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自动化毕业论文开题报告外文翻译说明书 基于PI算法的无刷直流电机控制系统设计【自动化毕业论文开题报告外文翻译说明书】

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基于PI算法的无刷直流电机控制系统设计【自动化毕业论文开题报告外文翻译说明书】.zip,自动化毕业论文开题报告外文翻译说明书,基于PI算法的无刷直流电机控制系统设计【自动化毕业论文开题报告外文翻译说明书】

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毕 业 设 计（论 文）任 务 书1本毕业设计（论文）课题应达到的目的： 1. 复习和巩固所学的各科知识，培养学生综合运用所学理论知识和专业技能的能力。会分析解决自动化应用中的实际问题，并具初步的设计及应用维护能力。 2. 掌握调查研究、中外文献检索与阅读的能力； 3. 定性与定量相结合的独立研究与论证的能力； 4. 实验方案的制定、仪器设备的选用、安装、调试及实验数据的测试、采集与分析处理的能力； 5. 设计、计算与绘图的能力，包括使用计算机的能力； 6. 逻辑思维与形象思维相结合的文字及口头表达的能力； 7. 撰写设计说明书或论文的能力。 2本毕业设计（论文）课题任务的内容和要求（包括原始数据、技术要求、工作要求等）： 1.本课题要求设计工业缝纫机的控制系统，电机采用为500W三相BLDC，单片机采用电机专用微控器瑞萨79F9211。要求实现如下：手把信号检测：根据手把的AD值进行调速。霍尔信号检测：霍尔传感器集成于电机内部，根据检测霍尔信号确定IGBT的导通顺序。速度控制：通过定时器阵列单元TAUS和变频控制功能用于产生控制电机的PWM波，并且根据手把信号来调节PWM的占空比，以及用改进的PI算法来进行调速。数码管设定与显示：数码管用于显示当前电机的转向、参数的设置及错误标志。设计指标：最大速度3600r/min、转速平稳，稳定转速波动5r/min、启动时间300ms，超调小。 2.按时完成开题报告书。 3.按时完成毕业设计外文参考资料。 4.能够圆满完成指导老师布置的课题任务，设计方案合理，能够体现一定的创新性。 5.按时参加答辩，在答辩前各项规定的资料要齐全。 毕 业 设 计（论 文）任 务 书3对本毕业设计（论文）课题成果的要求包括图表、实物等硬件要求： 1.按期完成一篇符合金陵科技学院论文规范的毕业设计说明书（毕业论文），能详细说明设计步骤和思路； 2.能有结构完整，合理可靠的技术方案； 3.能有相应的电气部分硬件电路设计说明； 4.有相应的图纸和技术参数说明。 4主要参考文献： 1 阮毅, 陈伯时. 电力拖动自动控制系统运动控制系统M. 北京: 机械工业出版社, 2013 2 钟晓伟,宋蛰存,许刚. 电动自行车用无刷直流电机控制系统设计J. 电机与控制应用, 2011, 38(1): 20-24 3 刘登, 李辉, 孙永奎等. 工业缝纫机控制系统设计J. 微特电机, 2011(7): 63-66 4 周华伟, 温旭辉, 赵峰等. 一种具有预测功能的抗积分饱和PI速度控制器J. 电机与控制学报, 2012, 16(3): 15-20 5 黄海波, 兰建平, 张凯. 基于LPC1769芯片的无刷直流电机智能控制J. 电机与控制应用, 2013, 40(9): 22-26 6 夏长亮, 无刷直流电机控制系统M. 北京: 科学出版社, 2009 7 陈小永. 直流无刷电机控制技术研发D山东：中国石油大学(华东), 2008 8 刘刚, 王志强, 房建成. 永磁无刷直流电机控制技术与应用M. 北京: 机械工业出版社, 2008 9 刘贺平, 汪芳君, 张春梅. 基于DSP的直流无刷电机数字控制系统的设计J. 电力系统及其自动化学报, 2008, 1(1): 80-83 10 汪小锋. 基于PWM的直流无刷电机控制系统D南京：南京理工大学, 2008 11 孙冠群, 于少娟. 控制电机与特种电机及其控制系统M. 北京：北京大学出版社, 2011 12 胡发焕, 唐军, 邱小童. 模糊自适应PI控制在直流无刷电动机调速系统的应用J. 制造技术与机床, 2012(6):188-191 13 姜志海. 单片机的C语言程序设计与应用M. 电子工业出版社, 2008 14 褚新惠, 官洪运, 单一帆等. 基于DSP的无刷直流电机调速系统J. 微计算机信息, 2007(8): 175-176 15 俞志文, 姜淑忠, 李燕, 基于改进型PI算法的无刷直流电动机控制J. 微特电机, 2009, 37(9): 57-58 毕 业 设 计（论 文）任 务 书5本毕业设计（论文）课题工作进度计划：课题工作进度计划 2015.11.102015.12.13 调研、收集相关资料、对学生进行初步辅导，拟题、选题、填写任务书； 2015.12.152015.12.31 学生查看任务书，为毕业设计的顺利完成，进行前期准备。12月31日前正式下发任务书；12月21日两个系提交专业选题分析总结（撰写要求详见对内通知中附件2）； 2016.01.092016.04.05 学生在指导教师的具体指导下进行毕业设计创作；拟定论文提纲或设计说明书（下称文档）提纲；撰写及提交开题报告、外文参考资料及译文、论文大纲； 在2016年4月5日前学生要提交基本完成的毕业设计创作成果以及文档的撰写提纲，作为中期检查的依据。指导教师指导、审阅，定稿由指导教师给出评语，对论文主要工作未通过的学生下发整改通知； 2016.04.062016.04.10 提交中期课题完成情况报告给指导教师审阅；各专业组织中期检查（含毕业设计成果验收检查）； 2016.04.112016.05.10 进行毕业设计文档撰写；2016年5月8日为学生毕业设计文档定稿截止日； 2016年5月9日-13日，指导教师和评阅教师通过毕业设计（论文）管理系统对学生的毕业设计以及文档进行评阅，包括打分和评语。5月1日前，做好答辩安排，通知学生回校进行答辨； 2016.05.142016.05.15 查看答辩安排，毕业设计（论文）小组答辩； 2016.05.162016.05.29 对未通过答辨的学生进行二次答辨。完成毕业设计的成绩录入； 2016.05.302016.06.07 根据答辩情况修改毕业设计（论文）的相关材料，并在毕业设计（论文）管理系统中上传最终稿，并且上交纸质稿。2016年6月7日为学生毕业设计文档最终稿提交截止日； 2016.06.072016.06.30 各系提交本届毕业设计（论文）的工作书面总结及相关材料。 所在专业审查意见：通过负责人： 2015 年 12 月21 日 毕 业 设 计（论文） 开 题 报 告 1结合毕业设计（论文）课题情况，根据所查阅的文献资料，每人撰写不少于1000字左右的文献综述： 本课题研究的题目是基于PI算法的无刷直流电机控制系统设计，具体的实现方式是同单片机为控制核心和数据处理中心，通过采集无刷直流电机的实时速度作为反馈，通过PI算法改变控制电机的PWM的占空比实现对无刷直流电机的转速控制。目前国外在以单片机为核心的数字化的无刷直流电机控制技术方面做的相当成熟，但我国在这方面的研制工作起步较晚，并且主要集中在一些研究所和高等院校，经过这些年的努力，基于PI算法的无刷直流电机控制系统的研究已经取得了很多成果，在这方面的技术也逐渐成熟，但是还没有形成成熟的产品，主要还是采用国外成熟的系统。因此，建立以单片机为控制核心的无刷直流电机控制系统具有重要的现实意义和广阔的发展前景。 随着单片机技术、电力电机技术及电机调速技术的高速发展，逐渐形成了由无刷结构代替有刷结构、由数字控制代替模拟控制的局面。在电机的数字调速控制中，选择高效可靠的控制单片机将使控制系统的硬件电路简单可靠、软件编制方便，系统整体性能得以提高。功能完善的单片机能很好的适应复杂的电机数字控制系统，对其外围电路加以合理设计，可以在非常恶劣的环境中稳定工作。（1）历史发展： 电力电子技术、功率半导体器件的发展对电机控制技术的发展影响极大。近30年来，电力电子技术的迅猛发展，带动和改变着电机控制的面貌和应用。在单向通用电动机的电子驱动电路中，主要的器件是晶闸管，后来是用相位控制的双向可控硅。在这以后，这种半控型功率器件一直主宰着电机控制市场。到70和80年代才先后出现了全控型功率器件GTO晶闸管、GTR、POWER-MOSFET、IGBT和MCT等。利用这种有自关断能力的器件，取消了原来普通晶闸管系统所必需的换相电路，简化了电路结构，提高了效率，提高了工作频率，降低了噪声，也缩小了电力电子装置的体积和重量。后来，谐波成分大、功率因数差的相控变流器逐步由斩波器或PWM变流器所代替，明显地扩大了电机控制的调运范围，提高了调速精度，改善了快速性、效率和功率因数。 直流电机脉冲宽度调制(Pulse Width Modulation-简称PWM)调速系统产生于70年代中期。最早用于不可逆、小功率驱动，例如自动跟踪天文望远镜、自动记录仪表等 。近十多年来，由于晶体管器件水平的提高及电路 技术的发展，同时又因出现了宽调速永磁直流电机，它们之间的结合促使PWM技术的高速发展，并使电气驱动技术推进到一个新的高度。 在国外，PWM最早是在军事工业以及空间技术中应用。它以优越的性能，满足那些高速度、高精度随动跟踪系统的需求。近八、九年来，进一步扩散到民用工业，特别是在机床行业、自动生产线及机器人等领域中广泛应用。 如今，电子技术、计算机技术和电机控制技术相结合的趋势更为明显，促进电机控制技术以更快的速度发展着。 （2）现状评述： 由于我国在单片机控制无刷直流电机技术上起步较晚，现在并未形成一系列成行的产品，现场主要以进口的调速控制器为主。我国无刷直流电机控制系统还存在功能单一、调速性能较差、稳定性差、智能化程度较低等缺点。 无刷直流电机以其控制性能好、效率高；体积小、功率密度大；噪音小、寿命长等优越的性能在工业控制过程中显得更为重要。随着科学技术的不断提高，单片机和电机控制技术的不断完善，人们正在积极研究符合现代工业技术特点的无刷直流电机控制器。 （3）发展趋势： 随着智能化设备的兴起，无刷直流电机控制系统将朝着多功能化、智能化、网络化、可靠性等方向发展：多功能化：无刷直流电机控制系统将向多功能化方向发展，改变当前单一控制功能的状态，使其具有多种保护、故障记录、事故分析等功能；智能化：无刷直流电机控制系统将向智能化方向发展，使其具有现场处理问题和事故的能力；网络化：无刷直流电机控制系统以微处理器为核心，将它集成为计算机通信网络中的通信节点，采用数字通信技术，组成通信网络，完成信息的传输、设备资源的共享；可靠性：无刷直流电机控制系统将向更为可靠的方向发展，任何系统首先要具备可靠性，增强可靠性也将是人们研究的一个重点。参考文献： 1 钟晓伟，宋蛰存，许刚. 电动自行车用无刷直流电机控制系统设计J. 电机与控制应用, 2011, 38(1): 20-24.2 刘登, 李辉，孙永奎等. 工业缝纫机控制系统设计J. 微特电机, 2011(7): 63-66. 3 周华伟, 温旭辉, 赵峰等. 一种具有预测功能的抗积分饱和PI速度控制器J. 电机与控制学报, 2012,16(3):15-20. 4 贡俊，陆国林.无刷直流电机在工业中的应用前景和发展J.微特电机，2008(5):14-17. 5 罗隆福，杨艳，方日杰.无刷直流电动机中有待深入研究的主要问题J.微电机，2002，35(1):15-16. 6 丁芝琴.基于霍尔传感器的电机测速装置设计J.农机化研究，2010(5):81-83. 7 王家军，齐冬莲.运动控制系统的发展与展望J.电气时代，2004(10):54-56.8 郗志刚，周宏甫.运动控制器的发展与现状J.电气传动自动化，2005,27(3):10-13. 9 潘建.无刷直流电机控制器MC33035的原理及应用J.国外电子元器件,2003,8. 10 褚新惠,官洪运,单一帆等.基于DSP的无刷直流电机调速系统J.微计算机信息,2007,2. 11 梁正峰，王磊.电动自行车用无刷直流电动机控制系统研究J.电气传动自动化.2004,26(3):1-3. 12 胡宝兴.墓于DSP的电动自行车用无刷直流电机控制系统的研究J.浙江工业大学，2005. 13尹衍辰，范瑜.基于C51的永磁无刷电动机控制器设计J.中小型电机，2005，32(6):130-14. 14 谭建成.无刷直流电动机无传感器控制集成电路J.电机电器技术，2003,2：6-9. 15 林寿英.基于FPGA的直流电机控制器的研究与实现J.福建农机，2009(4):31-34. 16 郑吉，王雪普.无刷直流电机控制技术综述J.微特电机，2002，10(2):11-13. 17 黄海波, 兰建平, 张凯. 基于LPC1769芯片的无刷直流电机智能控制J. 电机与控制应用, 2013,40(9):22-26.毕 业 设 计（论文） 开 题 报 告 2本课题要研究或解决的问题和拟采用的研究手段（途径）： 1、本课题要解决的问题（1）控制系统使用什么芯片为控制核心和数据处理中心。（2）系统采用什么方式对无刷直流电机的转速进行测量。（3）系统采用什么算法对无刷直流电机的转速进行稳定控制。（4）系统选择什么显示设备，对转速及设定转速进行显示。（5）系统通过何种方式对设定的电机转速进行更改。2、设计途径（1）系统采用Atmel公司的AT89S52单片机为控制核心和数据处理中心，AT89S55单片机是美国ATMEL公司生产的高性能8位单片机，可以兼容MCS-51指令系统，器件片内置有通用8位中央处理器和Flash存储单元，AT89S52具有强大的控制功能，广泛应用于各种控制领域；且该单片机成本较低，用法简单。（2）系统采用对射式光电开关与码盘配合的方式对无刷电机的转速进行实时采集；单片机通过计数器与定时器配合对电机转速进行实时读取。（3）系统通过PID算法实现对电机转速的稳定控制。PID算法是应用最为广泛的一种自动控制算法。它具有原理简单、易于实现、适用面广、控制参数相互独立、参数的选定比较简单等优点。（4）系统选择LCD1602作为显示设备。1602液晶也叫1602字符型液晶，是一种业字符型液晶，能够同时显示16x2，即32个字符；它是一种专门用来显示字母、数字、符号等的点阵型液晶模块。该显示器具有价格低廉、控制简单等优点。（5）系统选用按键作为系统的输入设备，用来改变转速的设定值。按键采用普通的微动开关，单片通过对I/O口的扫描确定按下的按键，并执行相应的设置程序。毕 业 设 计（论文） 开 题 报 告 指导教师意见：1对“文献综述”的评语：文献综述内容能够结合研究课题，对包含的研究内容的相关背景、基础知识、发展现状等进行阐述，同时还对本课题所研究的任务进行了一定的概述，对课题的进一步研究有一定的指导意义，参考文献合理，符合规范。该论文构思较为严密。论题较为新颖，具有一定的社会现实意义，可以开题，进行写作。2对本课题的深度、广度及工作量的意见和对设计（论文）结果的预测：本课题研究的任务是基于PI算法的无刷直流电机控制系统设计，作者通过实例调研，查阅专业资料，提出了一种基于微控制器和驱动电路的方案,并采用经典PID控制算法控制PWM的占空比的方法进行调速，已取得初步的结果，相信在后续的努力中一定能够实现最终的设计任务和结果。3.是否同意开题： 同意 不同意 指导教师： 2016 年 02 月 17 日所在专业审查意见：同意 负责人： 2016 年 03 月 22 日英文文献Electronic systems are used for handing information in the most general sense; this information may be telephone conversation, instrument read or a companys accounts, but in each case the same main type of operation are involved: the processing, storage and transmission of information. in conventional electronic design these operations are combined at the function level; for example a counter, whether electronic or mechanical, stores the current and increments it by one as required. A system such as an electronic clock which employs counters has its storage and processing capabilities spread throughout the system because each counter is able to store and process numbers. Present day microprocessor based systems depart from this conventional approach by separating the three functions of processing, storage, and transmission into different section of the system. This partitioning into three main functions was devised by Von Neumann during the 1940s, and was not conceived especially for microcomputers. Almost every computer ever made has been designed with this structure, and despite the enormous range in their physical forms, they have all been of essentially the same basic design.In a microprocessor based system the processing will be performed in the microprocessor itself. The storage will be by means of memory circuits and the communication of information into and out of the system will be by means of special input/output(I/O) circuits. It would be impossible to identify a particular piece of hardware which performed the counting in a microprocessor based clock because the time would be stored in the memory and incremented at regular intervals but the microprocessor. However, the software which defined the systems behavior would contain sections that performed as counters. The apparently rather abstract approach to the architecture of the microprocessor and its associated circuits allows it to be very flexible in use, since the system is defined almost entirely software. The design process is largely one of software engineering, and the similar problems of construction and maintenance which occur in conventional engineering are encountered when producing software. Fig.1.1 Three Sections of a Typical MicrocomputerThe figure1.1 illustrates how these three sections within a microcomputer are connected in terms of the communication of information within the machine. The system is controlled by the microprocessor which supervises the transfer of information between itself and the memory and input/output sections. The external connections relate to the rest (that is, the non-computer part) of the engineering system.Although only one storage section has been shown in the diagram, in practice two distinct types of memory RAM and ROM are used. In each case, the word memory is rather inappropriate since a computers memory is more like a filing cabinet in concept; information is stored in a set of numbered boxes and it is referenced by the serial number of the box in question. Microcomputers use RAM (Random Access Memory) into which data can be written and from which data can be read again when needed. This data can be read back from the memory in any sequence desired, and not necessarily the same order in which it was written, hence the expression random access memory. Another type of ROM (Read Only Memory) is used to hold fixed patterns of information which cannot be affected by the microprocessor; these patterns are not lost when power is removed and are normally used to hold the program which defines the behavior of a microprocessor based system. ROMs can be read like RAMs, but unlike RAMs they cannot be used to store variable information. Some ROMs have their data patterns put in during manufacture, while others are programmable by the user by means of special equipment and are called programmable ROMs. The widely used programmable ROMs are erasable by means of special ultraviolet lamps and are referred to as EPROMs, short for Erasable Programmable Read Only Memories. Other new types of device can be erased electrically without the need for ultraviolet light, which are called Electrically Erasable Programmable Read Only Memories, EEPROMs.The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor.The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor.The microprocessor , memory and input/output circuit may all be contained on the same integrated circuit provided that the application does not require too much program or data storage . This is usually the case in low-cost application such as the controllers used in microwave ovens and automatic washing machines . The use of single package allows considerable cost savings to e made when articles are manufactured in large quantities . As technology develops , more and more powerful processors and larger and larger amounts of memory are being incorporated into single chip microcomputers with resulting saving in assembly costs in the final products . For the foreseeable future , however , it will continue to be necessary to interconnect a number of integrated circuits to make a microcomputer whenever larger amounts of storage or input/output are required.Another major engineering application of microcomputers is in process control. Here the presence of the microcomputer is usually more apparent to the user because provision is normally made for programming the microcomputer for the particular application. In process control applications the benefits lf fitting the entire system on to single chip are usually outweighed by the high design cost involved, because this sort lf equipment is produced in smaller quantities. Moreover, process controllers are usually more complicated so that it is more difficult to make them as single integrated circuits. Two approaches are possible; the controller can be implemented as a general-purpose microcomputer rather like a more robust version lf a hobby computer, or as a packaged system, signed for replacing controllers based on older technologies such as electromagnetic relays. In the former case the system would probably be programmed in conventional programming languages such as the ones to9 be introduced later, while in the other case a special-purpose language might be used, for example one which allowed the function of the controller to be described in terms of relay interconnections, In either case programs can be stored in RAM, which allows them to be altered to suit changes in application, but this makes the overall system vulnerable to loss lf power unless batteries are used to ensure continuity of supply. Alternatively programs can be stored in ROM, in which case they virtually become part of the electronic hardware and are often referred to as firmware. More sophisticated process controllers require minicomputers for their implementation, although the use lf large scale integrated circuits the distinction between mini and microcomputers, Products and process controllers of various kinds represent the majority of present-day microcomputer applications, the exact figures depending on ones interpretation of the word product. Virtually all engineering and scientific uses of microcomputers can be assigned to one or other of these categories. But in the system we most study Pressure and Pressure Transmitters. Pressure arises when a force is applied over an area. Provided the force is one Newton and uniformly over the area of one square meters, the pressure has been designated one Pascal. Pressure is a universal processing condition. It is also a condition of life on the planet: we live at the bottom of an atmospheric ocean that extends upward for many miles. This mass of air has weight, and this weight pressing downward causes atmospheric pressure. Water, a fundamental necessity of life, is supplied to most of us under pressure. In the typical process plant, pressure influences boiling point temperatures, condensing point temperatures, process efficiency, costs, and other important factors. The measurement and control of pressure or lack of it-vacuum-in the typical process plant is critical.The working instruments in the plant usually include simple pressure gauges, precision recorders and indicators, and pneumatic and electronic pressure transmitters. A pressure transmitter makes a pressure measurement and generates either a pneumatic or electrical signal output that is proportional to the pressure being sensed.In the process plant, it is impractical to locate the control instruments out in the place near the process. It is also true that most measurements are not easily transmitted from some remote location. Pressure measurement is an exception, but if a high pressure of some dangerous chemical is to be indicated or recorded several hundred feet from the point of measurement, a hazard may be from the pressure or from the chemical carried.To eliminate this problem, a signal transmission system was developed. This system is usually either pneumatic or electrical. And control instruments in one location. This makes it practical for a minimum number of operators to run the plant efficiently.When a pneumatic transmission system is employed, the measurement signal is converted into pneumatic signal by the transmitter scaled from 0 to 100 percent of the measurement value. This transmitter is mounted close to the point of measurement in the process. The transmitter output-air pressure for a pneumatic transmitter-is piped to the recording or control instrument. The standard output range for a pneumatic transmitter is 20 to 100kPa, which is almost universally used.When an electronic pressure transmitter is used, the pressure is converted to electrical signal that may be current or voltage. Its standard range is from 4 to 20mA DC for current signal or from 1 to 5V DC for voltage signal. Nowadays, another type of electrical signal, which is becoming common, is the digital or discrete signal. The use of instruments and control systems based on computer or forcing increased use of this type of signal.Sometimes it is important for analysis to obtain the parameters that describe the sensor/transmitter behavior. The gain is fairly simple to obtain once the span is known. Consider an electronic pressure transmitter with a range of 0600kPa.The gain is :defined as the change in output divided by the change in input. In this case, the output is electrical signal (420mA DC) and the input is process pressure (0600kPa). Thus the gain. Beside we must measure Temperature Temperature measurement is important in industrial control, as direct indications of system or product state and as indirect indications of such factors as reaction rates, energy flow, turbine efficiency, and lubricant quality. Present temperature scales have been in use for about 200 years, the earliest instruments were based on the thermal expansion of gases and liquids. Such filled systems are still employed, although many other types of instruments are available. Representative temperature sensors include: filled thermal systems, liquid-in-glass thermometers, thermocouples, resistance temperature detectors, thermostats, bimetallic devices, optical and radiation pyrometers and temperature-sensitive paints.Advantages of electrical systems include high accuracy and sensitivity, practicality of switching or scanning several measurements points, larger distances possible between measuring elements and controllers, replacement of components(rather than complete system), fast response, and ability to measure higher temperature. Among the electrical temperature sensors, thermocouples and resistance temperature detectors are most widely used.译文：广义地说，微型计算机控制系统（单片机控制系统）是用于处理信息的，这种被用于处理的信息可以是电话交谈，也可以是仪器的读数或者是一个企业的帐户，但是各种情况下都涉及到相同的主要操作：信息的处理、信息的存储和信息的传递。在常规的电子设计中，这些操作都是以功能平台方式组合起来的，例如计数器，无论是电子计数器还是机械计数器，都要存储当前的数值，并且按要求将该数值增加1。一个系统例如采用计数器的电子钟之类的任一系统要使其存储和处理能力遍布整个系统，因为每个计数器都能存储和处理一些数字。现如今，以微处理器为基础的系统从常规的处理方法中分离了出来，它将信息的处理，信息的存储和信息的传输三个功能分离形成不同的系统单元。这种主要将系统分成三个主要单元的分离方法是冯-诺依曼在20世纪40年代所设想出来的，并且是针对微计算机的设想。从此以后基本上所有制成的计算机都是用这种结构设计的，尽管他们包含着宽广的物理形式与物理结构，但从根本上来说他们均是具有相同基本设计的计算机。在以微处理器为基础的系统中，处理是由以微处理器为基础的系统自身完成的。存储是利用存储器电路，而从系统中输入和输出的信息传输则是利用特定的输入/输出（I/O）电路。要在一个以微处理器为基础的时钟中找出执行具有计数功能的一个特殊的硬件组成部分是不可能的，因为时间存储在存储器中，而在固定的时间间隔下由微处理器控制增值。但是，规定系统运转过程的软件却规定了包含实现计数器计数功能的单元部分。由于系统几乎完全由软件所定义，所以对微处理器结构和其辅助电路这种看起来非常抽象的处理方法使其在应用时非常灵活。这种设计过程主要是软件工程，而且在生产软件时，就会遇到产生于常规工程中相似的构造和维护问题。图1.1 微型计算机的三个组成部分图1.1显示出了微型计算机中这三个单元在一个微处理器控制系统中是如何按照机器中的信息通信方式而联接起来的。该系统由微处理器控制，微处理器能够对其自身的存储器和输入/输出单元的信息传输进行管理。外部的连接部分与工程系统中的其余部分（即非计算机部分）有关。尽管图中显示的只有一个存储单元，但是在实际中却有RAM和ROM两种不同的存储器被使用。在每一种情况下，由于概念上的计算机存储器更像一个公文柜，上述的“存储器”一词是非常不恰当的；信息被存放在一系列已数字标记过的的“箱子”中，而且可以按照问题由“箱子”的序列号进行相关信息的参考定位。微计算机控制系统经常使用RAM（随机存取存储器），在RAM中，数据可以被写入，并且在需要的时候，可以被再次读出。这种数据能以任意一种所希望的次序从存储器中读出，而不必按照写入时的相同次序读出，所以有“随机”存取存储器。另一类型ROM（只读存储器）是用来保持信息的，它们是不受微处理器影响的固定的信息标本；这些信息在电源切断后不会丢失，并通常用来保存规定微处理器化系统运转过程的程序。ROM可像RAM一样被读取，但与RAM不一样的是不能用来存储可变的信息。有些ROM在制造时将其数据标本放入，而另外的则可通过特殊的设备由用户编程，所以称为可编程ROM。被广泛使用的可编程ROM可利用特殊