嵌入式系统的发展与展望

IT产业高度发达,嵌入式系统功不可没,以至于无处不见嵌入式系统;嵌入式系统家族庞大,涵盖内容广泛,涉及学科多样,了解其家族成员及发展历史,正确理解其概念体系及发展趋势,对于今后的"智慧地球"具有重大意义;总结了国内外的相关文献,概述了嵌入式系统的体系结构,分析了所面临的挑战,讨论了与相关技术的关系,最后展望了发展前景。     

嵌入式系统安全问题调查与分析

随着电子信息技术的发展及人民生活水平的提升,嵌入式系统及相关设备已经广泛地应用在生产生活的各个方面。近年来,随着智能手机、平板电脑等嵌入式移动终端设备的迅速普及,嵌入式系统的安全性问题在无线通信的过程中开始显得日益突出。从嵌入式系统安全性问题的特点、评价、框架结构3个不同层面,分别对其进行了较为深入的调查、分析和研究。     

基于比较策略的嵌入式系统性能基准测试研究

嵌入式系统受成本、功耗、芯片体积和开发周期等多种因素的制约,其性能往往难以满足应用需求,充分发挥嵌入式系统的潜能对嵌入式系统设计尤为重要。为此,需要对嵌入式系统进行性能基准测试,指导嵌入式系统设计的技术选型和决策,在满足应用需求的前提下,达到最佳性能/价格比。该文分析了嵌入式系统性能基准测试的基本原理和性能指标,介绍了几种常用的嵌入式系统性能评测基准及其适用范围,提出了一种运用对比策略进行嵌入式系统性能测试的测试方法和测试环境的构成,实现了一种嵌入式性能测试工具,并对相关的嵌入式系统及构件进行了性能测试。最后对嵌入式系统性能基准测试研究存在的主要问题进行了评价。     

嵌入式系统软件远程在线升级的研究与实现

介绍了基于Internet通信方式的嵌入式系统软件远程在线升级的实现方案,其中详细介绍了软硬件实现原理、相关嵌入式软件及升级应用软件的设计。通过对嵌入式系统软件升级流程的分析,提出了一种简便、实用、可靠的软件升级服务器与嵌入式系统交互的新方法,包括对嵌入式系统代码区域的处理等。该实现方案可在计算机测控系统和工业控制设备的嵌入式系统中推广应用。     

绿色计算与绿色嵌入式系统

绿色计算是一种先进的计算技术,其目的是利用先进的思想、技术和方法来降低 计算系统的能耗,从而减少对人和环境的影响。而今嵌入式系统占整个计算系统的绝大多数,因此,嵌入式系统也需要绿色计算技术,使其能耗降低而不影响其性能。先对绿色计算的研究现状进行综述。然后对绿色嵌入式系统进行定义,并对其内涵进行探讨。最后对绿色嵌入式系统的绿色评价进行了讨论,对绿色嵌入式系统待研究的内容进行了探究。主要创新点在于利用绿色计算思想,提出了绿色嵌入式系统的概念,并对其相关问题进行了研究,指出了绿色嵌入式系统待研究的内容和方向。     

TKScope全面支持AVR内核、C166内核和C8051F系列的仿真

TKScope仿真器自上市以来，不断地新增支持内核的种类和芯片型号，使其仿真家族日趋庞大。同时，也进一步巩固了TKScope仿真器在嵌入式系统仿真领域的地位。     

嵌入式监控系统实现技术及在废水处理中的应用

介绍了嵌入式监控系统的相关实现技术,通过对嵌入式监控系统可重配置要求的分析,设计了嵌入式监控系统各功能模块。并以二次纤维造纸废水处理的中试系统为对象,采用Windows CE.NET操作系统验证了所设计的嵌入式监控系统的可行性。     

基于单片机的嵌入式视频系统设计分析

简要介绍了基于单片机系统的嵌入式视频系统的设计原理及其常见的相关技术方面的问题。既对单片机的软硬件结构进行了剖析,又专门针对嵌入式视频系统进行了由浅入深、由表及里的阐述。对于深入研究、开发嵌入式视频系统起到了较好的指导作用。     

嵌入式Internet的实现技术与安全问题分析

本文简要介绍了嵌入式系统相关理论、嵌入式Internet的基本概念以及嵌入式系统接入Internet的条件,重点讨论了嵌入式系统接入Internet的实施方案,并对嵌入式Internet的安全机制与防御方法进行了详细论述。     

USB 接口技术在嵌入式系统中的应用研究

简单介绍了USB接口技术的原理及其优点。基于嵌入式系统与USB设备等不能直接传输数据及嵌入式系统大容量存储难等问题的现状,提出了在嵌入式系统中集成USBHost功能以解决这一问题。     

Population evolution analysis in collective intelligence design ecosystem

The Collective Intelligent Design Ecosystem is a dynamic ecosystem founded on an online design platform that leverages collective intelligence to support the creation of novel products. The system's primary components are its users and designers. Maintaining the system's sustainability requires expanding the scale of the designer and user populations as it evolves to stabilize. However, the unity of ecological interactions between various populations is fragmented in contemporary studies of population-scale evolution, and the parameterization of evolutionary models is illogical. To overcome this gap, this research provides a population evolution model of collective intelligent design incorporating participants' intra- and interspecific ecological connections. The model's validity is verified by the evolutionary simulation of 110 designers and 5990 users of China's largest collective intelligence design platform, the Zhubajie platform, and illuminating conclusions are in turn drawn from this simulation. First, the designer's influence on the user is greater than the user's impact on the designer. Second, keeping current members engaged is more crucial to the system's viability than luring in new ones. Third, fostering collaboration among designers while retaining user competitiveness can promote system growth. Fourth, decreasing the reliance between particular designers and users might hasten the system's evolution.     

基于时-频域指标的控制系统演化校正

针对控制系统校正器参数适应系统时-频域特定性能要求的问题,提出一种基于自适应粒子群算法的控制系统校正方法。它以系统的时域误差积分指标为目标函数,以系统的幅值裕度、相角裕度等频域指标为约束条件建立优化模型。再利用罚函数,将该带约束的目标函数转化无约束的目标函数。之后,在Matlab环境下,将自适应粒子群算法与Simulink仿真技术相结合,优化控制系统校正器参数,从而实现控制系统校正。仿真结果表明,这种方法简单、高效,所设计的校正器性能优异,十分适合于工程应用。     

Nonlinear controls for a class of discrete‐time bilinear systems

For a discrete‐time neutrally stable bilinear system, a nonlinear state feedback control based on the passivity design has been proposed to stabilize the system globally and asymptotically. This paper shows that the decay rate resulting from the passivity control is not exponential, and the system's response speed becomes very sluggish asymptotically. A ‘normalized’ nonlinear control is therefore proposed to achieve exponential stability. The new exponentially stabilizing control not only improves the system's response speed, but also enhances the system's robustness against small parametric perturbations. Copyright © 2003 John Wiley & Sons, Ltd.     

Towards validation and refinement of rule-based systems

A methodology for the validation of rule-based expert systems is presented as a multi-step process that has three central themes: (1) creation of a useful set of test inputs that cover the domain; (2) a methodology that evaluates the system's responses to the test inputs and compares it to the responses of a panel of human experts; and (3) use of the validation results for system refinement. The presented methodology is performed in a loop. The starting point is a rule base and the loop ends up in a (hopefully) better rule base. The first three steps of this process have been published as separate issues in earlier papers by the authors. Here, these issues are just outlined and references are provided for detailed information. This paper gives an overview of the entire process and describes the relation between its steps. The last step, system refinement, is the new scientific issue here and thus, presented in more detail. Here, the rules are modified according to the results of evaluating the test cases. The base of this rule base reconstruction is both a 'rule-associated validity' and the existence of a 'better rated' human solution.     

采暖通风与空调系统中冷却塔传热效率的回归模型

优化采暖通风与空调(HVAC)系统的控制策略能够节能降耗,但是HVAC系统模型的高复杂度不利于在规定时间内实施对HVAC系统控制策略的优化.为降低模型复杂度,提出HVAC系统中冷却塔水侧传热效率的回归模型,并利用回归分析得到模型的系数.数值分析显示,冷却塔水侧传热效率的回归模型的计算时间大约是原始模型计算时间的1%,所得数值结果与原始模型的相对误差小于0.4%.     

A translator system for the MATLAB language

A whole‐program MATLAB to C translation system is presented. The paper outlines the motivation for the problem, discusses the system's architecture, its features and limitations. The translator's operation is explained using an example input program. Details are given on how the system implements and specializes some of the language's built‐in primitives. Finally, the paper reports measurements evaluating the execution time and memory usage of the translated sources, and the compilation time required for the translations. Copyright © 2006 John Wiley & Sons, Ltd.     

Retrieval of software components using a distributed web system

Software reuse is important, especially product reuse. This paper describes a retrieval system for software components, the most popular form of product reuse. The system is distributed and embedded in the web and is based on structured retrieval using a classification schema.After defining the requirements for the system, we first discuss the advanced outside functionalities of the component retrieval system, as its multi-paradigmatic classification approach, the ability to extend/change the schema, the navigational facility through different views, and the system's interface to search engines. Then, the most interesting topics of the system's realization are discussed, as dynamic web page generation and personalization, how the specific environments for different roles are built, how schema modification is handled, and how the system was designed being driven by software for reuse. Some measurements of the system's outside behavior and its convenience for users are given.     

霍尔传感器对Buck变换器滑模控制系统的影响分析

针对霍尔传感器的未建模动态和滑模控制器的非线性,研究两者的共同作用对Buck变换器谐波性能的影响.基于变换器的数学模型和Lyapunov稳定性定理,给出传统滑模控制器参数的整定方法;在此基础上,利用描述函数法和奈奎斯特稳定性判据,分析常规忽略传感器作用下的系统稳定性.考虑霍尔传感器的测量性能,建立Buck变换器-传感器的联合数学模型,利用奈奎斯特稳定性判据推导出保证系统临界稳定的约束条件,从理论上证明霍尔传感器诱发谐波的必然性,并揭示了滑模控制器参数和传感器参数对系统谐波幅频性能的数学影响关系.仿真结果表明了所提出方法的正确性和有效性.     

IT系统结构关系可视化系统

IT系统结构关系可视化系统是一个利用三维可视化技术构建业务至IT设施的可视化管理模型,以立体、仿真、实时互动的方式,呈现系统业务、系统、流程以及支撑的物理设备之间关系的Web系统[1].可以直观的展示不同层次应用节点的业务关系、应用与组件之间所属关系、逻辑组件与物理实体的对应关系、应用业务流向关系、系统监控信息和按条件显示拓扑等,并且支持针对某一节点发生故障的定位及影响分析、故障回溯功能.可视化系统数据来源于配置管理模块、后端使用Struct2+Hibernate4+Spring3技术,前端可视化模块使用Unity3D引擎.整个可视化系统具有使用方便、扩展性好、面向服务、支持配置化、数据呈现直观等特性.     

UFMC系统载波干扰抑制改进算法

针对ICI自消除算法导致UFMC系统频带利用率过低的问题,提出一种联合部分自消除和加升余弦窗的改进方案。该方案具体通过在UFMC系统发射端子带边界插入自消除子载波,并在UFMC系统接收端进行时域加窗来达到抑制UFMC系统干扰、提升系统的频带利用率的目的。对算法进行MATLAB仿真实验,当子带两侧设置4个自消除子载波时,相较自消除算法,系统载波干扰比增大,同时系统的频谱利用率也提升了10%。仿真结果表明,所提算法能够有效抑制ICI,提高系统抗干扰性能,同时提升系统频带利用率。