Mechatronics - May 2013

Mechanical Engineering (Semester 6)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) Define mechatronics and describe key elements of the mechatronics system.(5 marks) 1 (b) Explain how bit addressing is distinguished from byte addressing in 8051 microcontroller.(5 marks) 1 (c) Convert the following state-space system of a single input single output system into a transfer function

Here x₁ and x₂ are state variables, u(t) is a force vector and y(t) being the system response.(5 marks) 1 (d) Examine stability by Routh's criterion of control system having characteristic equation
s⁵+s⁴+2s³+2s²+3s+15=0.(5 marks) 2 (a) Explain 8051 microcontroller with neat functional block diagram.(10 marks) 2 (b) A unity feedback system has:

i) if r(t)=4t and k=2 find steady state error
ii) if it is desired to have a steady state error 0.2, find corresponding value of 'k'
iii) find steady state error if input is changed to 2+6t and value of 'k' to be 10.(10 marks) 3 (a) Two double acting hydraulic cylinders A, B are selected for an industrial application. The sequence of movement for cylinder piston is proposed as -
A+DelayB+(AB)-
Draw the electrohydraulic circuit using 4/3 double solenoid as final directional control valves.(10 marks) 3 (b) Explain following set of instructions of 8051 microcontroller
i) MOV
ii) POP
iii) INC
iv) MUL
v) XCH(10 marks) 4 (a) A process control system illustrated in figure 1 is desired to fill the bottle and convey this. The outlet valve is opened to fill the bottle as when the limit switch senses the presence of bottle and is closed automatically when the photosensor produces the signal as when the bottle is filled. The level of water in tank is maintained through a control valve. Develop a PLC ladder logic diagram for this control application.
(10 marks) 4 (b) With a neat sketch explain interfacing of stepper motor with 8051 microcontroller.(10 marks) 5 (a) Two pneumatic cylinders: A (single acting) and B (double acting) are selected for an industrial application. The sequence of movement for cylinder piston is as proposed below -
A+DelayB+DelayA-DelayB-
Further 3/2 single solenoid spring return valve for cylinder A and 5/2 double solenoid valve for cylinder B is selected to act as a final directional control valve. Design electropneumatic circuit for the proposed sequence.(10 marks) 5 (b) Write a note on
i) ON/OFF controller
ii) Servomotor(10 marks) 6 (a) Draw the root locus of the feedback system whose open loop transfer function is given by
(10 marks) 6 (b) Explain the factors to be considered for selecting a PLC for control application.(5 marks) 6 (c) What are the main advantages of a PID controller?(5 marks) 7 (a) Sketch a Nyquist diagram of the system having open loop transfer function
(10 marks) 7 (b) For a unity feedback control system having

Determine
i) characteristic equation
ii) natural frequency and damping ratio
iii) time at which 1^st undershoot will occur
iv) time period of oscillations
v) number of cycles output will perform before settling down(10 marks)