From PI to 8, Control in a Unified Framework

Based on a recently presented evaluation method, tuning rules are introduced and compared for a series of PID related controllers. For all of them, the integral gain and the high frequency gain (the parameters in a PI controller), are used as the main tuning parameters. As these directly correspond to well known properties of a control system, they are easy to handle for an operator. It is also shown that a well tuned PID controller augmented by a low pass filter, to increase the roll off rate, is quite competitive to a PID weighted 31, controller, and superior to the common PI weighted 31, controller.