Tutorial -3 DEPARTMENT OF MECHANICAL ENGINEERING FACULTY OF ENGINEERING Tutorial No-3 1. 2. 3. Find the output for a unit step input for the following first order transfer functions. Also check what happens to the output when the time goes to infinity 1 ( )= ( )= ( )= ( )= +1 Find the output for a unit step input for the following first order transfer functions. Also check what happens to the output when the time goes to infinity. (1) ( )( (2) ( ) )( ) (3) ( If the output of a second order function is given by ) (4) ( ) ( )= + + where > 0, 0 < < 1 Show that the output for a unit step input is a decaying oscillatory function. Find the final value when the time goes to infinity. Also show that the time to reach the maximum peak is where = 1 − . Also find the maximum peak value. 4. Take the transfer function obtained in tutorial 2 question 3 where it is given by 1 + S(T1 + T2 ) + S2T1T2 ----------------------------------1 + S(T1 + T2 + T3) + S2T1T2 and T1, T2 and T3 are time constants that is greater than zero. a) Show that the system will not get oscillatory output in the natural motion. b) Show that the system is stable. c) Sketch the output time function for a unit step input. 5. Find the steady state error for a unit step input, ramp input and parabolic for the questions in Tutorial 2, question 2 and question 3. Prepared By Dr. V P C Dassanayake 1