I remember someone (maybe Joep?) has tested a PID library a while ago. I'm not sure it was here or on jallist. Anyone remember? I've seen a thermostat with fuzzy logic enhanced PID, where the P, I and d parameters should be different than those used in classic PID. The thermostat have an auto-learning mode where is optimising the PID parameters by itself, based on the temperature variation after a few ON-OFF commands. Once the system is optimised it works fine until the load is heavily changing.
I'm curious how can be used such algorithm for driving a load with variable PWM frequency. Right now I'm heating something with an unpredictive behaviour (it can increase it's temperature or not). One requested effect (which is not thermal) appears better with the finest granularity of the pulse (high PWM frequency, many pulses), but controlling the secondary effect (heating) means a large granularity of the pulse (small PWM frequency, less pulses). So, the process optimalisation require an automating switching (better a proportional one) between those two situations. The simplest way I'm thinking is defining a delta range before reaching the requested temperature which can control the frequency of the PWM. How this sound to you guys? thx, Vasile -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
