PID controller parameter tuning method - Database & Sql Blog Articles

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There are many methods for PID controller parameter tuning. There are two general categories:
The first is the theoretical calculation tuning method. It is mainly based on the mathematical model of the system, and the controller parameters are determined through theoretical calculations. The calculation data obtained by this method may not be directly usable, and must be adjusted and modified through engineering practice.
The second is the engineering setting method, which relies mainly on engineering experience and is directly carried out in the test of the control system. The method is simple and easy to grasp, and is widely used in engineering practice.
The engineering tuning method of PID controller parameters mainly includes critical ratio method, reaction curve method and attenuation method.
The critical ratio method is generally used now.
The tuning steps of the PID controller parameters using this method are as follows:
(1) First pre-select a sampling period that is short enough for the system to work;
(2) Add only the proportional control link until the system has a critical oscillation in the step response of the input, and record the proportional amplification factor and the critical oscillation period at this time;
(3) Calculate the parameters of the PID controller by a formula under a certain degree of control.
PID parameter setting: It is based on the familiarity of experience and technology, and the measurement value tracking and set value curve are referenced to adjust the size of P\I\D.
The engineering tuning of PID controller parameters, the empirical data of PID parameters in various adjustment systems can be referred to below:
Temperature T: P=20~60%, T=180~600s, D=3-180s
Pressure P: P=30~70%, T=24~180s,
Liquid level L: P=20~80%, T=60~300s,
Flow rate L: P=40~100%, T=6~60s.
Commonly used words:
Parameter tuning finds the best, from small to large, the first step is the proportional and post-integration. Finally, the differential plus curve is oscillated very frequently. The proportional disk needs to be enlarged to float around the big bay, and the proportional disk is slower than the return curve. The fluctuation period of the downward curve is long, and the integration time is longer. The oscillation frequency of the curve is fast. The differential is first lowered and the fluctuation is large and the fluctuation is slow. The differential time should lengthen the two curves of the ideal curve, 4 to 1 before the high and then lower
A look at the second adjustment and multi-analysis, the adjustment quality will not be low