嵌入式系统在远程复位控制中的应用

介绍了基于嵌入式系统在远程复位控制器中的研制与实现.系统采用AT89C52单片机作为控制核心,MT8870为音频解码芯片,以PSTN公话网为信号传输控制介质.系统包括语音电路、自动检测和摘机挂机电路,驱动电路等单元,着重描述了该系统的各模块组成、原理及具体的电路实现,该系统通用性较强,在实际应用中收到了很好的效果.     

基于MATLAB图形用户界面的电路分析演示系统

基于MATLAB图形用户界面设计向导GUI,开发了电路分析演示系统,将电路课程中的重点和难点内容以文字、图表、曲线等形式直观地表现出来.以二阶电路时域分析模块为例,介绍了系统主界面设计及软件编程方法.实践表明,该系统界面良好、操作方便,便于理解电路基本原理及分析方法,有益于提高课堂教学效果.     

单片机系统通用接口电路的设计

介绍一种用于单片机应用系统的通用接口电路,该电路采用8255作为接口芯片,可外接键盘、显示器和打印机,以构成最简单的单片机应用系统.重点介绍了硬件电路的组成和程序设计.     

基于自适应无源化的蔡氏电路混沌同步

根据蔡氏电路混沌系统的特点,得出了蔡氏电路混沌驱动系统与响应系统的误差系统.根据混沌系统的同步条件,可将混沌的同步问题转化成为误差系统的稳定性问题,即使混沌同步误差系统渐近稳定以实现混沌同步控制.针对蔡氏电路混沌系统的误差系统,采用自适应无源化方法,设计了使同步误差系统渐近稳定的具有自适应功能的反馈镇定器.该控制方法实现了2个蔡氏电路混沌系统同步,仿真研究验证了该方法的有效性.     

基于TMS320F2812的最小系统设计

介绍了基于TMS320F2812的最小应用系统的整体设计过程,针对系统硬件设计的调试过程中的注意事项进行了阐述,尤其是对电源电路、复位电路、JTAG、时钟电路及外部扩展电路的设计提出了可行性方案.该方案以电路板形式在对全自主机器人的控制系统中得到了应用.     

基于单片机的工业园区废气监测系统设计与实现

本文针对排放的工业废气进行连续自动的检测,设计了一种工业废气远程监测系统.该系统以单片机为主控,设计了气体传感器检测电路、废气温湿度数据采集电路、光照强度采集电路等,可实现对工业园区的废气的连续自动检测.把测量的结果通过网络发送到服务器上位机中,在系统中还可以实现对多个检测点的在线监测.实际测试结果表明,该系统可有效地监测到有害气体,达到实时预警的目的.     

基于FPGA的两路视频同步播放系统的设计

为了实现基于嵌入式系统的两路视频的同步播放控制,本文提出了根据图像内容检测达到两路视频同步播放控制的设计思想.根据该思想设计了基于FPGA的实验电路,构建了完整的系统实验硬件平台.该系统平台的建立.证明了基于嵌入式电路的以图像内容检测为手段的两路图像同步播放控制的可行性.     

一种交流伺服控制系统的硬件设计研究

提出一种基于TMS320LF2407A+EP1K30TC144-1的交流伺服控制系统,以实现高性能的伺服控制.详细介绍了系统的组成和部分接口电路的设计,其中包括DSP与FPGA接口电路、模拟量输入转换电路、差分整形电路、E2PROM扩展电路、人机接口电路.该系统配置相应的软件可以驱动交流异步电机、永磁同步伺服电机、无刷直流电机.     

基于数字罗盘HMR3000的智能寻向系统的设计

以C8051F020单片机为控制核心、数字罗盘HMR3000为磁北传感器,设计了基于数字罗盘HMR3000的智能寻向系统.硬件部分详述了方位信号通信电路、步进电机驱动电路、键盘电路和LCD显示电路等;软件部分重点研究了系统主程序、方位通信子程序、数据处理子程序和步进电机驱动子程序等.分析了系统误差并提出了使用注意事项.经过调试,该系统具有寻向速度可调、精度较高、方向自动保持等优点.     

基于LPC1766的农产品流通追溯系统设计

针对农产品流通过程中来源跟踪难、去向查证难等问题,研究开发了农产品流通追溯系统.该系统硬件采用Cortex-M3内核嵌入式处理器LPC1766,包括信号调理与A/D转换电路、RFID身份识别接口电路、以太网接口电路和其它外围接口电路.软件以keil μVision3 IDE为开发平台,论述了重量采集、RFID身份识别、二维条码打印、数据上传等的实现算法,并通过UDP的方式实现了分布式控制.实验结果表明,该追溯系统适用性强,追溯精度高,能有效提高交易管理水平,并能实现对产品责任主体的跟踪与追溯.     

HelSweeper: Screw-sweeps of canal surfaces

A tube is a solid bounded by the union of a one-parameter family of circles that may be decomposed into canal-surfaces and planar disks or annuli. A screw-sweep is the region swept by a shape during a screw motion. HelSweeper computes the boundary of a screw-sweep of an arbitrary union of tubes and polyhedra. To do so, it generates a superset of faces, splits them at their intersections, and selects the face portions that form the desired boundary. The novelty of the proposed approach lies in the fact that the faces contributed to this superset by a tube are each a screw-sweeps of a rigid curve (generator), which is the locus of grazing points, and that each grazing point is formulated as the intersection of a circle of the tube with a corresponding screw-plane. Hence, each such face is a one-parameter family of helices, each being the screw-sweep of a grazing point.     

Control of Motion of an Actively Bending Body in Channels with Dry Friction

Mechanics is described and equations are given of the motion of an actively bending homogeneous body of a finite thickness in a channel with dry friction under conditions of a weak bending. Control is suggested of the motion of a body in a sinusoidal channel, which retains a continuous first derivative of the controlling moment and a bounded second derivative. A process is described of the maximization of the speed of motion by control and then by the choice of the best parameters of a channel. Control is also considered of other modes of the motion of a body in the same channel.     

Applying the extended Kalman filter to systems described by nonlinear differential-algebraic equations

This paper describes a method for the state estimation of nonlinear systems described by a class of differential-algebraic equation models using the extended Kalman filter. The method involves the use of a time-varying linearisation of a semi-explicit index one differential-algebraic equation. The estimation technique consists of a simplified extended Kalman filter that is integrated with the differential-algebraic equation model. The paper describes a simulation study using a model of a batch chemical reactor. It also reports a study based on experimental data obtained from a mixing process, where the model of the system is solved using the sequential modular method and the estimation involves a bank of extended Kalman filters.     

Construction of a supermicro sense of force feedback and vision for micro-objects: development of a haptic device

This research aims to develop a combined sense system that uses both the force feedback and visual feedback to establish the shape of microscopic features of a microsample. It is thought that the efficiency of minute procedures would be improved if the operator could obtain a sense of force while using a manipulator. We used a cantilever to touch a minute object and obtain a reaction force from the degree of bending. We made a haptic device which gives a sense of that force to the operator, who can feel the force when a user touches a sample with a cantilever. In addition, when the haptic device is used in simulations, the user can feel a force just as if the user had touched a sample.     

High-Order Accurate Adaptive Kernel Compression Time-Stepping Schemes for Fractional Differential Equations

We present a goal-oriented a posteriori error estimator for finite element approximations of a class of homogenization problems. As a rule, homogenization problems are defined through the coupling of a macroscopic solution and the solution of auxiliary problems. In this work we assume that the homogenized problem is known and that it depends on a finite number of auxiliary problems. The accuracy in the goal functional depends therefore on the discretization error of the macroscopic and the auxiliary solutions. We show that it is possible to compute the error contributions of all solution components separately and use this information to balance the different discretization errors. Additionally, we steer a local mesh refinement for both the macroscopic problem and the auxiliary problems. The high efficiency of this approach is shown by numerical examples. These include the upscaling of a periodic diffusion tensor, the case of a Stokes flow over a porous bed, and the homogenization of a fuel cell model which includes the flow in a gas channel over a porous substrate coupled with a multispecies nonlinear transport equation.     

Vague集向Fuzzy集转化的一种新方法

提出Vague值向Fuzzy值转化的实用方法的定义。针对文献[6]中的一个Vague值向Fuzzy值转化的均值修正法,提出了加权均值修正法,并证明了这种方法同样是Vague值向Fuzzy转化的一种非常实用的方法。     

A superscalar simulation employing poisson distributed stalls

This paper presents a statistical approach to estimating the performance of a superscalar processor. Traditional trace-driven simulators can take a large amount time to conduct a performance evaluation of a machine, especially as the number of instructions increases. The result of this type of simulation is typically tied to the particular trace that was run. Elements such as dependencies, delays, and stalls are all a direct result of the particular trace being run, and can differ from trace to trace. This paper describes a model designed to separate simulation results from a specific trace. Rather than running a trace-driven simulation, a statistical model is employed, more specifically a Poisson distribution, to predict how these types of delay affects performance. Through the use of this statistical model, a performance evaluation can be conducted using a general code model, with specific stall rates, rather than a particular code trace. This model allows simulations to quickly run tens of millions of instructions and evaluate the performance of a particular micro-architecture while at the same time, allowing the flexibility to change the structure of the architecture.     

Branching processes of Petri nets

Summary The notion of a branching process is introduced, as a formalization of an initial part of a run of a Petri net, including nondeterministic choices. This generalizes the notion of a process in a natural way. It is shown that the set of branching processes of a Petri net is a complete lattice, with respect to the natural notion of partial order. The largest element of this lattice is the unfolding of the Petri net.     

The probabilistic orienteering problem

The probabilistic orienteering problem (POP) is defined on a directed graph where a cost is associated with each arc and a prize is associated with each node. Moreover, each node will be available for visit only with a certain probability. A server starts from a fixed origin, has a given budget to visit a subset of nodes, and ends at a fixed destination. In a first stage, a node subset has to be selected and a corresponding a priori path has to be determined such that the server can visit all nodes in the subset and reach the destination without exceeding the budget. The list of available nodes in the subset is then revealed. In a second stage, the server follows the a priori path by skipping the absent nodes. The POP consists in determining a first-stage solution that maximizes the expected profit of the second-stage path, where the expected profit is the difference between the expected total prize and the expected total cost.We discuss the relevance of the problem and formulate it as a linear integer stochastic problem. We develop a branch-and-cut approach for the POP and several matheuristic methods, corresponding to different strategies to reduce the search space of the exact method. Extensive computational tests on instances with up to 100 nodes show the effectiveness of the exact method and the efficiency of the matheuristics in finding high quality solutions in a few minutes. Moreover, we provide an extended analysis on a subset of instances to show the value of explicitly modeling the stochastic information in the problem formulation.