What is a PID regulator? What are the three parts of a PID regulator?

What is a PID controller?

PID regulator is an automatic control system based on the proportional-integral-differential (PID) control algorithm. It realizes automatic control by continuously adjusting the control quantity so that the output value of the controlled object gradually approaches the target value. PID regulator is widely used in various industrial automation control systems, such as temperature control, pressure control, flow control, etc. It calculates the proportional, integral and differential values ​​of the error signal, and then adds them up by weight to obtain the control quantity. Specifically, the control output of the PID regulator is:

Output = Kp × deviation + Ki × integral deviation + Kd × differential deviation

Among them, Kp, Ki and Kd are proportional coefficient, integral time and differential time respectively, and the deviation is the error between the target value and the feedback signal. The proportional control (P control) in the PID regulator adjusts the control amount by the size of the error signal, the integral control (I control) adjusts the control amount by the integral value of the error signal, and the differential control (D control) adjusts the control amount by the rate of change of the error signal. The combination of the three control methods can quickly respond to and stably control the output value of the controlled object.

What are the three parts of the PID controller?

The PID regulator usually consists of the following three parts:

Proportional controller (P controller): The function of the proportional controller is to generate an output signal proportional to the deviation according to the deviation. The proportional coefficient Kp determines the size of the output signal. When the deviation changes, the output signal will also change. The proportional controller is mainly used to eliminate deviations and quickly respond to external interference and changes.

Integral controller (I controller): The function of the integral controller is to generate an output signal proportional to the integral of the deviation based on the integral value of the deviation. The integral time Ti (or integral coefficient Ki) is an important parameter of the integral controller. It controls the speed of the integral action and determines the system's ability to correct persistent deviations. The integral controller is mainly used to eliminate persistent deviations and enhance the stability and accuracy of the system.

Differential controller (D controller): The function of the differential controller is to generate an output signal proportional to the rate of change of the deviation according to the rate of change of the deviation. The differential time Td (or differential coefficient Kd) is an important parameter of the differential controller. It controls the speed of the differential action and determines the system's ability to suppress fast-changing signals. The differential controller is mainly used to suppress the interference of the system to external disturbances and reduce the oscillation and shock of the system.

The three control modes of proportional, integral and differential interact with each other and can effectively control the output value of the controlled object and achieve precise automatic control.

Function of pid controller

PID regulator is a commonly used controller. Its main function is to control the output value of the controlled object through the interaction of three control methods: proportional, integral and differential, to achieve precise automatic control. Specifically, PID regulator has the following functions:

Eliminate deviation: When the output value of the controlled object is inconsistent with the set value, the PID regulator can generate an output signal proportional to the deviation. By controlling the input of the controlled object, the deviation can be eliminated and the output value of the controlled object can be stabilized near the set value.

Improve stability: PID regulator can enhance the system's ability to correct continuous deviations and improve system stability through integral control.

Improve control accuracy: PID regulator can suppress the interference of the system to external disturbances through differential control, reduce system oscillation and shock, and improve control accuracy.

Fast response: The PID regulator can quickly respond to external interference and changes through proportional control, quickly adjust the output value of the controlled object, and achieve fast response.

Adaptive adjustment: The PID regulator can adaptively adjust the control parameters according to the actual output value and set value of the controlled object to achieve more precise control.

In short, PID regulator has a wide range of applications in the field of automatic control and can be used to control various controlled objects, such as temperature, pressure, flow, etc.