PID range

[Pardis.km]

hello to you everybody.

What is the acceptable range of PID gains (Kp,KI,Kd) in different process?
for example, what is PID gain in temperature process in big industry?
or pressure process in pneumatic process?

What number should I start quantifying in different processes?

Thank you  for your comment.

[GerdW]

Hi Pardis,

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@Pardis.km wrote:

What is the acceptable range of PID gains (Kp,KI,Kd) in different process?

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The PID gains need to fit to the system in the control loop!

It doesn't matter if that system is located in "big industry" or "pneumatic process"…

What is your goal with that question? What do you really want to know instead of just some PID gain numeric values?

[Pardis.km]

Thanks for your comment.

I want to tune the PID gains in a temperature (or pressure) process. I want to quantify Kp (or Ki, Kd).

what is this range for quantification?

start from 10 to 100?

Start from 0 to 10,000? It is very difficult.

Starting from 3,500 to 10,000? If I do not know this range, it is very difficult and time consuming.

So it's important for me to know how to start tuning gains from what number?

For tuning PID gains in different processes, from what number to what number should I try?

Thank you a lot.

[GerdW]

Hi Pardis,

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@Pardis.km wrote:

So it's important for me to know how to start tuning gains from what number?

For tuning PID gains in different processes, from what number to what number should I try?

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You don't "just try", but you should start with an "educated guess"!

Have you heard about Ziegler-Nichols before? Did you read any books on PID controllers?

I usually start with a step response of the actuator in the control loop:

• you can determine a P gain from ratio between pv change and output value change
• you can determine an I gain from delay between output value step and pv settlement…