kamenges
Member
Last Friday Peter got this thread going about PID tuning:
http://www.plctalk.net/qanda/showthread.php?t=36407
One of the things that came up pretty quick is that mathematically you can make any two pole system that is open loop stable as responsive as you want with a PD controller and still keep it stable. Most of us realized that this doesn't happen is real life. Sooner or later you will get the gains so high that the system will become unstable. There are definite causes of this, not the least of which are control system output saturation, actuator saturation and discrete processing update rates.
So one logical question is how do we find that point? Given things like update rate and maximum output how do we know how far left we can put our poles?
I'm getting snoozy. Have a good night everyone.
Keith
http://www.plctalk.net/qanda/showthread.php?t=36407
One of the things that came up pretty quick is that mathematically you can make any two pole system that is open loop stable as responsive as you want with a PD controller and still keep it stable. Most of us realized that this doesn't happen is real life. Sooner or later you will get the gains so high that the system will become unstable. There are definite causes of this, not the least of which are control system output saturation, actuator saturation and discrete processing update rates.
So one logical question is how do we find that point? Given things like update rate and maximum output how do we know how far left we can put our poles?
I'm getting snoozy. Have a good night everyone.
Keith