PID词汇英汉互译

PID控制工程控制和数学物理方面PID（比例积分微分）英文全称为Proportion Integration Differentiation，它是一个数学物理术语。

PID由8位端口优先级加端口号组成，端口号占低位，默认端口号优先级128。

1自动化工业自动化水平已成为衡量各行各业现代化水平的一个重要标志。

同时，控制理论的发展也经历了古典控制理论、现代控制理论和智能控制理论三个阶段。

智能控制的典型实例是模糊全自动洗衣机等。

自动控制系统可分为开环控制系统和闭环控制系统。

一个控制系统包括控制器、传感器、变送器、执行机构、输入输出接口。

控制器的输出经过输出接口、执行机构，加到被控系统上；控制系统的被控量，经过传感器，变送器，通过输入接口送到控制器。

不同的控制系统，其传感器、变送器、执行机构是不一样的。

比如压力控制系统要采用压力传感器。

电加热控制系统的传感器是温度传感器。

PID控制及其控制器或智能PID控制器（仪表）已经很多，产品已在工程实际中得到了广泛的应用，有各种各样的PID控制器产品，各大公司均开发了具有PID参数自整定功能的智能调节器(intelligent regulator），其中PID控制器参数的自动调整是通过智能化调整或自校正、自适应算法来实现。

有利用PID控制实现的压力、温度、流量、液位控制器，能实现PID控制功能的可编程控制器(PLC），还有可实现PID控制的PC系统等等。

可编程控制器（PLC) 是利用其闭环控制模块来实现PID控制，而可编程控制器（PLC）可以直接与ControlNet 相连，如Rockwell的PLC-5等。

还有可以实现PID控制功能的控制器，如Rockwell 的Logix产品系列，它可以直接与ControlNet相连，利用网络来实现其远程控制功能。

开环控制开环控制系统（open-loop control system）是指被控对象的输出（被控制量）对控制器（controller)的输出没有影响。

PID controllerA proportional–integral–derivative controller (PID controller) is a generic .control loop feedback mechanism widely used in industrial control systems. A PID controller attempts to correct the error between a measured process variable and a desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly.The PID controller calculation (algorithm) involves three separate parameters; the Proportional, the Integral and Derivative values. The Proportional value determines the reaction to the current error, the Integral determines the reaction based on the sum of recent errors and the Derivative determines the reaction to the rate at which the error has been changing. The weightedsum of these three actions is used to adjust the process via a control element such as the position of a control valve or the power supply of a heating element. By "tuning" the three constants in the PID controller algorithm the PID can provide control action designed for specific process requirements. The response of the controller can be described in terms of the responsiveness of the controller to an error, the degree to which the controller overshoots the setpoint and the degree of system oscillation. Some applications may require using only one or two modes to provide the appropriate system control. This is achieved by setting the gain of undesired control outputs to zero. A PID controller will be called a PI, PD, P or I controller in the absence of the respective control actions. PI controllers are particularly common, since derivative action is very sensitive to measurement noise, and the absence of an integral value may prevent the system from reaching its target value due to the control action.The PID control scheme is named after its three correcting terms, whose sum constitutes the manipulated variable (MV). Hence:where Pout, Iout, and Dout are the contributions to the output from the PID controller from each of the three terms, as defined below.1. Proportional termThe proportional term makes a change to the output that is proportional to the current error value. The proportional response can be adjusted by multiplying the error by a constant Kp, called the proportional gain.The proportional term is given by:WherePout: Proportional outputKp: Proportional Gain, a tuning parametere: Error = SP − PVt: Time or instantaneous time (the present)A high proportional gain results in a large change in the output for a given change in the error. If the proportional gain is too high, the system can become unstable (See the section on Loop Tuning). In contrast, a small gain results in a small output response to a large input error, and a less responsive (or sensitive) controller. If the proportional gain is too low, the control action may be too small when responding to system disturbances.In the absence of disturbances, pure proportional control will not settle at its target value, but will retain a steady state error that is a function of the proportional gain and the process gain. Despite the steady-state offset, both tuning theory and industrial practice indicate that it is the proportional term that should contribute the bulk of the output change.2.Integral termThe contribution from the integral term is proportional to both the magnitude of the error and the duration of the error. Summing the instantaneous error over time (integrating the error) gives the accumulated offset that should have been corrected previously. The accumulated error is then multiplied by the integral gain and added to the controller output. The magnitude of the contribution of the integral term to the overall control action is determined by the integral gain, Ki.The integral term is given by:Iout: Integral outputKi: Integral Gain, a tuning parametere: Error = SP − PVτ: Time in the past contributing to the integral responseThe integral term (when added to the proportional term) accelerates the movement of the process towards setpoint and eliminates the residual steady-state error that occurs with a proportional only controller. However, since the integral term is responding to accumulated errors from the past, it can cause the present value to overshoot the setpoint value (cross over the setpoint and then create a deviation in the other direction). For further notes regarding integral gain tuning and controller stability, see the section on loop tuning.3 Derivative termThe rate of change of the process error is calculated by determining the slope of the error over time (i.e. its first derivative with respect to time) and multiplying this rate of change by the derivative gain Kd. The magnitude of the contribution of the derivative term to the overall control action is termed the derivative gain, Kd.The derivative term is given by:Dout: Derivative outputKd: Derivative Gain, a tuning parametere: Error = SP − PVt: Time or instantaneous time (the present)The derivative term slows the rate of change of the controller output and this effect is most noticeable close to the controller setpoint. Hence, derivative control is used to reduce the magnitude of the overshoot produced by the integral component and improve the combined controller-process stability. However, differentiation of a signal amplifies noise and thus this term in the controller is highly sensitive to noise in the error term, and can cause a process to become unstable if the noise and the derivative gain are sufficiently large.4 SummaryThe output from the three terms, the proportional, the integral and the derivative terms are summed to calculate the output of the PID controller. Defining u(t) as the controller output, the final form of the PID algorithm is:and the tuning parameters areKp: Proportional Gain - Larger Kp typically means faster response since thelarger the error, the larger the Proportional term compensation. An excessively large proportional gain will lead to process instability and oscillation.Ki: Integral Gain - Larger Ki implies steady state errors are eliminated quicker. The trade-off is larger overshoot: any negative error integrated during transient response must be integrated away by positive error before we reach steady state.Kd: Derivative Gain - Larger Kd decreases overshoot, but slows down transient response and may lead to instability due to signal noise amplification in the differentiation of the error.PID控制器比例积分微分控制器（PID调节器）是一个控制环，广泛地应用于工业控制系统里的反馈机制。

外文资料与翻译PID Contro lIntroductionThe PID controller is the most common form of feedback. It was an essential element of early governors and it became the standard tool when process control emerged in the 1940s. In process control today, more than 95% of the control loops are of PID type, most loops are actually PI control. PID controllers are today found in all areas where control is used. The controllers come in many different forms. There are standalone systems in boxes for one or a few loops, which are manufactured by the hundred thousands yearly. PID control is an important ingredient of a distributed control system. The controllers are also embedded in many special purpose control systems. PID control is often combined with logic, sequential functions, selectors, and simple function blocks to build the complicated automation systems used for energy production, transportation, and manufacturing. Many sophisticated control strategies, such as model predictive control, are also organized hierarchically. PID control is used at the lowest level; the multivariable controller gives the set points to the controllers at the lower level. The PID controller can thus be said to be the “bread and butter of control engineering. It is an important component in every co ntrol engineer’s tool box.PID controllers have survived many changes in technology, from mechanics and pneumatics to microprocessors via electronic tubes, transistors, integrated circuits. The microprocessor has had a dramatic influence the PID controller. Practically all PID controllers made today are based on microprocessors. This has given opportunities to provide additional features like automatic tuning, gain scheduling, and continuous adaptation.6.2 The AlgorithmWe will start by summarizing the key features of the PID controller. The “textbook” version of the PID algorithm is described by:()()()()⎪⎪⎭⎫ ⎝⎛++=⎰dt t de d e t e K t u T T d t i 01ττ 6.1 where y is the measured process variable, r the reference variable, u is the control signal and e is the control error （e =sp y − y ）. The reference variable is often calledthe set point. The control signal is thus a sum of three terms: the P-term （which is proportional to the error）, the I-term （which is proportional to the integral of the error）, and the D-term （which is proportional to the derivative of the error）. The controller parameters are proportional gain K, integral time T i, and derivative time T d. The integral, proportional and derivative part can be interpreted as control actions based on the past, the present and the future as is illustrated in Figure 2.2. The derivative part can also be interpreted as prediction by linear extrapolation as is illustrated in Figure 2.2. The action of the different terms can be illustrated by the following figures which show the response to step changes in the reference value in a typical case.Effects of Proportional, Integral and Derivative ActionProportional control is illustrated in Figure 6.1. The controller is given by D6.1E with T i= and T d=0. The figure shows that there is always a steady state error in proportional control. The error will decrease with increasing gain, but the tendency towards oscillation will also increase.Figure 6.2 illustrates the effects of adding integral. It follows from D6.1E that the strength of integral action increases with decreasing integral time T i. The figure shows that the steady state error disappears when integral action is used. Compare with the discussion of the “magic of integral action” in Sec tion 2.2. The tendency for oscillation also increases with decreasing T i. The properties of derivative action are illustrated in Figure 6.3.Figure 6.3 illustrates the effects of adding derivative action. The parameters K and T i are chosen so that the closed loop system is oscillatory. Damping increases with increasing derivative time, but decreases again when derivative time becomes too large. Recall that derivative action can be interpreted as providing prediction by linear extrapolation over the time T d. Using this interpretation it is easy to understand that derivative action does not help if the prediction time T d is too large. In Figure 6.3 the period of oscillation is about 6 s for the system without derivative Chapter 6. PID ControlFigure 6.1Figure 6.2Derivative actions cease to be effective when T d is larger than a 1 s (one sixth of the period). Also notice that the period of oscillation increases when derivative time is increased.A PerspectiveThere is much more to PID than is revealed by （6.1）. A faithful implementation of the equation will actually not result in a good controller. To obtain a good PID controller it is also necessary to consider。

PID（比例积分微分）介绍转自：by夏沫 Arachnid一、PID（比例积分微分）介绍PID（比例积分微分）英文全称为Proportion Integration Differentiation，它是一个数学物理术语。

PID是以它的三种纠正算法而命名。

受控变数是三种算法（比例、积分、微分）相加后的结果，即为其输出，其输入为误差值（设定值减去测量值后的结果）或是由误差值衍生的信号。

若定义u（t）为控制输出，PID算法可以用下式表示：其中•Kp ：比例增益，是调适参数•Ki ：积分增益，也是调适参数•Kd ：微分增益，也是调适参数•e ：误差=设定值（SP）- 回授值（PV）•t ：目前时间•τ：积分变数，数值从0到目前时间 t目前工业自动化水平已成为衡量各行各业现代化水平的一个重要标志。

同时，控制理论的发展也经历了古典控制理论、现代控制理论和智能控制理论三个阶段。

智能控制的典型实例是模糊全自动洗衣机等。

自动控制系统可分为开环控制系统和闭环控制系统。

一个控制系统包括控制器、传感器、变送器、执行机构、输入输出接口。

控制器的输出经过输出接口、执行机构，加到被控系统上；控制系统的被控量，经过传感器，变送器，通过输入接口送到控制器。

不同的控制系统，其传感器、变送器、执行机构是不一样的。

比如压力控制系统要采用压力传感器。

电加热控制系统的传感器是温度传感器。

目前，PID 控制及其控制器或智能PID控制器（仪表）已经很多，产品已在工程实际中得到了广泛的应用，有各种各样的PID控制器产品，各大公司均开发了具有PID参数自整定功能的智能调节器(intelligentregulator)，其中PID控制器参数的自动调整是通过智能化调整或自校正、自适应算法来实现。

有利用PID控制实现的压力、温度、流量、液位控制器，能实现PID控制功能的可编程控制器(PLC)，还有可实现PID控制的PC系统等等。

可编程控制器(PLC) 是利用其闭环控制模块来实现PID控制，而可编程控制器(PLC)可以直接与ControlNet相连，如Rockwell的PLC-5等。

英语资料及译文About PID controlRecently automation technology is based on the concept of feedback. Elements of feedback theory consist of three parts: measurement, comparison and implementation. Measurement variables of concern, compared with expectations, with the control system to correct the error response.The theory and application of automatic control, the key is to make the correct measurement and comparison of how best to rectify the system.PID (proportional - integral - differential) controller as the first practical use of the controller more than 50 years of history, is still the most widely used industrial controller. Simple PID controller, the use of the system does not accurately model a prerequisite that they have become the most widely used controller.PID controller is the proportion of cells (P), integral unit (I) and the differential unit (D) component.Because of its wide range of uses, the use of flexible, has been serialized products, the use of only three parameters setting (Kp, Ti and Td) can be. In many cases, does not necessarily need all three modules, which can take 1-2 unit, but the proportion of the control unit is essential.First of all, PID broad range of applications. Although many industrial processes or time-varying non-linear, but can be simplified through their basic non-linear and dynamic characteristics of the system over time, so that you can control the PID.Secondly, PID parameter can tune easier. That is, PID parameters Kp, Ti and Td can be based on the dynamic characteristics of the process of setting a timely manner. If the dynamic characteristics of the process ofchange, for example, changes may be caused by the load dynamic characteristics of the system changes, PID parameters can be re-tuning.Third, PID controller in practice is to be improved continuously, the following are two examples of improvements.In factories, we always see a lot of loops are in manual, and because of the difficulty of the course so that the "automatic" mode, a smooth working. As a result of these deficiencies, the use of the industrial control system PID is always subject to product quality, safety, waste production and energy problems. PID parameter self-tuning PID parameters in order to deal with this problem setting generated. Now, the auto-tuning or self-tuning of PID controller is a business single-loop controllers and distributed control system of a standard.In some cases the system-specific design of PID controller to control very well, but they are there are still some problems to be solved: If self-tuning should be based on the model, in order to re-PID tuning parameters online to find and maintain a good process model is more difficult. When closed-loop works, the requirements in the process of inserting must have a test signal. This method will cause disturbance, so model-based PID parameter self-tuning is not too good in the industrial applications.If self-tuning control law based on the often difficult to load disturbance caused by the impact and dynamic characteristics of the process of the impact of changes in the distinction between the effects of so disturbed overshoot controller will have to create a self-adaptive unnecessary conversion. In addition, since the control law based on the maturity of the system is not the stability of analytical methods, the reliability of parameter tuning, there are many problems.Therefore, many self-tuning PID controller parameters work in the auto-tuning mode and not in the self-tuning mode. Auto-tuning is oftenused to describe the state of open-loop based on a simple process model to determine automatic calculation of PID parameters.PID in controlling nonlinear, time-varying, coupling and parameter uncertainty and structural complexity of the process, the work is not very good. The most important thing is, if the PID controller can not control the complexity of the process, regardless of how not to use transfer parameters.Despite these shortcomings, PID controller is sometimes the most simple is the best controller.At present, the level of industrial automation has become a measure of the level of modernization in all walks of life an important sign. At the same time, the development of control theory has also experienced a classical control theory, modern control theory and intelligent control theory of three stages. Classic example of intelligent control is ambiguous, such as full-automatic washing machine. Automatic control system can be divided into open-loop control systems and closed-loop control system.A control system, including controllers, sensors, transmitters, implementing agencies, input and output interfaces. Controller's output after the output interface, the implementing agencies, added to the system was charged with; control system charged with the amount, after the sensor, transmitter, through the input interface to the controller. Different control system, the sensor, transmitter, the executing agency is not the same. For example pressure sensors need to be used in pressure control system. Electric heating control system is the sensor temperature sensor. At present, PID control and PID controller or a smart controller (instrument) has a lot of products have been in practice in engineering is widely used, there are a wide range of PID controller products, major companies have developed with PID parameter self-tuning regulator function smart (intelligent regulator), which the PID controller parameters are automatically adjusted through the intelligent or self-tuning, adaptivealgorithms to achieve. PID control are achieved using pressure, temperature, flow, liquid level controller, PID control functions to achieve the programmable logic controller (PLC), also enables the PC system, PID control and so on. Programmable Logic Controller (PLC) is the use of its closed-loop control module to achieve PID control, and programmable logic controller (PLC) can be connected directly with the ControlNet, such as Rockwell's PLC-5 and so on. There can be the controller PID control functions, such as Rockwell's Logix product line, it can be connected directly with the ControlNet, using the Internet to achieve its long-range control functions.1, Open-loop control systemOpen-loop control system is the object of the output (volume control) on the controller does not affect the output. In this control system, do not rely on volume will be charged back to the formation of anti-any closed-loop circuit.2, Closed-loop control systemClosed-loop control system is characterized by the output of the system object (volume control) will be sent back to the impact of anti-output controller to form one or more of the closed-loop. Closed-loop control system has positive feedback and negative feedback, if the feedback signal and the system to set the value of the signal the other hand, is referred to as negative feedback, if the same polarity is called positive feedback, the general closed-loop control system using negative feedback, also known as negative feedback control system. Closed-loop control system has many examples. For example, people with negative feedback is a closed-loop control system, the eye is the sensor to act as a feedback, the human body system through the constant variety of the right to make amendments to the final action. If there are no eyes, there is no feedback loops, it became an open-loop control system. Another example, when a full-automatic washing machine with a realcontinuously check whether the washed clothing, and wash off automatically after the power supply, it is a closed-loop control system.3, Step responseStep response refers to a step input (step function) when added to the system, the system output. Steady-state error is the system response into the steady-state, the system's desired output and actual output of the difference. The performance of control system can be stable, accurate and fast three words to describe. Stability is the stability of the system, a system must be able to work, first of all must be stable, from the step response should be a convergence point of view; quasi-control system refers to the accuracy, control precision, stability is usually state error description, it said the system output steady-state value and the difference between expectations; fast control system refers to the rapid response, and usually to a quantitative description of the rise time.4, Theory and the characteristics of PID controlIn engineering practice, the most widely used control laws regulate the proportional, integral, differential control, referred to as PID control, also known as PID regulator. PID controller has been available for nearly 70 years of history, which in its simple structure, stable, reliable, easy to adjust and become the main industrial control technologies. When charged with the structure and parameters of the object can not completely grasp, or lack of accurate mathematical model, control theory it is difficult using other techniques, the system controller structure and parameters have to rely on experience and on-site testing to determine when the application PID control of the most convenient technology. That is, when we do not fully understand the system and charged with an object, or can not be an effective means of measuring system parameters to obtain the most suitable PID control technology. PID control, in practice there are PI and PD control. PID controller is the error of the system, using proportional, integral, differential calculationfor the control of the volume control.The ratio of (P) controlProportional control is one of the most simple control methods. The controller's output and input error signal proportional to the relationship. The output has the existence of steady-state error when there is only a proportional control system.Integral (I) controlIn integral control, the controller's output and input error signal is proportional to the integral relationship. For an automatic control system, if steady-state error exists after entering the steady-state, the control system is referred to as steady-state error or having a poor system. In order to eliminate steady-state error, the controller must be the introduction of the "key points." Points of error depend on the time of the points of the increase over time, will increase the integral term. In this way, even if the error is very small, integral term will increase as time increases, it increased to promote the output of the controller so that steady-state error further reduced until zero. Therefore, the proportional + integral (PI) controller, you can make the system after entering the steady-state non-steady-state error.Differential (D) controlIn the differential control, the controller's output and input of the differential error signal (the rate of change of error) is directly proportional to the relationship. Automatic control system to overcome the errors in the adjustment process may be unstable or even oscillation. The reason is because of greater inertial components (links) or there is lag components, can inhibit the role of error, the changes always lag behind changes in error. The solution is to inhibit the changes in the role of error "in advance", that is close to zero in the error and suppress the role of error should be zero. This means that the controller only the introduction of the "proportion" of often is not enough, the proportion of the role isonly to enlarge the amplitude error, the current need to increase the "differential item" that can change the trend of prediction error, In this way, with the proportion of + differential controller, will be able to advance so that the role of inhibitory control error equal to zero or even negative, thus avoiding the amount charged with a serious overshoot. Therefore, greater inertia of the charged object or lag, the proportion of + differential (PD) controller to improve the system in the regulation of the dynamic characteristics of the process.PID控制简介当今的自动控制技术都是基于反馈的概念。

P I D中英文对照翻译中英文互译PID Contro lIntroductionThe PID controller is the most common form of feedback. It was an essential element of early governors and it became the standard tool when process control emerged in the 1940s. In process control today, more than 95% of the control loops are of PID type, most loops are actually PI control. PID controllers are today found in all areas where control is used. The controllers come in many different forms. There are standalone systems in boxes for one or a few loops, which are manufactured by the hundred thousands yearly. PID control is animportant ingredient of a distributed control system. The controllers are also embedded in many special purpose control systems. PID control is often combined with logic, sequential functions, selectors, and simple function blocks to build the complicated automation systems used for energy production, transportation, and manufacturing. Many sophisticated control strategies, such as model predictive control, are also organized hierarchically. PID control is used at the lowest level; the multivariable controller gives the set points to thecontrollers at the lower level. The PID controller can thus be said to be the “bread and butter of control engineering. It is an important componen t in every control engineer’s tool box.PID controllers have survived many changes in technology, from mechanics and pneumatics to microprocessors via electronic tubes, transistors, integrated circuits. Themicroprocessor has had a dramatic influence the PID controller. Practically all PIDcontrollers made today are based on microprocessors. This has given opportunities to provide additional features like automatic tuning, gain scheduling, and continuous adaptation.6.2 The AlgorithmWe will start by summarizing the key features of the PID controller. The “textbook” version of the PID algorithm is described by:()()()()⎪⎪⎭⎫ ⎝⎛++=⎰dt t de d e t e K t u T T d t i 01ττ 6.1 where y is the measured process variable, r the reference variable, u is the controlsignal and e is the control error （e =sp y − y ）. The reference variable is often called the set point. The control signal is thus a sum of three terms: the P-term （which isproportional to the error ）, the I-term （which is proportional to the integral of the error ）, and the D-term （which is proportional to the derivative of the error ）. The controller parameters are proportional gain K , integral time T i , and derivative time T d . The integral, proportional and derivative part can be interpreted as control actions based on the past, the present and the future as is illustrated in Figure 2.2. The derivative part can also be interpreted as prediction by linear extrapolation as is illustrated in Figure2.2. The action of the different terms can be illustrated by the following figures which show the response to step changes in the reference value in a typical case.Effects of Proportional, Integral and Derivative ActionProportional control is illustrated in Figure 6.1. The controller is given by D6.1E with T i =∞ and T d =0. The figure shows that there is always a steady state error in proportionalcontrol. The error will decrease with increasing gain, but the tendency towards oscillation will also increase.Figure 6.2 illustrates the effects of adding integral. It follows from D6.1E that the strength of integral action increases with decreasing integral time T i. The figure shows that the steady state error disappears when integral action is used. Compare with the discussion of the “magic of integral action” in Section 2.2. The tendency for oscillation also increases with decreasing T i. The properties of derivative action are illustrated in Figure 6.3.Figure 6.3 illustrates the effects of adding derivative action. The parameters K and T i are chosen so that the closed loop system is oscillatory. Damping increases with increasing derivative time, but decreases again when derivative time becomes too large. Recall that derivative action can be interpreted as providing prediction by linear extrapolation over the time T d. Using this interpretation it is easy to understand that derivative action does not help if the prediction time T d is too large. In Figure 6.3 the period of oscillation is about 6 s for the system without derivative Chapter 6. PID ControlFigure 6.1Figure 6.2Derivative actions cease to be effective when T d is larger than a 1 s (one sixth of the period). Also notice that the period of oscillation increases when derivative time is increased. A PerspectiveThere is much more to PID than is revealed by （6.1）. A faithful implementation of the equation will actually not result in a good controller. To obtain a good PID controller it is also necessary to consider 。

英语资料及译文About PID controlRecently automation technology is based on the concept of feedback. Elements of feedback theory consist of three parts: measurement, comparison and implementation. Measurement variables of concern, compared with expectations, with the control system to correct the error response.The theory and application of automatic control, the key is to make the correct measurement and comparison of how best to rectify the system.PID (proportional - integral - differential) controller as the first practical use of the controller more than 50 years of history, is still the most widely used industrial controller. Simple PID controller, the use of the system does not accurately model a prerequisite that they have become the most widely used controller.PID controller is the proportion of cells (P), integral unit (I) and the differential unit (D) component.Because of its wide range of uses, the use of flexible, has been serialized products, the use of only three parameters setting (Kp, Ti and Td) can be. In many cases, does not necessarily need all three modules, which can take 1-2 unit, but the proportion of the control unit is essential.First of all, PID broad range of applications. Although many industrial processes or time-varying non-linear, but can be simplified through their basic non-linear and dynamic characteristics of the system over time, so that you can control the PID.Secondly, PID parameter can tune easier. That is, PID parameters Kp, Ti and Td can be based on the dynamic characteristics of the process of setting a timely manner. If the dynamic characteristics of the process ofchange, for example, changes may be caused by the load dynamic characteristics of the system changes, PID parameters can be re-tuning.Third, PID controller in practice is to be improved continuously, the following are two examples of improvements.In factories, we always see a lot of loops are in manual, and because of the difficulty of the course so that the "automatic" mode, a smooth working. As a result of these deficiencies, the use of the industrial control system PID is always subject to product quality, safety, waste production and energy problems. PID parameter self-tuning PID parameters in order to deal with this problem setting generated. Now, the auto-tuning or self-tuning of PID controller is a business single-loop controllers and distributed control system of a standard.In some cases the system-specific design of PID controller to control very well, but they are there are still some problems to be solved: If self-tuning should be based on the model, in order to re-PID tuning parameters online to find and maintain a good process model is more difficult. When closed-loop works, the requirements in the process of inserting must have a test signal. This method will cause disturbance, so model-based PID parameter self-tuning is not too good in the industrial applications.If self-tuning control law based on the often difficult to load disturbance caused by the impact and dynamic characteristics of the process of the impact of changes in the distinction between the effects of so disturbed overshoot controller will have to create a self-adaptive unnecessary conversion. In addition, since the control law based on the maturity of the system is not the stability of analytical methods, the reliability of parameter tuning, there are many problems.Therefore, many self-tuning PID controller parameters work in the auto-tuning mode and not in the self-tuning mode. Auto-tuning is oftenused to describe the state of open-loop based on a simple process model to determine automatic calculation of PID parameters.PID in controlling nonlinear, time-varying, coupling and parameter uncertainty and structural complexity of the process, the work is not very good. The most important thing is, if the PID controller can not control the complexity of the process, regardless of how not to use transfer parameters.Despite these shortcomings, PID controller is sometimes the most simple is the best controller.At present, the level of industrial automation has become a measure of the level of modernization in all walks of life an important sign. At the same time, the development of control theory has also experienced a classical control theory, modern control theory and intelligent control theory of three stages. Classic example of intelligent control is ambiguous, such as full-automatic washing machine. Automatic control system can be divided into open-loop control systems and closed-loop control system.A control system, including controllers, sensors, transmitters, implementing agencies, input and output interfaces. Controller's output after the output interface, the implementing agencies, added to the system was charged with; control system charged with the amount, after the sensor, transmitter, through the input interface to the controller. Different control system, the sensor, transmitter, the executing agency is not the same. For example pressure sensors need to be used in pressure control system. Electric heating control system is the sensor temperature sensor. At present, PID control and PID controller or a smart controller (instrument) has a lot of products have been in practice in engineering is widely used, there are a wide range of PID controller products, major companies have developed with PID parameter self-tuning regulator function smart (intelligent regulator), which the PID controller parameters are automatically adjusted through the intelligent or self-tuning, adaptivealgorithms to achieve. PID control are achieved using pressure, temperature, flow, liquid level controller, PID control functions to achieve the programmable logic controller (PLC), also enables the PC system, PID control and so on. Programmable Logic Controller (PLC) is the use of its closed-loop control module to achieve PID control, and programmable logic controller (PLC) can be connected directly with the ControlNet, such as Rockwell's PLC-5 and so on. There can be the controller PID control functions, such as Rockwell's Logix product line, it can be connected directly with the ControlNet, using the Internet to achieve its long-range control functions.1, Open-loop control systemOpen-loop control system is the object of the output (volume control) on the controller does not affect the output. In this control system, do not rely on volume will be charged back to the formation of anti-any closed-loop circuit.2, Closed-loop control systemClosed-loop control system is characterized by the output of the system object (volume control) will be sent back to the impact of anti-output controller to form one or more of the closed-loop. Closed-loop control system has positive feedback and negative feedback, if the feedback signal and the system to set the value of the signal the other hand, is referred to as negative feedback, if the same polarity is called positive feedback, the general closed-loop control system using negative feedback, also known as negative feedback control system. Closed-loop control system has many examples. For example, people with negative feedback is a closed-loop control system, the eye is the sensor to act as a feedback, the human body system through the constant variety of the right to make amendments to the final action. If there are no eyes, there is no feedback loops, it became an open-loop control system. Another example, when a full-automatic washing machine with a realcontinuously check whether the washed clothing, and wash off automatically after the power supply, it is a closed-loop control system.3, Step responseStep response refers to a step input (step function) when added to the system, the system output. Steady-state error is the system response into the steady-state, the system's desired output and actual output of the difference. The performance of control system can be stable, accurate and fast three words to describe. Stability is the stability of the system, a system must be able to work, first of all must be stable, from the step response should be a convergence point of view; quasi-control system refers to the accuracy, control precision, stability is usually state error description, it said the system output steady-state value and the difference between expectations; fast control system refers to the rapid response, and usually to a quantitative description of the rise time.4, Theory and the characteristics of PID controlIn engineering practice, the most widely used control laws regulate the proportional, integral, differential control, referred to as PID control, also known as PID regulator. PID controller has been available for nearly 70 years of history, which in its simple structure, stable, reliable, easy to adjust and become the main industrial control technologies. When charged with the structure and parameters of the object can not completely grasp, or lack of accurate mathematical model, control theory it is difficult using other techniques, the system controller structure and parameters have to rely on experience and on-site testing to determine when the application PID control of the most convenient technology. That is, when we do not fully understand the system and charged with an object, or can not be an effective means of measuring system parameters to obtain the most suitable PID control technology. PID control, in practice there are PI and PD control. PID controller is the error of the system, using proportional, integral, differential calculationfor the control of the volume control.The ratio of (P) controlProportional control is one of the most simple control methods. The controller's output and input error signal proportional to the relationship. The output has the existence of steady-state error when there is only a proportional control system.Integral (I) controlIn integral control, the controller's output and input error signal is proportional to the integral relationship. For an automatic control system, if steady-state error exists after entering the steady-state, the control system is referred to as steady-state error or having a poor system. In order to eliminate steady-state error, the controller must be the introduction of the "key points." Points of error depend on the time of the points of the increase over time, will increase the integral term. In this way, even if the error is very small, integral term will increase as time increases, it increased to promote the output of the controller so that steady-state error further reduced until zero. Therefore, the proportional + integral (PI) controller, you can make the system after entering the steady-state non-steady-state error.Differential (D) controlIn the differential control, the controller's output and input of the differential error signal (the rate of change of error) is directly proportional to the relationship. Automatic control system to overcome the errors in the adjustment process may be unstable or even oscillation. The reason is because of greater inertial components (links) or there is lag components, can inhibit the role of error, the changes always lag behind changes in error. The solution is to inhibit the changes in the role of error "in advance", that is close to zero in the error and suppress the role of error should be zero. This means that the controller only the introduction of the "proportion" of often is not enough, the proportion of the role isonly to enlarge the amplitude error, the current need to increase the "differential item" that can change the trend of prediction error, In this way, with the proportion of + differential controller, will be able to advance so that the role of inhibitory control error equal to zero or even negative, thus avoiding the amount charged with a serious overshoot. Therefore, greater inertia of the charged object or lag, the proportion of + differential (PD) controller to improve the system in the regulation of the dynamic characteristics of the process.PID控制简介当今的自动控制技术都是基于反馈的概念。

The significance of PID controlThe current level of industrial automation industries to measure the level of modernization has become an important symbol. Meanwhile, the control also experienced the development of the theory of classical control theory, modern control theory and intelligent control theory of three stages. Intelligent control is a typical example of fuzzy automatic washing machine. Open-loop control system can be divided into control systems and closed-loop control system. A control system including controller, sensors, transmitters, actuators, input and output interfaces. Controller's output through the output interface, the implementing agency, added to the charged system; control system, the amount charged, through sensors, transmitters, sent to the controller through the input interface. Different control systems, sensors, transmitters, actuators are not the same. Such as pressure control system pressure sensor to be used. Electric heating control system sensor is a temperature sensor. At present, PID control and controller or intelligent PID controller (instrument) has a lot of products have been in the engineering practice has been widely applied, there is a wide range of PID controllers, the major companies have developed PID parameter self-tuning capabilities of intelligent controller (intelligent regulator), which automatically adjusts the PID controller parameters are adjusted through the intelligent or self-correction, adaptive algorithms to achieve. PID control are achieved using pressure, temperature, flow, liquid level controller, PID control can achieve programmable controller (PLC), also allows PID control of PC systems, etc.. Programmable Logic Controller (PLC) is to use the closed-loop PID control module to achieve control, programmable logic controller (PLC) can be connected directly with ControlNet, such as Rockwell's PLC-5 and so on. PID control function also allows the controller, such as Rockwell's Logix product line, which can be connected directly with ControlNet, use the network to achieve its remote control functions.1, the open-loop control systemOpen-loop control system (open-loop control system) is charged with theobject output (controlled variables) on the controller (controller) did not affect the output. In this control system, not dependent on the amount will be charged against sending it back to form any closed loops.2, closed loop control systemClosed loop control system (closed-loop control system) is characterized by the system control object output (controlled variables) will affect the controller against the output sent back to form one or more closed loop. Closed-loop control system has positive feedback and negative feedback, if the feedback signal and system for a given value of signal contrast, is known as negative feedback (Negative Feedback), if the same polarity is called positive feedback, the general closed-loop negative feedback control systems are used , also known as negative feedback control system. Many examples of closed loop control system. Such person is a negative feedback loop control system, the eye is the sensor, as feedback, the human system through constant correction to all the right moves last. If there are no eyes, no feedback loop, will become an open-loop control system. Other cases, when a truly automatic washing machines have to continuously check whether clothes washed, and cut off the power automatically after cleaning, it is a closed loop control system.3, step responseStep response is a step input (step function) added to the system, the system outputs. Steady-state error is the response of the system into steady state, the system's expected output and actual output of the difference. Control system performance can be stable, accurate, fast and three words to describe. Stability is the stability of the system (stability), a system to work properly, first of all must be stable, from the step response appears to be that convergence; quasi-control system refers to the accuracy, control precision, usually stable state error to (Steady-state error) description, it said the system output and the expected steady-state value of the difference; faster control system response is fast, usually the rise time to quantify.4, PID control principles and characteristicsIn engineering practice, the most widely used regulator control law is proportional, integral, differential control, referred to as PID control, also known as PID regulator. PID controller has been developed for nearly 70 years, it is its simple structure, stable, reliable, easy to adjust and become one of the main techniques of industrial control. When the structure and parameters of the object and can not fully grasp, or lack of accurate mathematical models, control theory is difficult to use other technologies, the system controller structure and parameters must rely on experience and on-site commissioning to determine, when applied PID control technique is more convenient. That is, when we do not fully understand a system and the controlled object, or can not be an effective means of measurement to obtain system parameters, the most suitable PID control technology. PID control, in practice there are PI and PD control. PID controller is the error according to the system, using proportional, integral, differential calculation of the volume control to control.Proportion (P) controlProportional control is the most simple control method. The controller's output and the input error signal proportional. When only a proportional control system output when there is steady-state error (Steady-state error).Integral (I) controlIn integral control, the controller's output and the input error signal proportional to the integral. An automatic control system into the steady state if there is steady-state error, claimed that this control system is called a steady-state error or poor system (System with Steady-state Error). In order to eliminate steady state error, the controller must introduce the "integral term." Integral term of the error depends on the time integral, as time increases, integral term will increase. Thus, even if the error is very small, integral term will increase over time to increase its promotion of the controller output increases to further reduce the steady-state error, until zero. Therefore, the ratio of + integral (PI) controller allows the systemto enter steady state of no steady state error.Differential (D) controlIn the differential control, the controller output and differential input error signal (ie, rate of change of error) is proportional to. Automatic control system to overcome the errors in the adjustment process of oscillation or even instability may occur. The reason is because of greater inertia components (links), or a lag (delay) component, can inhibit the role of error, the changes always lag behind changes in the error. The solution is to change the role of inhibition of error, "ahead", that is close to zero in the error and suppress the role of error should be zero. This means that the controller only the introduction of the "ratio" item is often not enough, the proportion of item only to enlarge the role of the magnitude of the error, but now need to increase the "differential item" that can change the trend of forecast errors, In this way, with the proportion of + differential controller, it can advance to the role of inhibition of the control error is zero, even negative, thus avoiding the charged amount of serious overshoot. Therefore have greater inertia or lag the controlled object, proportional + derivative (PD) controller5, PID controller tuningTuning PID controller is the core of the control system design. It is based on the characteristics of controlled process to determine the proportion of PID controller coefficients, integral time and derivative time, the size of the. PID controller tuning are many ways to sum up, there are two categories: First, tuning the theoretical calculation. It is mainly based on the mathematical model, through theoretical calculations to determine the controller parameters. This method the calculated data may not be directly used, it must adjust and revise engineering. Second, the tuning method works, it mainly relies on engineering experience, directly in the control experiments carried out, and the method is simple, easy to master, in engineering practice is widely used. PID controller parameter tuning method works, mainly the critical ratio, reaction curve and attenuation. Three methods have their own characteristics, their common points are the experiment, and then follow theempirical formula works on the controller parameter tuning. But no matter which method used by the controller parameters are needed in the actual operation of the final adjustment and improvement. Now commonly used is the critical ratio method. PID controller using the method parameter setting of the following steps: (1) first pre-select a short enough sampling period of the system to work; (2) by adding proportional control only part until the system appears critical step response input oscillation Note the amplification factor and the proportion of time critical oscillation period; (3) a certain degree of control in the formula be adopted under the PID controller parametersPID控制的意义目前工业自动化水平已成为衡量各行各业现代化水平的一个重要标志。

PID参数如何设定调节PID（比例积分微分）英文全称为Proportion Integration Differentiation，它是一个数学物理术语。

PID控制简介目前工业自动化水平已成为衡量各行各业现代化水平的一个重要标志。

同时，控制理论的发展也经历了古典控制理论、现代控制理论和智能控制理论三个阶段。

智能控制的典型实例是模糊全自动洗衣机等。

自动控制系统可分为开环控制系统和闭环控制系统。

一个控控制系统包括控制器﹑传感器﹑变送器﹑执行机构﹑输入输出接口。

控制器的输出经过输出接口﹑执行机构﹐加到被控系统上﹔控制系统的被控量﹐经过传感器﹐变送器﹐通过输入接口送到控制器。

不同的控制系统﹐其传感器﹑变送器﹑执行机构是不一样的。

比如压力控制系统要采用压力传感器。

电加热控制系统的传感器是温度传感器。

目前，PID控制及其控制器或智能PID控制器（仪表）已经很多，产品已在工程实际中得到了广泛的应用，有各种各样的PID控制器产品，各大公司均开发了具有PID参数自整定功能的智能调节器(intelligentregulator)，其中PID控制器参数的自动调整是通过智能化调整或自校正、自适应算法来实现。

有利用PID控制实现的压力、温度、流量、液位控制器，能实现PID控制功能的可编程控制器(PLC)，还有可实现PID控制的PC 系统等等。

可编程控制器(PLC)是利用其闭环控制模块来实现PID控制，而可编程控制器(PLC)可以直接与ControlNet相连，如Rockwell的PLC-5等。

还有可以实现PID控制功能的控制器，如Rockwell的Logix产品系列，它可以直接与ControlNet 相连，利用网络来实现其远程控制功能。

1、开环控制系统开环控制系统(open-loopcontrolsystem)是指被控对象的输出(被控制量)对控制器(controller)的输出没有影响。

在这种控制系统中，不依赖将被控量反送回来以形成任何闭环回路。

PID是英文单词比例（Proportion），积分（Integral），微分（Differential coefficient）的缩写。

PID调节实际上是由比例、积分、微分三种调节方式组成，它们各自的作用如下：
比例调节作用：是按比例反应系统的偏差，系统一旦出现了偏差，比例调节立即产生调节作用用以减少偏差。

比例作用大，可以加快调节，减少误差，但是过大的比例，使系统的稳定性下降，甚至造成系统的不稳定。

积分调节作用：是使系统消除稳态误差，提高无差度。

因为有误差，积分调节就进行，直至无差，积分调节停止，积分调节输出一常值。

积分作用的强弱取决与积分时间常数Ti，Ti越小，积分作用就越强。

反之Ti大则积分作用弱，加入积分调节可使系统稳定性下降，动态响应变慢。

积分作用常与另两种调节规律结合，组成PI调节器或PID调节器。

微分调节作用：微分作用反映系统偏差信号的变化率，具有预见性，能预见偏差变化的趋势，因此能产生超前的控制作用，在偏差还没有形成之前，已被微分调节作用消除。

因此，可以改善系统的动态性能。

在微分时间选择合适情况下，可以减少超调，减少调节时间。

微分作用对噪声干扰有放大作用，因此过强的加微分调节，对系统抗干扰不利。

此外，微分反应的是变化率，而当输入没有变化时，微分作用输出为零。

微分作用不能单独使用，需要与另外两种调节规律相结合，组成PD或PID控制器。