【机械类文献翻译】PLC控制系统设计的要点.doc

毕业设计（论文）开题报告题目： 定量给料机控制系统设计 信机 系 机械工程及自动化 专业学 号： 0923153 学生姓名： 盛阳阳 指导教师： 黄敏 （职称：副教授 ） 课题来源自拟题目科学依据（1）课题科学意义随着工业生产的迅速发展，导致了定量给料机的需求量日益增大。定量给料设备已广泛应用于冶金、建材、电力、化工、食品等各种行业中。比如药物的生产，机械浇铸生产。定量给料机是对散状物料进行连续称量给料的理想设备，是集输送、称重计量和定量控制为一体的高科技产品，是根据我国现有工艺工况改进后的新一代产品，它以技术先进、稳定可靠、性价比高、经久耐用而著称。能适应各种生产环境，对各种块、粒状物料（如石灰石、铁粉、粘土）和粉状物料（如粉煤灰、水泥）等进行连续给料、计量，为各种工业现场的生产控制、管理提供准确的计量数据。配有RS485上位机通讯接口，可与中央控制机组成DCS系统。定量给料机的出现解放了人工劳动力，使给料更加智能化，更加精确。促进了工业的发展。（2） 定量给料机的研究状况及其发展前景在的日常生活中，已经很少见到纯单体的物质了，复合材料在工业、农业、日常生活中起着越来越重要的作用。如常见的家电、汽车、飞机制造过程中用的塑料，是由 PP 或 PE 等原材料以一定的配方和工艺制成的；食品中的巧克力、高档饼干等等是由多种食品按照一定的配比，经过一定的工艺制成的；医药领域中的多种中西药都是由多种药材按照一定的配比，制造成特殊功效的药品；日用品中用的洗发液，洗衣粉/剂，灭虫剂等等均为配方产品。研究内容 熟悉定量给料机的发展历程，使用领域； 熟练掌握定量给料机的基本工作原理； 熟练掌握并且完成系统的硬件选型、接口电路设计； 掌握并完成控制软件设计；拟采取的研究方法、技术路线、实验方案及可行性分析实验方案:通过参阅借来的参考资料，网上的介绍以及对定量给料机进行实体观察，了解定量给料机的工作原理。提出任务分析对控制系统需求确定任务要求，完成设计任务书。选定最优方案该阶段目标为提出原理性的设计方案。技术设计阶段明确系统控制要求完成硬件选型、接口电路设计，控制软件设计,并画出电气图、写出使用说明书、标准明细表、其他技术文件等。实验通过通过自行设计控制系统，从而达到预期的控制。研究计划及预期成果研究计划：2012年11月12日-2013年12月2日：按照任务书要求查阅论文相关参考资料，填写毕业设计开题报告书；完成一篇英文文献翻译；2012年12月3日-2013年2月17日： 进行专业实训，填写毕业实习实训报告；2013年2月18日-3月9日： 进行需求分析和可行性分析。构建论文框架完成第一章节绪论部分,按格式要求确定参考文献和四篇英文文献；2013年3月10日： 将在此之前做的所有的相关资料交给导师检查，填写中期进表；2013年3月10日- 3月20日： 对定量给料机机械部分做一个简单的设计、描述；2013年3月21日- 4月9日： 对控制系统做初步的设计、介绍，选择好系统的硬件选型，接口电路；2013年4月10日- 4月24日： 完成系统全部设计，并提供一份控制软件；2013年4月24日-5月5日： 进行实验检验，撰写毕业论文和相关资料。2013年5月6日-5月20日：完善毕业论文以及相关资料，为答辩做好充分的准备。预期成果：照计划安排进行本设计，对给料机设计的系统能良好的完成需要的动作。完成控制系统总体方案设计、控制系统的硬件选型、接口电路设计；写出控制软件1套。完成设计说明书的撰写，并翻译外文资料1篇。特色或创新之处 主题明确，有针对性,稳定, 易操作, 通用性强。 使用简易，功能完善。已具备的条件和尚需解决的问题 实验方案思路已经非常明确，已经确定总目标，策略。 给料机控制部分的设计，plc电气方面的硬件选择，所需软件。指导教师意见 指导教师签名：年 月 日教研室（学科组、研究所）意见 教研室主任签名： 年 月 日系意见 主管领导签名： 年 月 日英文原文Plc control system design elementsSubmitted: -; Accepted: March 27, 2002; Published: September 25, 2002Pavan K. Heda 1 , Kapiamba Muteba 2 and Larry L. Augsburger 21 Personal Products Company, Division of McNeil-PPC, Skillman, NJ 085582 Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD 21201ABSTRACTOriginally, the PLC was represented by the acronym PC. There was some confusion with using this acronym as it is commonly accepted to represent personal computer. Therefore, PLC is now commonly accepted to mean programmable logic contoller.A PLC is a user-friendly, microprocessor-based specialized computer that carries out control functions of many types and leves of complexity. Its purpose is to monitor crucial process parameters and adjust process operations accordingly. It can be programmed, controlled, and operated by a person unskilled in operating computer. Essentially, a PLCs operator draws the lines and devices of ladder diagrams with a keyboard onto a display screen. The resulting drawing is converted into computer machine language and run as a user program1.The computer takes the place of much of the external wiring required for control of a process. The PLC will operate any system that has output devices that go on and off (known as discrete, or digital, outputs). It can also operate any system with variable (analog) outputs. The PLC can be operated on the input side by on-off devices (discrete, or digital) or by variable (analog) input devices.KEYWORDS: PLC, programmable logic contoller.In the automated control domain, PLC is one kind of important control device. At present, in the world has more than 200 factories to produce more than 300 varieties PLC product, applies in the automobile (23%), the grain processing (16.4%), chemistry/drugs manufacture (14.6%), the metal/mine (11.5%), the paper pulp/papermaking (11.3%) and so on the profession. In order to make fellow beginners conveniently to understand PLC, this article to the PLC development, the basic structure, the disposition, using and so on the elementary knowledge makes a synopsis.First, PLC development courseIn the industrial production process, the massive switches quantity sequential control, it carries on the smooth movement according to the logical condition, and defers to the logical relations to carry on the chain-like protection movement the control, and massive data acquisition. In the tradition, these functions are realize through air operated or the electricity control system. In 1968 American GM (general automobile) the company proposed the substitution continues the electricity control device the request, the second year, the American numeral company developed based on the integrated circuit and the electronic technology control device, used sequenced the method to apply for the first time to the electrical control, this was the first generation of programmable foreword controller, called Programmable Controller (PC)2. After the personal computer (is called PC) to develop, in order to be convenient, also in order to reflect the programmable controller the function characteristic, the programmable foreword controller chooses a name is Programmable Logic Controller (PLC), now, still frequently was called PLC PC. The PLC definition has many kinds. The international electrician committee (IEC) to PLC the definition is: The programmable controller is one kind of digital operation operation electronic system, specially for applies under the industry environment designs3. It uses the programmable foreword the memory, uses for to carry out the logic operation, the sequential control in its internal storage, fixed time, counts with operation the and so on arithmetic operation instruction, and through digital, the simulation input and the output, controls each kind of type the machinery or the production process. The programmable foreword controller and its the related equipment, all should according to easy form a whole with the industry control system, is easy to expand its function the principle design.On the century 80's to the 90's intermediate stages, are PLC develop the quickest time, the yearly rate continuously maintenance are 30-40%. In this time, PLC in the processing simulation quantity ability, the digital operation ability, the man-machine connection ability and the networking capability obtains the large scale enhancement, PLC gradually enters the process control domain, substituted in certain applications has been at the dominant position in the process control domain the DCS system.PLC has the versatility strongly, the easy to operate, the adaption surface broad, the reliability high, the antijamming ability strong, the programming is simple and so on the characteristic. PLC in the industrial automation control specially is in the sequential control status, in future which may foresee, is unable to substitute.Second, PLC constitution From the structure the minute, PLC divides into the stationary type and the combined type (module type) two kinds. Stationary PLC including the CPU board, the I/O board, demonstrated the kneading board, the memory block, the power source and so on, these element groups synthesize a not dismantable whole. Module type PLC including the CPU module, the I/O module, the memory, the power source module, the ledger wall or the rack, these modules may defer to the certain rule combination disposition. Second, PLC constitution4.Third, CPU constitutionCPU is the PLC core, plays nerve center's role, every time wraps PLC at least to have CPU, it function receive and storage user program and data which entrusts with according to the PLC system program, with scanning way gathering the condition or the data which sends by the scene input device, and stores the stipulation in the register, simultaneously, diagnoses the power source and in the PLC internal circuit active status and the programming process grammatical error and so on. After enters the movement, reads from the user program memory by the strip takes the instruction, the duty which stipulated according to the instruction produces the corresponding control signal again after the analysis, directs the related control circuit5. CPU mainly by the logic unit, the controller, the register and realizes the data, the control and the condition main line constitution which between them relates, the CPU unit also includes the periphery chip, the main line connection and the related electric circuit. The memory mainly uses in the stored routine and the data, is the PLC essential composition unit.Looked like in the user, nonessential multianalysis CPU internal circuit, but or should have the enough understanding to each part of work mechanism. The CPU controller controls the CPU work, reads by it takes the instruction, the interpretive order and carries out the instruction. But the work rhythm by shakes the signal control. The logic unit uses in to carry on the numeral or the logic operation, works under the controller direction. The register participation operation, coexists stores the operation the intermediate result, it also is works under the controller direction. The CPU speed and the memory capacity are the PLC important parameter, they are deciding the PLC working speed, the IO quantity and the software capacity and so on, therefore is limiting the control scale.Fourth, I/O modulePLC and the electrical return route connection, is (I/O) completes through the input output unit. The I/O module integrated the PLC I/O electric circuit, its input temporary storage device reflection input signal condition, output point reflection output latch condition. The load module transforms the electrical signal the digital signal to enter the PLC system, the output module is opposite. I/O divides into the switch quantity input (DI), switch quantity output (DO), simulation quantity input (AI), simulation quantity output (AO) and so on module.The switch quantity is refers has and closes (or 1 and 0) two kind of conditions signals, the simulation quantity is only a quantity which refers continuously changes. Commonly used I/O classifies as follows:Switch quantity: Divides equally according to the voltage water, has 220VAC, 110VAC, 24VDC, divides according to the isolation way, has the relay isolation and the transistor isolation. Simulation quantity: Divides according to the signal type, has the electric current (4-20mA,0-20mA), the voltage (0-10V,0-5V, -10-10V) and so on, divides according to the precision, has 12bit,14bit,16bit and so on. Besides above general I/O, but also has the special I/O module, like module and so on thermal resistance, thermo-element, pulse. According to the I/O points determination module specification and the quantity, the I/O module may be many may be few, but its biggest number the basic disposition ability which can manage CPU, namely biggest ledger wall or rack Key slot number limit.Fifth, power source moduleThe PLC power source uses in is the PLC various modules integrated circuit provides the work power source. At the same time, some also provides 24V for the input circuit the work power source. The mains input type includes: (What the alternating current supply (220VAC or 110VAC), the direct-current power supply is commonly used is 24VAC).Sixth, ledger wall or rackThe majority module type PLC use ledger wall or the rack, its function is: On the electricity, realizes during various modules relation, enables CPU to visit on the ledger wall all modules, on the machinery, realizes during various modules connection, enable various modules to constitute a whole.Seventh, PLC system other equipment1st, programs the equipment: The programming is the PLC development application, the monitor movement, the inspection maintains the essential component, uses in to program, makes some hypotheses to the system, monitors the system working condition which PLC and PLC controls, but it not directly participates in the scene control movement. Small programming PLC generally has the grasping programming, at present generally (movement programming software) acts as the programming by the computer. 2nd, man-machine contact surface: The simplest man-machine contact surface is the indicating lamp and the button, at present the liquid crystal screen (or touches screen) a formula writing style operator terminal application to be more and more widespread, (movement configuration software) acts as the man-machine contact surface by the computer extremely to popularize. 3rd, input-output device: Uses in permanently the memory user data, like EPROM, EEPROM reading in, bar code microreader, input simulation quantity potentiometer, printer and so on.Eighth, PLC correspondence networkingDepends upon the advanced industry network technology to be allowed rapidly effectively to collect, the transmission produces and manages the data. Therefore, the network is more and more remarkable in the automated system integration project importance, even some people proposed the "network is the controller" viewpoint view. PLC has the correspondence networking the function, it causes between PLC and PLC, PLC and on between the position computer and all that intelligent equipment can exchange the information, forms a unified whole, the realization disperser common control. Most PLC has the RS-232 connection, but also has some in sets has supports respective correspondence agreement the connection.PLC correspondence, but also the realization mutually has not been operational, IEC had stipulated the many kinds of field bus standard, the PLC various factories have the use. (Specially is center large-scale control system) says regarding an automated project, the choice network count for much. First, the network will have to be open, facilitates the different equipment the integration and the future system scale expansion; Next, in view of the different network level transmission performance requirement, the choice network form, this must in thoroughly understand this network standard the agreement, under the mechanism premise carries on; Once more, the synthesis considered system cost, equipment compatibility, scene environment serviceable and so on concrete question, determined the different level uses network standard.Today, the big unit growth in the PLC industy is at the low end-where small keeps getting smaller. When a few years ago the micro PLC entered the market, some thougt that these devices had “bottomed out”. Now,nano PLCs-generally defined as those with 16 or fewer I/O-are spreading. Some can fit