This app allows straightforward design of PID-Type controllers based on the results from a relay tuning experiment and Ziegler-Nichols tuning rules. This is the paid upgrade from PIDControl. In addition the the features of the free version, you can:

• Export tuning results in an e-mail
• Set the number of significant digits displayed in the calculator
• Save values entered in tuning calculator even if the App is quit or the phone rebooted
• Add “Clear All” button to calculator
• Save last use tab

Future updates will add customizable tuning rules, tuning based on step tests and other tuning rules.

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When put under closed loop control with a relay, i.e., an on/off controller, a process is put into sustained oscillations. From the amplitude of input and output the ultimate process gain can be computed. The period of oscillation is the ultimate process period. These two parameters are traditionally obtained from open loop experiments which can be time consuming and unsafe because the process can become unstable. Using a relay controller these values can be obtained quickly and safely.

A convenient input form allows entry of experiment parameters and results. Quickly select controller type (P, PI, PID) and mode (slow, normal, fast) to determine tuning parameters.

Keywords: PID, Control, Tuning, Ziegler Nichols, Relay, Åström, Hägglund