Hello,
I've been tinkering with PIDs for a while now and have a pretty good understanding of all of the terms. I typically set my initial (first try) proportional gain using the "Raise it until the output oscillates and then lower it until it doesn't anymore" method. That's been pretty effective but can take an incredibly long time, especially when dealing with heating and cooling applications.
I'd like to learn how to get an initial (ballpark) Kc value from doing a bump test. I've read the article on controlguru.com about how to calculate this from dividing the change in the process variable (%) by the change in output (%) but it's still a bit unclear. Does anybody have any rules of thumbs for determining an initial Kc value from the bump test?
Also, controlguru.com suggests leaving the reset rate equal to the process time. Have you folks found that to be a good initial setting for reset?
Thanks!
I've been tinkering with PIDs for a while now and have a pretty good understanding of all of the terms. I typically set my initial (first try) proportional gain using the "Raise it until the output oscillates and then lower it until it doesn't anymore" method. That's been pretty effective but can take an incredibly long time, especially when dealing with heating and cooling applications.
I'd like to learn how to get an initial (ballpark) Kc value from doing a bump test. I've read the article on controlguru.com about how to calculate this from dividing the change in the process variable (%) by the change in output (%) but it's still a bit unclear. Does anybody have any rules of thumbs for determining an initial Kc value from the bump test?
Also, controlguru.com suggests leaving the reset rate equal to the process time. Have you folks found that to be a good initial setting for reset?
Thanks!