基于ARM的嵌入式系统的以太网接口芯片设计

在网络技术应用日益广泛的今天,网络传输是最经济有效的数据传输方式之一.随着网络和嵌入式系统的发展,嵌入式系统与网络的结合已经成为最新的研究动向.本文使用处理器S3C44B0X和10MB以太网接口芯片RTL8019AS,设计了一种基于ARM的嵌入式系统以太网接口方案.这种设计结构简单,实现方便,具有很好的实用价值.     

CAN总线与以太网互联的网关设计

提出一种以ARM嵌入式系统为控制核心的嵌入式网关的实现方法。通过分析以太网络与CAN总线的特点给出了网关的硬件和软件设计方案,ARM通过串行外设接口与以太网控制器进行数据通信,实现与以太网的互联。设计综合分析表明:该嵌入式网关具有结构简单、通用性强、易于开发维护等特点。     

嵌入式通用千兆以太网接口的设计与实现

以现场可编程门阵列FPGA和千兆以太网网络控制器AX88180为硬件平台,针对嵌入式设备资源有限的特点,提出了一种通用的嵌入式设备千兆以太网接口设计与实现方案.详细阐述了系统的组成结构、工作原理;讨论了以太网TCP/IP网络协议的基本体系结构;总结提出了适合嵌入式设备的TCP/IP网络协议实现方法;给出了网络驱动和数据处理的设计流程以及仿真结果;并实际测试了系统的通信性能,给出了实验结果.实际应用证明该设计通用、灵活,可以根据实际需求实现各种嵌入式设备的千兆以太网接入,而千兆以太网更高的传输带宽优势,可以满足大数据量传输的要求.     

基于PIC18F67J60的嵌入式以太网接口设计

文中以PIC18F67J60单片机为核心,完成了嵌入式系统以太网接口的硬件平台设计,通过简化网络层次体系结构,搭建了简单的协议栈,进而完成了系统软件的设计,实现了嵌入式系统通过以太网与计算机进行通信的功能.该接口既可作为对嵌入式系统进行远程控制的控制接口,也可接入信号采集子系统,作为嵌入式系统通过以太网进行远程信息采集的通信接口.实际应用中,该接口具有实现形式简单、实时性强、性能稳定等特点,适宜远程信息采集系统使用.     

嵌入式以太网接口的研究与实现

结合目前以太网技术在嵌入式领域中的应用,提出了基于单片机C8051F020和以太网控制器CP2200的嵌入式以太网接口设计方案,采用适用于CP220X系列以太网控制器的TCP/IP协议栈,实现接口以太网通信.文中阐述了设计思想和接口电路的设计,重点对设计中的关键性问题:单片机看门狗定时寄存器的设置,接口电路的复位时序,网络数据的传输以及以太网的实时性作了详细的探讨和分析.该设计实现的接口电路硬件少,可在系统编程,通用性强,可以根据应用环境的需要,接入到各种嵌入式设备.     

基于Nucleus PLUS嵌入式以太网接口的设计与实现

提出一种在LPC2292(ARM7)为CPU、Nucleus PLUS为实时操作系统的系统平台上,以RTL8019AS为网络控制芯片构建嵌入式以太网接口的设计思想与实现方法,详细阐述了Nucleus PLUS在ARM7上的移植方案以及在该系统平台下以太网驱动程序的开发方法.实际运行结果表明,该系统设计合理,运行稳定可靠,具有实际的应用价值.     

基于以太网的数据通信接口设计

介绍了以PC104总线为例的嵌入式系统与以太网DM9008控制器接口的硬件设计和编程。     

基于以太网的嵌入式远程监控系统的实现

提出了一种基于以太网的嵌入式远程监控系统的实现方案。介绍了嵌入式远程监控系统的组成及结构,包括硬件和软件组成。采用32位ARM微处理器作为主控制器,同时提供高速的以太网接入通道,并运行嵌入式Linux系统支持以太网通信协议。建立在Linux系统上的以CGI实现的WEB服务向远程客户端用户提供标准的调用接口。     

基于Rabbit2000的嵌入式以太网络接口设计与开发

分析了嵌入式设备的发展及其网络通信技术的研究现状和缺陷，针对中小型嵌入式设备处理能力有限的特点，阐述了利用一种低端微处理器Rabbit2000设计嵌入式设备以太网接口的方法，给出了硬件接口电路的详细设计和软件设计的主要框架及利用非阻塞流式套接字实现的网络通信流程图。实践表明：具有以太网接口的嵌入式设备信息承载量大，传输速率快，便于与Internet集成，该以太网接口模块无需修改即可直接嵌入到其他中小型设备中，可大大缩短开发周期，值得推广。     

基于DSP的嵌入式系统以太网接入技术研究

在分析嵌入式系统以太网接入技术的基础上,介绍了基于DSP的嵌入式系统以太网接人方案硬件设计以及嵌入式TCP／IP协议的实现过程,并通过实验验证了方案的可行性。     

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。     

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.     

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.     

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.     

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.     

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...     

OPTIMIZATION METHOD ON IMPELLER MERIDIONAL CONTOUR AND 3D BLADE

An optimization method for 3D blade and meridional contour of centrifugal or mixed-flow impeller based on the 3D viscous computational fluid dynamics (CFD) analysis is proposed. The blade is indirectly parameterized using the angular momentum and calculated by inverse design method. The design variables are separated into two categories: the meridional contour design variables and the blade design variables. Firstly, only the blade is optimized using genetic algorithm with the meridional contour remained constant. The artificial neural network (ANN) techniques with the training sample data schemed according to design of experiment theory are adopted to construct the response relation between the blade design variables and the impeller performance. Then, based on the ANN approximated relation between the meridional contour design variables and impeller performance, the meridional contour is optimized. Fewer design variables and less calculation effort is required in this method that may be widely used in the optimization of three-dimension impellers. An optimized impeller in a mixed-flow pump, where the head and the efficiency are enhanced by 12.9% and 4.5% respectively, confirms the validity of this newly proposed method.