PI settings for integrating processes based on ultimate cycle information

Presents simple proportional integral (PI) tuning formulas for integrating processes. They are based on the knowledge of the ultimate gain and the ultimate period. This information can be obtained by performing a classical ultimate cycle experiment or by using the relay feedback technique. Refined settings are proposed when the process gain is known. The tuning method is based on a maximum peak resonance specification. The results are compared to those obtained with the Ziegler-Nichols settings. Coherent performances are obtained over a wide range of linear integrating processes