当前位置:文档之家› PLC控制系统 英文文献+翻译

PLC控制系统 英文文献+翻译

PLC控制系统  英文文献+翻译
PLC控制系统  英文文献+翻译

Beer filling, Gland machine PLC control system

1.Intorduction

Malt beer production process is divided into manufacturing, manufacturing wort, before fermentation, after fermentation, filtration sterilization, packaging, and so few procedures. Beer filling, Gland part of a packaging machine processes. The membrane filtration of beer after the pipeline into the rotary Jiugang, then the valve into the bottle of wine, Gland, was bottled beer. Beer filling, Gland machine's efficiency and degree of automation direct impact on the level of beer production. China's beer industry to meet the increasing scale of production and the demand for beer modern high-speed filling machinery filling the requirements of domestic beer manufacturers are actively seeking to transform the unit or the filling of beer production equipment, making it a good use Performance, advanced technology and high production efficiency and operating a safe and secure, low maintenance costs of the modernization of beer filling machine.

2. Filling beer, Gland principle and control aircraft parts

Liquid filling machine by filling principle can be divided into atmospheric filler,filling machines and vacuum pressure on the filling machine. Beer filling,Gland-filling method used pressure is higher than the atmospheric pressure under the filling, storage of the cylinder pressure than the pressure of the bottle, beer bottle into the liquid on pressure.

Technology at home and abroad to achieve the filling line is basically: The Rotary Jiugang the rotating movement, placed in Jiugang slots on the empty bottles through the machinery will be fixed at the upper Jiugang vacuum valve to open, closed Vacuum bottles for good treatment, Bozhuan stem from operating, open the valve of the bottle filling CO2 gases, vacuum convex .Round to open the vacuum valve, the bottle will air mixed with CO2 out of gas, open the valve again, the CO2 gas bottle filling, the filling valve on the pressure valve in the bottle close to back-pressure gas pressure at the open-Jiuye Pingbi into the bottle, through pneumatic or electrical control filling valve to achieve the filling of beer. Today's advanced international beer filling, Gland machine control system mainly by the photoelectric switch position detection part and take the bottles with, Jiugang speed part, dominated by the PLC, touch screen and other components. Filling, Gland of the mechanical structure and PLC programmable control devices, frequency stepless speed regulation, human-computer interface, and other modern means of complete automatic control technology, the combination of a mechanical and electrical integration.

3. Controlled part of the programme

Many domestic beer manufacturers are now using the filling, Gland of the control system of uneven degree of automation; button and all the manual switch technology have set up operations in a box on the panel, PLC controller for the majority of Japanese companies or OMRON Mitsubishi's early products, equipment chain of control, less protection settings, plus the beer filling the scene poor environment, humidity, such as contact with the switch contacts serious corrosion, the system's signal detection of the high failure rate, resulting in equipment control system Operation of low reliability, the normal operation of equipment, such as

short-cycle phenomenon.

To the actual transformation of the Dandong Yalu River Brewery Co., Ltd. of filling, Gland machine control system as an example, the transformation of methods to clarify the control of such equipment thinking and ideas, according to the scene of the actual process conditions, to prepare the operation of the PLC Procedures. For beer filling, Gland control system of the actual situation and in accordance with the actual process conditions at the scene, re-design of the equipment of the PLC control system. This transformation of the same methods and ideas can be applied to other liquids and the transformation of filling equipment.

3.1 system hardware configuration

Japan's Mitsubishi Corporation to use the FX2N128MRPLC use the system to replace the original 2-OMRON's C60P PLC, the original system of the PLC is due to old models, and computer on-line communications need to configure special converters, the system need to increase the external I / O input points , The extension of spare parts more difficult to find. FX2N128MRPLC is an integrated 128-point I / O controller of the box, a computing speed, command rich, high-cost performance, on-line programming simple and easy extension of the advantages of the Mitsubishi FX series, features the strongest small controller .

(1) by the Mitsubishi 900 series of 970 GOT human-computer touch screen system to replace the original use of the button panel display equipment and monitor the operation of operating parameters. 970GOT HMI for the 16-color high-brightness significantly, through the convergence of connectivity and FX2N128MRPLC directly connected to the CPU, achieving rapid response. Has many maintenance features, such as the list-editing features, ladder monitoring (troubleshooting) function, the system

monitoring functions to find fault and maintenance of PLC Systems. (2) filling, Gland of the frequency converter in the transformation of no replacement, on-site detection signal means-testing is still used switch, switch for detecting long-term work in the humidity of the great occasions, the choice of capacitive proximity switches, according to PLC I / O terminal of the connection mode, select the type of close PNP switch, the control system of Figure 1.

3.2 Systems Programming

PLC controller programming focus and the core is around Jiugang the rotation speed control and Jiugang on 60 bottles of detecting the location of the displaced, broken bottles, empty bottles at the location of testing and related displacement filling Such as control valves. The bottles displacement of testing procedures, using a Mitsubishi PLC in the left command.Figure 1 control system structure diagram .

Bottles displacement of detection, using the left-PLC command, which commands the whole of one of the core control procedures, the main electrical switch detection and bottles at the bottle simultaneously detect mobile, the main motor to every week, just to the corresponding Jiugang Have a bottle of, PLC unit within the internal correspondence that 60 bottles of the unit for the M500 ~ M559, the number of units by the first letter K is set to K60, with each change in a second letter K is set to K1, M50 Reaction of the empty bottles in the short position, and detect the location of the motor speed to go on the frequency shift in the corresponding unit within the built-in "1" or "0", control valves and the corresponding mixing caps The motor stopped and opened. Continuous detection system in place after the 90 empty bottles, stop stirring caps the motor running, testing the number of bottles in accordance with the user's requirements can be arbitrary.

A bottle of detection. Rotary Jiugang through pressure to back pressure with the bottle of liquor in the process of empty bottles in the back-pressure, because the bottle itself may crack and other reasons leading to a sudden burst bottles, which need to detect the location of unexploded bottle bottle, in this bottle - The position opened purge solenoid valves, compressed air out, broken bottles at the bottle-blowing from the position in a row after the purge and several bottles of the electromagnetic valve open jet, a high-pressure spray Shuizhu, in the break Bottle position around a few bottles of spray bottles in a row. Detection of broken bottles and bottle-detection switch simultaneously detect movement of breaking bottles, to the main motor of each week, precisely corresponding Jiugang passed a bottle of, PLC unit within the internal correspondence that 20 broken bottles at the unit for the M600 ~ M619, unit With the number of the first letter K is set to K20, with each change in a second letter K is set to K1, M52 response to the location of the broken bottles and detected the location of the motor speed to the frequency shift continue, In the corresponding unit within the built-in "1" or "0", control and the corresponding jet purge solenoid valve opened and stopped. Continuous Spray and purge solenoid valve open to listen, time stopped in accordance with technological requirements can be arbitrary.

System security is to control access to the caps simultaneously tracking, not only accurately detect the electrical switching speed detection, the broken bottles into the bottle and detection switch detection switch three conditions.

970GOT human-computer touch-screen terminals operated by the software company's Mitsubishi GT WORKS package, which is a GT Designer with the entire GOT9000 series of graphics software packages. The package is simple, prior to a personal computer simulation on the configuration

and debug, after the man-machine operators to download terminals. At the same time, because the man-machine interface and a touch-screen role, will set common switch on the screen to facilitate the operation. And also to increase the number of features, such as setting alarm information.

4.After transformation control system

System at the normal operation of the machine for automatic control, in accordance with bottles into and out of the bottle for lack or slow pace set by running into the bottle stall bottles, no less than a bottle cap, automatic washing bottles burst, filling automatic back-pressure position , Covered under the system automatically lose covered a stop and safety protection, such as the coordination of action interlock. All the original button after the operation of the touch screen on.

5.Detection of the state control system monitoring

Detection switch into the bottle and break bottles detection switch bottles of pressure by testing each part of the small metal plates above the location of a photoelectric pulse output, a further PLC acquisition, as each bottle of the pressure above the small metal plates is the location of activities , In the machine running after some time, some pressure above the small bottles of iron tablets and detection switch in the location of displacement, resulting in detection switch mistaken judgement, if not for the judgement of bottles of bottles, bottle explosion Lou Jian, misuse, such as the seizure of output errors So that the PLC have mistaken action, such as a back-pressure, unexploded bottle blowing, washing, stirring cap control system malfunction, such as failure phenomenon.

Before the transformation of the daily production process, encountered this phenomenon, the operatives could only switch to the

various functional or manual control buttons reach the stall so that the equipment work in the absence of monitoring state, the machine lost control function. Caused a lot of production of raw materials such as gas, water, wine waste. Only in the production of intermittent, can be fitter and maintenance electrician in accordance with the detection of small switch on the light-emitting diodes and anti-displacement by adjusting the distance only 5 ~ 8 mm detection switch installation location, and switch to fix detection of small metal plates Gap. This means of detection is very backward, after adjustment reaction to the results, timely response can not be adjusted results.

In view of this testing situation, after the transformation of the filling, Gland control system configuration, this part of a new detection and integration in human-computer touch screen, complete bottle of detection.

In human-computer touch screen interface on the page display, respectively, at customs, such as electromagnetic motor mixing valve switch state are in different colors to show, very intuitive.

Increase the system's functions is to ensure the irrigation of the machine-Gland normal operation of automated control system specifically designed to.

6 Concluding remarks

After the transformation of the control system will greatly simplify the complicated mechanical structure, the running and control of inspection, the degree of automation systems meet the design requirements, greatly reducing the operational strength of the labor so that the shrub-like beer output than in the past Raising more than 30 percent, greatly reduce the failure rate. Embodies the modern equipment of automatic control technology. In the digestion and absorption of today's

industrial control on the basis of advanced technology innovation, development of domestic technology from the most advanced filling control system.

啤酒灌装、压盖机PLC控制系统

1. 引言

啤酒生产过程分为麦芽制造、麦芽汁制造、前发酵、后发酵、过滤灭菌、包装等几道工序。啤酒灌装、压盖机部分属于包装工序。啤酒经膜过滤后由管路送入回转酒缸,再经酒阀进入瓶子中,压盖后获得瓶装啤酒。啤酒灌装、压盖机的工作效率和自动化程度的高低直接影响啤酒的日产量。

为了满足我国啤酒行业日益扩大生产规模的需求和啤酒现代化灌装机械高

速灌装的要求,国内各啤酒生产厂家都在积极寻求或改造本单位的啤酒灌装生产设备,使其成为具有良好的使用性能,先进的技术水平及高生产效率、运行稳妥可靠、维护成本低的啤酒现代化灌装机。

2. 啤酒灌装、压盖机工作原理和控制部分构成

液体灌装机按灌装原理可分为常压灌装机、压力灌装机和真空灌装机。啤酒灌装、压盖机采用压力灌装方法,是在高于大气压力下进行灌装,贮液缸内的压力高于瓶中的压力,啤酒液体靠压差流入瓶内。

目前国内外实现灌装工艺路线基本上是:利用回转酒缸产生的旋转运动,使安放在酒缸槽位上的空瓶通过机械机构将固定在酒缸上部的欲抽真空阀打开,对已封好的瓶子进行抽真空处理,拨转外操作阀杆,打开气阀,对瓶内充填CO2

气体,抽真空凸轮继续打开真空阀,将瓶内空气与CO2混合气体抽出,气阀再次打开,对瓶内充填CO2气体,灌装阀内的液阀在瓶内压力接近背压气体压力时打开,酒液顺瓶壁注入瓶内,通过气动或电动控制灌装阀实现啤酒的灌装。

当今国际先进的啤酒灌装、压盖机的控制系统主要由光电开关位置检测部分、走瓶带、酒缸转速的变频调速部分、主控由可编程控制器、触摸屏等组成。灌装、压盖机的机械结构装置与PLC可编程控制、变频无级调速、人机界面等现代自动控制技术手段完整的结合,形成机电一体化。

3. 控制部分改造方案

国内很多啤酒厂家现使用的灌装、压盖机的控制系统的自动化程度参差不齐;所有手动按钮和工艺开关都设置在一个操作箱的面板上,PLC控制器大都为日本OMRON公司或三菱公司的早期产品,设备连锁控制、保护设置少,加之啤酒灌装的现场环境恶劣,潮湿度大,使开关等接触触点锈蚀严重,系统的信号检测部分故障率较高,造成设备控制系统运行的可靠性低,设备正常运行周期短等现象。

以实际改造的丹东鸭绿江啤酒有限公司的灌装、压盖机的控制系统为例,介绍改造方法,阐明改造这类设备的控制思想和思路;根据现场的实际工艺条件,重新编写了PLC的运行程序。针对啤酒灌装、压盖机控制系统的实际状况,并根据现场的实际工艺条件,重新设计了设备的PLC控制系统。这种改造方法和思路同样可以应用与其他液体介质灌装设备的改造。

3.1 系统硬件配置

使用日本三菱公司的FX2N128MRPLC替换原系统使用的2台OMRON公司的

C60P PLC,原系统的PLC由于是老型号产品,和计算机联机需要配置特殊的通讯转换器,系统需要增加外部I/O输入点时,扩展模块备件较难寻。FX2N128MRPLC 是集成128点I/O的箱体式控制器,具有运算速度快,指令丰富、性能价格比高、联机编程简单、扩展方便等优点,是三菱FX系列中功能最强的小型控制器。

(1) 采用三菱公司的900系列的970GOT人机触摸屏替换原系统使用的面板按钮并监控显示设备的运行工作参数。970GOT HMI为高亮度的16色显,通过汇流连接和FX2N128MRPLC的CPU直接连接,实现快速回应。具有许多维护功能,如列表式编辑功能、梯形图监控(故障查找)功能、系统监控功能等用来查找故障和维护PLC系统。

(2) 灌装、压盖机的变频器在改造中没有更换,现场检测信号的手段仍然采用开关式检测,因检测开关长期工作在湿度很大的场合,因此选择电容式的接近开关,根据PLC I/O端子的接线方式,选择PNP型的接近开关。

3.2. 系统程序设计

PLC控制器的程序设计重点和核心是围绕着酒缸的旋转速度控制和酒缸上

60个瓶位相关位置的检测移位、破瓶、空瓶瓶位相关位置的检测移位和相关灌装阀等的控制。其中的瓶位移位检测程序中,采用了三菱PLC位左移指令。

瓶位移位检测,采用PLC位左移指令,这条指令是整个子控制程序的核心之一,主电机和瓶位检测开关同步检测移动的酒瓶,主电机每转一周,正好对应酒缸转过一个瓶位,PLC内部单元内对应这60个瓶位的单元为M500~M559,单元个数用第一个字母K设置为K60,每次变化一位用第二个字母K设置为K1,M50反应了瓶位的空、缺位置,并将检测到的这个位置以电机转速的频率移位下去,在内部相应的单元内置"1"或"0",控制相应的阀门和搅拌瓶盖的电机的开与停。系统在连续检测90个空瓶位后,停止搅拌瓶盖的电机的运行,检测瓶位的个数可以根据用户的要求任意设定。

出瓶位检测。回转酒缸通过压力往瓶内背压装酒的过程中,空瓶在背压后,可能由于瓶子本身裂纹等原因导致突然爆瓶,这就需要检测出爆瓶瓶子的位置,在这个瓶位的位置进行打开吹扫电磁阀,喷出压缩空气,将瓶位上的碎瓶片吹离位置,在连续吹扫几个瓶位后,在打开喷射电磁阀,喷射出高压水注,在对破瓶位置周围瓶位连续喷射几个瓶位。

破瓶检测和瓶位检测开关同步检测移动的破瓶,主电机每转一周,正好对应酒缸转过一个瓶位,PLC内部单元内对应这20个破瓶位的单元为M600~M619,单元个数用第一个字母K设置为K20,每次变化一位用第二个字母K设置为K1,M52反应了破瓶的位置,并将检测到的这个位置以电机转速的频率移位下去,在内部相应的单元内置"1"或"0",控制相应的喷射和吹扫电磁阀开与停。连续喷射和吹扫电磁阀的开听、停时间可以根据工艺要求任意设定。

系统自动化运行可靠的保障就是控制进出瓶盖的同步跟踪,既准确检测电机转速检测开关、破瓶检测开关和进瓶检测开关三个条件。

970GOT人机触摸屏操作终端机的软件采用三菱公司的GT WORKS软件包,其中GT Designer是一个用与整个GOT9000系列的绘图套装软件。该软件包操作简单,事先可在个人计算机上组态并仿真调试,完毕后下载至人机操作终端机。同时,因为人机界面又具有触摸屏的作用,将常用的开关设在显示屏上,方便操作。还可并以增加一些功能,如设置报警信息等。

4.改造后控制系统功能

系统正常运行时,机器为自动控制,根据进出瓶带上瓶的满缺,按设定速度或慢速运行,进瓶档瓶,无瓶不下盖,爆瓶自动冲洗,灌装位置自动背压,下盖输盖系统的自动开停和安全保护等动作的协调联锁。原来所有按钮的操作改造后都在触摸屏上进行。

5.控制系统检测状态的监控功能

进瓶检测开关和破瓶检测开关通过检测每个压瓶部分上面的小铁片的位置,产生光电脉冲输出,再有PLC采集,由于每个压瓶部分上面的小铁片的位置是活动的,在机器运行一段时间后,压瓶部分上面的小铁片和检测开关的位置发生位移,造成检测开关误判断,如没瓶判断为有瓶,爆瓶漏检、误检等造成输出失误,使PLC产生误动作,造成如背压、爆瓶吹、洗、瓶盖搅拌系统控制失灵等故障现象。

在改造前的日常生产过程中,碰到这种现象时,操作工只能将各个功能开关或按扭打到手动控制档位,使机器设备工作在无监控状态下,机器失去自动控制功能。造成了很大的生产原料如气、水、酒的浪费。只能在生产的间歇,才能由维修钳工和电工根据检测开关上的小发光二极管的亮和灭通过调整位移距离只有5~8mm的检测开关的安装位置,来修正检测开关和小铁片的间隙。这种检测手段非常落后,调整后的效果反应致后,不能及时反应调整结果。

针对这种检测状况,结合改造后的灌装、压盖机控制系统的配置,新增了这部分检测功能,并集成在人机触摸屏中,完成瓶位检测。

在人机触摸屏的界面分页显示屏上,可以分别时关、搅拌电机等电磁阀的开关状态都以不同颜色来显示,非常直观。

增加这套系统功能的是为保证灌状压盖机的自动化控制系统正常运行而专门设计的。

6.结束语

改造后的控制系统大大地简化了复杂的机械结构,经现场运行情况和控制效果检验,系统的自动化程度达到了设计要求,大大减少了操作人员的劳动强度,使啤酒灌状的日产量比过去提高30%以上,故障率大大减低。体现了现代设备的

自动控制技术。是在消化、吸收当今工业控制的先进技术的基础上加以创新、研制而成的目前国内技术最先进的灌装控制系统。

英文文献翻译

中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离,该技术需使用长柱色谱法。尽管这种技术得到的效果非常好,但是其需要消耗大量的时间,并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时,这些问题显得更加突出。近年来,几种制备系统已经进行了改进,能将分离时间减少到1-3h,并允许各成分的分辨率ΔR f≥(使用薄层色谱分析进行分析)。在这些方法中,在我们的实验室中,媒介压力色谱法1和短柱色谱法2是最成功的。最近,我们发现一种可以将分离速度大幅度提升的技术,可用于反应产物的常规提纯,我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等(ΔR f≥),而且构建这个系统花费非常低,并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础,专门针对快速分离,介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的,优化实验使用苯甲醇作为样本,放在一个20mm*5in.的硅胶柱60内,使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间(r)和峰宽(w,w/2)的比率进行测定的(Figure 1),结果如图2-4所示,图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。

毕业设计外文翻译附原文

外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华

外文资料名称: Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处:Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件: 1.外文资料翻译译文 2.外文原文

应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金,洪城铱昌,宰瑾李, 刘链柱译 摘要:旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率,压降,并切成尺寸被粒度对应于分级收集的50%的效率进行了研究。颗粒切成大小降低入口面积,体直径,减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法,用于收集在家庭中产生的粉尘。 摘要及关键词:吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子,工作场所,或其他建筑,因此,室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物,毒物,食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤,预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中,吸入压力下降说唱空转成比例地清洗的时间,以及纸过滤器也应定期更换,由于压力下降,气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形,在粗颗粒(>2.0微米)模式为主要的外部来源,如风吹尘,海盐喷雾,火山,从工厂直接排放和车辆废气排放,以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式,典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克,可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。

毕业论文英文参考文献与译文

Inventory management Inventory Control On the so-called "inventory control", many people will interpret it as a "storage management", which is actually a big distortion. The traditional narrow view, mainly for warehouse inventory control of materials for inventory, data processing, storage, distribution, etc., through the implementation of anti-corrosion, temperature and humidity control means, to make the custody of the physical inventory to maintain optimum purposes. This is just a form of inventory control, or can be defined as the physical inventory control. How, then, from a broad perspective to understand inventory control? Inventory control should be related to the company's financial and operational objectives, in particular operating cash flow by optimizing the entire demand and supply chain management processes (DSCM), a reasonable set of ERP control strategy, and supported by appropriate information processing tools, tools to achieved in ensuring the timely delivery of the premise, as far as possible to reduce inventory levels, reducing inventory and obsolescence, the risk of devaluation. In this sense, the physical inventory control to achieve financial goals is just a means to control the entire inventory or just a necessary part; from the perspective of organizational functions, physical inventory control, warehouse management is mainly the responsibility of The broad inventory control is the demand and supply chain management, and the whole company's responsibility. Why until now many people's understanding of inventory control, limited physical inventory control? The following two reasons can not be ignored: First, our enterprises do not attach importance to inventory control. Especially those who benefit relatively good business, as long as there is money on the few people to consider the problem of inventory turnover. Inventory control is simply interpreted as warehouse management, unless the time to spend money, it may have been to see the inventory problem, and see the results are often very simple procurement to buy more, or did not do warehouse departments . Second, ERP misleading. Invoicing software is simple audacity to call it ERP, companies on their so-called ERP can reduce the number of inventory, inventory control, seems to rely on their small software can get. Even as SAP, BAAN ERP world, the field of

PLC外文文献翻译

Programmable logic controller A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or lighting fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. 1.History The PLC was invented in response to the needs of the American automotive manufacturing industry. Programmable logic controllers were initially adopted by the automotive industry where software revision replaced the re-wiring of hard-wired control panels when production models changed. Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using hundreds or thousands of relays, cam timers, and drum sequencers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire each and every relay. In 1968 GM Hydramatic (the automatic transmission division of General Motors) issued a request for proposal for an electronic replacement for hard-wired relay systems. The winning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, designated the 084 because it was Bedford Associates' eighty-fourth project, was the result. Bedford Associates started a new company dedicated to developing, manufacturing, selling, and servicing this new product: Modicon, which stood for MOdular DIgital CONtroller. One of the people who worked on that project was Dick Morley, who is considered to be the "father" of the PLC. The Modicon brand was sold in 1977 to Gould Electronics, and later acquired by German Company AEG and then by French Schneider Electric, the current owner. One of the very first 084 models built is now on display at Modicon's headquarters in North Andover, Massachusetts. It was presented to Modicon by GM, when the unit was retired after nearly twenty years of uninterrupted service. Modicon used the 84

计算机网络-外文文献-外文翻译-英文文献-新技术的计算机网络

New technique of the computer network Abstract The 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the people's work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application. keywords Internet Network System Digital Certificates Grid Storage 1. Foreword Internet turns 36, still a work in progress Thirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress. University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce Spam (junk mail) and security troubles. All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today. Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Klein rock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other "nodes" joined the fledgling network.

毕业设计英文翻译

使用高级分析法的钢框架创新设计 1.导言 在美国,钢结构设计方法包括允许应力设计法(ASD),塑性设计法(PD)和荷载阻力系数设计法(LRFD)。在允许应力设计中,应力计算基于一阶弹性分析,而几何非线性影响则隐含在细部设计方程中。在塑性设计中,结构分析中使用的是一阶塑性铰分析。塑性设计使整个结构体系的弹性力重新分配。尽管几何非线性和逐步高产效应并不在塑性设计之中,但它们近似细部设计方程。在荷载和阻力系数设计中,含放大系数的一阶弹性分析或单纯的二阶弹性分析被用于几何非线性分析,而梁柱的极限强度隐藏在互动设计方程。所有三个设计方法需要独立进行检查,包括系数K计算。在下面,对荷载抗力系数设计法的特点进行了简要介绍。 结构系统内的内力及稳定性和它的构件是相关的,但目前美国钢结构协会(AISC)的荷载抗力系数规范把这种分开来处理的。在目前的实际应用中,结构体系和它构件的相互影响反映在有效长度这一因素上。这一点在社会科学研究技术备忘录第五录摘录中有描述。 尽管结构最大内力和构件最大内力是相互依存的(但不一定共存),应当承认,严格考虑这种相互依存关系,很多结构是不实际的。与此同时,众所周知当遇到复杂框架设计中试图在柱设计时自动弥补整个结构的不稳定(例如通过调整柱的有效长度)是很困难的。因此,社会科学研究委员会建议在实际设计中,这两方面应单独考虑单独构件的稳定性和结构的基础及结构整体稳定性。图28.1就是这种方法的间接分析和设计方法。

在目前的美国钢结构协会荷载抗力系数规范中,分析结构体系的方法是一阶弹性分析或二阶弹性分析。在使用一阶弹性分析时,考虑到二阶效果,一阶力矩都是由B1,B2系数放大。在规范中,所有细部都是从结构体系中独立出来,他们通过细部内力曲线和规范给出的那些隐含二阶效应,非弹性,残余应力和挠度的相互作用设计的。理论解答和实验性数据的拟合曲线得到了柱曲线和梁曲线,同时Kanchanalai发现的所谓“精确”塑性区解决方案的拟合曲线确定了梁柱相互作用方程。 为了证明单个细部内力对整个结构体系的影响,使用了有效长度系数,如图28.2所示。有效长度方法为框架结构提供了一个良好的设计。然而,有效长度方法的

外文文献及翻译

文献翻译 原文 Combining JSP and Servlets The technology of JSP and Servlet is the most important technology which use Java technology to exploit request of server, and it is also the standard which exploit business application .Java developers prefer to use it for a variety of reasons, one of which is already familiar with the Java language for the development of this technology are easy to learn Java to the other is "a preparation, run everywhere" to bring the concept of Web applications, To achieve a "one-prepared everywhere realized." And more importantly, if followed some of the principles of good design, it can be said of separating and content to create high-quality, reusable, easy to maintain and modify the application. For example, if the document in HTML embedded Java code too much (script), will lead the developed application is extremely complex, difficult to read, it is not easy reuse, but also for future maintenance and modification will also cause difficulties. In fact, CSDN the JSP / Servlet forum, can often see some questions, the code is very long, can logic is not very clear, a large number of HTML and Java code mixed together. This is the random development of the defects. Early dynamic pages mainly CGI (Common Gateway Interface, public Gateway Interface) technology, you can use different languages of the CGI programs, such as VB, C / C + + or Delphi, and so on. Though the technology of CGI is developed and powerful, because of difficulties in programming, and low efficiency, modify complex shortcomings, it is gradually being replaced by the trend. Of all the new technology, JSP / Servlet with more efficient and easy to program, more powerful, more secure and has a good portability, they have been many people believe that the future is the most dynamic site of the future development of technology. Similar to CGI, Servlet support request / response model. When a customer submit a request to the server, the server presented the request Servlet, Servlet responsible for handling requests and generate a response, and then gave the server, and then from the server sent to

变电站_外文翻译_外文文献_英文文献_变电站的综合概述

英文翻译 A comprehensive overview of substations Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of power’s transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life. Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the country's economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability,

毕业设计_英语专业论文外文翻译

1. Introduction America is one of the countries that speak English. Because of the special North American culture, developing history and the social environment, American English has formed its certain unique forms and the meaning. Then it turned into American English that has the special features of the United States. American English which sometimes also called United English or U.S English is the form of the English language that used widely in the United States .As the rapid development of American economy, and its steady position and strong power in the world, American English has become more and more widely used. As in 2005, more than two-thirds of English native speakers use various forms of American English. The philologists of the United States had divided the English of the United States into four major types: “America n creating”; “Old words given the new meaning”; “Words that eliminated by English”;“The phonetic foreign phrases and the languages that are not from the English immigrates”[1]. Compared to the other languages, American English is much simple on word spelling, usage and grammar, and it is one of the reasons that American English is so popular in the world. The thesis analyzes the differences between American English and British English. With the main part, it deals with the development of American English, its peculiarities compared to that of British English, its causes and tendency. 2. Analyses the Differences As we English learners, when we learning English in our junior or senior school, we already came across some words that have different spellings, different pronunciations or different expressions, which can be represented by following contrasted words: spellings in "color" vs. "colour"; pronunciations in "sec-re-ta-ry" vs. "sec-re-try";

英文文献及中文翻译

毕业设计说明书 英文文献及中文翻译 学院:专 2011年6月 电子与计算机科学技术软件工程

https://www.doczj.com/doc/e93493962.html, Overview https://www.doczj.com/doc/e93493962.html, is a unified Web development model that includes the services necessary for you to build enterprise-class Web applications with a minimum of https://www.doczj.com/doc/e93493962.html, is part of https://www.doczj.com/doc/e93493962.html, Framework,and when coding https://www.doczj.com/doc/e93493962.html, applications you have access to classes in https://www.doczj.com/doc/e93493962.html, Framework.You can code your applications in any language compatible with the common language runtime(CLR), including Microsoft Visual Basic and C#.These languages enable you to develop https://www.doczj.com/doc/e93493962.html, applications that benefit from the common language runtime,type safety, inheritance,and so on. If you want to try https://www.doczj.com/doc/e93493962.html,,you can install Visual Web Developer Express using the Microsoft Web Platform Installer,which is a free tool that makes it simple to download,install,and service components of the Microsoft Web Platform.These components include Visual Web Developer Express,Internet Information Services (IIS),SQL Server Express,and https://www.doczj.com/doc/e93493962.html, Framework.All of these are tools that you use to create https://www.doczj.com/doc/e93493962.html, Web applications.You can also use the Microsoft Web Platform Installer to install open-source https://www.doczj.com/doc/e93493962.html, and PHP Web applications. Visual Web Developer Visual Web Developer is a full-featured development environment for creating https://www.doczj.com/doc/e93493962.html, Web applications.Visual Web Developer provides an ideal environment in which to build Web sites and then publish them to a hosting https://www.doczj.com/doc/e93493962.html,ing the development tools in Visual Web Developer,you can develop https://www.doczj.com/doc/e93493962.html, Web pages on your own computer.Visual Web Developer includes a local Web server that provides all the features you need to test and debug https://www.doczj.com/doc/e93493962.html, Web pages,without requiring Internet Information Services(IIS)to be installed. Visual Web Developer provides an ideal environment in which to build Web sites and then publish them to a hosting https://www.doczj.com/doc/e93493962.html,ing the development tools in Visual Web Developer,you can develop https://www.doczj.com/doc/e93493962.html, Web pages on your own computer.

PLC的应用外文文献翻译、中英文翻译、外文翻译

Application of PLC PLC is one kind specially for the digital operation operation electronic installation which applies under the industry environment designs. It uses may the coding memory, uses for in its internal memory operation and so on actuating logic operation, sequence operation, time, counting and arithmetic operation instructions, and can through digital or the simulation-like input and the output, controls each type the machinery or the production process. PLC and the related auxiliary equipment should according to form a whole easy with the industrial control system, easy to expand its function the principle to design.” In the 1970s the last stage, the programmable controller entered the practical application development phase, the computer technology has introduced in comprehensively the programmable controller, causes its function to have the leap. The higher operating speed, the subminiature volume, the more reliable industry antijamming design, the simulation quantity operation, the PID function and the extremely high performance-to-price ratio has established it in the modern industry status. In the early-1980s, the programmable controller has obtained the widespread application in the advanced industrial nation. This time programmable controller develops the characteristic is large-scale, the high velocity, the high performance, the product seriation. This stage's another characteristic is in the world produces the programmable controller's country to increase day by day, the output rises day by day. This symbolizes that the programmable controller marched into the mature stage. The 20th century last stage, the programmable controller's development characteristic was even more adapts in the modern industry need. From the control scale, this time has developed the large-scale machinery and subminiature machine; From the control, was born various special function unit, used in the pressure, the temperature, the rotational speed, the displacement and so on all kinds of control situation; From product necessary ability, has produced each kind of man-machine contact surface unit, the correspondence unit, caused to apply the programmable controller's industrial control equipment necessary to be easier. At present, the programmable controller in domain and so on machine manufacture, petroleum chemical industry, metallurgy steel and iron, automobile, light industry applications obtained the considerable development.

相关主题
文本预览
相关文档 最新文档