Trial and Error Control Approach
Trial and Error Control Approach
(OP)
The regular control loop aims to keep the process variable nearby a desired set point by changing the controlled variable (the output) as a function of the error (difference between process variable and set point). With the trial and error approach, the control system aims to "improve" the process variable (e.g. raise the yield or efficiency) by continuously changing the controlled variable and "checking the result": if the process variable improves, the system will keep on changing the output in the same direction. If it does not, the change direction will go the other way. Of course, many other issues are involved, such as the change cycle, the amount of change, etc.
Anyone heard of an application using this trial and error approach to an automatic controller?
Thanks to all
Anyone heard of an application using this trial and error approach to an automatic controller?
Thanks to all





RE: Trial and Error Control Approach
RE: Trial and Error Control Approach
Cheers,
MVD
RE: Trial and Error Control Approach
RE: Trial and Error Control Approach
These dynamics can be calculated with dynamic process models or measured, i.e. with a step response on the process. Once you know the process dynamics (behaviour) one can select the most appropriate Proportional, Integral and Deravitive action in the controller. Trail and error (for me at least) suggests "monkey around a bit and see what happens". This is not how correctly tuned automatic controllers work.
Please see also: Http://www.controlstation.com/
RE: Trial and Error Control Approach
RE: Trial and Error Control Approach
It's mostly a set of IF THEN rules fed by linguistic variables as colder, warmer, hot. The controller output is set by addition the series of (sometimes contradictory) requirements.
See also: http://www.fuzzytech.com
And demo on: http://www.iit.nrc.ca/IR_public/fuzzy/fuzzyShower.html
Hope this helps.