A 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 weighted sum 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 set point and the degree of system oscillation. Note that the use of the PID algorithm for control does not guarantee optimal control of the system or system stability.
Some applications may require using only one or two modes to provide the control 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.
比例積分微分控制器（PID控制器）是一個(gè)通用的控制回路的反饋機(jī)制，廣泛應(yīng)用于工業(yè)控制系統(tǒng)。 PID控制器試圖糾正誤差之間的測量過程變量和一個(gè)理想的設(shè)定值，通過計(jì)算，然后輸出糾正后的輸出值，可以調(diào)整的過程。
PID控制器的計(jì)算（計(jì)算），涉及三個(gè)不同的參數(shù);比例，積分和微分。比例值確定的反應(yīng)到目前的誤差，積分決定反應(yīng)的基礎(chǔ)上，總結(jié)最近的誤差和微分決定的反應(yīng)率在哪些誤差已發(fā)生變化。加權(quán)這三個(gè)行為，是用來調(diào)整的過程中，通過控制元件來控制一個(gè)控制閥得位置或電源供應(yīng)的一個(gè)加熱元件。
“微調(diào)”PID控制器的三個(gè)常量PID控制器可以提供控制行動(dòng)，專為特定進(jìn)程的要求?？刂破鞯姆磻?yīng)可以說是對一個(gè)誤差得響應(yīng)，在某種程度上控制超過設(shè)定程度的系統(tǒng)振蕩。請注意，使用該P(yáng)ID控制算法的控制并不能保證最優(yōu)控制或系統(tǒng)的穩(wěn)定性。
一些應(yīng)用程序可能只需要一個(gè)或兩個(gè)模式，以提供適當(dāng)?shù)南到y(tǒng)控制。這是所取得的設(shè)置增益控制不受歡迎的產(chǎn)出為零。 PID控制器可以被稱為的PI，PD，P或I控制器，在沒有各自的控制行動(dòng)的時(shí)候。 PI控制器是特別常見，由于微分對測量噪音非常敏感，由于控制作用缺少積分可能防止系統(tǒng)達(dá)到其設(shè)定值。