(1) Trial and error method
The trial and error method is to manually select PID parameters to make the control system respond to the predetermined requirements. This method is both simple and complex. In simple terms, if you have experience and luck, you may quickly achieve the goal in SIMULINK. In difficult terms, in on-site practice, it may take a lot of time and effort to adjust the three parameters, but the task is not completed.
(2) Critical proportionality method
The critical proportionality method is to adjust the proportionality only under the action of P to make the system oscillate in equal amplitude, and then calculate the PID value effect according to the formula. The left half is the system oscillates in equal amplitude, and the right half is the control effect. The curve effect of PID critical proportionality control through MATLAB simulation.
(3) Attenuation curve method
The attenuation curve method is to adjust the proportionality only under the action of P to attenuate the system response curve in a 4:1 or 10:1 ratio, and then calculate the PID value effect according to the formula. The left half is the system attenuation curve, and the right half is the control effect. The curve effect controlled by PID attenuation curve method through MATLAB simulation.
(4) Reaction curve method
The response curve method is to add a step signal in the open-loop state, then approximate the original system with a first-order pure lag system, and calculate the PID value effect based on the Z-N or C-C formula. The left half is the system response curve, and the right half is the control effect. A third-order system, the relevant parameters obtained by the critical proportionality method. The following figure shows the curve effect controlled by PID response curve method through MATLAB simulation.