To reduce the steady-state error, a lag controller will be added to the system. Create an new m-file , and enter the following commands. Once again, click on the real axis around -0.4. You should have the following response. As you can see, the steady-state error has been reduced to near zero.
Slight overshoot is a result of the zero added in the lag controller.
Now all of the design criteria have been met and no further iterations will be needed. We would like to hear about difficulties you had with the tutorials, suggestions you have for improvement, errors that you found, or any other comments that you have. 26 Dec 2000.