Yes, beware of the so called experts. Many have experience with only a particular system and think the way they tuned that system applies to all. How can one give advice unless they know what the system is?aju said:We Always Found Out That Tuning Pid Always Create Some Problem
aju said:Can Any Body Suggest Easy Way To Tune Pid With Less Efforts An Dexact Way By Consuming Less Time
What does the derivative gain do? What improvement are you looking for?John Gaunt said:Add some D if you find it provides any improvement.
Why not?John Gaunt said:(usually it won't)
Peter Nachtwey said:Why not?
[/font]castlerock said:From www.simplesolvers.com
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[font=Verdana, Arial, Helvetica, sans-serif]Many control systems will, in fact, work quite well with only Proportional Control.[/font]
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[/font]castlerock said:[font=Verdana, Arial, Helvetica, sans-serif]I guess it depends on what your working on.[/font]
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Peter Nachtwey said:[/size]
Which systems? I know temperature systems, and velocity systems don't work properly with proportional only control. I do mainly position control applications. I know that proportional gain alone is unsatisfactory so I wonder what these simpleminds are sovling. It bothers me there is so much bad information out there. It is obvious to me these guys don't have experience in these types of systems and are making general statements that are misleading to rookies.
Links have been posted to this site many times. Does anyone know what it means?rsdoran said:This may be of interest, especially if you have/use Matlab.
http://www.engin.umich.edu/group/ctm/PID/PID.html
Examples are available at the bottom of the page.
Peter Nachtwey said:Links have been posted to this site many times. Does anyone know what it means?
For instance, in the proportional control section, what values of Kp cause the system to be:
1. Over damped
2. Critically damped
3. Under damped
Over shoot, Right. Overtemp? Wrong.CroCop said:1. Too much P, overshoot, ie overtemp
Wrong. Critically damped means no over shoot.CroCop said:2. Just right amount of P. On a step change, the PV typically has a small overshoot, but comes right back to the setpoint.
It depends upon the system doesn't it? On temperature and velocity systems you are right. On a position control system you would be wrong if it weren't for static friction.CroCop said:3. Not enough P. PV doesn't meet the SP, ie, doesn't come up to temp.
Bob, you are right about the damping factor. However, what values of Kp are required to achieve those damping factors?Bob O said:I will take a quick stab at this...It has bee a long time since playing with this. My vibrations book is at work so I can't check this.
1. Dampening Ratio >1
2. " " =1
3. " " <1