊条生产线生产现状的基础上,结合现在使用的包装方式,采用伺服电机控制焊条计数,由旋转编码器进行计数设定,用红外线探测头控制被追踪的焊条,到达分离位置进行分离,完成计数。结果设定150根焊条为1个包装,伺服电机的追踪运动,能准确找到开始计数的被追踪焊条,计数没有偏差,焊条包装每包的质量误差不超过企业标准要求。结论设计制造的焊条在线计数装置,能很好地完成输送带上大量焊条的分包计数,能在实际生产中代替人工,提高效率。     

介电谱法监测贴壁细胞生长的研究

使用介电谱方法监测了贴壁细胞培养过程中细胞数目的变化。贴壁细胞在经修饰过的培养皿底面生长,连续5天每隔12小时取样测量其在0．1-10MHz范围内的介电谱,同时检测培养液中谷氨酰胺、葡萄糖和乳酸的浓度变化。对测得的介电谱值进行了误差修正,以消除杂散电容和电极极化的影响。经修正的细胞电容与细胞数间存在明显的线性相关性,而代谢产物及消耗物则与电容没有明显的关联。此实验为贴壁细胞的培养提供了一种可行的在线监测方法。     

FPGA的双时间法在变粘度油流量装置上的应用

由于变粘度油流量标准装置标准器容积较小,检定时间短,容易产生较大的计时计数误差.现根据双时间脉冲插值计数原理,以现场可编程门阵列(FPGA)为主要硬件研制了高精度计数系统,用于解决检定过程记录脉冲个数不足的问题,实现对检定时间和标准体积管及被检表发送脉冲数的精确记录.实验结果表明,脉冲插值效果良好.     

线性摩擦焊机振动装置中双凸轮机构设计与分析

目的针对现有机械式线性摩擦焊机振动频率较低、工作效率不高和稳定性不佳等问题,通过改进目前振动装置中使用的机构来获取更高的振动频率和稳定性。方法分析焊机现在使用曲柄连杆和机构的优缺点,对比选择采用凸轮机构,并提出增加凸轮的组数来获取更高的振动频率,并以双凸轮机构为例,通过自行设计凸轮结构并进行运动学分析,来验证增设凸轮组数的可行性。结果采用双凸轮机构的线性摩擦焊接设备,机构旋转一次,焊件往返两次,效率能够提升2倍,且机构运动全程过渡自然、无死点和惯性力产生,具有较好的稳定性。相较于现有振动装置上使用的机构,双凸轮机构在振动频率上提升了2倍,证明了增设凸轮组数可以获得更高的振动频率。     

Study of an improved Allyl Di-Glycol carbonate sheet for high energy proton detection

An allyl di-glycol carbonate (ADC) sheet which has been utilised as a neutron detector for personal dosimetry has recently been studied for its application as a device for radiation exposure control for astronauts in space, where protons are the dominant radiation. It is known that the fabrication process, modified by adding some kind of antioxidant to improve the sensitivity of ADC to high energy protons, causes a substantial increase in false tracks, which disturb the automatic counting of proton tracks using the auto-image analyser. This made clear the difficulty of fabricating ADC sheets which have sufficient sensitivity to high energy protons, while maintaining a good surface. In this study, we have tried to modify the fabrication process to improve the sensitivity to high energy protons without causing a deterioration of the surface condition of ADC sheets. We have successfully created fairly good products.