Robot Kinematics and

Dynamics
Mrs. Deepti Khimani
 Agenda
• Introduction to Robotics
• Robotics History
• Classification of Robots
• Robot Anatomy
 Robot
Definition:
A robot is a software controllable mechanical
device that uses sensors to guide one or
more end-effectors through programmed
motions in a workspace in order to
manipulate physical objects.
 Robotics
A branch of engineering which deals with the
study of different types of robots, their
designs, their constructions, operations,
performance, applications.
It is the combination of machine tool
technology and computer science and is a
form of industrial automation.
1920

The idea of a robot is not new. For thousands of

years man has been imagining intelligent
mechanized devices that perform human-like
tasks. He has built automatic toys and
mechanisms and imagined robots in drawings,
books, plays and science fiction movies.
Robotics History
What is the definition of a 'robot'?
"A reprogrammable, multifunctional
manipulator designed to move material,
parts, tools, or specialized devices
through various programmed motions for
the performance of a variety of tasks"
Robot Institute of America, 1979

Where did the word 'robot' come from?

In fact, the term "robot" was first used in 1920 in a play
called "R.U.R." Or "Rossum's universal robots" by the
Czech writer Karel Capek. The plot was simple: man makes
robot then robot kills man! Many movies that followed
continued to show robots as harmful, menacing machines.
Robotics History
Robotics Terminology
The term 'robotics' refers to the
study and use of robots. The term
was coined and first used by the
Russian-born American scientist
and writer Isaac Asimov (born Jan.
2, 1920, died Apr. 6, 1992). Asimov
wrote prodigiously on a wide
variety of subjects. He was best
known for his many works of
science fiction.

The most famous include I Robot (1950), The Foundation Trilogy (1951-52),
Foundation's Edge (1982), and The Gods Themselves (1972), which won both
the Hugo and Nebula awards. He also wrote the three “Laws of Robotics for
which he is also famous.
Robotics History

More movies, however, like

the 1977 "star wars", portray
robots such as "C3PO" and
"R2D2" as man's helpers.
"Number five" in the movie
"short circuit" and C3PO
actually take on a human
appearance. These robots,
which are made to look
humans are called "androids".
Robotics History
However, robots of today are not exactly
the walking, talking intelligent machines
of movies, stories and our dreams.
Today, we find most robots working for
people in factories, warehouses, and
laboratories. In the future, robots may
show up in other places: our schools, our
homes, even our bodies.
 Robotics History
Today fully functioning
androids are many years away
due to the many problems that
must be solved. However, real,
working, sophisticated robots
are in use today and they are
revolutionizing the workplace.
These robots do not resemble
the emotional android concept
of robots. They are industrial
manipulators and are really
computer controlled "arms
and hands".
 Robotics History
Robots have the potential to change our economy, our
health, our standard of living, our knowledge and the
world in which we live. As the technology progresses,
we are finding new ways to use robots.

Each new use

brings new hope
and possibilities,
but also potential
dangers and risks.
 Robotics History
Benefits of Robots
⚫ Robots offer specific
benefits to workers,
industries and countries. If
introduced correctly,
industrial robots can
improve the quality of life
by freeing workers from
dirty, boring, dangerous
and heavy labor.
Robotics History
Robotics for bio-production
Many robots for
bio-production have been
developed in the world and it
is predicted that they will be
commercialized in the 21st
century, since some of them
were already commercialized
by some companies in Japan
and European countries.
A tomato and cherry tomato
harvesting robot, a cucumber
harvesting robot, a
multi-operation robot to
work in grapevine yard, and a
chrysanthemum cutting
sticking robot.
Robotics History EMT
HAZBOT III is part of
JPL's Emergency Response
Robotics Project, a five-year
effort begun in 1991 to
apply robotics technology
to the safe handling of
hazardous materials.
Robots such as HAZBOT
also hold potential for use
in mining and law enforcement.

"It's almost standard now to have robots on

bomb squads in major cities, but it took
several years for the idea to catch on," said
Richard Welch.
Robotics History
And Future

Future missions to
space will include
many robotic
vehicles designed to
perform specific
tasks both
autonomous and
remote controlled.
 Robotics History
And Future
The Mars 2003 Rover
Project was designed to
have two scientific rovers
spirit and opportunity going
to Mars in 2003.
Each rover searched for
evidence of liquid water.
Robotics History
•The planet Saturn, with its
famous icy rings, and its
enigmatic moon, Titan, are
the prime scientific targets
of the international Cassini
mission, the most ambitious
and far-reaching planetary
exploration ever mounted.

NASA's Cassini spacecraft successfully

launched on October 15, 1997. It’s
robotic rover then landed on Saturn in
October of 2004.
 ROBOT
• Defined by Robotics Industry Association
(RIA) as
– a re-programmable, multifunctional manipulator
designed to move material, parts, tools or
specialized devices through variable programmed
motion for a variety of tasks
• possess certain anthropomorphic
characteristics
– mechanical arm
– sensors to respond to input
– Intelligence to make decisions
Robot Anatomy
Robotic Anatomy
A Robot is a system, consists of the following elements, which are
integrated to form a whole

Articulated - Jointed arm.

Degrees of freedom - Each plane in which a robot can maneuver.

Telerobotics - Robot that is operated remotely.

Link - Mechanical structure of robotic manipulator is a mechanism,

whose members are rigid links or bars.

Joint - Two links are connected together by a joint.

 Robot Anatomy
• Manipulator / Rover : This is the main body of the Robot
and consists of links, joints and structural elements of
the Robot.

• End Effector : This is the part that generally handles

objects, makes connection to other machines, or
performs the required tasks.

It can vary in size and complexity from an end effector

on the space shuttle to a small gripper.
• Acutators : Actuators are the muscles of the manipulators.
Common types of actuators are servomotors, stepper
motors, pneumatic cylinders etc.

• Sensors : Sensors are used to collect information about the

internal state of the robot or to communicate with the outside
environment. Robots are often equipped with external
sensory devices such as a vision system, touch and tactile
sensors etc which help to communicate with the environment

• Controller : The controller receives data from the computer,

controls the motions of the actuator and coordinates these
motions with the sensory feedback information.
 Types of Joints
Robot joints refer to the movable components of the robot that
result in relative motions between adjacent links.
Out of five joints, two are linear which means the relative motion
between the adjacent links is translational.
The other three are rotary which means the relative motion of the links
involves rotations between them.
 Types of Joints
https://www.youtube.com/watch?v=SMcqUjQ2Swo&t=381s

The five types of mechanical joints for robots include:

Collinear Joints
In the linear joints, the relative motion featured by the adjacent links is meant to
be parallel. This means that the input and output links are sliding in a linear
motion. This kind of movement results in a translational motion.

This kind of linear motion can be achieved in several ways including the use of
the telescoping mechanism and piston.

This type of joint is also referred to as the L- joint.

 Types of Joints
Orthogonal Joints

The orthogonal joints are also popularly referred to as the type O-joints. They
feature a relative movement taken by the input link and output link. This kind
of motion involved in the Orthogonal joints is a translational sliding motion.
However unlike the linear joints arrangement, with the Orthogonal joint, the
output link is perpendicular to the input link.
Rotational Joints

When it comes to the rotational joints, you’ll find the use of rotational relative
motions that come in handy for robot manipulators working in multiple
workspaces. These movements are carried out with the axis of rotation
perpendicular to the axes of the input and output links. These rotational joints
are also referred to as Type R joints.
 Types of Joints
Twisting Joints

This type of joint features rotary motion that also results in some degree of
rotation when in use. The movement in these joints is relative to the axis of
rotation that is perpendicular to the axes of the input and output links. The
twisting joints are also referred to as type T joints.
Revolving Joints

In the revolving joints, things are a bit different compared to the others.
These joints also feature a rotational movement that comes in handy in
different applications. The movement of these joints features motion between
the two links. The axis of the input link is designed to be parallel to the axis of
rotation of the joint. On the other hand, the axis of the output link is designed
to be perpendicular to the axis of rotation of the joint. This type of joint is also
referred to as the Type V joint.
 Types of Joints
Different robots will feature the use of different types of mechanical joints.

Articulated

The articulated robot design will most likely come with different ranges and
combinations of rotary joints. This range may feature simple 2 joint structures
and move to more complex structures with 10 or more joints. With this design,
the arm is connected to the base with the use of a twisting joint while the links
in the arm are connected by rotary joints.
Cartesian

With the cartesian robots, the design features the use of three linear joints.
These joints are featured on the cartesian plane that involves X, Y, and Z.
These robots may also feature an attached wrist with easier rotational joints
for movement. This particular kind of robot is also referred to as rectilinear or
gantry.
 Types of Joints
Cylindrical

The cylindrical robot features a rotary joint that is attached to the base and
one linear joint used to connect the different links. Given that cylindrical
robots work within a cylindrical-shaped work scope, the rotational and linear
motion come in handy to ensure that precision is attained.
Polar

In the polar design of robots, the arm is connected to the base using a
twisting joint. At times you’ll also find the use of a combination of two rotary
joints and one linear joint. Since this robot is also referred to as a spherical
robot, the work scope to be featured will also be spherical. The axes used in
this robot form a polar coordinate system that allows the manipulator to work
with ease.
 Types of Joints
SCARA : Selective Compliance Assembly Robot Arm

The SCARA robot is a popular option among many manufacturers especially

those who are looking to automate their assembly processes. This robot is
usually cylindrical and works in relatively cylindrical work scope. It features the
use of two parallel joints that come in handy in the assembly process. These
joints provide compliance in one selected plane as the robot is in use.
Delta

The delta robots are designed with a spider-like build that allows them to offer
great services to their users. They are built from parallelograms that are joined
and connected to a common base. The joints featured on this type of robot
are both rotational and linear. This allows the robot to move a single end of
arm tooling in a dome-shaped work area. It enhances its performance to
ensure that the development of different tasks is carried out accurately.
 Degree of Freedom
Degrees of freedom (DOF) refers to the number of independent movements a
robotic arm can make
The more degrees of freedom, the more skilled and flexible the arm.
A single joint that can rotate 360 degrees provides one degree of freedom.
Most robotic arms have several joints, each contributing one or more degrees
of freedom.
For example, a shoulder joint that can move vertically and horizontally
provides two degrees of freedom, and an elbow joint adds another.
Degree of Freedom
 Degree of Freedom
A three-degree arm can move up and down, left and right, and in and out. This
provides basic functionality — but limited flexibility.

The 3 DOF located in the wrist of a robotic system:

Pitch : Bend or up and down movement.
Yaw : Right and left movement.
Roll : Swivel or rotation of the wrist/hand
On the other hand, five or six degrees of freedom allow for a greater range of
motion and more complex movements. Highly articulated arms with seven
degrees of freedom or more can perform high-dexterity tasks.
 Degree of Freedom
Robotic arms vary greatly in complexity, number of joints, and ability. This
means that they’re suited for different tasks.

● SCARA robots typically have three degrees of freedom. Their two

rotational joints on a horizontal plane and one vertical joint allow precise
movement within a defined workspace. They're excellent for assembly
tasks (like screw driving, part fitting), pick-and-place operations, and
dispensing applications.

● Cartesian robots also often have three degrees of freedom. Their three
linear joints (X, Y, and Z axes) enable them to move along straight lines,
prioritizing precision within large workspaces. They're often very common
in pick-and-place applications, transport, palletizing, and dispensing tasks
where speed is less important than accuracy
 Degree of Freedom
● Six-axis articulated robots have the highest flexibility with six degrees
of freedom. Their six rotational joints mimic a human arm, allowing
intricate movements, object manipulation at various angles, and
adaptability to complex tasks. They're extremely versatile and used in
applications like welding, painting, assembly, and palletizing.

● Delta robots usually have three or four degrees of freedom. Though the
exact configuration can vary, their unique design focuses on precise and
extremely fast movement within a dome-shaped workspace. They're
excellent for high-volume pick-and-place tasks, especially in the
packaging and food processing industries
 Degree of Freedom
● Collaborative robots (Cobots) can have varying degrees of freedom,
but the priority is on safe operation alongside humans. Their DOF might
be slightly less focused on pure flexibility, as their sensors and safety
features are equally important for their intended use. They're increasingly
used in assembly tasks, machine tending, inspection, and other
applications where human-robot collaboration is preferred — and
beneficial.
 Types of Manipulators
Serial manipulator : It carries less load compared to parallel manipulator due to
cantilevered structure.
 Types of Manipulators
Parallel Manipulator :
A parallel manipulator, or parallel kinematic machine, is generally defined as a
mechanism whose end-effector is linked to a base by multiple independent kinematic
chains, called limbs.
 Work Envelope concept
• Depending on the configuration and size of the
links and wrist joints, robots can reach a
collection of points called a Workspace.
https://www.youtube.com/watch?v=_canCYWZPsc

• Alternately Workspace may be found empirically,

by moving each joint through its range of
motions and combining all space it can reach
and subtracting what space it cannot reach
 Robot Configurations
Some of the commonly used configurations in Robotics are

• Cartesian/Rectangular Gantry(3P) : These Robots are made of 3

Linear joints that orient the end effector, which are usually followed
by additional revolute joints.
Gantry Robot
 Robot Configurations (cont’d)
• Cylindrical (R2P): Cylindrical coordinate Robots have 2 prismatic
joints and one revolute joint.
 Cylindrical Robot - Work
Envelope
It can move it’s
gripper within a
volume described
by a cylinder.
 Robot Configurations (cont’d)
• Spherical joint (2RP): They follow a spherical coordinate system,
which has one Prismatic joint and two rotary joints.
 Spherical Robot - Work
Envelope
The envelope
is shaped like
a section of a
sphere with
upper and
lower limits
imposed by
the angular
rotations of
the arm.
 Robot Configurations (cont’d)
• Articulated/anthropomorphic(3R) :An articulated robot’s joints are
all revolute, similar to a human’s arm.
 Robot Configurations (cont’d)
The envelope is
circular when
viewed from the
top of the robot.
When looked from
the side, the
envelope has a
circular outer
surface with an
inner scalloped
surface.
 Robot Configurations (cont’d)
• Selective Compliance Assembly Robot Arm (SCARA) (2R1P):
They have two revolute joints that are parallel and allow the Robot to
move in a horizontal plane, plus an additional prismatic joint that
moves vertically
Robot Configurations (cont’d)
Robot Configurations
 Classification of robots
Robots are classified based on the following points:
1. Power source
2. Degree of freedom
3. Arm geometry or coordinate system
4. Intelligence level
5. Types of motion
6. Control Methods
 Classification of robots
Classification based on power source:

a. Electrical: electricity is the major source of energy.

b. Pneumatic: air pressure is used here.
c. Hydraulic: fluid pressure is used.
It provides a large amount of power. Therefore it is used to
handle heavy loads.
 Classification of robots
Classification based on DOF:
1. 3 DOF
2. 6 DOF
Classification based on Arm geometry:
1. Cartesian coordinate arm configuration
2. Cylindrical coordinate arm configuration
3. Spherical or polar coordinate arm configuration
4. Jointed arm or articulated or revolute coordinate arm
configuration
 Classification of robots
Classification based on Intelligence level:
This classification is based on the level of technology applied to
the robot. Intelligent robots have a variety of sensors and artificial
intelligence.

Classification based on Types of motion:

This classification is based on straight line motion, circular
motion or slew motion
 Classification of Robots
Classification based on control methods:
This classification is based on
A. Motion control strategy
B. How the motion path is achieved

Based on motion control strategy, it is classified as

1. Robot that is servo controlled (closed loop)
2. Robot that is non-servo controlled (open loop).

The majority of industrial robots today are servo controlled.

 Classification of Robots
Based on How the motion path is achieved, it is
classified as :
1. Point-To-Point (PTP) control: the robot arm moves from one
desired point to the next without regard to the path taken between
them. It is used for assembly, palletizing, and machine-tool
loading/unloading
2. Continuous Path (CP) control: the robot arm moves along a
continuous path with specified orientation
 Repeatability, Precision,
Compliance
Repeatability:
It is a measure of the difference in value between two successive
measurements under the same conditions.
In Robotics repeatability is defined as the closeness between the actual
positions attained by the end effector for the same command. Repeatability
references a robot’s ability to return to the exact same position over and over.
Precision:
Precision means the ‘closeness of agreement’ between independent
measurements of a quantity under the same conditions without any reference
to the true value.
Compliance:
In industrial robotics, the term compliance refers to flexibility and suppleness
(opposite to stiffness). A compliant end effector can reach several positions and
exert different forces on a given object. A non-compliant (stiff) robot end
effector has predetermined positions or trajectories.
 Mobile Robots Classification
1. Wheeled Robots : Smooth terrain
2. Tracked Robots : Inbetween
3. Multi-legged Robots : Rough terrain
 End-effector
It is the part attached at the end of a robot manipulator.
This is equivalent to the human hand.

There are two types of end-effectors

1. Gripper 2. Tools

Examples of end-effectors are two-fingered gripper, welding gun,

paintbrush, welding electrode, gas-cutting torch, painting brush
 Grippers
Grippers are end-effectors which are used to grasp and hold an
object/workpiece or a tool and to load/unload an object from/to a
machine or conveyor.
Grippers are mechanical in nature using a combination of
mechanisms driven by electric, hydraulic, or pneumatic powers.
Types of grippers:

1. Mechanical Grippers, 2. Pneumatic Gripper,

3. Magnetic Gripper 4. Vacuum Grippers,
5. Adhesive Grippers 6. Active and Passive Grippers
A highly sophisticated attempt at reproducing
the human-hand force-closure end effector
Mechanical Grippers :
A gripper uses its fingers or jaws to hold an object.
They can hold an object by physical constriction or by friction.
They are usually fitted with pads, for greater friction that leads to
better grip.
Mechanical grippers have their jaw movements through rotational or
translational motion using a transmission element like linkages or
gears.
The gripper mechanism translates the power input (electric, hydraulic
or pneumatic) into the grasping action of the fingers.
A basic force-closure end effector
Magnetic Gripper :
The principle of a magnetic gripper is based on the magnetic
property of a gripper. Hence, they can be used only for ferrous
objects.
Magnetic grippers can have either (i) permanent magnets, or
(ii) electromagnets.
Electromagnetic grippers are easy to control requiring only a DC
power source
Grippers with permanent magnets do not require any external
power source to operate the magnets. Also there are no electric
sparks in handling hazardous materials. But they require an
external stripping mechanism during the release of the object.
Advantages of magnetic grippers:
1. Variations in object sizes can be tolerated.
2. Operations are very fast.
3. Require only one surface to hold an object.

Disadvantages of magnetic grippers:

1. Difficulty to pick thin sheets one at a time because the
magnetic force penetrates through more than one sheet. As a
result, more than one sheet is picked up.
2. Permanent magnets are demagnetized when heated.
Vacuum Grippers :
The vacuum grippers use suction cups (vacuum cups) as pick up
devices.
The term "vacuum" is used to describe the zone of pressure
below atmospheric pressure. Vacuum is a negative gauge
pressure.
The vacuum is generated by an electromechanical pump or a
compressed air-driven pump. The vacuum flow must not be
interrupted.
Vacuum grippers are suitable to handle large flat objects. But the
object’s surface should not have any holes.
Pneumatic Gripper :
A pneumatic gripper uses compressed air and pistons to operate
its 'jaws' (also known as 'fingers').
Pneumatic grippers hold the object with the help of suction cups.

Advantages of pneumatic grippers: low cost, large grip force

range, fast response.
Disadvantages of pneumatic grippers: limited position control,
requires compressed air to function.
An example of a vacuum gripper which uses suction cups made
of elastic materials is shown below:
Adhesive Grippers :
Adhesive Grippers use an adhesive substance to hold the load.
They are used to handle fabrics and other lightweight materials.
But since the adhesive substance loses its effectiveness with
repeated use, it has to be continuously fed.

Active and Passive Grippers :

Active grippers require continuous pressurization during gripping
and holding.
Passive gripper requires power to open and close but not to
maintain a grip. So it can be used in environments with limited
energy availability (e.g. solar or battery power).
 Processing Tools

The end effectors that can be used as tools serve various

purposes, including spot-welding in an assembly, spray-painting
where uniformity of painting is necessary, and other purposes
where the working conditions are dangerous for human beings.
Surgical robots have end effectors that are specifically
manufactured for the purpose.
The tools available are:
welding head
Paint spray gun
drill and milling cutters
scalpel, tool for surgeries
 ROBOT PROGRAMMING
• The definition of robot programming is the method of inputting
specific instructions for a robot to carry out automated tasks.
• Instructions are entered into the robot's control system which then
moves the motors, or actuators, on each axis.
• The first digitally operated and programmable robot was invented by
George Devol in 1954. It was ultimately called the Unimate.
• This later laid the foundations of the modern robotics industry.
• Typically performed using one of the following
– Off line
• robot programming languages
• task level programming
 Teach Pendant
– On line
• teach pendant
• lead through programming
 Use of Teach Pendant
• hand held device with switches used to control the robot
motions
• End points are recorded in controller memory
• sequentially played back to execute robot actions
• trajectory determined by robot controller
• suited for point to point control applications
• Easy to use, no special programming skills required
• Useful when programming robots for wide range of
repetitive tasks for long production runs
 Lead Through Programming
• lead the robot physically through the required sequence
of motions
• trajectory and endpoints are recorded, using a sampling
routine which records points at 60-80 times a second
• when played back results in a smooth continuous motion
• large memory requirements
 Programming Languages
• Motivation
– need to interface robot control system to external
sensors, to provide “real time” changes based on
sensory equipment
– computing based on geometry of environment
– ability to interface with CAD/CAM systems
– meaningful task descriptions
– off-line programming capability
 • Each robot manufacturer has their own robot
programming language
• No standards exist
• Portability of programs virtually non-existent
• Large number of robot languages available
– AML, VAL, AL, RAIL, RobotStudio, etc. (200+)
 Robot Programming
● A manufacturing language (AML) was a completely new
programming language developed by IBM to support the R/S 1
assembly robot. It was a subroutine-oriented, interpreted language
which ran on the Series/1 minicomputer.
● Variable Algorithmic Language (VAL) is a computer-based control
system and language designed specifically for use with Unimation
Inc. industrial robots. The VAL robot language is permanently
stored as a part of the VAL system.
● RAIL language includes three data types like Paths, Points, and
Reference Frames for robot locations. It has several special-purpose
commands for interfacing a robot with other equipments. Apart
from these functions, this robot language also provides many
programming features.
End of module 1

Thank you !