What is pid control?

PID control, also known as proportional integral differential control, is a widely used control method in industrial control systems.

First, the basic concept of PID control

PID control is a feedback control method, which adjusts the output of the system by proportional, integral and differential operations on the deviation between the input and output of the system, thus achieving the expected control effect. PID control consists of three basic parts: proportion (P), integral (I) and differential (D).

1, proportional part:

According to the size of the input deviation, adjust the output in proportion. The larger the proportional coefficient, the faster the output response, but it is easy to overshoot; The smaller the proportional coefficient, the slower the output response, but the larger the steady-state error.

2. Overall part:

The input deviation is integrated to eliminate the steady-state error. The larger the integration time constant, the stronger the energy knife to eliminate the steady-state error, the smaller the constant effect of integration time, and the weaker the ability to eliminate the steady-state error.

3. Differential part:

Differential the input deviation to reduce the dynamic deviation of the system. The greater the differential time constant, the stronger the ability to suppress the dynamic deviation of the system, and the smaller the differential time constant, the weaker the ability to suppress the dynamic deviation of the system.

Second, the characteristics of PID control

1, simple algorithm:

PID control algorithm is simple and easy to understand and realize.

2, good robustness:

PID control is insensitive to the change of system parameters and has strong robustness.

3, high reliability:

PID control has high reliability. When the system fails, the stability of the system can be maintained by adjusting the parameters.

4. Strong adaptability:

PID control is suitable for all kinds of control systems and can meet different control requirements.

Application of PID control;

1, used in various industrial process control systems.

PID control is widely used in various industrial process control systems because of its simplicity, reliability and strong adaptability, such as temperature control, pressure control and liquid level control. At the same time, PID control is also widely used in smart homes, autonomous driving, drones and other non-industrial fields.

2. In terms of temperature, pressure and liquid level control.

In the aspect of temperature control, PID control can realize accurate temperature control by adjusting the power output of the heater. In pressure control, PID control can achieve stable pressure control by adjusting the opening of the valve. In the aspect of liquid level control, PID control can realize accurate liquid level control by adjusting the working frequency of the pump.

3. It is applied to robot control, power system control and other fields.

For example, in robot control, PID control can be used to adjust the posture and position of the robot, and in power system control, PID control can be used to adjust parameters such as voltage and frequency of the power system.