控制系统

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The centrifugal governor is an early proportional control mechanism.

[离心式调速器是早期的比例控制机制。]


A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large Industrial control systems which are used for controlling processes or machines.

A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large Industrial control systems which are used for controlling processes or machines.

控制系统使用控制循环来管理、命令、引导或调节其他设备或系统的行为。它的范围从使用恒温器控制家用锅炉的单个家庭供暖控制器到用于控制过程或机器的大型工业控制系统。


For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant to the same value as the setpoint.

For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant to the same value as the setpoint.

对于连续调制控制,使用反馈控制器来自动控制过程或操作。该控制系统将被控制的程序变数的值或状态与期望值或设定值进行比较,并将差值作为控制信号,使电站的程序变数输出与设定值相同。


For sequential and combinational logic, software logic, such as in a programmable logic controller, is used.

For sequential and combinational logic, software logic, such as in a programmable logic controller, is used.

对于顺序逻辑和组合逻辑电路逻辑,使用软件逻辑,例如可编程序控制器逻辑。


Open-loop and closed-loop control

There are two common classes of control action: open loop and closed loop. In an open-loop control system, the control action from the controller is independent of the process variable. An example of this is a central heating boiler controlled only by a timer. The control action is the switching on or off of the boiler. The process variable is the building temperature. This controller operates the heating system for a constant time regardless of the temperature of the building.

There are two common classes of control action: open loop and closed loop. In an open-loop control system, the control action from the controller is independent of the process variable. An example of this is a central heating boiler controlled only by a timer. The control action is the switching on or off of the boiler. The process variable is the building temperature. This controller operates the heating system for a constant time regardless of the temperature of the building.

有两种常见的控制动作: 开环和闭环。在开环控制系统中,来自控制器的控制动作独立于程序变数。这方面的一个例子是一个中央供暖锅炉只由一个定时器控制。控制动作是开启或关闭锅炉。程序变数是建筑物的温度。无论建筑物的温度如何,这个控制器都能在一个固定的时间内操作供暖系统。


In a closed-loop control system, the control action from the controller is dependent on the desired and actual process variable. In the case of the boiler analogy, this would utilise a thermostat to monitor the building temperature, and feed back a signal to ensure the controller output maintains the building temperature close to that set on the thermostat. A closed loop controller has a feedback loop which ensures the controller exerts a control action to control a process variable at the same value as the setpoint. For this reason, closed-loop controllers are also called feedback controllers.[1]

In a closed-loop control system, the control action from the controller is dependent on the desired and actual process variable. In the case of the boiler analogy, this would utilise a thermostat to monitor the building temperature, and feed back a signal to ensure the controller output maintains the building temperature close to that set on the thermostat. A closed loop controller has a feedback loop which ensures the controller exerts a control action to control a process variable at the same value as the setpoint. For this reason, closed-loop controllers are also called feedback controllers.

在闭环控制系统中,控制器的控制动作取决于期望的和实际的程序变数。在锅炉模拟的情况下,这将利用一个恒温器来监测建筑物的温度,并反馈一个信号,以确保控制器的输出保持建筑物的温度接近恒温器设定的温度。一个闭环控制器有一个反馈回路,它确保控制器施加一个控制动作来控制一个与设定值相同的程序变数。因此,闭环控制器也称为反馈控制器。


Feedback control systems

Example of a single industrial control loop; showing continuously modulated control of process flow.

Example of a single industrial control loop; showing continuously modulated control of process flow.

单个工业控制回路的例子; 显示过程流程的连续调制控制。

文件:Ideal feedback model.svg
A basic feedback loop
A basic feedback loop

一个基本的反馈回路


In the case of linear feedback systems, a control loop including sensors, control algorithms, and actuators is arranged in an attempt to regulate a variable at a setpoint (SP). An everyday example is the cruise control on a road vehicle; where external influences such as hills would cause speed changes, and the driver has the ability to alter the desired set speed. The PID algorithm in the controller restores the actual speed to the desired speed in the optimum way, with minimal delay or overshoot, by controlling the power output of the vehicle's engine.

In the case of linear feedback systems, a control loop including sensors, control algorithms, and actuators is arranged in an attempt to regulate a variable at a setpoint (SP). An everyday example is the cruise control on a road vehicle; where external influences such as hills would cause speed changes, and the driver has the ability to alter the desired set speed. The PID algorithm in the controller restores the actual speed to the desired speed in the optimum way, with minimal delay or overshoot, by controlling the power output of the vehicle's engine.

在线性反馈系统的情况下,控制回路包括传感器、控制算法和执行器,其目的是在设定点调节变量(SP)。一个日常的例子是公路车辆上的巡航控制; 在这种情况下,诸如山坡之类的外部影响会导致速度变化,而驾驶员有能力改变所需的设定速度。控制器中的 PID 算法通过控制汽车发动机的功率输出,以最小的延迟或超调将实际转速恢复到期望转速。


Control systems that include some sensing of the results they are trying to achieve are making use of feedback and can adapt to varying circumstances to some extent. Open-loop control systems do not make use of feedback, and run only in pre-arranged ways.

Control systems that include some sensing of the results they are trying to achieve are making use of feedback and can adapt to varying circumstances to some extent. Open-loop control systems do not make use of feedback, and run only in pre-arranged ways.

控制系统,包括一些传感的结果,他们正在努力实现是利用反馈,可以适应不同的情况在一定程度上。开环控制系统不利用反馈,只以预先安排的方式运行。


Logic control

Logic control systems for industrial and commercial machinery were historically implemented by interconnected electrical relays and cam timers using ladder logic. Today, most such systems are constructed with microcontrollers or more specialized programmable logic controllers (PLCs). The notation of ladder logic is still in use as a programming method for PLCs.[2]

Logic control systems for industrial and commercial machinery were historically implemented by interconnected electrical relays and cam timers using ladder logic. Today, most such systems are constructed with microcontrollers or more specialized programmable logic controllers (PLCs). The notation of ladder logic is still in use as a programming method for PLCs.

工业和商业机械的逻辑控制系统过去是通过使用梯形逻辑的互联电气继电器和凸轮定时器来实现的。今天,大多数这样的系统是由微控制器或更专业的可编程逻辑控制器(plc)构成的。梯形逻辑的符号仍然被用作 plc 的编程方法。


Logic controllers may respond to switches and sensors, and can cause the machinery to start and stop various operations through the use of actuators. Logic controllers are used to sequence mechanical operations in many applications. Examples include elevators, washing machines and other systems with interrelated operations. An automatic sequential control system may trigger a series of mechanical actuators in the correct sequence to perform a task. For example, various electric and pneumatic transducers may fold and glue a cardboard box, fill it with product and then seal it in an automatic packaging machine.

Logic controllers may respond to switches and sensors, and can cause the machinery to start and stop various operations through the use of actuators. Logic controllers are used to sequence mechanical operations in many applications. Examples include elevators, washing machines and other systems with interrelated operations. An automatic sequential control system may trigger a series of mechanical actuators in the correct sequence to perform a task. For example, various electric and pneumatic transducers may fold and glue a cardboard box, fill it with product and then seal it in an automatic packaging machine.

逻辑控制器可能响应开关和传感器,并可能导致机械启动和停止各种操作通过执行器的使用。在许多应用中,逻辑控制器被用来安排机械操作的顺序。例子包括电梯,洗衣机和其他系统与相关的操作。自动顺序控制系统可以按照正确的顺序触发一系列机械执行器来执行任务。例如,各种电动和气动传感器可以折叠和胶合纸板箱,填写产品,然后密封在一个自动包装机。


PLC software can be written in many different ways – ladder diagrams, SFC (sequential function charts) or statement lists.[3]

PLC software can be written in many different ways – ladder diagrams, SFC (sequential function charts) or statement lists.

PLC 软件可以用许多不同的方式编写——梯形图、顺序功能图或报表列表。


On–off control

On–off control uses a feedback controller that switches abruptly between two states. A simple bi-metallic domestic thermostat can be described as an on-off controller. When the temperature in the room (PV) goes below the user setting (SP), the heater is switched on. Another example is a pressure switch on an air compressor. When the pressure (PV) drops below the setpoint (SP) the compressor is powered. Refrigerators and vacuum pumps contain similar mechanisms. Simple on–off control systems like these can be cheap and effective.

On–off control uses a feedback controller that switches abruptly between two states. A simple bi-metallic domestic thermostat can be described as an on-off controller. When the temperature in the room (PV) goes below the user setting (SP), the heater is switched on. Another example is a pressure switch on an air compressor. When the pressure (PV) drops below the setpoint (SP) the compressor is powered. Refrigerators and vacuum pumps contain similar mechanisms. Simple on–off control systems like these can be cheap and effective.

开关控制使用在两种状态之间突然切换的反馈控制器。一个简单的双金属家用恒温器可以描述为一个开关控制器。当室内温度(PV)低于用户设置(SP)时,加热器就会打开。另一个例子是空气压缩机上的压力开关。当压力(PV)下降到设定点(SP)以下时,压缩机启动。冰箱和真空泵也有类似的机理。像这样简单的开关控制系统可以是廉价和有效的。


Linear control

Linear control systems use negative feedback to produce a control signal to maintain the controlled PV at the desired SP. There are several types of linear control systems with different capabilities.

Linear control systems use negative feedback to produce a control signal to maintain the controlled PV at the desired SP. There are several types of linear control systems with different capabilities.

线性控制系统使用负反馈产生控制信号,以保持受控 PV 在所需的 sp. 。有几种类型的线性控制系统具有不同的能力。


Proportional control

文件:Second order transfer function.svg
Step responses for a second order system defined by the transfer function [math]\displaystyle{ H(s)=\frac{\omega^2_n}{s^2+2\zeta\omega_ns+\omega^2_n} }[/math], where [math]\displaystyle{ \zeta }[/math] is the damping ratio and [math]\displaystyle{ \omega_n }[/math] is the undamped natural frequency.

Step responses for a second order system defined by the [[transfer function [math]\displaystyle{ H(s)=\frac{\omega^2_n}{s^2+2\zeta\omega_ns+\omega^2_n} }[/math], where [math]\displaystyle{ \zeta }[/math] is the damping ratio and [math]\displaystyle{ \omega_n }[/math] is the undamped natural frequency.]]

由[[传递函数 < math > h (s) = frac { omega ^ 2 _ n }{ s ^ 2 + 2 zeta omega _ ns + omega ^ 2 _ n } </math > 定义的二阶系统的阶跃响应,其中 < math > zeta </math > 是阻尼比,< math > omega _ n </math > 是未阻尼的自然频率]


Proportional control is a type of linear feedback control system in which a correction is applied to the controlled variable which is proportional to the difference between the desired value (SP) and the measured value (PV). Two classic mechanical examples are the toilet bowl float proportioning valve and the fly-ball governor.

Proportional control is a type of linear feedback control system in which a correction is applied to the controlled variable which is proportional to the difference between the desired value (SP) and the measured value (PV). Two classic mechanical examples are the toilet bowl float proportioning valve and the fly-ball governor.

比例控制是一种线性反馈控制系统,其中对被控变量进行修正,修正值与期望值(SP)和实测值(PV)之间的差值成正比。两个经典的机械例子是马桶浮子比例阀和飞球调速器。


The proportional control system is more complex than an on–off control system, but simpler than a proportional-integral-derivative (PID) control system used, for instance, in an automobile cruise control. On–off control will work for systems that do not require high accuracy or responsiveness, but is not effective for rapid and timely corrections and responses. Proportional control overcomes this by modulating the manipulated variable (MV), such as a control valve, at a gain level which avoids instability, but applies correction as fast as practicable by applying the optimum quantity of proportional correction.

The proportional control system is more complex than an on–off control system, but simpler than a proportional-integral-derivative (PID) control system used, for instance, in an automobile cruise control. On–off control will work for systems that do not require high accuracy or responsiveness, but is not effective for rapid and timely corrections and responses. Proportional control overcomes this by modulating the manipulated variable (MV), such as a control valve, at a gain level which avoids instability, but applies correction as fast as practicable by applying the optimum quantity of proportional correction.

比例控制控制系统比开关控制系统更复杂,但比比例积分微分(PID)控制系统更简单,例如,用于汽车巡航控制。开关控制将适用于不要求高准确度或响应能力,但对快速和及时的修正和响应不够有效的系统。比例控制通过调节操纵变量,如控制阀,在增益水平上避免不稳定,但通过应用最佳比例修正量,尽可能快地进行修正,从而克服了这一问题。


A drawback of proportional control is that it cannot eliminate the residual SP–PV error, as it requires an error to generate a proportional output. A PI controller can be used to overcome this. The PI controller uses a proportional term (P) to remove the gross error, and an integral term (I) to eliminate the residual offset error by integrating the error over time.

A drawback of proportional control is that it cannot eliminate the residual SP–PV error, as it requires an error to generate a proportional output. A PI controller can be used to overcome this. The PI controller uses a proportional term (P) to remove the gross error, and an integral term (I) to eliminate the residual offset error by integrating the error over time.

比例控制的一个缺点是它不能消除剩余的 SP-PV 误差,因为它需要一个误差来产生一个比例输出。一个 PI 控制器可以用来解决这个问题。PI 控制器采用比例项(p)消除粗差,积分项(i)通过积分误差消除残差。


In some systems there are practical limits to the range of the MV. For example, a heater has a limit to how much heat it can produce and a valve can open only so far. Adjustments to the gain simultaneously alter the range of error values over which the MV is between these limits. The width of this range, in units of the error variable and therefore of the PV, is called the proportional band (PB).

In some systems there are practical limits to the range of the MV. For example, a heater has a limit to how much heat it can produce and a valve can open only so far. Adjustments to the gain simultaneously alter the range of error values over which the MV is between these limits. The width of this range, in units of the error variable and therefore of the PV, is called the proportional band (PB).

在一些系统中,对于 MV 的范围有实际的限制。例如,加热器能产生的热量是有限制的,阀门只能打开这么远。调整增益同时改变误差值的范围,超过这些限制之间的 MV 是。这个范围的宽度,以误差变量和 PV 为单位,称为比例带(PB)。


Furnace example

When controlling the temperature of an industrial furnace, it is usually better to control the opening of the fuel valve in proportion to the current needs of the furnace. This helps avoid thermal shocks and applies heat more effectively.

When controlling the temperature of an industrial furnace, it is usually better to control the opening of the fuel valve in proportion to the current needs of the furnace. This helps avoid thermal shocks and applies heat more effectively.

在控制工业炉的温度时,通常最好根据炉子当前的需要按比例控制燃料阀的开度。这有助于避免热冲击和更有效地应用热量。


At low gains, only a small corrective action is applied when errors are detected. The system may be safe and stable, but may be sluggish in response to changing conditions. Errors will remain uncorrected for relatively long periods of time and the system is overdamped. If the proportional gain is increased, such systems become more responsive and errors are dealt with more quickly. There is an optimal value for the gain setting when the overall system is said to be critically damped. Increases in loop gain beyond this point lead to oscillations in the PV and such a system is underdamped. Adjusting gain to achieve critically damped behavior is known as tuning the control system.

At low gains, only a small corrective action is applied when errors are detected. The system may be safe and stable, but may be sluggish in response to changing conditions. Errors will remain uncorrected for relatively long periods of time and the system is overdamped. If the proportional gain is increased, such systems become more responsive and errors are dealt with more quickly. There is an optimal value for the gain setting when the overall system is said to be critically damped. Increases in loop gain beyond this point lead to oscillations in the PV and such a system is underdamped. Adjusting gain to achieve critically damped behavior is known as tuning the control system.

在低增益情况下,当检测到错误时,只应用一个小的纠正措施。该系统可能是安全和稳定的,但可能是迟缓的反应,以不断变化的条件。在相当长的一段时间内,错误仍然没有得到纠正,系统被过阻尼。如果比例增益增加,这样的系统响应更快,错误处理更快。当整个系统被称为严重阻尼时,增益设置有一个最佳值。增加环路增益超过这一点导致振荡的光伏和这样的系统是欠阻尼。调整增益以达到临界阻尼的行为被称为调整控制系统。


In the underdamped case, the furnace heats quickly. Once the setpoint is reached, stored heat within the heater sub-system and in the walls of the furnace will keep the measured temperature rising beyond what is required. After rising above the setpoint, the temperature falls back and eventually heat is applied again. Any delay in reheating the heater sub-system allows the furnace temperature to fall further below setpoint and the cycle repeats. The temperature oscillations that an underdamped furnace control system produces are undesirable.

In the underdamped case, the furnace heats quickly. Once the setpoint is reached, stored heat within the heater sub-system and in the walls of the furnace will keep the measured temperature rising beyond what is required. After rising above the setpoint, the temperature falls back and eventually heat is applied again. Any delay in reheating the heater sub-system allows the furnace temperature to fall further below setpoint and the cycle repeats. The temperature oscillations that an underdamped furnace control system produces are undesirable.

在阻尼不足的情况下,炉子加热很快。一旦达到设定点,在加热器子系统和炉壁中储存热量,将使测量的温度上升超过所需的温度。当温度上升到设定点以上时,温度回落,最终再次加热。任何加热子系统再加热的延迟都会使炉温进一步下降到设定点以下,循环重复。低阻尼炉子控制系统产生的温度振荡是不可取的。


In a critically damped system, as the temperature approaches the setpoint, the heat input begins to be reduced, the rate of heating of the furnace has time to slow and the system avoids overshoot. Overshoot is also avoided in an overdamped system but an overdamped system is unnecessarily slow to initially reach setpoint respond to external changes to the system, e.g. opening the furnace door.

In a critically damped system, as the temperature approaches the setpoint, the heat input begins to be reduced, the rate of heating of the furnace has time to slow and the system avoids overshoot. Overshoot is also avoided in an overdamped system but an overdamped system is unnecessarily slow to initially reach setpoint respond to external changes to the system, e.g. opening the furnace door.

在临界阻尼系统中,当温度接近设定值时,热输入开始减少,加热速率有时间放慢,系统避免超调。在过阻尼系统中也可以避免过冲,但是过阻尼系统在最初到达设定点时会不必要地缓慢,因为它会对系统的外部变化作出反应,例如:。打开炉门。


PID control

A block diagram of a PID controller

[ PID 控制器的框图]

文件:PID Compensation Animated.gif
Effects of varying PID parameters (Kp,Ki,Kd) on the step response of a system.

Effects of varying PID parameters (Kp,Ki,Kd) on the step response of a system.

不同 PID 参数(k < sub > p ,k < sub > i ,k < sub > d )对系统阶跃响应的影响。

Pure proportional controllers must operate with residual error in the system. Though PI controllers eliminate this error they can still be sluggish or produce oscillations. The PID controller addresses these final shortcomings by introducing a derivative (D) action to retain stability while responsiveness is improved.

Pure proportional controllers must operate with residual error in the system. Though PI controllers eliminate this error they can still be sluggish or produce oscillations. The PID controller addresses these final shortcomings by introducing a derivative (D) action to retain stability while responsiveness is improved.

纯比例控制器必须在系统中具有剩余误差。虽然 PI 控制器消除了这个错误,但是它们仍然可以迟缓或者产生振荡。PID 控制器通过引入一个导数(d)动作来解决这些最终的缺点,以保持稳定性,同时提高响应速度。


Derivative action

The derivative is concerned with the rate-of-change of the error with time: If the measured variable approaches the setpoint rapidly, then the actuator is backed off early to allow it to coast to the required level; conversely, if the measured value begins to move rapidly away from the setpoint, extra effort is applied—in proportion to that rapidity to help move it back.

The derivative is concerned with the rate-of-change of the error with time: If the measured variable approaches the setpoint rapidly, then the actuator is backed off early to allow it to coast to the required level; conversely, if the measured value begins to move rapidly away from the setpoint, extra effort is applied—in proportion to that rapidity to help move it back.

导数与误差随时间的变化率有关: 如果被测量的变量迅速接近设定值,那么执行器就会提前退出,使其滑行到所需的水平; 反之,如果被测量的值开始迅速远离设定值,就会施加额外的努力ーー与该速度成比例,以帮助将其移回。


On control systems involving motion-control of a heavy item like a gun or camera on a moving vehicle, the derivative action of a well-tuned PID controller can allow it to reach and maintain a setpoint better than most skilled human operators. If derivative action is over-applied, it can, however, lead to oscillations.

On control systems involving motion-control of a heavy item like a gun or camera on a moving vehicle, the derivative action of a well-tuned PID controller can allow it to reach and maintain a setpoint better than most skilled human operators. If derivative action is over-applied, it can, however, lead to oscillations.

在控制系统中,涉及到一个重物的运动控制,如枪或摄像机在移动的车辆,一个调整良好的 PID 控制器的导数行动可以使它达到和保持一个设定点比最熟练的人类操作员更好。然而,如果微分作用被过度应用,它可以导致振荡。


Integral action

文件:Change with Ki.png
Change of response of second-order system to a step input for varying Ki values.

Change of response of second-order system to a step input for varying Ki values.

变 Ki 值下二阶系统对阶跃输入响应的变化。


The integral term magnifies the effect of long-term steady-state errors, applying an ever-increasing effort until error is removed. In the example of the furnace above working at various temperatures, if the heat being applied does not bring the furnace up to setpoint, for whatever reason, integral action increasingly moves the proportional band relative to the setpoint until the PV error is reduced to zero and the setpoint is achieved.

The integral term magnifies the effect of long-term steady-state errors, applying an ever-increasing effort until error is removed. In the example of the furnace above working at various temperatures, if the heat being applied does not bring the furnace up to setpoint, for whatever reason, integral action increasingly moves the proportional band relative to the setpoint until the PV error is reduced to zero and the setpoint is achieved.

积分项放大了长期稳态误差的影响,不断加大努力直到误差被消除。在以上不同温度下工作的炉子为例,如果施加的热量没有使炉子达到设定点,不管出于什么原因,积分作用越来越多地使比例带相对于设定点移动,直到 PV 误差减少到零并达到设定点。


Ramp up % per minute

Some controllers include the option to limit the "ramp up % per minute". This option can be very helpful in stabilizing small boilers (3 MBTUH), especially during the summer, during light loads. A utility boiler "unit may be required to change load at a rate of as much as 5% per minute (IEA Coal Online - 2, 2007)".[4]模板:Fv

Some controllers include the option to limit the "ramp up % per minute". This option can be very helpful in stabilizing small boilers (3 MBTUH), especially during the summer, during light loads. A utility boiler "unit may be required to change load at a rate of as much as 5% per minute (IEA Coal Online - 2, 2007)".

一些控制器包括限制“斜坡每分钟上升% ”的选项。这种选择可以非常有助于稳定小锅炉(3 MBTUH) ,特别是在夏季,在轻负荷。电站锅炉“可能需要以每分钟5% 的速度改变负荷(IEA Coal Online-2,2007)”。


Other techniques

It is possible to filter the PV or error signal. Doing so can help reduce instability or oscillations by reducing the response of the system to undesirable frequencies. Many systems have a resonant frequency. By filtering out that frequency, stronger overall feedback can be applied before oscillation occurs, making the system more responsive without shaking itself apart.

It is possible to filter the PV or error signal. Doing so can help reduce instability or oscillations by reducing the response of the system to undesirable frequencies. Many systems have a resonant frequency. By filtering out that frequency, stronger overall feedback can be applied before oscillation occurs, making the system more responsive without shaking itself apart.

这是可能的过滤光伏或错误信号。这样做可以减少系统对不希望的频率的响应,从而减少系统的不稳定性或振荡。许多系统都有一个共振频率。通过过滤掉这个频率,在振荡发生之前可以应用更强的整体反馈,使系统在没有自身振荡的情况下反应更快。


Feedback systems can be combined. In cascade control, one control loop applies control algorithms to a measured variable against a setpoint but then provides a varying setpoint to another control loop rather than affecting process variables directly. If a system has several different measured variables to be controlled, separate control systems will be present for each of them.

Feedback systems can be combined. In cascade control, one control loop applies control algorithms to a measured variable against a setpoint but then provides a varying setpoint to another control loop rather than affecting process variables directly. If a system has several different measured variables to be controlled, separate control systems will be present for each of them.

反馈系统可以结合起来。在串级控制中,一个控制回路针对一个设定值对被测变量采用控制算法,然后为另一个控制回路提供一个可变设定值,而不是直接影响过程变量。如果一个系统有几个不同的测量变量需要控制,每个变量都会有独立的控制系统。


Control engineering in many applications produces control systems that are more complex than PID control. Examples of such fields applications fly-by-wire aircraft control systems, chemical plants, and oil refineries. Model predictive control systems are designed using specialized computer-aided-design software and empirical mathematical models of the system to be controlled.

Control engineering in many applications produces control systems that are more complex than PID control. Examples of such fields applications fly-by-wire aircraft control systems, chemical plants, and oil refineries. Model predictive control systems are designed using specialized computer-aided-design software and empirical mathematical models of the system to be controlled.

控制工程在许多应用中产生的控制系统比 PID 控制更复杂。这些领域应用的例子包括电传飞机控制系统、化工厂和炼油厂。模型预估计控制系统是使用专门的计算机辅助设计软件和被控系统的经验数学模型来设计的


Fuzzy logic

Fuzzy logic is an attempt to apply the easy design of logic controllers to the control of complex continuously varying systems. Basically, a measurement in a fuzzy logic system can be partly true, that is if yes is 1 and no is 0, a fuzzy measurement can be between 0 and 1.

Fuzzy logic is an attempt to apply the easy design of logic controllers to the control of complex continuously varying systems. Basically, a measurement in a fuzzy logic system can be partly true, that is if yes is 1 and no is 0, a fuzzy measurement can be between 0 and 1.

模糊逻辑是将易于设计的逻辑控制器应用于复杂连续变化系统的一种尝试。基本上,一个模糊逻辑系统中的度量可以是部分正确的,即如果是是1,否是0,一个模糊度量可以介于0和1之间。


The rules of the system are written in natural language and translated into fuzzy logic. For example, the design for a furnace would start with: "If the temperature is too high, reduce the fuel to the furnace. If the temperature is too low, increase the fuel to the furnace."

The rules of the system are written in natural language and translated into fuzzy logic. For example, the design for a furnace would start with: "If the temperature is too high, reduce the fuel to the furnace. If the temperature is too low, increase the fuel to the furnace."

系统的规则用自然语言编写,并转换成模糊逻辑。例如,炉子的设计是这样开始的: “如果温度太高,减少燃料到炉子。如果温度太低,就增加加热炉的燃料。”


Measurements from the real world (such as the temperature of a furnace) are converted to values between 0 and 1 by seeing where they fall on a triangle. Usually, the tip of the triangle is the maximum possible value which translates to 1.

Measurements from the real world (such as the temperature of a furnace) are converted to values between 0 and 1 by seeing where they fall on a triangle. Usually, the tip of the triangle is the maximum possible value which translates to 1.

来自真实世界的测量值(比如火炉的温度)通过观察它们落在三角形上的位置,被转换为0到1之间的值。通常,三角形的顶端是最大可能值,也就是1。<!-- 请解释一下,想必需要两个输入传感器才能形成一个三角形,一个刚好位于一条直线上,更多的传感器将填充 n 维空间。-->


Fuzzy logic, then, modifies Boolean logic to be arithmetical. Usually the "not" operation is "output = 1 - input," the "and" operation is "output = input.1 multiplied by input.2," and "or" is "output = 1 - ((1 - input.1) multiplied by (1 - input.2))". This reduces to Boolean arithmetic if values are restricted to 0 and 1, instead of allowed to range in the unit interval [0,1].

Fuzzy logic, then, modifies Boolean logic to be arithmetical. Usually the "not" operation is "output = 1 - input," the "and" operation is "output = input.1 multiplied by input.2," and "or" is "output = 1 - ((1 - input.1) multiplied by (1 - input.2))". This reduces to Boolean arithmetic if values are restricted to 0 and 1, instead of allowed to range in the unit interval [0,1].

然后,模糊逻辑将布尔逻辑修改为算术逻辑。通常“ not”操作是“ output = 1-input” ,“ and”操作是“ output = input. 1乘以 input. 2” ,“ or”是“ output = 1-(1- input. 1)乘以(1- input. 2)”。如果值被限制为0和1,而不是允许在单位时间间隔[0,1]范围内,那么这就简化为布尔运算。


The last step is to "defuzzify" an output. Basically, the fuzzy calculations make a value between zero and one. That number is used to select a value on a line whose slope and height converts the fuzzy value to a real-world output number. The number then controls real machinery.

The last step is to "defuzzify" an output. Basically, the fuzzy calculations make a value between zero and one. That number is used to select a value on a line whose slope and height converts the fuzzy value to a real-world output number. The number then controls real machinery.

最后一步是“去模糊化”输出。基本上,模糊计算使值介于0和1之间。该数字用于选择一条线上的值,该线的斜率和高度将模糊值转换为一个真实的输出数字。这个数字控制着真正的机器。


If the triangles are defined correctly and rules are right the result can be a good control system.

If the triangles are defined correctly and rules are right the result can be a good control system.

如果三角形定义正确,规则正确,那么结果就是一个好的控制系统。


When a robust fuzzy design is reduced into a single, quick calculation, it begins to resemble a conventional feedback loop solution and it might appear that the fuzzy design was unnecessary. However, the fuzzy logic paradigm may provide scalability for large control systems where conventional methods become unwieldy or costly to derive.

When a robust fuzzy design is reduced into a single, quick calculation, it begins to resemble a conventional feedback loop solution and it might appear that the fuzzy design was unnecessary. However, the fuzzy logic paradigm may provide scalability for large control systems where conventional methods become unwieldy or costly to derive.

当一个鲁棒模糊设计被简化为一个单一的,快速的计算,它开始类似于一个传统的反馈回路解决方案,它可能显示模糊设计是不必要的。然而,模糊逻辑范式可能为大型控制系统提供可伸缩性,传统的方法变得笨拙或昂贵的推导。


Fuzzy electronics is an electronic technology that uses fuzzy logic instead of the two-value logic more commonly used in digital electronics.

Fuzzy electronics is an electronic technology that uses fuzzy logic instead of the two-value logic more commonly used in digital electronics.

模糊电子学是一种使用模糊逻辑代替数字电子学中常用的二值逻辑的电子技术。


Physical implementation

文件:Leitstand 2.jpg
A DCS control room where plant information and controls are displayed on computer graphics screens. The operators are seated as they can view and control any part of the process from their screens, whilst retaining a plant overview.

A DCS control room where plant information and controls are displayed on computer graphics screens. The operators are seated as they can view and control any part of the process from their screens, whilst retaining a plant overview.

一个 DCS 控制室,工厂信息和控制信息显示在计算机图形学屏幕上。操作员坐着,因为他们可以从他们的屏幕上观察和控制过程的任何部分,同时保留工厂的概况。

文件:Hydraulic press control panel.jpg
A control panel of a hydraulic heat press machine with dedicated software for that function

A control panel of a hydraulic heat press machine with dedicated software for that function

液压热压机的控制面板,有专门的软件来实现这一功能

The range of implementation is from compact controllers often with dedicated software for a particular machine or device, to distributed control systems for industrial process control.

The range of implementation is from compact controllers often with dedicated software for a particular machine or device, to distributed control systems for industrial process control.

实现的范围从紧凑型控制器往往与专门的软件为一个特定的机器或设备,以分布式控制系统的工业过程控制。


Logic systems and feedback controllers are usually implemented with programmable logic controllers.

Logic systems and feedback controllers are usually implemented with programmable logic controllers.

逻辑系统和反馈控制器通常用可编程逻辑控制器来实现。


See also


References

模板:More citations needed

  1. "Feedback and control systems" - JJ Di Steffano, AR Stubberud, IJ Williams. Schaums outline series, McGraw-Hill 1967
  2. Kuphaldt, Tony R. "Chapter 6 LADDER LOGIC". Lessons In Electric Circuits -- Volume IV. Archived from the original on 12 September 2010. Retrieved 22 September 2010.
  3. Brady, Ian. "Programmable logic controllers - benefits and applications" (PDF). PLCs. Archived (PDF) from the original on 2 February 2014. Retrieved 5 December 2011.
  4. "Energy Efficient Design of Auxiliary Systems in Fossil-Fuel Power Plants" (PDF). ABB. p. 262. Archived (PDF) from the original on 2014-08-05. Retrieved 2014-04-07. |section= ignored (help)


External links

模板:Wikibooks

  • SystemControl Create, simulate or HWIL control loops with Python. Includes Kalman filter, LQG control among others.
  • Python Control System (PyConSys) Create and simulate control loops with Python. AI for setting PID parameters.

Category:Control theory

范畴: 控制理论

Category:Control engineering

类别: 控制工程

Category:Systems engineering

类别: 系统工程

Category:Systems theory

范畴: 系统论

Category:Automation

类别: 自动化


This page was moved from wikipedia:en:Control system. Its edit history can be viewed at 控制系统/edithistory