Help questions: PID parameter tuning
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Instrument control, PID adjustment parameters, the smaller the proportion P, the closer the control curve is to a straight line. Is this the better the effect?
The smaller P is, the smaller the change in control output will be. This is possible when the load is relatively stable. However, when the load changes greatly, it cannot be adjusted in time, which will cause the deviation to become larger.
It's definitely wrong to say this. It will cause too much fluctuation. I can't tell you the details.
The size of the proportional adjustment amplitude, integral to eliminate residual difference and differential to eliminate delay, adjust in advance
The differential is adjusted according to the frequency of deviation change. The greater the frequency of deviation change, the output increases. The smaller the frequency of deviation change, the smaller the output. In general, in order to prevent the output from oscillating, the differential is set to zero and PI adjustment is used.
Personally, I think you need to first figure out whether your P refers to proportion or proportional time. The relationship between the two adjustment functions and the numerical value is completely opposite! If it is a proportion, the smaller the value, the greater the effect. For proportional time, as the value increases, the effect becomes greater. Although there are many tuning formulas to refer to for PID tuning, and there are also some general rules to learn from, my personal operation * It is customary to slowly explore the rules of each control loop by yourself. Such adjustments are more in line with the actual working conditions of the device and more appropriate. Of course, this requires time to accumulate some conventional methods and master some rules.
During PID adjustment, if any of these three parameters is set to O, it means that it does not work.
Please tell me what the adjustment formula is. I am a layman and I have adjusted an unimportant regulating valve. It is purely a matter of ignorance.