基于AT89C2051单片机的智能涡轮流量计的设计

给出了以AT89C2051为核心,利用单片机的运算和控制功能,并采用串口液晶显示模块实时显示所测流速和流量的涡轮流量计设计方案。同时,该方案还提供了可以更改流量计参数的功能,根据不同的油料采取不同的参数适应相应的变化,使油速和油量的测量的精确性得到了很大的提高。该方案由于使用了串口液晶显示模块和E2PROM,因而可在节约系统资源的基础上保证测量精度和系统实时性。     

基于AT89S52单片机的装载称重控制器设计

给出了以AT89S52为核心,利用单片机的运算和控制功能,并采用串口液晶显示模块实时显示所测货物的重量和累计重量装载称重控制器设计方案。同时该方案还提供将装卸货物的单车量、日累加量、总累加量以无线通讯方式传输至上位机,供上位机显示和处理的功能。     

基于C51单片机的暖气热量测量计费装置

针对目前北方地区采暖控制和收费缺陷,给出了一种基于C51单片机的暖气热量测量计费装置,利用单片机对数据的处理和控制功能,采用串口液晶显示模块实时显示所测的室内温度,流体温度以及所消耗的热量值。同时,利用温度传感器对单片机的反馈控制步进电机转动改变阀口的大小,实现水流速度的改变,从而达到改变室内温度的目的。     

基于AT89S52与LD3320的智能门锁设计

提出了一种智能门锁的设计方案。该方案以AT89S52单片机为核心,配置矩阵键盘和AT24C02存储芯片实现密码设置与保存,采用LD3320模块与单片机串口通讯实现门锁的语音识别加密,利用ESP8266WIFI模块实现门锁开关的无线控制。系统具有关门提醒和温湿度检测功能,采用LCD液晶显示,操作方便,使用灵活可靠,具有较好的实用价值和推广意义。     

基于ARM单片机的无线涡轮流量计的设计

传统涡轮流量计需要铺设电源线和信号传输电缆,使用起来极不方便。而现有的无线通信方式繁多,特点不一,为了实现计量点分散情况下流量计的远程实时报警、监测流量等功能,对主要无线通信方式进行了简要分析。给出了以ARM单片机为核心处理器,集成无线通信模块的流量计设计方案,并对涡轮流量计的软硬件进行了具体设计。该方案能够实现流量测量、数据存储、流量显示、远程实时报警、远程监控等功能。     

手持电动工具多传感器信息采集系统设计与实现

为了实时检测手持电动工具的所处状态,实现后期对角磨机处于危险情况的预警设计,该文基于多传感器信息采集系统设计思路,构建了由基于555时基电路的单电容测量模块、内置A/D转换器电阻测量模块、基于MPU-6050六轴运动数据测量模块、原始数据读取及转化处理单片机模块、将转换信号发送至上位机的串口模块、蓝牙无线传输模块、上位机系统模块等组成的一种手持电动工具运行参数的多传感器信息采集系统。该系统可快速直观地反映和分析载体各项状态参数,解决了手持电动工具运行使用过程中的运动与状态实时监测问题。     

基于GPRS的无线水质自动监测系统的研究

该系统在传统工艺的基础上利用AT89C51单片机和基于GPRS的新型无线通讯模块相结合实现了水质自动监测系统的设计。下位机水质参数处理采用了信息融合技术,提高了检测精度;利用串口并通过DTU模块将数据传送至水质监控中心,快速准确地实现对水质状况的实时监测。系统功耗小、成本低、实时在线、不受地理位置限制等优点。     

基于液晶显示模块与单片机的数字化角度测量装置

在简述液晶显示模块与单片机工作原理及技术特点的基础上,讲述了其在数字化角度测量装置中的应用,介绍了系统工作原理、接口电路、软硬件实现方法,并给出了程序流程图及部分子程序。结果表明采用液晶显示模块与单片机配合使用的角度测量装置测量实时性好,动态显示直观,性能稳定。     

多路信号采集及显示实验仪器设计

研究了基于MAX114多路信号采集及显示实验仪器系统的实现方案、组成结构及软件设计。应用单片机控制AD转换器件及液晶显示模块实现了对多种传感器的数据采集及信号测量,可简单实现对多种传感器信号的采集与处理;为传感器信号测量提供了一个平台。该实验仪器可以对4路模拟信号进行采样,采样精度为8位,转换速率可达1MSPS;同时该实验仪器具有对4路传感器模拟信号进行加工处理并具有液晶实时显示的功能。     

基于STM32的CAN总线测试平台设计

针对建筑电气与安防系统中不同波特率和不同协议的CAN总线网络节点,以STM32F103单片机为主控制器,设计了一种CAN总线测试平台。给出了该平台的硬件电路和软件设计方案。其中,硬件电路包括MCU控制模块、CAN总线接口模块、按键及开关模块、一键下载/串口通信模块与SWD调试模块等。软件部分包括波特率设置模块、CAN数据封装模块、串口/CAN转发模块、数据反射模块、灯光信号处理模块等。功能方面,该测试平台具有CAN总线信号反射、串口/CAN数据双向转发两种功能。经调试表明,该测试平台通讯可靠,灵活性高,可扩展空间大,达到预期设计目的。     

一种新型的电容式油气两相流相份额传感器

本文介绍了一个高精度的电容式两相流相份额传感器。该传感器是非插入式,传感部件与测量电路集成一体,排除了寄生电容和杂散电容的影响,使测量精度和稳定性大大提高;输出是直流电压信号,便于计算机自动采集数据;动态反应快,适于实时在线测量。可用于管内油气两相流相份额测量、流型识别、两相流量测量和流动状态监测     

Dynamic performance analysis of turbine flow sensor based on CFD simulations

The research on the dynamic performance of flowmeters has great significance for the accurate measurement of flow onsite. A simulation method for dynamic characteristics of turbine flow sensor was proposed in this study. This method was used to investigate the dynamic performance of three turbine flow sensors with different diameters. The amplitude-frequency characteristic, phase-frequency characteristic, transfer function, and step response are analyzed based on the results of the simulation. The results indicate that turbine flow sensors can be analyzed as a first-order system. The frequency of pulse flow is the main factor affecting the sensor's performance. The phase difference increases as the frequency increases, and the maximum phase difference reaches 50°. The gain of the small-diameter turbine flow sensor is susceptible, while the phase difference and time constant of the large-diameter turbine flow sensor are susceptible. For step flow, the time constant generated by the negative step is larger than that by the positive step. The analysis results provide bases for evaluating the dynamic performance of turbine flow sensors used online.     

阵列式静电传感器结构设计与优化研究

气固两相流广泛存在于自然界和工业生产过程中,利用阵列式静电传感器感应成像系统可以对两相流的流型、截面分布等信息进行可视化监测,进而得到其流动特性、运输效率、安全状况等情况,对于两相流体的理论研究以及相关生产过程的安全化、高效化和实时控制等具有重要意义。本文提出了一种新型的阵列式静电传感器结构,通过有限元方法分析静电传感器敏感场特性,进而验证传感器的结构参数对测量结果的影响;建立了两相流流动的仿真模型,通过对比传感器不同结构参数下的敏感特性,对相关参数进行优化,对提高静电成像系统的成像精度与准确度具有重要意义。     

Note: anti-strong-disturbance signal processing method of vortex flowmeter with two sensors

Some digital signal processing methods have been used to deal with the output signal of vortex flowmeter for extracting the flow rate frequency from the noisy output of vortex flow rate sensor and achieving the measurement of small flow rate. In applications, however, the power of noise is larger than that of flow rate sometimes. These strong disturbances are caused by pipe vibration mostly. Under this condition the previous digital signal processing methods will be unavailable. Therefore, an anti-strong-disturbance solution is studied for the vortex flowmeter with two sensors in this Note. In this solution, two piezoelectric sensors are installed in the vortex probe. One is called the flow rate sensor for measuring both the flow rate and vibration noise, and the other is called the vibration sensor for detecting the vibration noise and sensing the flow rate signal weakly at the same time. An anti-strong-disturbance signal processing method combining the frequency-domain substation algorithm with the frequency-variance calculation algorithm is proposed to identify the flow rate frequency. When the peak number of amplitude spectrum of the flow rate sensor is different from that of the vibration sensor, the frequency-domain subtraction algorithm will be adopted; when the peak number of amplitude spectrum of the flow rate sensor is the same as that of the vibration sensor, the frequency-variance calculation algorithm will be employed. The whole algorithm is implemented in real time by an ultralow power micro control unit (MCU) to meet requirements of process instrumentation. The experimental results show that this method can obtain the flow rate frequency correctly even if the power of the pipe vibration noise is larger than that of the vortex flow rate signal.     

科里奥利质量流量计在线连续测量流体密度的理论分析

科里奥利质量流量计是一种直接测量流体质量流量的仪表，同时可在线检测流体密度，出于对其传感器结构优化设计的目的，建立了振动微分方程，其解可给出流体密度在线检测的依据，并给出密度与温度的对应关系，得出给U型管谐振频率的推导结果，并进行具体计算的验证。     

变传感器设定值的科氏质量流量管控制方法

在科氏质量流量计中,流量管的稳幅振动是准确测量的前提。当两相流发生时,科氏质量流量管无法维持在最佳幅值下振动,导致传感器输出信号幅值波动大。针对两相流下流量管幅值控制面临的问题,分析影响流量管振动幅值大小和稳定性的因素,提出跟踪传感器信号幅值、变传感器信号设定值的控制方法,在研制的数字式科氏质量流量变送器上实时实现,并在气-液两相流实验装置上进行2种设定值方法的对比实验。实验结果表明,在不同含气量和控制及时性的情况下,变传感器设定值的控制方法均具有良好的信号跟踪和幅值控制的性能,流量管振动较平稳,传感器信号幅值波动范围小,极大地减小了两相流测量过程中的波动性。     

Design of a three-dimensional current sensor with measuring upwelling

A new three-dimensional flow velocity sensor which can measure upwelling was proposed. This sensor was composed of horizontal flow sensor and vertical flow sensor, and it can measured horizontal flow and tiny upwelling separately. The structure of horizontal flow and vertical flow velocity measuring device were analyzed and optimized based on static simulation, static calculation and an experiment. The results show that the sensor can measure both the small upwelling and the horizontal flow velocity in principle. Based on the root of energy loss, the amplifying structure was optimized. After optimization, the magnification factor was increased by 436.84%. According to experimental results, mechanical analysis of cross beams and static simulation, there was a good linear relationship between the flow resistance around the sphere and the output strain of the horizontal velocity measuring device, and it can be used to measure the horizontal flow velocity.     

采用流场分析提高涡轮流量传感器性能的研究

以10 mm口径液体涡轮流量传感器为研究对象,经过对传感器内部流场进行分析,提出通过减小靠近叶片顶端的叶片受力面积,提高传感器测量性能的方法。从对特性曲线的分析出发,结合传感器数学模型,提出了一种利用不同流量点的仪表系数平方差Δ(K~2)评价传感器性能的方法。在此基础上,结合CFD仿真和传感器样机实验测试,研究了不同叶轮叶片形状参数对传感器性能的影响。实验结果表明:改变叶轮叶片形状能有效提高传感器的测量性能,切角参数为0.25时,传感器性能最优;此方法同样适用于其他口径涡轮流量传感器结构的优化。     

基于双线性插值法的比例方向阀死区补偿方法

为解决比例方向阀死区引起的流量非线性等问题,常常采用智能控制算法和死区补偿相结合的方法,这些方法往往都依赖于阀芯位移传感器和精确的比例方向阀模型,而对于无位移传感器的比例方向阀则无法应用,因此针对无位移传感器的比例方向阀,设计了能够不依赖位移传感器而进行死区补偿的双线性插值补偿策略。自研发的控制器采集压力传感器获取的进、出口压力值和输入电压值,进行双线性插值计算后输出校正后的电压值,以校正后的电压值代替输入电压值调节比例方向阀阀口开度以补偿死区,从而解决由死区引起的流量非线性等问题。试验结果表明,该死区补偿方法,可有效地减小无位移传感器比例方向阀的死区和滞环。     

High-resolution gas–oil two-phase flow visualization with a capacitance wire-mesh sensor

The application of a novel wire-mesh sensor based on electrical capacitance (permittivity) measurements for the investigation of gas–oil two-phase flow in a vertical pipe of 67 mm diameter under industrial operating conditions is reported in this article. The wire-mesh sensor employed can be operated at up to 5000 frames per second acquisition speed and at a spatial resolution of 2.8 mm. By varying the gas and liquid flow rates, different flow patterns, such as bubbly, slug and churn flow, were produced and investigated. From the images of gas void fraction distribution, quantitative flow structure information, such as time series of cross-sectional void fraction, radial void fraction profiles and bubble size distributions, was extracted by special image-processing algorithms.