Steady State Errors

Where,

• R(s) is the Laplace transform of the reference Input signal r(t)r(t)
• C(s) is the Laplace transform of the output signal c(t)c(t)

We know the transfer function of the unity negative feedback closed loop control system as

ote − If any of the above input signals has the amplitude other than unity, then multiply corresponding steady state error with that amplitude.

Note − We can’t define the steady state error for the unit impulse signal because, it exists only at origin. So, we can’t compare the impulse response with the unit impulse input as t denotes infinity.

Example

Simplify the above block diagram by keeping the unity negative feedback as it is. The following is the simplified block diagram.