Conference Contribution

Signal Filtering in PID Control

Tore Hägglund


The major input signals entering the PID controller are; the setpoint, the process output, and measurable load disturbances. By feeding these signals through suitable filters, the properties of the feedback loop can be improved significantly. This presentation will treat setpoint handling, feedforward from load disturbances, TITO (two input two output) control, noise filtering, and process dynamics compensation. An industrial case from the steel industry is also discussed.


PID control, feedforward, filtering, lead-lag filter, TITO control, decoupling, controller structures, steel industry


In IFAC Conference on Advances in PID Control, Brescia, Italy, March 2012.