THEORY EXAMINATION (SEM–VI) 2016-17 MECHATRONICS

MECHATRONICS (NME014)

SECTION – A

(Attempt All | 10 × 2 = 20 Marks)

(a) What do you understand by mechatronics?

Mechatronics is an integrated engineering discipline that combines mechanical engineering, electronics, control systems, and computer technology to design intelligent products and systems.

(b) Conventional system vs Mechatronics system design

(c) What are flip-flops?

Flip-flops are basic memory elements in digital electronics that can store one bit of data (0 or 1). Examples include SR, JK, D, and T flip-flops.

(d) What is JIT?

JIT (Just-In-Time) is a manufacturing philosophy in which materials are produced or delivered exactly when needed, reducing inventory cost and waste.

(e) What do you mean by bionics?

Bionics is the application of biological principles to engineering systems, such as robotic arms inspired by human limbs.

(f) Define robotics and laws of robotics

Robotics: The branch of engineering dealing with the design, construction, and operation of robots.

Laws of Robotics (Asimov):

A robot must not harm humans.

A robot must obey human commands unless it conflicts with the first law.

A robot must protect itself without violating the first two laws.

(g) What is a servomotor?

A servomotor is a feedback-controlled motor used for precise control of position, speed, and torque.

(h) What is an automatic control system?

An automatic control system is a system that controls output automatically using feedback without human intervention.

(i) Define smart sensors

Smart sensors are sensors with built-in signal processing, self-calibration, and communication capability.

(j) What are motion control devices?

Motion control devices control position, speed, and acceleration of mechanical systems, such as stepper motors, servomotors, and actuators.

SECTION – B

(Attempt Any Five | 5 × 10 = 50 Marks)

(a) Passive electrical components

Passive components do not generate energy.

Examples:                                                   Resistor: Limits current flow

Capacitor: Stores electrical energy             Inductor: Stores magnetic energy

Used in signal conditioning and filtering in mechatronic systems.

(b) Programmable Logic Controller (PLC) with ladder diagram

A PLC is a digital controller used for industrial automation.

Main parts: CPU, input module, output module, power supply.

Ladder Diagram (Motor Start-Stop):

Start switch (NO)                                          Stop switch (NC)

Motor coil with holding contact

PLC improves reliability and flexibility.

(c) Cam and follower with types

A cam converts rotary motion into linear motion.

Types of cams:                                             Disc cam

Cylindrical cam

Types of followers:                                     Knife edge

Roller                                                            Flat faced

Used in engines and automated machinery.

(d) Stepper motor / Stepper servomotor

A stepper motor moves in discrete angular steps.

Advantages:                                                High accuracy

Open-loop control                                       Simple construction

Disadvantages:                                           Low efficiency

Torque drops at high speed                         Resonance problem

(e) Features of Flexible Manufacturing System (FMS)

Computer-controlled machines                   Automated material handling

High flexibility                                              Reduced setup time

Improved productivity                                  FMS is widely used in modern manufacturing industries.

(f) Logic gates used in digital electronics

Logic gates perform logical operations.

Basic gates:                                                  AND

OR                                                                  NOT

Universal gates:                                           NAND

NOR                                                               Truth tables and symbols are drawn in the exam.

(g) Inversion of mechanism & mechanisms in mechatronics

Inversion: Obtaining different mechanisms from the same kinematic chain by fixing different links.

Examples:                                                      Slider crank mechanism

Four-bar mechanism                                      Geneva mechanism

(h) Performance parameters of transducers   Sensitivity

Accuracy                                                          Linearity

Resolution                                                        Range

Repeatability                                                    Response time

These parameters define transducer quality.

SECTION – C

(Attempt Any Two | 2 × 15 = 30 Marks)

 Measurement of Liquid Level in a Vessel

(a) Float-type level measurement

Uses a floating element connected to a potentiometer or encoder.

(b) Capacitive method

Capacitance changes with liquid level.

(c) Ultrasonic method

Uses time-of-flight of ultrasonic waves.

(d) Pressure-based method

Liquid level is measured using hydrostatic pressure.

Applications: tanks, boilers, chemical plants.

Transfer Function

Definition

A transfer function is the ratio of Laplace transform of output to input with zero initial conditions.

G(s)=Output(s)Input(s)G(s)=\frac{Output(s)}{Input(s)}G(s)=Input(s)Output(s)​

Determination

Write system differential equation

Apply Laplace transform

Take output/input ratio

Advantages

Simplifies system analysis

Useful for control design

Disadvantages

Not suitable for nonlinear systems

No information about physical structure

 Working of Pick and Place Robot

A pick and place robot performs repetitive material handling tasks.

Main components:

Robotic arm

End effector (gripper)

Sensors

Controller

Working:

Robot detects object

Gripper picks object

Arm moves to target location

Object is placed accurately

Applications:

Assembly lines

Packaging

Electronics manufacturing