Example: Calculate the steady state errors of unit step, unit ramp and unit parabolic inputs for the system shown in Figure 1.

  Solution: The open loop transfer function is:

 

 

Taking Z-transform

 

 

Exercises:

1) Calculate the steady state errors of unit step, unit ramp and unit parabolic inputs for the system shown in Figure 2. For a) T = 0.5 sec. b) T = 1 sec.

 

 

 

2)  Calculate the steady state errors of unit step, unit ramp and unit parabolic inputs for the system shown in Figure 3.