6.

12 Introduction to Robotics 203

3. Bevel gears: Bevel gears have teeth that are cut at an angle to transmit power
between shafts that are not parallel. Bevel gears are typically used for right angle
shaft applications.

4. Worm gears: Worm gears have a helical screw that meshes with a toothed wheel.
Worm gears are typically used for applications where high speed reduction and
high torque are required. Design of Gear Drives

The design of a gear drive depends on a number of factors, including:

1. The power to be transmitted

2. The desired speed ratio

3. The required torque

4. The shaft axis alignment

5. The operating environment

When designing a gear drive, it is important to consider the following factors:

1. Gear material: Gears can be made from a variety of materials, including steel,
iron, brass, and plastic. The material selected for the gears will depend on the
application and the required performance characteristics.

2. Gear tooth profile: The tooth profile of a gear has a significant impact on its
performance. The most common tooth profile for gears is the involute profile.

3. Gear lubrication: Gears must be properly lubricated to reduce friction and wear.
The type of lubricant used will depend on the application and the gear material.

Gear drives are essential components in a wide variety of machinery. They are used
to transmit power, change speed and torque, and change the direction of rotation. Gear
drives are designed to meet the specific requirements of each application.

6.12 Introduction to Robotics

Robotics is a branch of engineering and science that deals with the design, construction,
operation, and application of robots. Robots are machines that can perform tasks
204 Power Plants

automatically, either by programming or by following a set of instructions. They

can be used in a wide range of industries and applications, including manufacturing,
healthcare, logistics, and space exploration.

6.12.1 What are the different types of robots?

Robots can be classified into different types based on their size, shape, and capabilities.
Some common types of robots include:

1. Industrial robots: These robots are typically large and powerful, and are used
in manufacturing to perform repetitive tasks such as welding, painting, and
assembly.

2. Service robots: These robots are designed to perform tasks in non-industrial

settings, such as healthcare, hospitality, and retail. Examples of service robots
include surgical robots, delivery robots, and vacuum cleaners.

3. Collaborative robots: These robots are designed to work safely alongside humans
in shared workspaces. They are typically smaller and less powerful than industrial
robots, but they can be more simple and easier to program.

4. Mobile robots: These robots can move around independently, and are used in a
variety of applications, such as exploration, mapping, and delivery. Examples of
mobile robots include self-driving cars and drones.

6.12.2 How do robots work?

Robots are typically made up of four main components:

1. Actuators: Actuators are the motors and other devices that allow the robot to
move.

2. Sensors: Sensors provide the robot with feedback about its environment and its
own state.

3. Controller: The controller is the computer that processes the sensor data and sends
commands to the actuators.
6.12 Introduction to Robotics 205

4. Power supply: The power supply provides the robot with the energy it needs to
operate.

6.12.3 What are the applications of robotics?

Robots are used in a wide range of industries and applications, including:

1. Manufacturing: Robots are used in manufacturing to perform repetitive and

dangerous tasks, such as welding, painting, and assembly. This can help to
improve productivity, quality, and safety.

2. Healthcare: Robots are used in healthcare to perform surgery, assist with patient
care, and deliver medications.

3. Logistics: Robots are used in logistics to automate tasks such as picking and
packing orders, and transporting goods.

4. Space exploration: Robots are used in space exploration to explore other planets
and moons, and to perform tasks such as assembly and maintenance.

5. Agriculture: Robots are used in agriculture to plant and harvest crops, apply
pesticides, and monitor livestock. This can help to improve yields and reduce
labor costs.

6. Construction: Robots are used in construction to perform tasks such as welding,

bricklaying, and painting. This can help to improve safety and productivity.

7. Space exploration: Robots are used in space exploration to explore planets and
moons, conduct scientific experiments, and repair satellites.

8. Search and rescue: Robots can be used to search for and rescue people in dangerous
or inaccessible environments.

9. Disaster relief: Robots can be used to assist with disaster relief efforts, such as
clearing debris and delivering supplies.

10. Education and research: Robots are used in education and research to teach
students about robotics and to conduct experiments.
206 Power Plants

11. Entertainment: Robots are used in the entertainment industry to create special
effects, perform stunts, and provide customer service.

12. Deliver food and packages

13. Clean homes and offices

14. Provide companionship and assistance to the elderly and disabled

15. Perform surgery in remote locations

16. Explore dangerous and inaccessible environments

6.12.4 The future of robotics

Robotics is a rapidly growing field, and robots are becoming increasingly sophisticated
and capable. In the future, robots are likely to be used in even more industries and
applications, and to play an even greater role in our lives.

6.13 Introduction to Robotic Joints & links, configurations

Robotic joints are the mechanical elements that allow robots to move. They are typi-
cally classified into two types: linear and rotary. Linear joints allow for translational
movement, while rotary joints allow for rotational movement.
Some common examples of robotic joints include:

1. Linear joints:

(a) Prismatic joints: These joints allow for linear movement along a single axis.

(b) Cylindrical joints: These joints allow for linear movement along a single axis
and rotational movement around a parallel axis.

(c) Spherical joints: These joints allow for linear movement along any axis and
rotational movement around any axis.

2. Rotary joints:

(a) Revolute joints: These joints allow for rotational movement around a single
axis.
6.13 Introduction to Robotic Joints & links, configurations 207

(b) Universal joints: These joints allow for rotational movement around two
perpendicular axes.

Robotic links are the rigid segments that connect the joints of a robot. They can be
made of a variety of materials, such as metal, plastic, or carbon fiber.

The length and shape of the links determine the robot’s reach and workspace.
A robot’s configuration is defined by the positions of its joints. For example, the
configuration of a robot with three revolute joints would be defined by the three joint
angles. The configuration of a robot is important for determining its workspace and
kinematics.
Here are some examples of common robot configurations:

1. Cartesian: Cartesian robots have three linear joints that allow them to move
along the X, Y, and Z axes. These robots are commonly used in pick-and-place
applications.

2. Cylindrical: Cylindrical robots have one revolute joint and two linear joints. They
have a cylindrical workspace and are commonly used in assembly and welding
applications.

3. Spherical: Spherical robots have three revolute joints that allow them to move
in any direction. They have a spherical workspace and are commonly used in
painting and inspection applications.

4. Articulated: Articulated robots have four or more revolute joints. They have
a large workspace and are commonly used in industrial applications such as
welding and painting.

The type of joints and links used in a robot, as well as their configuration, determine
the robot’s capabilities and limitations. When choosing a robot for a particular appli-
cation, it is important to consider the robot’s workspace, reach, payload, and accuracy
requirements.
Each joint is connected to two links, an input link and an output link. Joint provides controlled
relative movement between the input link and output link. A robotic link is the rigid component
of the robot manipulator. Most of the robots are mounted upon a stationary base, such as the
floor. From this base, a joint-link numbering scheme may be recognized as shown in Figure 1.1.
The robotic base and its connection to the first joint are termed as link-0. The first joint in the
sequence is joint-1. Link-0 is the input link for joint-1, while the output link from joint-1 is link-1
which leads to joint-2. Thus link 1 is,simultaneously, the output link for joint-1 and the input link
for joint-2. This joint-link-numbering scheme is further followed for all joints and links in the
robotic systems

Types of joints:
a) Linear joint (type L joint) The relative movement between the input link and the output
link is a translational slidingmotion, with the axes of the two links being parallel.
b) Orthogonal joint (type U joint) This is also a translational sliding motion, but the input
and output links are perpendicular toeach other during the movement.
c) Rotational joint (type R joint) This type provides rotational relative motion, with the
axis of rotation perpendicular to the axesof the input and output links.
d) Twisting joint (type T joint) This joint also involves rotary motion, but the axis or
rotation is parallel to the axes of the twolinks.
e) Revolving joint (type V-joint, V from the “v” inrevolving) In this type, axis of input link is
parallel to the axis of rotation of the joint. However the axis ofthe output link is perpendicular to
the axis of rotation.

Robotic arm configurations: For body-and-arm configurations, there are many different
combinations possible for a three-degree-of-freedom robot manipulator, comprising any of the
five joint types. Common body-and-arm configurations are as follows.
1) Polar coordinate arm configuration
2) Cylindrical coordinate arm configuration
3) Cartesian coordinate arm configuration
4) Jointed arm configuration.