基于SOPC的CAN总线系统设计与实现

提出了一种基于SOPC(片上可编程系统)的CAN总线系统,介绍了CAN总线控制器IP核的设计方法和系统结构,并在Altera的FPGA芯片上实现了集成微处理器核、存储器、CAN控制器IP核以及控制器软件的完整CAN总线系统,通过测试该CAN总线系统的具有良好的工作性能.     

基于单片机的CAN总线接口设计与实现

在CAN总线节点中,采用AT89C52、独立控制器SJA1000、高速光耦合器6N137和CAN总线收发器82C250设计了硬件电路,并进行了CAN总线智能节点的软件设计。CAN通信接口接收到上位机的数据后,便向总线上的各个节点传播。实验结果表明,该智能节点具有实时性好、扩展性能好、可靠性高、抗干扰能力强等特点,初步达到较高的性能指标。     

基于IP核复用技术的CAN总线SOPC设计

提出了一种基于IP核复用技术的CAN总线SOPC的设计方案.介绍了CAN总线控制器IP核的设计架构,并在CycloneⅢ型FPGA芯片上实现了一个集8051单片机核、存储器核、CAN控制器IP核以及嵌入式软件为一体的完整CAN总线系统,通过软件仿真和硬件测试都表明该系统性能良好.     

基于CAN总线的车身点焊监控系统设计

介绍了一种具有CAN总线通信功能的汽车车身点焊控制器.系统采用CAN现场总线作为通信传输方式组建了监控网络,设计以AT89C51单片机和CAN总线控制器为核心的通信模块,使点焊控制器具有通信功能.设计了底层电阻焊网络控制器的通信控制程序,通信软件和上层管理软件,实现了下位机与上位机之间数据的实时传输.该控制器通信速度快,工作稳定,可应用于汽车车身点焊车间的网络化管理.     

基于STM32的数据采集及存储系统设计

设计了一种基于STM32微控制器平台的数据采集存储及显示系统。STM32通过串口中断接收七孔探针的数据后,再通过IIC总线读取导航模块JY901数据;然后将采集到的数据存储于Micro SD卡中并发向上位机,同时将七孔探针的初始数据显示在OLED液晶屏上。使用该系统成功地实现了数据的采集存储及显示。     

智能测控终端到PC机的数据转存器

研制了一种具有USB接口和I2C总线接口的数据转存器,通过它可以方便地实现以单片机为核心的测控终端与PC机之间相互传递数据.存储器采用具有I2C总线的EEPROM芯片AT24C512作为数据存储芯片,利用USB总线转接芯片CH341A实现PC机读取EEPROM中数据的功能.文中介绍了CH341芯片、AT24C512芯片及I2C总线,设计了转存器的硬件结构,研制了转存器与测控终端和PC机通信的相关硬件及软件.     

生物质电厂上料控制系统中CAN总线智能节点的设计

搭建了生物质电厂上料系统的CAN总线控制网络,并对其CAN总线智能节点进行了硬件和软件设计。该CAN总线智能节点采用SJA1000为总线控制器,配合微处理器AT89S52和CAN总线驱动器PCA82C250实现智能节点的控制功能及数字量输入、输出和串行通讯功能。在进行电路设计时充分考虑了电磁干扰对系统的影响,采用高速光耦作为中间连接,从硬件上加强了系统的抗干扰能力,增强了系统的可靠性和稳定性。     

基于SOPC的步进电机加减速PWM控制器IP核设计

为解决步进电机运动系统中电机加速和减速过程的控制等问题,将脉冲宽度调制(PWM)和现场可编程门阵列(FPGA)IP核技术应用到设计方案中.提出了一种基于可编程片上系统(SOPC)实现步进电机加减速PWM控制器IP核的设计方法,并以此说明了该设计思想及其实现途径.通过HDL硬件描述语言编写功能逻辑、Avalon总线接口与...     

基于DeviceNet现场总线的两轴伺服电机运动控制器

文中设计了基于AT89C51、LS7266R1和SJA1000的DeviceNet总线电机运动控制器.给出了运动控制器的总体结构,分析了AT89C51与LS7266R1的接口电路、AT89C51与DeviceNet总线接口电路.最后分析了系统软件设计的关键.根据该方法设计的运动控制器,经济、实用,能够充分利用DeviceNet现场总线.     

智能温度采集控制系统的研究

采用STC89C52单片机为控制器、DS18B20为温度传感器,以电磁阀为控制机构,实现了温度的智能采集与控制;采用LCD显示器实现了菜单操作的人机交互界面;采用DS1302提供时钟基础,采用AT24C02实现了数据存储。通过系统仿真及实际样机测试,表明该方案可以出色地完成温度的测控,且操作简单方便,具有一定的推广价值。     

飞行时间质谱仪射频四极杆驱动器的研制

针对自制垂直引入式飞行时间质谱仪（orthogonal extraction time-of-flight mass spectrometer, O-TOFMS）的需要,运用直接数字频率合成 (direct digital frequency synthesis,DDS)技术,研制了射频四极杆的高压射频驱动电路装置。该驱动器频率可调范围为0.5~2 MHz,幅度最高达到1 000 Vp-p。该射频四极杆驱动器（radio frequency quadrupole driver,RFQ Driver）可用于分子离子反应器（molecule ion reactor,MIR）和RFQ驱动,其结构简洁、成本低、性能稳定可靠。     

Rapid one-of-a-kind production

To shorten the product development cycle time and reduce the cost at the same time, which is very critical for the survival of those small and mid-sized one-of-a-kind production (SMOKP) companies, various computer communication, simulation and computer aided engineering and management techniques have been widely used in these SMOKP companies. However, according to our study, the applications of these advanced computer technologies in these SMOKP companies are lack of system integration and synergy, which result in communication errors, reworks, duplications and hence a longer product development lead time and a higher cost. To solve this problem, an inter/intranet based computer aided rapid product development system is presented in this paper. This system consists of a number of inter/intranet based computer models or sub-systems for supporting rapid development of a one-of-a-kind product. It also employs a novel concurrent product development strategy called “prototype based incremental product development strategy” and an integrated product data structure called “product production structure”. Some industrial implementations of the proposed system, product development strategy and product data structure are also reported in the paper.     

Rapid one-of-a-kind production

To shorten the product development cycle time and reduce the cost at the same time, which is very critical for the survival of those small and mid-sized one-of-a-kind production (SMOKP) companies, various computer communication, simulation and computer aided engineering and management techniques have been widely used in these SMOKP companies. However, according to our study, the applications of these advanced computer technologies in these SMOKP companies are lack of system integration and synergy, which result in communication errors, reworks, duplications and hence a longer product development lead time and a higher cost. To solve this problem, an inter/intranet based computer aided rapid product development system is presented in this paper. This system consists of a number of inter/intranet based computer models or subsystems for supporting rapid development of a one-of-a-kind product. It also employs a novel concurrent product development strategy called “prototype based incremental product development strategy” and an integrated product data structure called “product production structure”. Some industrial implementations of the proposed system, product development strategy and product data structure are also reported in the paper.     

从光电容积图中提取脉搏率、呼吸率和心率的新方法

光电容积描记图(PPG)是一种利用光学技术无创检测人体心血管脉搏波的方法。PPG信号来源于MIMIC数据库,它含有许多生理信息。本文提出了将集合经验模态分解(EEMD)、倒谱、快速傅里叶变化和过零点检测相结合的方法,从PPG中可靠地估算脉搏率(PR)、心率(HR)和呼吸频率(RR)。首先,将PPG信号通过EEMD分解为有限个固有模态函数(IMF)。因为EEMD有自适应滤波特性,所以估算不同的生理参数时,可以用不同的IMF分量来重构信号。其次,估算脉搏率时,舍去低频含有伪迹的IMF,再通过过零点检测可以得到瞬时脉搏率。然后,估算心率时,用1 Hz~1.67 Hz(60次/分钟~100次/分钟)的IMF来重构信号,再求倒谱,选取反映心脏活动的频带来得到心率。最后,估算呼吸率时,用0.05 Hz~0.75 Hz(3次/分钟~45次/分钟)的IMF来重构信号,然后对呼吸信号求快速傅里叶变化得到频谱图,寻找频谱图中的峰值得到呼吸率。对来自MIMIC数据库的53个成人PPG信号进行了仿真。仿真结果表明使用该综合信号处理方法提取的生理参数与实际生理参数一致,且该方法有运算量小,精确度高的优点(误差不超过1.17%)。     

简介虚拟制造中的网络虚拟现实技术

介绍了网络虚拟现实建模语言（VRML），VRML具有动态对象描述和超链接、通用性、扩展性、易实现性等特点。VRML浏览器和生成VRML文件的工具广泛使用于多种平台的计算机，是虚拟制造VM与虚拟设计中的网络虚拟现实技术的基础。     

UPLC-MS/MS测定二苯甲烷二异氰酸酯

建立了二苯甲烷二异氰酸酯（MDI）的超高效液相色谱-串联质谱（UPLC-MS/MS）联用的分析方法。实验用甲醇作衍生试剂,将二苯甲烷二异氰酸酯衍生成二苯甲烷二氨基甲酸甲酯（MDC）,通过测定二苯甲烷二氨基甲酸甲酯来确定二苯甲烷二异氰酸酯的含量。实验采用Waters Acquity BEH C18超高效液相色谱柱,甲醇-0.1%甲酸作为梯度洗脱液,二苯甲烷二氨基甲酸甲酯在1.5 min内与其他化合物进行完全分离,经四极杆质谱选择离子监测模式检测。线性范围为2~100 μg/L,检出限为1 μg/L,相关系数0.999 4。考察了水、甲酸、甲酸铵流动相体系,以及进样量大小对样品的分离效果,发现甲酸流动相体系的分离效果优于其他两种流动相体系,同时发现在进样量大时出现平头峰。并且在优化条件下,对实际样品中游离的二苯甲烷二异氰酸酯进行了测定。     

血清AFP、CA199、GGT、ALP联检肝癌早期诊断价值

目的:探讨甲胎蛋白(AFP)、糖类抗原199(CA199)、谷氨酰转肽酶(GGT)和碱性磷酸酶(ALP)单独或联合检测对原发性肝癌(PHC)的早期诊断价值。方法:本研究为回顾性研究,筛选2016年-2019年本院87例原发性肝癌(PHC)患者、105例慢性乙肝患者及104例健康志愿者,收集不同组首次入院和体检外周血检测数据和其他临床资料。比较各血清指标在组间差异性,分析了血清学指标与入组PHC临床分期和病理分型的相关性,进一步利用ROC曲线法分析血清指标单项与联合诊断的灵敏度、特异度。结果:AFP、CA199、GGT、ALP检测均值在PHC组均明显高于慢乙肝组和健康体检组。AFP阳性检测值与PHC临床分期(r=0.9536)和病理分型(r=0.525)呈正相关性。AFP诊断PHC灵敏度和特异性分别为60.87%和77.97%、精准度AUC为0.726。联合四项指标检测灵敏度、特异度和AUC分别为75.36%、65.64%、0.806。结论:AFP、CA199、GGT、ALP四项指标联合检测可提高原发性肝癌早期诊断的准确率,操作性强且易于推广。     

Effect on crystalline structure of AISI M2 steel using tungsten–thorium electrode through MRR,EWR, and surface finish

To investigate on the crystalline structure of AISI M2 steel by using tungsten–thorium electrode in electrical discharge machining (EDM) process was studied. Furthermore, the investigation were carried out for finding the value of material removal rate (MRR), electrode wear rate (EWR) and surface roughness (SR) of tool steel material depending upon three variable input process parameters. On the basis of weight loss, the value of MRR and EWR were calculated at optimized process parameter. Subsequently, surface topography of the processed material were examined through different characterization techniques like scanning electron microscopy (SEM), Optical surface profiler (OSP) and Atomic force microscopy (AFM), respectively. In XRD study, broadening of the peak was observed which confirmed the change in material properties due to the homogeneous dispersion of the particles inside the matrix. Lowest surface roughness and MRR of 0.001208 mg/min was obtained. Minimum surface roughness was obtained 1.12 μm and 2.18427 nm by OSP and AFM study, respectively. Also, minimum EWR was found as 0.013986 mg/min.     

A novel virtual instrument for power quality surveillance based in higher-order statistics and case-based reasoning

This paper presents the performance results of a Virtual Instrument (VI) based in Case-Based Reasoning (CBR), conceived to online monitor the power-quality. The PC-based instrument receives data through a DAQ board and a differential probe, while maintaining economy by eliminating the extra network construction and hardware. Being flexible, presents an user-friendly interface and a large data storage capacity, since it uses the hard disk. The computational guts of the instrument are based in third and fourth-order statistics (along with the variance), which enhance detection capability and reject noise influence. A time-domain sliding window sweeps the register under test and offers a time-variation pattern which reflects the deviation of the statistical estimator with respect to the steady state. This three-valued time-series comprises variance, skewness and kurtosis evolution, and constitutes a triple input to the innovative CBR module, which in turn is capable of distinguishing electrical anomalies among five categories (the sixth is reserved to the healthy signal): non-50 Hz, 50-Hz-asymmetrical, 50-symmetrical non-sinusoidal, swell and sag. Online surveillance tests developed over the local electrical network show acceptable accuracy (96%).