Closed Loop Tuning

Introduction

This short simulation has been set up for the user to practise tuning a controller using the Zeiglar Nichols Closed Loop Response Method.

In this exercise it is simply a matter of using the Java applet below to practise the closed loop method following the simple guidelines given and then filling out the form to make sure that the right answers have been obtained.

There are six stages:

Set Up System With Proportional Only Control

The applet below shows a process which is being controlled with a proportional only controller. All you have to do is alter the gain of the process until the response oscillates with a constant amplitude.

Enter Ultimate Gain

Once you have found the Ultimate Gain please enter the value in the box below.

Ultimate Gain

Evaluate Ultimate Period

Now look at the response and evaluate the Ultimate Period. Please enter this value in the box below.

Ultimate Period

Obtain the Controller Parameters

The next stage is to use the above values to fill in the table.

Controller Type Gain Reset Derivative
P /2 - -
PI /2.2 Pu/1.2 -
PID /1.7 Pu/2 Pu/8

Controller Type Gain Reset Time
Proportional
Proportional Integral

Comparison With Actual Values

Once you have entered your values, please click here to find out how close you are to the actual answers:

Controller Type Gain Reset Time How Close?
Proportional
Proportional Integral

Run Process With Control

Finally it is possible to try out the above values in the simulation below and hence do some fine tuning to find the optimum values.

Please move Back to try open loop method or Return to The Virtual Control Laboratory