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Question 1
(a) i) Dynamic System Modelling is used in the design of control system. List the main steps of this process. (5 marks)
ii) List 5 advantages of closed-loop systems over open-loop systems. (5 marks)
(b)A particular closed loop system has a pair of complex conjugate poles at: s = -3.5 ± j4.2
i)Sketch the pole/zero diagram and state the frequency of oscillation and the system time- constant. (4 marks)
ii)The system gain constant is 2.5, determine the system’s closed loop transfer function and hence calculate the system’s closed loop step response.

Question 2
(a)i) Open-loop frequency response tests are sometimes carried out on a system.

Why is this carried out, and briefly explain the procedure. (7 marks)

ii)On the Nichols chart in the exam book, sketch a typical open loop frequency response of an UNSTABLE system. (2 marks)

iii)If a system is predicted to be unstable from the open loop frequency response, what step would then be taken to stabilise the system

(b)i) Sketch the Root Locus as K varies for a 3rd order system with 3 open loop poles and no zeroes. Assume all poles are real. (4 marks)

ii)Explain the behaviour of this closed loop system as K varies from 0 to ∞. (8 marks)

iii)State the change in the closed loop system behaviour if the least significant open loop is moved to the left.

Question 3
a)Find the state equations and output equation for the system whose transfer function is
( ) = 2s+1
s2+7s+9
b)A transducer is used to convert physical phenomenon into a readable format, i.e. system state. Many factors must be considered when selecting a transducer for a particular application.
List FOUR headings that must be considered, and for each state ONE parameter. [8 marks]

Question 4
a)What does signal conditioning mean in instrumentation Explain the three types of signal conditioning function.
[4 marks]
b)A system’s close-loop block diagram is shown as below.
( ) is the process and ( ) is the feedback device.
Draw the block diagram of a computer control system for this system by adding the components / ,
/ , digital PID controller in the block diagram.
[6 marks]

c)What is zero-order hold (ZOH) Find out the transfer function of a ZOH.
[15 marks]