PID控制理论大讨论

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PID控制理论大讨论。
先来个老外的wiki: http://en.wikipedia.org/wiki/PID_controller#Loop_tuning

Proportional term

The proportional term produces an output value 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 constant.


The proportional term is given by:

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 less sensitive controller. If the proportional gain is too low, the control action may be too small when responding to system disturbances. Tuning theory and industrial practice indicate that the proportional term should contribute the bulk of the output change.[citation needed]

Plot of PV vs time, for three values of Kp (Ki and Kd held constant)

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Integral term

The contribution from the integral term is proportional to both the magnitude of the error and the duration of the error. The integral in a PID controller is the sum of the instantaneous error over time and 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 integral term is given by:

The integral term accelerates the movement of the process towards setpoint and eliminates the residual steady-state error that occurs with a pure proportional controller. However, since the integral term responds to accumulated errors from the past, it can cause the present value to overshoot the setpoint value (see the section on loop tuning).

Plot of PV vs time, for three values of Ki (Kp and Kd held constant)

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Derivative term

The derivative of the process error is calculated by determining the slope of the error over time and multiplying this rate of change by the derivative gain . The magnitude of the contribution of the derivative term to the overall control action is termed the derivative gain, .

The derivative term is given by:

Derivative action predicts system behavior and thus improves settling time and stability of the system.[7][8]

Plot of PV vs time, for three values of Kd (Kp and Ki held constant)

圆点博士跟我学

dlyt03 发表于 2013-5-16 10:38
感觉PID 控制很深奥，弄懂了很牛！！

晚点来翻译，一起讨论。从基本理论，到实际应用，到生动化讲解。 大家来多多参与。

小菜儿

博士开启讲座模式啦！！！顶顶顶~~~

奋斗哥

准备好小板凳，纸笔，听课

suyong_yq

搞个PID的算法库就最好啦，简单配置一下就可以方便应用到任何一个应用中。

woaidabaobao

好多E文，E文不好，看着头疼，等博士翻译，带领学习~~~

js200300953

如果只是应用，没必要搞那么复杂吧。实际用就几行代码。

圆点博士跟我学

从理论到应用。讲完理论，js200300953来给大家说下应用。