PID parameter debugging steps - Solutions - Huaqiang Electronic Network

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No control algorithm is more efficient and convenient than the PID adjustment rule. Now some of the funky point regulators are basically derived from the PID. It can even be said that the PID regulator is the other control adjustment algorithm.
Why is the PID application so extensive and long-lasting?
Because PID solves the most basic problem that automatic control theory has to solve, it is the stability, rapidity and accuracy of the system. Adjusting the PID parameters can achieve the system's load capacity and anti-interference ability under the premise of system stability. At the same time, the integral term is introduced in the PID regulator, and the system adds a zero point to make it a first order or For systems above the first order, the steady-state error of the system step response is zero.
Due to the wide variety of controlled objects in the automatic control system, the parameters of the PID must also change to meet the performance requirements of the system. This brings considerable trouble to the user, especially for beginners. The following is a brief introduction to the general steps to debug PID parameters:
1. The negative feedback automatic control theory is also called the negative feedback control theory. First check the system wiring and make sure the feedback from the system is negative feedback. For example, the motor speed control system, the input signal is positive, when the motor is required to rotate forward, the feedback signal is also positive (PID algorithm, error = input - feedback), and the higher the motor speed, the larger the feedback signal. The rest of the system is the same as this method.
2. General principles of PID debugging
a. Increase the proportional gain P when the output does not oscillate.
b. When the output does not oscillate, reduce the integral time constant Ti.
c. Increase the differential time constant Td when the output does not oscillate.
3. General procedure
a. Determine the proportional gain P
When determining the proportional gain P, first remove the integral term and the derivative term of the PID, generally let Ti=0, Td=0 (see the parameter setting description of PID for details), so that the PID is pure proportional adjustment. The input is set to 60%~70% of the maximum allowed by the system, and the proportional gain P is gradually increased by 0 until the system oscillates; in turn, the proportional gain P from this time gradually decreases until the system oscillation disappears, recording At this time, the proportional gain P sets the proportional gain P of the PID to 60% to 70% of the current value. Proportional gain P debugging is completed.
b. Determine the integral time constant Ti
After the proportional gain P is determined, the initial value of a larger integral time constant Ti is set, and then Ti is gradually decreased until the system oscillates, and then, in turn, Ti is gradually increased until the system oscillation disappears. Record Ti at this time, and set the integration time constant Ti of the PID to 150% to 180% of the current value. The integration time constant Ti is completed.
c. Determine the integration time constant Td
The integral time constant Td is generally not required to be set and is 0. To set, as in the method of determining P and Ti, take 30% of the oscillation.
d. The system is unloaded and loaded and coordinated, and the PID parameters are fine-tuned until the requirements are met.