Q1) Discuss the definition of the following terms in robotics: Denavit-Hartenberg representation,

forward kinematics, inverse kinematics, trajectory planning.

1. Denavit-Hartenberg Representation (DH Representation): DH Representation is a
method to mathematically model a robot's joint motions using four parameters per joint,
simplifying the analysis of its kinematics and transformations between links.

2. Forward Kinematics: Forward Kinematics involves determining the end-effector's

position and orientation based on joint variables, crucial for understanding how a robot's
links move relative to each other.
3. Inverse Kinematics: Inverse Kinematics is the process of calculating the joint variables
needed to position the robot's end-effector at a desired location and orientation, essential
for precise control of robotic manipulators.
4. Trajectory Planning: Trajectory Planning is the task of generating a time-based
sequence of robot configurations to smoothly navigate between waypoints, considering
constraints like joint limits and avoiding collisions.

Q2) Discuss how the Jacobian of a robot can be obtained.

To obtain a robot's Jacobian matrix, which shows how the end of the robot moves in response to
its joints moving. First, figure out how the end of the robot moves based on the joints using the
forward kinematics. Then, differentiate this movement to find out how joint movements affect
the end's speed. This gives you a relationship between the end's speed and the joint speeds in a
matrix J.The Jacobian has numbers that represent how each joint speed affects the end's
movement in terms of position and orientation. These numbers come from calculating how the
end's position and orientation change with small changes in each joint. Finally, by putting the
actual joint values into the Jacobian matrix, you get a numerical matrix that shows how the
robot's joints control the end's motion for a specific setup.

Q3) Discuss the application of Jacobian in a robot control.

The Jacobian matrix is like a special tool for controlling robots. It helps the robot do things like
moving its arm or hand in specific ways. For example, if we want the robot's hand to move
faster, the Jacobian helps us figure out how fast the robot's arm joints need to move. It also helps
the robot move exactly where we want it to, avoid getting stuck in tricky situations, and control
how much force it uses when touching things. The Jacobian is like a guide that the robot uses to
know how to move and do things in the right way.

Q5) Describe briefly about social and economic issues in robotic applications
Q6) Provide an example of Online programming and Offline programming for robotic system (one
each).

Offline Programming - Text-based programming (Python) and Graphical offline programming

Online Programming - Lead-Through (Hand guiding) and Drive-Through (Teach pendant)

Q7) Describe an advantage and disadvantage (each one) of lead through

programming of robot as compared to other methods.

Advantage – The robot is able to travel in a desired movement as it is programmed using numerical
coordinates, and it is being stored in external controller memory

Disadvantage – It stops the operation until it has been programmed, causing disruptive to the whole
system. Also, it requires training to learn and program which might be difficult for skilled crafts
people who are not familiarize with programming.

Q8) Discuss briefly how a robot can be programmed in different ways of programming
approaches.
Q9) Roomba is a popular autonomous vacuum cleaner. Explain that Roomba can be considered
as a robot and it is categorized as a service robot.
Q11) Robotic systems play crucial roles in Industrial Revolution (IR) 3.0 and IR 4.0. However, their
features and roles are not the same in both. Outline the distinctive features that the robotic
systems have in IR 4.0 era as compared to those in IR 3.0 era.

Q12) Illustrate the application of Jacobian in a robot control. A diagram may be used.
Q14) With the aid of labelled diagram, discuss why inverse kinematics is important in practical
for robot control.
Q15) Industrial robots can be classified according to their joint configuration to move the robots'
hand. With the aid of labeled diagrams, briefly discuss the common robot configurations.

Cartesian (Rectangular) Configuration: In this setup, the robot's joints move in a way that's similar
to how a person's arm moves. It has three joints, with the axes perpendicular to each other. This
kind of robot can move its hand in straight lines along the X, Y, and Z directions.

Cylindrical Configuration: A cylindrical robot has two rotary joints, similar to a human's
shoulder and elbow joints. These joints let the robot move its arm in a circular motion and
also extend and retract the arm like a telescope.
 Spherical Configuration: Spherical robots have two rotary joints and one prismatic joint.
They allow the robot's hand to move in any direction with a wide range of motion. Think of it
like a human's shoulder, elbow, and wrist movement combined.

Articulated (Anthropomorphic) Configuration: This configuration closely resembles the

human arm with shoulder, elbow, and wrist joints. It's more flexible and can reach many
different positions, making it versatile for various tasks.

Q16) Discuss briefly any three of the robot characteristics that are most important in specifying a
robot for any applications.

Payload Capacity: The payload capacity defines the maximum weight a robot can handle, affecting its
ability to perform tasks safely and effectively. Choosing a robot with the appropriate payload capacity
ensures it can manage the required loads without straining its components.

Reach and Workspace: Reach and workspace describe a robot's operational reach and the area
it can cover, influencing its versatility in different environments and task scenarios. Selecting a
robot with the right reach and workspace ensures it can access all necessary points and adapt to
various tasks within its working area.
Accuracy and Repeatability: Accuracy represents a robot's precision in placing its end-effector,
while repeatability measures its consistency in achieving the same position. High accuracy and
repeatability are vital for applications demanding quality and precision, ensuring reliable and
consistent performance throughout the task.
Q17) Briefly discuss about 4 major components to form a robot.
1. Sensors: Sensors are the robot's "senses." They provide information about the robot's
environment, such as detecting objects, measuring distances, capturing images, or sensing
temperature and touch. Sensors enable the robot to perceive and understand its
surroundings, which is crucial for making intelligent decisions and adapting to changes.
2. Actuators: Actuators are the "muscles" of the robot. They carry out actions based on the
robot's decisions. These components can include motors, pneumatic or hydraulic systems,
and other mechanisms that create movement, allowing the robot to manipulate objects,
move its parts, or navigate its environment.
3. Controller: The controller is the "brain" of the robot. It processes information from
sensors, makes decisions based on programming or algorithms, and sends commands to
actuators to perform specific tasks. The controller's intelligence determines how the robot
responds to its environment and executes its intended actions.
4. Mechanical Structure: The mechanical structure is the "body" of the robot. It provides
the physical form and structure to hold the sensors, actuators, and controller in place. The
design of the mechanical structure depends on the robot's intended tasks and
environment, ranging from simple arms for industrial robots to complex bodies for
humanoid or mobile robots.

Q18) Briefly discuss about 4 types of grippers which can be found in industry.

1. Parallel Grippers: Parallel grippers have two opposing jaws that move parallel to each
other to grasp an object. They are versatile and widely used due to their simple design
and ability to grip various shapes and sizes. These grippers are suitable for applications
where precision and a strong grip are required.
2. Vacuum Grippers: Vacuum grippers use suction to hold onto objects. They are useful
for picking up items with flat surfaces, like sheets of paper or boxes. Vacuum grippers
are commonly used in packaging, material handling, and assembly lines.
3. Three-Fingered Grippers: Three-fingered grippers mimic the human hand with three
fingers. They provide more flexibility in gripping objects with irregular shapes or varying
sizes. These grippers are often used for delicate tasks like picking up fragile items or
manipulating complex objects.
4. Angular Grippers: Angular grippers have jaws that move at an angle to each other.
They are suitable for gripping objects in confined spaces or for accessing objects at odd
angles. These grippers are often used in situations where parallel grippers might not fit.
Q19) Briefly discuss about 4 notable actuators in robotics.
1. DC Motors: Direct Current (DC) motors are widely used actuators in robotics. They
convert electrical energy into rotational motion. DC motors are known for their
simplicity, ease of control, and ability to provide precise position and speed control. They
find applications in various robot joints and mobile platforms.
2. Servo Motors: Servo motors are a type of DC motor with built-in feedback mechanisms,
such as encoders. This feedback allows for accurate control of position, speed, and
torque. Servo motors are commonly used for tasks that require high precision, like
robotic arms and articulated mechanisms.
3. Stepper Motors: Stepper motors move in discrete steps, making them suitable for
applications requiring precise control and positioning. They are often used in situations
where the robot needs to move in fixed increments, such as 3D printers, CNC machines,
and robotics arms.
4. Pneumatic Actuators: Pneumatic actuators use compressed air to create motion. They
are valued for their high force-to-weight ratio, making them suitable for tasks that require
a strong grip or lifting capability. Pneumatic actuators are commonly used in industrial
applications, like pick-and-place systems and robotic assembly lines.

Q20) Briefly discuss about some aspects which are used to characterize robot specification.
1. Payload Capacity: Payload capacity refers to the maximum weight a robot can carry or
manipulate. It's crucial to match the robot's payload capacity with the objects it needs to
handle for safe and effective operation.
2. Reach and Workspace: Reach defines how far the robot can stretch its end-effector,
while workspace encompasses the area the robot can cover. These aspects determine the
robot's operational flexibility and suitability for specific tasks and environments.
3. Degrees of Freedom (DOF): DOF indicates the number of independent ways a robot can
move. Higher DOF can enable more complex movements and tasks, but also increase the
complexity of control and programming.
4. Accuracy and Repeatability: Accuracy measures how precisely a robot can position its
end-effector, while repeatability gauges its ability to achieve the same position
repeatedly. These aspects are crucial for tasks demanding precision and consistency.
5. Speed and Acceleration: Speed and acceleration characterize how fast a robot can move
its parts. These factors influence the robot's efficiency in completing tasks and its
adaptability to dynamic environments.
6. Controller and Programming: The type of controller and programming capabilities
determine how easily a robot can be programmed and controlled for various tasks.
Intuitive interfaces and versatile programming languages simplify robot operation.
 7. Sensors and Perception: Sensors, such as cameras, proximity sensors, and force sensors,
provide information about the robot's environment. The type and quality of sensors
influence the robot's ability to interact with its surroundings.
8. End-Effector and Tooling: The end-effector is the "hand" of the robot, and its design
varies based on the application. Choosing the right end-effector or tooling is essential to
perform specific tasks effectively.
9. Environment and Safety: The robot's intended environment, such as indoor or outdoor,
clean or harsh conditions, influences its design and protective measures. Safety features
are crucial to prevent accidents involving human operators.
10. Cost and Return on Investment (ROI): The cost of the robot, including maintenance
and training expenses, is a significant factor. Assessing the potential ROI based on
increased productivity and efficiency is essential for selecting the right robot.

Q21) Discuss the advantages and disadvantages of robots in the perspective of automation
industry.
Advantages:
1. Increased Productivity: Robots can work tirelessly and consistently without breaks,
leading to increased production rates and reduced cycle times. This boosts overall
productivity in manufacturing and other industries.
2. Precision and Accuracy: Robots can perform tasks with high precision and accuracy,
resulting in consistent quality and reduced errors. This is crucial in industries requiring
tight tolerances and strict quality control.
3. Safety Enhancement: Robots are well-suited for hazardous environments or tasks that
pose risks to human workers, such as working with toxic chemicals, high temperatures, or
confined spaces. Their use improves workplace safety by minimizing human exposure to
danger.
 4. Cost Efficiency: While the initial investment may be significant, robots can lead to long-
term cost savings by reducing labor costs, minimizing defects, and improving operational
efficiency.
5. Flexible Automation: Robots can be reprogrammed or reconfigured to handle different
tasks or adapt to changing production needs, providing flexibility in manufacturing
processes.
6. 24/7 Operation: Robots can operate continuously, allowing for round-the-clock
production and reduced downtime, which is particularly advantageous for industries with
high demand and stringent deadlines.
Disadvantages:
1. High Initial Investment: The cost of purchasing and setting up robots, along with
training and maintenance expenses, can be a significant upfront investment that may be
challenging for some businesses.
2. Complex Programming: Programming robots can be complex and time-consuming,
requiring skilled personnel or specialized software. Changes to tasks may necessitate
reprogramming, adding to operational complexity.
3. Limited Adaptability: While robots offer flexibility, some tasks that require fine motor
skills or complex decision-making are still better suited for human workers.
4. Job Displacement Concerns: The increased use of robots can lead to concerns about job
displacement and unemployment for human workers in certain industries.
5. Maintenance and Downtime: Robots require regular maintenance to ensure optimal
performance, and breakdowns can lead to production downtime. Maintenance can also be
expensive and require skilled technicians.
6. Lack of Human Touch: Industries that involve human creativity, emotional intelligence,
or intricate problem-solving may not be suitable for full automation, as robots lack the
human touch in such contexts.

Q22) Describe alternative approach to solve a robot inverse kinematics when the robot
configuration is complicated so that it is difficult to solve by using geometric
and algebraic approach.
1. Numerical Optimization: Numerical optimization involves iteratively adjusting joint
angles to minimize the difference between desired and calculated end-effector positions,
utilizing optimization algorithms and cost functions for accuracy.
2. Iterative Methods: Iterative methods like the Jacobian transpose technique refine joint
angles step by step, guided by the Jacobian matrix, to gradually bring the end-effector
closer to the target position.
 3. Gradient Descent: Gradient descent optimization adjusts joint angles based on the
gradient of a cost function, aiming to minimize position errors by iteratively moving in
the direction of steepest decrease.
4. Inverse Kinematics Libraries: Inverse kinematics libraries offer pre-built functions for
numerically solving complex robot configurations, saving time and effort by providing
ready-made tools for intricate kinematic problems.
5. Machine Learning Techniques: Machine learning, including neural networks,
approximates inverse kinematics mappings, learning to predict joint angles from end-
effector positions, which is particularly useful for challenging geometries.
Q23)
Trajectory planning holds immense importance in robot control as it orchestrates the robot's
movements with precision and efficiency. By designing smooth and optimal paths for the robot's
end-effector, trajectory planning ensures seamless motion, minimizing abrupt changes that can
lead to inefficiencies or damage. This planning process becomes particularly vital in dynamic
environments where obstacles and conditions might change, allowing the robot to adapt its path
in real-time while avoiding collisions. Additionally, trajectory planning takes into account
obstacles and aims to find the shortest, obstacle-free route between points, optimizing task
completion time and reducing wear on mechanical components. Overall, trajectory planning
guarantees safe, accurate, and efficient robot operations, making it a fundamental aspect of
effective robot control mechanisms.