06.11.2015
AST303-1 Quiz-2
Derive the closed-loop transfer function for the system
Solution:
closed-loop transfer function =
C (s)
,
R (s)
2 POINTS where
C (s) = G1 (s) E (s) ,
2 POINTS and
E (s) = R (s) + B (s) = R (s) + G2 (s) C (s) R (s) = E (s) G2 (s)

23.10.2015
AST303-2 Quiz-1
1-) At a (level) crossing of a highway with a railroad, by a control system the cars are made to stop at
the times when a train passes. What kind of a control system is this: open-loop or closed-loop? Why?
Solution:
Closed-loop

13.11.2015
AST303-2 Quiz-3
The figure below shows a closed-loop system with a reference input and a disturbance input:
The output C(s) when both the reference input and the disturbance input are present can be found as
C (s) =
1
1+GC (s)GP (s)
[GC (s) GP

06.11.2015
AST303-2 Quiz-2
Answer the questions below for the system given with the block diagram:
a) What is the feedforward transfer function of the system?
b) What is the total feedback transfer function of the system? [Hint: Decide whether the two fee

25.12.2015
AST303-2 Quiz-8
A thermometer requires 1 min to indicate 98% of the response to a step input. Assuming the thermometer to
be a first-order system, find the time constant.
If the thermometer is placed in a bath, the temperature of which is chang

23.10.2015
AST303-1 Quiz-1
1-) For Watts speed governor given in the figure below, state the following parts of the control system:
controlled variable, control signal, plant, disturbance.
Solution:
controlled variableengine speed, control signalamount of

13.11.2015
AST303-1 Quiz-3
The figure below shows a closed-loop system with a reference input and disturbance input. Obtain the
expression for the output C(s) when both the reference input and disturbance input are present.
Solution:
To find the response

28.11.2015
AST303 Homework 4
(Due 01 Dec Tuesday)
This homework is for your preparation for the Midterm on this Tuesday.
1-) Solve Example 3-1 and 3-2.
Bonus:In solving these examples, discuss why the serial
connected springs or dampers are under the effe

27.12.2015
AST303 Homework 8
(Due 31 Dec Thursday)
1-) Solve A-5-3.
2-) Consider the mechanical vibratory system
When 10 N of force (step input) is applied to the system, the mass oscillates as
Determine m, b, and k of the system from this response curve.

25.12.2015
AST303-1 Quiz-8
Considering small deviations from steady-state operation, draw a block diagram of the air heating system shown
in the Figure. Assume that the heat loss to the surroundings and the heat capacitance of the metal parts of the
heate

18.12.2015
AST303-2 Quiz-7
Consider the liquid-level control system shown in the Figure. The controller is of the proportional type. The
set point of the controller is fixed. Assuming that changes in the variables are small, draw the block diagrams
of eac

18.12.2015
AST303-1 Quiz-7
Consider the liquid-level control system shown in the Figure. The controller is of the proportional type. The
set point of the controller is fixed. Assuming that changes in the variables are small, draw the block diagrams
of eac

04.12.2015
AST303-1 Quiz-5
Obtain the transfer function Xo (s)/Xi (s) of the mechanical system shown in Figure (a). Also obtain the transfer
function Eo (s)/Ei (s) of the electrical system shown in Figure (b). Show that these transfer functions of the two

27.11.2015
AST303-2 Quiz-4
Simplify the block diagram shown in figure. Obtain the transfer function relating C(s) and R(s).
Solution: For the solution check the problem A-2-2.

19.12.2015
AST303 Homework 7
(Due 25 Dec Frday)
1-) Show that the block diagram
which we drew at the end of Fridays lecture, is equivalent to the one given in Fig. 4-26(b)
of our textbook, which is
2-) Solve A-4-10 and A-4-11.
3-) Solve A-5-1 and B-5-1.
1

12.12.2015
AST303 Homework 6
(Due 18 Dec Frday)
Solve the problems A-4-1, B-4-1, B-4-2. For the Problem B-4-2, do not solve the last part
of the question which states Obtain the steady-state error when the disturbance qd is a
unit-step function.
1