PID Feedforward Loop


Thread Starter


I have a question to the experts of this forum.

I wish to know how is error calculated in PIDFF algorithms. In a general PID algorithm error e = PV-SP. The PID algorithm acts on this error.

But in a PIDFF control algorithm, is error E = PV-SP+FF? Will the PID algorithm act on this E (i.e., PV-SP+FF) OR E is still PV-SP and FF gets added later to the PID output of PV-SP?

thanks and regards
The Feed Forward action is normally added to the output of the PID loop. The FF value should not be used in calculating the e value of the controller.