# Ziegler Nichols Closed Loop Tuning Calculator

The closed loop Ziegler Nichols tuning method is widely taught in academics, but has limited practical application due to risks of driving a process into continuous cycles. This app makes it easy to calculate the closed loop tuning parameters by using the open loop process parameters (which are safer to obtain), and without the requiring a closed loop test on the process. This app will calculate the tuning parameters for a first order process with delay using the closed loop Ziegler Nichols tuning rules.

## Download

.xlsx file

## How to use

Key in the first order process parameters (Gain, lag and delay) into the spreadsheet, the tuning parameters for P only, PI and PID controllers are obtained. Note that this app requires a minimum amount of delay. A delay free system will not go into cycles with only a proportional controller, and hence this method will not work.

If the tuning parameters are not found, the cells show "#VALUE!" error. Also, the process gain must be scaled (dimensionless).

## How it works

The Ziegler Nichols tuning calculator works by using Named Formulae to calculate the ultimate gain and the critical frequency as described under this application of the Bode plot. The formulae used are similar those in the Bode plot app. There are additional formulae for calculating the ultimate Gain (Ku) and period of oscillations (Pu).

## Also See:

PID Loop SimulatorBode Plot Generator

PI Control of First Order Process

Simulation of On Off Control