基于单片机的相位差测量系统的设计

从硬件电路和软件设计两方面介绍了一种以单片机为主控器件的相位差测量系统的设计方案,此系统可用于两个同频率的正弦信号的相位差测量,并具有硬件电路简单、测量精度高、显示直观等优点,有一定的使用价值。     

基于红外光电传感器的转速测量系统设计

该文设计了以AT89C51单片机为核心的一种基于红外光电传感器的智能转速测量系统。系统采用红外光电传感器采集信号,利用整形电路获取转数计数器的计数脉冲,通过单片机进行数据处理,最后用LED数码管对测量结果进行显示。研究结果表明,该系统硬件电路简单、精度高、抗干扰能力强、测量速度快。     

基于PIC16F877多路巡检控制仪的研制

介绍一种以单片机PIC16F877为核心、由信号转换处理电路、LED显示电路、按键输入电路、继电器输出控制电路、模拟量输出电路、RS232通讯电路等组成的多路巡检控制仪。它可实现16路多种输入信号的测量。     

自动化单片机系统中的电机转速测量电路设计

使用基于测速发电机测量电路和光电码盘测量电路,受到现场环境干扰,导致测量误差偏大,针对该问题,提出了自动化单片机系统中的电机转速测量电路设计。获取供电电路中的电源电压,并将其输入到电压比较电路中以转换比较电压。通过整流滤波,将转换结果转换成正、负压。在中央处理机上输入处理结果,完成对电机转速的检测。在保证电机稳定转动前提下,设计以TMS320F28031型号主芯片为主的单片机测量电路,连接6个电阻、2个电容和4个稳压二极管,确保在调整过程中将电路产生的反电动势消解,在TMS320F28031型主芯片中使电路输出电压小于模拟压缩端口。采集器采样开关由控制脉冲控制,从而实现脉冲计数。为了保证反馈速度,采用两个不同时间的控制脉冲锁定数据处理方向的控制脉冲。采用低通滤波锁定锁相环,避免现场干扰。由实验结果可知,该电路测量误差最大为0.3,最小为0.1,实现对电机的平滑启动。     

同频率正弦信号动态相位差的测量

给出了两同频率正弦信号之间动态相位差的一种测量设计,对测量方法和电路元件都作了比较详细的分析说明,该测量系统不但能显示出两信号相位差的大小,而且还能显示出两信号相位之间的超前或滞后关系.     

原位海水总磷总氮传感器的微光信号检测电路设计

为实现海水原位总磷总氮传感器的微光信号检测,设计了基于正交同步检波功能的电路,分别对完全消解、显色后的海水样品进行不同波长条件下分光光度测量。对不同波长LED进行调制和信号的I/V转换,正交同步检波电路完成微光信号检测;经A/D转换,低通滤波电路后输入单片机进行处理;通过数字滤波算法进行平滑降噪处理,实现原位海水总磷总氮传感器的微光信号检测。实验表明:基于该电路的传感器具有精度高、稳定性好,抗干扰能力强、功耗低等优点。     

基于STM32的音频信号分析仪的设计与实现

该文主要论述了基于STM32F407VET6单片机的音频信号分析仪的具体实现。输入信号先经过信号调理电路处理后,经高性能12位并行ADS7819采样后再进入STM32控制器。该系统采用基-2时间抽取FFT算法分析音频信号的频谱,这样大大降低了运算量。该系统可以分析音频信号频谱和测量正弦信号失真度。可测量输入信号的频谱范围为20 Hz~10 kHz,输入电压幅值范围(峰-峰值)为5 mV~5 V。此外,系统还可以判定输入信号的周期性并测量其周期等功能。     

简易多功能计数器的设计

设计了一个简易多功能计数器,由89C52单片机控制。配合相应的测量电路以及相应的软件,实现对频率、周期和时间间隔,被测信号峰值、温度等的测量,可记录10个历史数据,且具有掉电保持功能。其主要电路包括电平电路、时基电路、测频电路、测周电路、测温电路,键盘输入电路,显示电路等,信号输入后先自动判断频率的范围,然后选择需要的测量电路.通过单片机对数据进行处理,在误差允许的范围内显示各个测量值。     

电力电容器在线测量仪的设计

设计了一种基于C8051F020单片机的电力电容器在线测量仪。该设计主要包含四部分:单片机模块、直流电源电路模块、信号调理电路模块和数据运算模块。创新点是将标准电容比对电路作为该测量仪的前置检测输入单元,采用同步采样技术,使得测量的电容容值不受电源电压波动的影响。该电力电容器可在线测量、精度高,具有很好的实用价值。     

基于单片机的电机转速测量系统的设计

为了研制简单可靠的直流电机测速装置,提出了基于单片机和集成芯片设计电机转速测量系统的方案.介绍了霍尔传感器测速的工作原理,设计了系统的硬件电路和软件.该系统以AT89S51单片机为核心,主要包括电源模块、按键模块、转速测量电路模块和显示模块等,通过将脉冲信号送入单片机系统进行计数运算,并将转速测量结果显示在LED上.运行试验表明,系统结构简单,工作稳定可靠,满足电机的测速要求.     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.