(SEM VIII) THEORY EXAMINATION 2023-24 AUTOMATION AND ROBOTICS

SECTION A

(Attempt all | 2 × 10 = 20 Marks)

a. Types of automation
The main types of automation are fixed automation, programmable automation, and flexible automation.

b. Applications of fluid power in automotive industry
Fluid power is used in braking systems, power steering, suspension systems, lifting mechanisms, and automated assembly lines.

c. Applications of transfer machines
Transfer machines are used in mass production for machining engine blocks, cylinder heads, gear housings, and automotive components.

d. Automated feeding system
An automated feeding system supplies parts automatically to machines or robots in the correct orientation and sequence without human intervention.

e. Important specifications of an industrial robot
Key specifications include payload capacity, reach, degrees of freedom, accuracy, repeatability, speed, and type of drive system.

f. Origin of robot
The term “robot” was first introduced by Karel Čapek in 1921, and the first industrial robot was developed by George Devol in 1954.

g. Pneumatic and hydraulic actuators in robotics
Pneumatic actuators use compressed air for motion, while hydraulic actuators use pressurized fluid to generate high force and torque.

h. Walkthrough method of robot programming
In walkthrough programming, the robot is manually guided through the desired path, and the motions are recorded for automatic repetition.

i. Machine loading and unloading applications
Robots are used to load raw materials into machines and unload finished parts, improving productivity and safety.

j. Advantages of robot arc welding
Robot arc welding provides consistent weld quality, higher speed, improved safety, and reduced human fatigue.

SECTION B

(Attempt any THREE | 10 × 3 = 30 Marks)

2(a) Benefits of automation and its practical significance

Automation improves productivity, product quality, consistency, and safety. It reduces labor cost, human error, and production time. In today’s age, automation is essential for mass production, precision manufacturing, global competitiveness, and handling complex tasks in industries like automotive, electronics, and pharmaceuticals.

2(b) Single station assembly machine

A single station assembly machine performs multiple assembly operations at one workstation. Components are fed automatically, positioned, assembled, and inspected in a fixed sequence.
Advantages include compact design, high accuracy, reduced handling time, and suitability for high-volume production.

2(c) Short notes

(i) Joint notation scheme
Joint notation describes robot joints using letters such as R (revolute), P (prismatic), C (cylindrical), and S (spherical). It helps identify robot configuration.

(ii) Work volume
Work volume is the three-dimensional space within which a robot can operate effectively. It depends on robot configuration, joint limits, and link lengths.

2(d) External and internal grippers

External grippers hold objects from the outside using jaws, while internal grippers expand inside hollow objects to grip them. External grippers are common in pick-and-place tasks, whereas internal grippers are used for cylindrical components.

2(e) Force and Torque sensor

Force and torque sensors measure interaction forces between robot and environment. They are used in assembly, polishing, and deburring operations.
Advantages: high precision, improved control
Disadvantages: high cost, sensitivity to noise

SECTION C

3(a) Advantages and disadvantages of pneumatics over hydraulics

Advantages:
Pneumatics are cleaner, cheaper, lighter, safer, and easier to maintain.

Disadvantages:
They provide lower force, less precision, and are affected by air compressibility compared to hydraulics.

3(b) Role of PLC in automation and robotics

Programmable Logic Controllers (PLCs) control industrial processes by monitoring inputs and controlling outputs. In robotics, PLCs manage sequencing, safety interlocks, sensor integration, and communication between machines, improving reliability and flexibility.

4(a) Configurations of automated flow line

Automated flow lines can be configured as in-line, rotary, or U-shaped layouts. Configuration depends on product type, production volume, material flow, and flexibility requirements.

4(b) Analysis of transfer lines with no internal parts storage

In transfer lines without internal storage, machines are tightly coupled. A failure at one station stops the entire line. Analysis focuses on cycle time, reliability, downtime, and system efficiency.

5(a) Four basic robot configurations

The four basic configurations are:

Cartesian (Rectangular) – linear motion along X, Y, Z axes

Cylindrical – rotary and linear motion

Spherical (Polar) – rotational joints with radial movement

Articulated – rotary joints similar to human arm

5(b) DH representation and coordinate frame assignment

Denavit–Hartenberg (DH) representation defines robot kinematics using four parameters: link length, link twist, link offset, and joint angle.
Steps:

Assign coordinate frames                                               Determine DH parameters

Form transformation matrices                                         Multiply matrices to obtain end-effector position

6(a) Degrees of freedom vs actuators (True/False)

True.
Degrees of freedom depend on the number of independent actuators controlling robot motion.

6(b) AC and DC servo motors as robot drive systems

DC servo motors offer fast response and easy control, while AC servo motors provide higher efficiency, better speed control, and low maintenance. Both are widely used in robotic drive systems.

7(a) VAL robot program for pick and place

A VAL program defines robot positions, gripper control, and motion commands to pick an object from a conveyor and place it at a target location using sequential instructions.

7(b) In-line robot cell and mobile robot cell

An in-line robot cell integrates robots along a production line for sequential operations.
A mobile robot cell uses autonomous robots for flexible material handling and transport.