In this work, two types of controller were designed for the nonlinear air blower system PT326 used at
the Instrumentation Laboratory Faculty Electrical Engineering, UiTM, Shah Alam. This work began with
collection of data from the experimental work. Once the S-shape of the system response was obtained,
the procedure of getting the process dead time, τD and time constant τC was applied to the S-shape form.
By determining these two values, the optimum values of PI and PID controllers can be calculated. From
the acquired data, the simulation model was developed in MATLAB/Simulink R2013a software using
the transfer function obtained from the open-loop control system. The modelling system is based on
the transfer function of open-loop air blower system PT326 before the design state of finding a suitable
controller can be suggested. The controller design of PI and PID was obtained using the first method
Ziegler-Nichols tuning rules. The result from the simulation shows that the Ziegler-Nichols first tuning
rules can be applied in designing the PI and PID controller based on S-shape response obtained in
open-loop test.