重庆大学-过程控制-process-control-中文-翻译-第八章

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重大自动化过程控制_process_control_中文_翻译_第三节新

Process Control College of Automation Chongqing University1Dynamic ResponseOutline:轮廓⏹Brief Review of the Dynamic Response简要回顾动态响应⏹First Order Models for Processes一阶模型的过程⏹Seconds Order Model for Processes二阶模型过程⏹Models for Process with Dead-Time死区时间的过程模型⏹Higher Order Models and Approximation高阶模型和近似⏹Special Features of Lead-Lag Process滞后过程的特殊特色The First Order Model of a ProcessQ,C inC1V1Whereis time constantThe general form of the 1st order model一阶模型的一般形式Steady state gain稳态增益The Second Order Model of a ProcessWhereare time constantsThe general form of the 2st order modelQ,C inV 1C 1C 2V 22'''22121222()()indC dC C t C dtdtττττ+++=)(01222t bx y a dtdya dt y d a =++withWith an ≠ 0和零初始条件Analysis of the 1st Order ProcessStep responsetransfer functionConsider a step input, x(t) =Mu(t), and X(s) = M/sThe output isThe time domain function isAnalysis of the 1st Order Process Step response阶跃响应Property 1性质1y increases from 0 to a new steadystate M K, thus self-regulatingy增加从0到一个新的稳态MK,从而自我调节Analysis of the 1st Order Process Step responseProperty 2性质2Steady state gain K = y/M,The larger gain K, the moresensitive is the output to thechange in the input增益K越大，输出随输入变化就越敏感Analysis of the 1st Order Process Step responseProperty 3At t=τ, the output isy =0.632MKThe formula above can be used to estimate space timeτ上面的公式可以用来估计空间时间τAnalysis of the 1st Order ProcessStep responseThe time domain function is 时域功能Property 4The shorter the space time τ, the faster reaches the new steady state0.25, 0.5, 1, 2Analysis of the 1st Order ProcessImpulse response脉冲响应transfer function传递函数Consider an impulse input, x(t) =M (t), and X(s) = M 考虑一个脉冲输入The output is Inverse transform反变换The output increases instantaneously at time t = 0, and decays exponentially to zero.输出瞬间增加在时间t= 0，且呈指数衰减到零Analysis of the 1st Order ProcessIntegrating process: Non-self-regulating 整合过程：非自我调节a= 0Laplace transformTime domain时域Analysis of the 1st Order Process⏹Integrating process: Non-self-regulating☐With step response, the output is a ramp function阶跃响应，输出的是一个斜坡函数☐With impulse response▪The output will not return to its original steady state▪输出不会回到原来的稳定状态▪Output value is the accumulation of what is added▪输出值会累积增加⏹Example can be☐Charging a capacity充电容量☐Filling up a tank 填充的水池Example: Show that a storage tank with pumps at its inlet and outletis a integrating process 表明储罐泵在其进口和出口是一个整合过程Mass balance of a continuous flow mixed tankat constant density is :质量守恒方程，在密度不变的情况下whereq in and q are the flow rates of the inlet and outlet q in and q 是进口和出口的流动速率A is the cross-section 截面h is the liquid level 液位hExample (cont.)⏹At steady state, we can define deviation variables⏹在稳定状态下,我们可以定义偏差变量h’=h – h s, q’in =q in – q s, and q’ =q – q s⏹Mass balance becomes⏹The general solution一般解Example (cont.)⏹The transfer function⏹Step input in either q’in or q’ Leading to a ramp response, thus no steady state阶跃输入q‘in 或q’，导致斜坡响应，因此，没有稳定的状态⏹The tank will overflow, while outlet slows down ⏹容器将溢出,当出口关小Setting q’in=constant, the transfer function is⏹The tank will be drained, while outlet speeds up ⏹容器内液体将流干，当流出速度增加Example (cont.): Visualize the integrating process 可视化的积分过程 pump 泵q inqq inqNon-Self-RegulatingThe tank will overflow, while step-in occursOther Typical1st Order ProcessesE= Voltage, 电压z = Position,K’= Spring constant弹性系数,f = friction coefficient摩擦系数Other Typical 1st Order Processes An Extra Example (cont.):RC i iVccV V dtdV RC -=where τ = RC is time constant K = 1 is steady state gain x(t) = V s is the input )1(/τt s c e V V --=Charging: Discharging:τ/t s c e V V -=Other Typical 1st Order ProcessesAn Extra Example (cont.):RCi iV )1(/τt s c e V V --=Charging:Discharging:τ/t s c e V V -=Analysis of the 2nd Order ProcessCorresponding Laplace Transform相应的拉普拉斯变换Where 说明：damping ratio阻尼比natural period of oscillation自然振荡周期natural frequency固有频率Analysis of the 2nd Order Process Characteristic polynomial特征多项式The poles are 极点是：Noticing again that a stable process requires再一次注意到一个稳定的过程需要ζ>τ)0(i.e.,>Three Cases of the PolesCase 1. overdamped process 过阻尼过程In term of the two time constants 依据两个时间常数Time constant can be derived below 被推倒21ττ and 1>ζ21ττ and or,In the case of having real poles, we have 在实极点的情况下，我们有Three Cases of the PolesCase 1. overdamped process 过阻尼过程How about the forms of transfer function in term of ? 传递函数有哪种形式按照/1 and /121ττ-- 1>ζStep response in term of the time constant 阶跃响应下的时间常数τResponse is sluggish compared with underdamped or critically damped processes 响应比较缓慢与欠阻尼或临界阻尼的进程相比Three Cases of the Poles三种极点ζCase 1. overdamped process过阻尼1>可视为时间常数Three Cases of the PolesCase 3. underdamped process 欠阻尼 10<≤ζStep responseBeing rearranged as被调整为The real part determines the exponential decay, thus the amount of can be considered as the time constant 决定了指数衰减，从而可视为时间常数τζ-τζTwo conjugate poles are两个共轭极点是τζτζ21-±-j based on 基于 τζ-τζKey Features of Underdamped Process 欠阻尼过程的主要特点(2) making control system design specifications with respect to the dynamic response 制作动态响应的控制系统设计规范⑴ fitting experimental data in the measurements of natural period and damping factor ,把测量自然周期和阻尼因子拟合过后的实验数据Features Derived from the figure for:图的特征Key Features of Underdamped Process1. Overshoot超调⏹The overshoot increases as ζ becomes smaller⏹The OS becomes zero as ζ approaches 1⏹The time to reach the peak value is Peak Time峰值时间T p⏹The time to hit the final value of y(t) is Rise Time上升时间 t rKey Features of Underdamped Process2. Frequency and Period周期⏹Noting that（注意）T=2 T p⏹The unit of the frequency is radian/time频率的单位是弧度/时间 The relationship between frequency and periodKey Features of Underdamped Process3. Settling time 调节时间 T s⏹The dominant factor forcing theoscillation to decay to zero is震荡衰减到0的主导因素是：)/(t e τζ-in ⏹To settle with ±5% of the final value is T s =3/(ζ/τ)⏹±5%误差带所需要的调节时间 T=⏹To settle with ±2% of the final value is T s =4/(ζ/τ)n ω1Key Features of Underdamped Process 4. Decay Ratio 衰减率OS为超调（overshoot）⏹The decay ratio is the square of the overshoot⏹Both quantities are functions of ζ only这两个量只是ζ函数（调节时间和衰减率）Other Typical 2nd Order ProcessesE= Voltage,z = Position,K’= Spring constant,f = Friction CoefficientM = Massh = forceProcesses with Dead Time过程控制的延迟时间The time delay between the input and output in a process输入与输出的时间延迟⏹Being also called dead time or transport lag传输延迟⏹The Laplace transform of a time delay is an exponentialfunction指数函数Processes with Dead Time A Simple ExampleProcesses with Dead Time⏹The 1nd and 2nd order models have the s-domain function S域函数⏹Td是延迟时间and⏹Dealing with the exponential functions处理的指数函数⏹Estimation with Taylor series expansion泰勒级数展开估计Estimation with Padé approximation (higher accuracy) Padé逼近估计（精度更高）Processes with Dead Time⏹The 1nd order Padé approximation⏹The Denominator introduces a negative pole, probably impacting thecharacteristic polynomial of the original process介绍了负极分母,可能影响特征多项式的原工艺⏹The numerator has a positive zero, making the process unstable分子有一个积极的零,使过程不稳定⏹The 2nd order Padé approximation⏹Having two negative poles and at least one zero⏹有两个负极点和至少一个零点Processes with Dead TimeExample: Using the 1nd order Padé approximation帕德近似to plot the step response of the 1st process with dead time 使用的一介帕德近似逼近延迟时间绘制的第一过程的阶跃响应Padé approximationObservation: the approximation is acceptable at larger timescompared with the original transfer function.逼近的函数和原函数相比可以接受Processes with Dead TimeExample (cont.) Generating the required plot 生成需要的图形（MATLAB ）Pad é approximationProcesses with Dead TimeThe response of the dead time processProcesses with Dead TimeTwo plants have different intermediate variables but have the same input-output behavior!两个工厂有不同的中间变量,但有相同的投入产出的行为!Processes with Dead TimeTwo plants have different intermediate variables but have the same input-output behavior!Higher Order Process⏹All linearized higher order system can be broken down into the 1st and 2nd order units所有线性化高阶系统可以分成一阶和二阶单位⏹The complex process like two interacting tanks can be formulated in coupled differential equations复杂的过程，像两个相互作用的容器能制定耦合微分方程⏹All these problems are considered linear⏹所有这些问题都能被线性化Higher Order ProcessA series of well-mixed vessels where the volumetric flow rate, and the respective volumes are constant 一系列混合容器，其中体积流速，和各自的容量是恒定的n 1n n n c c tc τ-=-d dHigher Order Process⏹A series of well-mixed vessels (cont.)混合容器☐The steady state gain is unity in the process 在过程中稳态增益不变☐The more tanks in the series, the more sluggish is the response of the overall process 容器越多，整个响应过程的滞后越长☐Processes that are products of the 1st order functions are called as multicapacity processes 多容量过程☐If all of space time （空间时间关系）are equal, nτττ=== (21)Higher Order ProcessExample: showing how the unit step response C n (t) becomes more sluggish as n increases 显示单位阶跃响应Cn(t)随著n 增加变得更加缓慢Higher Order ProcessExample (cont.) the Matlab code for the plot 绘制图形的MATLAB 代码The response is obviously slower, as n increses The curves can be approximated by the 1st order model with dead time 这些特征曲线可近似为滞后的一阶模型3=τApproximation of Higher Order Process⏹Higher models☐Being factored into the form partial functions考虑部分函数的形式☐Time constants have a large enough difference时间常数有很大的的差异⏹The reduced-order model approximation☐Throwing away the small time scale terms☐扔掉小时间关系☐Retaining the ones with dominant poles (larger time constants)☐固定主导极点(大时间常数)。

Introduction to Process Control 过程控制简介论文翻译

Unit 1 Introduction to Process ControlIn recent years the performance requirements for process plants have become increasingly difficult to satisfy. Stronger competition, tougher environmental and safety regulations and rapidly changing economic conditions have been key factors in the tightening of plant product quality specifications. A further complication is that modern processes have become more difficult to operate because of the trend toward larger, more highly integrated plants with smaller surge capacities between the various processing units. Such plants give the operators little opportunity to prevent upsets from propagating from one unit to other interconnected units. In view of the increased emphasis placed on safe. efficient plant operation, it is only natural that the subject of process control has become increasingly important in recent years. In fact, without process control it would not be possible to operate most modern processes safely and profitably, while satisfying plant quality standards.近年来，对于过程系统的执行的必要条件越来越难满足了，在紧缩的工厂产品质量规范中，强大的竞争，严峻的环境和安全规范，快速变化的经济状况，这些重要因素都是我们必须考虑的。

Control)中文译名统计过程控制系统

目录第一篇 SPC概述 (1)1．1SPC定义 (1)1．2SPC主要用途 (1)第二篇 DOSOFTSPC产品介绍 (2)2．1D OSOFT SPC产品体系 (2)2．2D OSOFT SPC产品特点 (3)2．3D OSOFT SPC功能特色 (4)2．4D OSOFT SPC功能介绍 (6)2．4．1 DosoftSPC数据采集 (6)2．4．2 DosoftSPC过程监控 (8)2．4．3 DosoftSPC质量追溯 (9)2．4．4 DosoftSPC统计分析 (10)2．4．5 DosoftSPC质量改进 (17)2．5D OSOFT SPC操作流程 (24)2．6D OSOFT SPC软件优势 (25)第三篇常见问题 (26)第一篇SPC概述1．1 SPC定义SPC（Statistical Process Control）中文译名“统计过程控制系统”，是应用于企业质量管理的至为有效的方法和工具，六西格玛的核心工具之一。

它运用数理统计的方法，对过程进行监控，对检测所得的各种质量数据进行统计分析，保证过程的稳定，提高过程能力，帮助质量管理人员有效的分析和解决质量问题，不断提升品质，有效地减少不良品的产生，从而大幅降低企业的成本，提高企业的经济效益和核心竞争力。

1．2 SPC主要用途企业质量管理三境界：●质量检验阶段：企业只进行质量的检验，不进行分析●质量分析阶段：企业采用EXCEL等简单工具，进行部分，不定期的问题分析●质量控制阶段：建立质量控制平台，进行预警，监控，分析，控制的闭环控制系统。

1、采用国际标准的质量过程控制系统，建立了从数据采集，过程监控，图形分析，过程控制的闭环控制平台——提高管理水平，加强质量意识。

2、提供了基于网络和数据库的数据分析工具，改变传统手工的简单烦琐图形绘制——提高办公效率，降低劳动强度，创造个性化工作环境。

3、建立统一分析标准，固化先进管理模式，保存完整质量数据——避免人为因素，减少员工流失带来的损失，保证系统可持续稳定运行。

Process Control Systems

Course Content
The topics that will be covered are aroduction to Process Control: Incentives and motivation for process control. 2. Mathematical Tools: Mathematical modeling of dynamic processes. Linearization of nonlinear systems. Laplace transforms.
Course Objectives
3. Use and apply modern computational techniques and tools (Matlab) for solving process control problems
4. Become familiar with industrial control systems, such as level control, flow control, pressure control, temperature control and concentration control mostly in chemical industry.
Course Textbook
• Pao C. Chau
Process Control: A First Course with MATLAB
Cambridge University Press, 1 edition, 2002
Additional References
• [1] D. E. Seborg, et. al, Process Dynamics and Control, Wiley; 2 edition, 2003 • [2] T. E. Marlin, Process Control, McGraw-Hill, 2nd edition, 2000 • [3] 邵裕森, 戴先中. 过程控制工程. 机械工业出版社, 2000 • [3] 王树青, 戴连亏, 于玲, 过程控制工程, 化学工业出版社, 2008 • [4] 何离庆, 张寿明, 朱文嘉, 过程控制系统与装置, 重庆大学出版社, 2006

Process Control过程控制

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零件冷加工 Parts cold working
折边机 Folding machine
冷加工下料资料 Cold working Cutting document 图纸 Drawing
焊前零件加工 Parts machining before welding 3.2 焊前装配Assemblg before 9 1 来料检验 Check dimension of parts 平台检验 Check platform
钻床和铣床加工 Drilling machine and Machine milling machine weld 卷尺 Tape 尺寸 Dimension
清单和图纸 Bills and drawings
检验所有来料零件 Check dimension of all parts 检验平台平整度 Check flatness of platform 1、在件7-3上敲出十字中心样冲 Stamp anvil on P7-3 2、根据装焊左右指导书装焊件7-1、件7-2、件7-3 Assemblg P7-1、P7-2andP7-3 according to G170418-01 在平台上划出安装线 Crossed on platform
备注 Remark
卷尺和激光水准仪装配 Tape and laser level Assemblg 打磨机 Grinding machine CO2 焊机 CO2 welder 外观 Appearance 焊接 Welding
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WPS和装焊作业指导书 WPS，Assemblg ＆ welding process G170418-01 焊前尺寸记录表：HL-W6L32CBF-ITP-3.2 Dimension inspection before weld： HL-W6L32CBF-ITP-3.2

重大自动化过程控制_process_control_中文_翻译_第一章

重⼤⾃动化过程控制_process_control_中⽂_翻译_第⼀章Process Control Systems过程控制系统College of Automation,Chongqing University过程控制⾃动化重庆⼤学1Outline of the IntroductionW hat Is Process Control?DefinitionA few examples and forms⼀些例⼦和形式W hat Does It Do?Differences from automatic control theory⾃动控制理论的差异?W hat to be controlled?How Does It Do?如何实现Formulating the problem制定问题Control Equipment and Process Equipment控制设备和⼯艺设备?M odeling the process of the Problem建模过程的问题Introduction to Process Control Operator’s View of Process Control操作员的观点的过程控制A Day in aLife of a PlantOperatorDefinitionThe technology ofcontrolling a series of events to transform a material into a desired end product is called process control.控制技术的⼀系列事件把资料达到所希望的最终产品,被称为过程控制Short examples:M aking of fire for cooking rice (primitive and modern)The fly-ball governor for steam engine control (1774)短的例⼦:让⽕煮⽶饭(原始的和现代)州长的fly-ball蒸汽发动机控制(1774)Tendency of industrial process controlbeing computerized,being automatized , andbeing instrumented w ith smart sensors and M EM S⼯业过程控制的趋势在计算机化,在潜意识中⾃动使⽤,被装备智能传感器和微机电系统(M EM S)A Few Examples1.Flow Control in Oil refinery Plant:Do w e run around the plant to adjust the valves w hen required?流量控制,是炼油⼚植物:我们到处跑植物调节阀门在需要的时候吗?A Few Examples2. pH ControlManual⼿册AutomatedpH controlA Few Examples:3. Room temperature controlA Few Example4. Watt Centralfugal Speed Governor ⽡特Centralfugal调速器A Few Examples5. Level Control液位控制A Few Examples6. Cross Direction ProceControl⼗字⽅向过程控制Several hundred sensors andactuators,M illisecond operation,Controlling paper thickness tow ithin microns!⼏百传感器和执⾏器,微操作,控制纸张厚度和在微⽶!A Few Examples7. Discrete M anufacturing Processes 离散型制造过程A Few Examples8. Typical continuous processes典型的连续过程A Few Examples9. Typical non-continuous processesA Few Examples10. A Semi-Continuous Process半连续过程How large shouldthe tank volume be?油箱体积是多⼤呢？Sample-Plant: M ill W ide Process Control轧机⼴泛的过程控制Sample Softw are: Honeyw ell Intellimap样品软件:霍尼韦尔IntellimapW hat Is Process Control?Summary of the Examples- Forms总结的例⼦-形式Discrete M anufacturing, M otion, and Packaging离散型制造、运动、和包装Robotic Assembly Line in Automotive Production机械的汽车⽣产流⽔线M etal Stamping for the discrete pieces of product 五⾦冲压为离散件产品Continuous Production of Fuels, Chemicals连续⽣产的燃料、化学品Room Temperature Control室温控制Nucleus Chemical Reactor核化学反应器Batch Production of intermediate/end products批量⽣产中间/终端产品Adhesives and gluesFood, Beverages, andM edicineW hat Is Process Control?Tedency: Being Compueterized, Automatized, and Instrumented by smart sensors and M EM S计算机化，⾃动化，和动态化由智能传感器和微机电系统Sensors, local indicators,and valves in the process传感器、当地的指标,和阀门在这个过程中Valve openingdetermined by thesignal from computerDisplays of variables, calculations, commands to valves andhistorical data are in the centralized control center.显⽰变量的影响,计算,命令对阀门和历史数据是在中央控制中⼼Differences from Automatic Control Theory⾃动控制理论的差异?Using Control Theory as a ToolSolving the Real-W orld Problems forM aintaining controlled variables at the desired values保持控制变量在期望值M anufacturing products w ith consistent quality w hen raw material properties change⽣产质量稳定的产品，原料性质改变时？Responding dangerous situations w ith given time危险的情况下和给定的时间响应Being Specialized by transducer作为专业的传感器Smart sensorsM EM S 微机电系统。

过程装备与控制工程专业英语翻译-完全版(课文阅读材料)综合各版精华

PART I 力学基础知识█Unit 1力系的一般平衡条件在这一节，我们将研究为了使一个物体保持平衡，作用在其上的力和力偶所必须满足的条件。

根据牛顿第一定律，施加在一个静止物体上的力系的合力一定为零。

然而，请注意这个定律对力矩或力系的转动效应只字未提。

显然，合力矩也一定为零，否则物体将会转动。

这里的基本问题是，按照先前的规定，牛顿第一定律（和第二定律）只适用于非常小的物体，或者尺寸可以忽略的非零质量的质点。

然而，它可以推广到下述有限尺寸的物体。

考虑一个由两个质点组成的系统，并假设1f 和2f 是由于它们之间相互作用产生的力(图.1.1)。

这些力称为内力，因为它们是由于系统内部的物体之间的相互作用而产生的。

假定内力服从牛顿第三定律，我们有12f f =-。

假如还有质点与系统外物体相互作用产生的力施加在质点上，如1,2F F 和3F ，这些力称为外力。

显然，作用在某个特定质点上的力一定有相同的作用点，因为质点的尺寸可以忽略。

如果系统内的每一个质点处于平衡，我们就可以说系统是平衡的。

这种情况下，依据牛顿第一定律，作用在每个质点上的力的合力一定为零。

对质点A 我们有： ∑=++=0121f F F F A而对质点B 有：∑032=+=F f F B 作用在系统上的力的总和为： 123120A B F F F F F F f f =+=++++=∑∑∑现在让我们来研究这些力对于某一点P 的合力矩。

参照图1.1，我们有：12()()P A B M r F r F =⨯+⨯∑∑∑ 其中0==∑∑B A F F ；如前所述，那么合力矩也一定为零。

由于力1f 和2f 有相同的作用线，力矩的平衡条件可以改写为：1121223()0P M r F F f f r F =⨯++++⨯=∑ 其中12f f =-；因此力和力矩的平衡条件就简化为：0321=++=∑F F F F和 111223()()()0P M r F r F r F =⨯+⨯+⨯=∑换句话说，如果系统处于平衡，那么作用在上面的外力和一定为零，并且这些外力对任一点的合力矩也一样为零。

Process Control 过程控制

Lesson 4 Process Control1 Process-Control PrinciplesProcess Control is the active changing of the process based on the results of process monitoring. In process control, the basic objective is to regular the value of some quantity. To regulate means to maintain that quantity at some desired value regardless of external influences. The desired value is called the reference value or setpoint.Figure 5.9 shows the process to be used for this discussion. Liquid is flowing into a tank at some rate Qin and out of the tank at some rate Qout. The liquid in the tank has some height or level h. It is known that the flow rate out varies as the square root of the height, so the higher the level the faster the liquid flows out. If the output flow rate is not exactly equal to the input flow rate, the tank will either empty, if Qin > Qout, or overflow, if Qout < Qin.This process has a property called self-regulation. This means that for some input flow rate, the liquid height will rise until it reaches a height for which the output flow rate matches the input flow rate. A self-regulating system does nit provide regulation of a variable to any particular reference value. In this example the liquid level will adopt some value foe which input and output flow rates are the same and there it will stay. If the input flow rate changed, then the level would change also, so it is not regulated to a reference value.Suppose we want to maintain the level at some particular value H in Figure 5.9, regardless of the input flow rate, then something more than self-regulation is needed.Human-Aided ControlHuman-aided control shows a modification of the tank system to allow artificial regulation of the level by a human. To regulate the level so that in maintains the value H it will be necessary to employ a sensor to measure the level. This has been provided via a sight tube. The actual liquid level or height is called the controlled variable. In addition, a value has been added so the output flow rate can be changed by the human. The output flow rate is called the manipulated variable or controlling variable.Now the height can be regulated apart from the input flow rate using the following strategy: The person measures the height in the sight tube and compares the value to the setpoint. If the measured value is larger, the human opens the value a little to let the flow out increase, and thus the level lowers toward the setpoint. If the measured value is smaller than the setpoint, the person closes the value a little to decrease the flow out and allow the level to rise toward the setpoint.By a succession of incremental opening and closing of the value, the human can bring the level to the setpoint value H and maintain it there by continuous monitoring of the sight tube and adjustment of the value.Automatic ControlTo provide automatic control, the system is modified using machines, electronics, or computers to replace the operations of the human. An instrument called a sensor is added that is able to measure the value of the level and convert it into a proportional signal. The signal is provided as input to a machine, an electronic circuit, or a computer, called the controller. This performs the function of the human in evaluating the measurement and providing an output signal to change the value setting via an actuator connected to the valve by a mechanical linkage.2 Identification of ElementsThe elements of a process-control system are defined in terms of separate functional parts of the system.ProcessIn general, a process can consist of a complex assembly of phenomena that relate to some manufacturing sequence. Many variables may be involved in such a process, and it may be desirable to control all these variables at the same time. There are single-variable process, in which only one variable is to be controlled, as well as multivariable processes, in which many variables, perhaps interrelated, may require regulation.MeasurementClearly, to effect control of a variable in a process, we must have information on the variable itself. Such information is found by measuring the variable. In general, a measurement refers to the conversion of the variable into some corresponding analog of the variable, such as a pneumatic pressure, an electrical voltage, or a current. A sensor is a device that performs the initial measurement and energy conversion of a variable into analogous electrical or pneumatic information. Further transformation or signal conditioning may be required to complete the measurement function. The result of the measurement is a representation of the value in some forms required by the other elements in the process-control operation.ControllerThe next step in the process-control sequence is to examine the error and determine what action, if any, should be taken. This part of the control system has many names; however, controller is the most common. The evaluation may be performed by an operator, by electronic signal processing, by pneumatic signal processing, or by a computer. The controller requires an input of both a measured indication of the controlled variable and a representation of the reference value of the variable, expressed in the same terms as the measured value.Control ElementThe final element in the process-control operation is the device that exerts a direct influence on the process; that is, it provides those required changes in the controlled variable to bring it to the setpoint. This element accepts an input from the controller, which is then transformed into some proportional operation performed on the process.3 Process-Control Block DiagramTo provide a practical, working description of process control, it is useful to describe the elements and operations involved in more generic terms. Such a description should be independent of a particular application and thus be applicable to all control situations. A model may be constructed using blocks to represent each distinctive element. The characteristics of control operation then may be developed from a consideration of the properties and interfacing of these elements. Figure 5.10 shows a general block diagram. The controlled variable in the process is denoted by e in this diagram, and the measured representation of the controlled variable is labeled b. The controlled variable setpoint is labeled r, for reference.The error detector is a subtracting-summing point that outputs an error signal e=r-b to the controller for comparison and action.The purpose of a block diagram approach is to allow the process-control system to be analyzed as the interaction of smaller and simpler subsystems. If the characteristics of each element of the system can be determined, then the characteristics of the assembled system can be established by an analytical marriage of these subsystems. The historical development of the system approach in technology is dictated by this practical aspect: first, to specify the characteristics desired of a total system and, then, to delegate the development of subsystems thatprovide the overall criteria..4 Control System EvaluationA process-control systems is used to regulate the value of some process variable. When such a system is in use, it is natural to ask, “How well is it working?” This is not an easy question to answer, because it is possible to adjust a control system to provide different kinds of response to errors. This section discusses some methods for evaluating how well the system is working.The variable used to measure the performance of the control system is the error, which is the difference between the constant setpoint or reference value r and the controlled variable c(t).Since the value of the controlled variable may vary in time, so may the error.In principle, the objective of a control system is to make the error exactly zero, but the control system responds only to errors. Conversely, if the error were zero and stayed zero, the control system would be doing nothing and would not be needed in the first place. Therefore, this objective can never be perfectly achieved, and there will always be some errors. The question of evaluation becomes one of how large the error is and how it varies in time.The purpose of the control system is to regulate the value of some variables. This requires that action be taken on the purpose itself in response to a measurement of the variable. If this is not done correctly, the control system can cause the process to become unstable. In fact, the more tightly we try to control the variable, the greater the possibility of an instability.The first objective, then, simply means that the control system must be designed and adjusted so the system is stable. Typically, as the control system is adjusted to give better control, the likelihood of instability also increases.。

processcontrol

Y(t)
1/Ti
ω
TI减小
t
§2-4 比例微分调节
工程上一般都是将比例和微分作用组合成比例-微分调节器，其输入输出关系为：微分部分输出与偏差的变化速度成正比，
de u K c (e TD ) u0 dt
即偏差变化大则输出增大。TD等于零时，微分作用消除，调节器变为比例调节。
由于微分作用的特点，使其对惯性较大的被控对象有“超前”调整作用，故一般用于有较大滞后被控对象的场合。微分时间常数调整得当，可使过渡过程缩短，增加系统稳定性，减少动态偏差。如果微分作用过大，系统将变得非常敏感，控制系统的控制质量将变差，甚至变成不稳定。实际调整TD的结果应使系统的闭环零点靠近系统的第二大极点，从而抵消第二大极点对系统过渡过程
其中 u2(t) = – u1(t – ∆t)
y(t) = y1(t) + y2(t) = y1(t) – y1(t – ∆t)
所需的阶跃响应即为
u
0
t
U1(t)
y1(t) = y(t) + y1(t – ∆t)
利用此结果递推作图得到阶跃响应如图示。 b.由阶跃响应确定近似传递函数的方法
y
t0
C B A
t
●对系统稳定性的影响：比例度越大，调节器输出变化小，被控变量变化缓慢，过渡过程平稳。随着比例度的减小，系统的稳定程度降低，其过渡过程逐渐从衰减振荡走向临界振荡直至发散振荡。
比例调节 ----- 是最基本、最主要、应用最普遍的控制规律（简单、快速、经济），通常
适用于干扰少、扰动幅度小、负荷变化不大、滞后较小或控制精度要求不高的场合。
O
C
冷凝水 0 μa μ1 μ0 μc 100

过程系统控制第00章-绪论

2024年7月19日星期五
Process System Engineering Principle
返回12
课程教学内容及要求
教学内容
第一章流体流动
第二章流体输送设备
第三章传热
第四章传热设备
第五章吸收
第六章蒸馏
第七章气液传质设备
第八章其它传递过程
2024年7月19日星期五
Process System Engineering Principle
显然，化工生产过程的核心是化学反应过程及其设备——反应器。其次是原料和产品的前处理、后处理过程（一般是物理过程）。
2024年7月19日星期五
Process System Engineering Principle
6
过程系统概念
工业生产过程的要求工业生产过程的基本要求：（1）安全生产。（2）单位产品的原材料和能源消耗尽量少。（3）副产品，特别是废物最好不要产生，防止对环境的污染。（4）生产设备的利用率要高。如何做到这一点？工程上是通过工业过程控制系统来操作和控制实际的工业生产过程。
式中：∑Qi—随物料进入系统的总热量，kJ或kW； ∑Qo—随物料离开系统的总热量，kJ或kW； QL—向系统周围散失的热量，kJ或kW。
2024年7月19日星期五
Process System Engineering Principle
17
课程教学内容及要求
教学要求
1、教学观点与重心：方法为主，知识为辅。古人云：“授人以鱼，不如授人以渔”，说的是传授给人既有的知识，不如传授给人学习知识的方法。道理其实很简单，鱼是目的，钓鱼是手段，一条鱼能解一时之饥，却不能解长久之饥，如果想永远有鱼吃，那就要学会钓鱼的方法。联合国教科文组织曾谈到：今后的文盲将不再是不识字的人，而是不会自学和学了知识不会应用的人。进一步说明，“授人以鱼，不如授人以渔；授人以渔，不如授人以欲。” 教育的最高的境界应当是超越方法论，应当是‚授人以欲。激发学生上进的欲望，让学生通过学习树立起自己的人生目标。

重庆大学过程控制 process control 中文翻译第五章 (2)

GL for the load (disturbance扰动)
Gc
for the controller
Gm for the measuring device（测量仪器）, with the steady state gain Km
Ga for the actuator（执行器） Reminder:
Introducing Km on R for summing up（总结） with the same units
Kd and Kp are steady state gains
4
Analysis of Single Loop Systems
Closed-Loop Transfer Functions
A
general SISO system
Temperature T is based on 1. inlet Ti, and 2. jacket temperature TH 套管温度TH
examples Choice of controllers
2
Analysis of Single Loop Systems
Closed-Loop Transfer Functions
A
general SISO system:
stirred-tank heater revisited 再来观察搅拌加热器模型 The heat balance is represented as 热平衡方程
Reminder: we are working with deviation variables（偏差变量）
12
Analysis of Single Loop Systems
Considerations of Choosing Variables

【测控专业英语】Process Control System过程控制系统解析

17
3 Controller
5 – The derivative mode (D) produces a control action
that is proportional to the rate at which the error is changing.
– 微分模式产生一个正比于偏差变化率的控制动作。
3
Main content
1
Process
Measuring Transmitter Controller Manipulating Element
2
3 4 5
Process Control
4
1 Process
– The process block in Fig. 7.1 represents everything performed in and by the equipment in which a variable is controlled. – The process includes everything that affects the controlled or process variable except the controller and the final control element.
16
3 Controller
4 – In fact, the rate that the correction increases is
proportional to the error signal. – 事实上，修正的速度是正比于偏差信号的。 – Mathematically, the integral control action is accomplished by forming the integral of the error signal. – 数学上，积分控制动作即是对偏差信号求取积分。

重庆大学-过程控制-process-control-中文-翻译-第十章(1)

S-loop control solution单环开环控制
1. measure T by TT, 2. compute p by TC,
TT TC
Tsp
3. send the p to the valve
4
Multiloop Systems
Cascade Control
Motivation of动机 Cascade Control
Problem (e): determine Kc of PI controller that guarantees system stable when I=0.5 without cascade
Solution: ➢system is a single-loop system when no cascade ➢characteristic equation of its closed-loop equation is
8
Multiloop Systems
Cascade Control
Cascade Control Solution Reducing the block diagram方块图
Setting Gm1=Gm2=1
where
9
Multiloop Systems
Cascade Control
Reducing the block diagram
FC in slave loop adjusts the regulating valve调节阀
▪ FC compares the desired and measured fuel gas flow rates
▪ responding immediately to fluctuations in the fuel gas flow 立即对波动的燃气速率做出反应

重庆大学-过程控制-process-control-中文-翻译-第一章

微操作,控制纸张厚度和在微米!
What Is Process Control?
A Few Examples
7. Discrete Manufacturing Processes 离散型制造过程
What Is Process Control?
A Few Examples
8. Typical continuous processes典型的连续过程
What Does It Do?
Differences from automatic control theory自动控制理论的差异 What to be controlled?
How Does It Do?如何实现
Formulating the problem制定问题 Control Equipment and Process Equipment控制设备和工艺设备 Modeling the process of the Problem建模过程的问题
4. Watt Centralfugal Speed Governor 瓦特Centralfugal调速器
What Is Process Control?
A Few Examples
5. Level Control液位控制
What Is Process Control?
A Few Examples
Process Control Systems 过程控制系统
College of Automation, Chongqing University
过程控制自动化重庆大学
Outline of the Introduction
What Is Process Control?
Definition A few examples and forms一些例子和形式

重庆大学-过程控制-process-control-中文-翻译-第一章

end product is called process control.控制技术的一系列事件把资料达到所希
望的最终产品,被称为过程控制
Short examples:
Making of fire for cooking rice (primitive and modern)The fly-ball governor for steam engine control (1774)短的例子:让火煮米饭(原始的和现代)州长的fly-ball蒸汽发动机控制(1774) Tendency of industrial process control
6. Cross Direction ProceControl十字方向过程控制
•Several hundred sensors and actuators,
•Millisecond operation, •Controlling paper thickness to
within microns!几百传感器和执行器,
16
What Is Process Control?
Summary of the Examples- Forms总结的例子-形式
Discrete Manufacturing, Motion, and Packaging离散型制造、运动、和包装
Robotic Assembly Line in Automotive Production机械的汽车生产流水线 Metal Stamping for the discrete pieces of product 五金冲压为离散件产品
Displays of variables, calculations, commands to valves and

重庆大学-过程控制-process-control-中文-翻译-第八章

重大自动化过程控制_process_control_中文_翻译_第三节新

Introduction to Process Control 过程控制简介论文翻译

Control)中文译名统计过程控制系统

Process Control Systems

Process Control过程控制

重大自动化过程控制_process_control_中文_翻译_第一章

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Process Control 过程控制

processcontrol

过程系统控制第00章-绪论

重庆大学 过程控制 process control 中文 翻译 第五章 (2)

【测控专业英语】Process Control System过程控制系统解析

重庆大学-过程控制-process-control-中文-翻译-第十章(1)

重庆大学-过程控制-process-control-中文-翻译-第一章

重庆大学-过程控制-process-control-中文-翻译-第一章

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重庆大学过程控制 process control 中文翻译第五章 (2)