Question

求一篇关于PID控制器的英语作文，包括PID的来源、控制参数等，80个词左右，最好有中文翻译，谢谢！

Answer 1

PID controllers can be stand-alone controllers (also called single loop controllers),
controllers in PLCs, embedded controllers, or software in Visual Basic or C# computer programs.
PID controllers are process controllers with the following characteristics:
 Continuous process control
 Analog input (also known as “measurement” or “Process Variable” or “PV”)
 Analog output (referred to simply as “output”)
 Setpoint (SP)
 Proportional (P) , Integral (I) , and/or Derivative (D) constants
Examples of “continuous process control” are temperature, pressure, flow, and level control.
For example, controlling the heating of a tank. For simple control, you have two temperature
limit sensors (one low and one high) and then switch the heater on when the low temperature
limit sensor turns on and then turn the heater off when the temperature rises to the high
temperature limit sensor. This is similar to most home air conditioning & heating thermostats.
In contrast, the PID controller would receive input as the actual temperature and control a
valve that regulates the flow of gas to the heater. The PID controller automatically finds the
correct (constant) flow of gas to the heater that keeps the temperature steady at the setpoint.
Instead of the temperature bouncing back and forth between two points, the temperature is held
steady. If the setpoint is lowered, then the PID controller automatically reduces the amount of gas
flowing to the heater. If the setpoint is raised, then the PID controller automatically increases the
amount of gas flowing to the heater. Likewise the PID controller would automatically for hot,
sunny days (when it is hotter outside the heater) and for cold, cloudy days.
PID 控制器可以是独立控制器(也可以叫做单回路控制器)，可编程控制器(PLCs)中的控
制器，嵌入式控制器或者是用Vb或C#编写的计算机程序软件。
PID 控制器是过程控制器，它具有如下特征：
 连续过程控制；
 模拟输入(也被称为“测量量”或“过程变量”或“PV”)；
 模拟输出(简称为“输出”)；
 基准点(SP)；
 比例、积分以及/或者微分常数；
“连续过程控制”的例子有温度、压力、流量及水位控制。例如。控制一个容器的热量。对于简单的控制，你使用两个具有温度限定功能的传感器(一个限定低温，一个限定高
温)。当低温限定传感器接通时就会打开加热器，当温度升高到高温限定传感器时就会关闭
加热器。这类似于大多数家庭使用的空调及供暖系统的温度自动调节器。
反过来，PID 控制器能够接受像实际温度这样的输入，控制阀门，这个阀门能够控制
进入加热器的气体流量。PID 控制器自动地找到加热器中气体的合适流量，这样就保持了
温度在基准点稳定。温度稳定了，就不会在高低两点间上下跳动了。如果基准点降低，PID
控制器就会自动降低加热器中气体的流量。如果基准点升高，PID 控制器就会自动的增加
加热器中气体的流量。同样地，对于高温，晴朗的天气(当外界温度高于加热器时)及阴冷，
多云的天气，PID 控制器都会自动调节。