Robotic

PAPER PRESENTATION ON ROBOTICS

ABSTRACT

Robots recently became a popular tool in raising interests in computing for
middle and high school students. First year computer science courses at several
university were developed which involves the programming of a robot instead of
the traditional software engineering based coursework

Robotics as an undergraduate area of study is fairly common, although
few universities offer robotics degrees. In the US, only Worcester Polytechnic
Institute offers a Bachelor of Science in Robotics Engineering. Universities that
have graduate degrees focused on robotics include Carnegie Mellon University,
MIT, UPENN and UCLA . In Australia, there are Bachelor of Engineering degrees
at the universities belonging to the Centre for Autonomous Systems (CAS)

The structure of a robot is usually mostly mechanical and can be called a
kinematic chain (its functionality being similar to the skeleton of the human body).
The chain is formed of links (its bones), actuators (its muscles) and joints which
can allow one or more degrees of freedom. Most contemporary robots use open
serial chains in which each link connects the one before to the one after it. These
robots are called serial robots and often resemble the human arm. Some robots,
such as the Stewart platform, use a closed parallel kinematical chain.

Contents

• Origins
• Components of robots
o Structure
o Actuation
o Manipulation
o Locomotion
 Rolling Robots
 Walking Robots
 Other methods of locomotion
o Human interaction
• Control
• Dynamics and kinematics
• conclusion

ROBOTICS

The Shadow robot hand system

Robotics is the science and technology of robots, and their design, manufacture,
and application. Roboticists also study electronics, mechanics and software.

Origins

Stories of artificial helpers and companions and attempts to create them have a
long history, but fully autonomous machines only appeared in the 20th century. The first
digitally operated and programmable robot, the Unimate, was installed in 1961 to lift hot
pieces of metal from a die casting machine and stack them. Today, commercial and
industrial robots are in widespread use performing jobs more cheaply or with greater
accuracy and reliability than humans. They are also employed for jobs which are too
dirty, dangerous or dull to be suitable for humans. Robots are widely used in
manufacturing, assembly and packing, transport, earth and space exploration, surgery,
weaponry, laboratory research, and mass production of consumer and industrial goods.

Components of robots

Structure

The structure of a robot is usually mostly mechanical and can be called a kinematic
chain (its functionality being similar to the skeleton of the human body). The chain is
formed of links (its bones), actuators (its muscles) and joints which can allow one or
more degrees of freedom. Most contemporary robots use open serial chains in which
each link connects the one before to the one after it. These robots are called serial
robots and often resemble the human arm. Some robots, such as the Stewart platform,
use a closed parallel kinematical chain. Other structures, such as those that mimic the
mechanical structure of humans, various animals and insects, are comparatively rare.
However, the development and use of such structures in robots is an active area of
research (e.g. biomechanics). Robots used as manipulators have an end effector
mounted on the last link. This end effector can be anything from a welding device to a
mechanical hand used to manipulate the environment.

Robotics suite

A robotics suite is a visual environment for robot control and simulation. They are
typically an end-to-end platform for robotics development and include tools for visual
programming and creating and debugging robot applications. Developers can often
interact with robots through web-based or visual interfaces.

Actuation

A robot leg powered by Air Muscles

Actuators are the "muscles" of a robot, the parts which convert stored energy into
movement. By far the most popular actuators are electric motors, but there are many
others, powered by electricity, chemicals, and compressed air.

• Motors: The vast majority of robots use electric motors, including brushed and
brushless DC motors.
• Stepper motors: As the name suggests, stepper motors do not spin freely like DC
motors; they rotate in discrete steps, under the command of a controller. This
makes them easier to control, as the controller knows exactly how far they have
rotated, without having to use a sensor. Therefore they are used on many robots
and CNC machines.
• Piezo motors: A recent alternative to DC motors are piezo motors or ultrasonic
motors. These work on a fundamentally different principle, whereby tiny
piezoceramic elements, vibrating many thousands of times per second, cause
linear or rotary motion. There are different mechanisms of operation; one type

uses the vibration of the piezo elements to walk the motor in a circle or a straight
line. Another type uses the piezo elements to cause a nut to vibrate and drive a
screw. The advantages of these motors are nanometer resolution, speed and
available force for their size. These motors are already available commercially,
and being used on some robots.
• Air muscles: The air muscle is a simple yet powerful device for providing a
pulling force. When inflated with compressed air, it contracts by up to 40% of its
original length. The key to its behavior is the braiding visible around the outside,
which forces the muscle to be either long and thin, or short and fat. Since it
behaves in a very similar way to a biological muscle, it can be used to construct
robots with a similar muscle/skeleton system to an animal.For example, the
Shadow robot hand uses 40 air muscles to power its 24 joints.
• Electroactive polymers: Electroactive polymers are a class of plastics which
change shape in response to electrical stimulation. They can be designed so that
they bend, stretch or contract, but so far there are no EAPs suitable for
commercial robots, as they tend to have low efficiency or are not robust. Indeed,
all of the entrants in a recent competition to build EAP powered arm wrestling
robots, were beaten by a 17 year old girl. However, they are expected to improve
in the future, where they may be useful for microrobotic applications.
• Elastic nanotubes: These are a promising, early-stage experimental
technology. The absence of defects in nanotubes enables these filaments to
deform elastically by several percent, with energy storage levels of perhaps 10J
per cu cm for metal nanotubes. Human biceps could be replaced with an 8mm
diameter wire of this material. Such compact "muscle" might allow future robots
to outrun and outjump humans.

Manipulation

Robots which must work in the real world require some way to manipulate
objects; pick up, modify, destroy or otherwise have an effect. Thus the 'hands' of a robot
are often referred to as end effectors, while the arm is referred to as a manipulator.
Most robot arms have replaceable effectors, each allowing them to perform some small
range of tasks. Some have a fixed manipulator which cannot be replaced, while a few
have one very general purpose manipulator, for example a humanoid hand.

• Mechanical Grippers: One of the most common effectors is the gripper. In its
simplest manifestation it consists of just two fingers which can open and close to
pick up and let go of a range of small objects.
• Vacuum Grippers: Pick and place robots for electronic components and for
large objects like car windscreens, will often use very simple vacuum grippers.
These are very simple astrictive devices, but can hold very large loads provided
the prehension surface is smooth enough to ensure suction.
• General purpose effectors: Some advanced robots are beginning to use fully
humanoid hands, like the Shadow Hand and the Schunk hand.These highly
dexterous manipulators, with as many as 20 degrees of freedom and hundreds of
tactile sensors

Locomotion

Rolling Robots

Segway in the Robot museum in Nagoya.

For simplicity, most mobile robots have four wheels. However, some researchers have
tried to create more complex wheeled robots, with only one or two wheels.

• Two-wheeled balancing: While the Segway is not commonly thought of as a
robot, it can be thought of as a component of a robot. Several real robots do use
a similar dynamic balancing algorithm, and NASA's Robonaut has been mounted
on a Segway.
• Ballbot: Carnegie Mellon University researchers have developed a new type of
mobile robot that balances on a ball instead of legs or wheels. "Ballbot" is a self-
contained, battery-operated, omnidirectional robot that balances dynamically on
a single urethane-coated metal sphere. It weighs 95 pounds and is the
approximate height and width of a person. Because of its long, thin shape and
ability to maneuver in tight spaces, it has the potential to function better than
current robots can in environments with people.

• Track Robot: Another type of rolling robot is one that has tracks, like NASA's
Urban Robot, Urbie.

Walking Robots

iCub robot, designed by the RobotCub Consortium

Walking is a difficult and dynamic problem to solve. Several robots have been made
which can walk reliably on two legs, however none have yet been made which are as
robust as a human. Typically, these robots can walk well on flat floors, and can
occasionally walk up stairs. None can walk over rocky, uneven terrain. Some of the
methods which have been tried are:

• ZMP Technique: The Zero Moment Point (ZMP) is the algorithm used by robots
such as Honda's ASIMO. The robot's onboard computer tries to keep the total
inertial forces (the combination of earth's gravity and the acceleration and
deceleration of walking), exactly opposed by the floor reaction force (the force of
the floor pushing back on the robot's foot). In this way, the two forces cancel out,
leaving no moment (force causing the robot to rotate and fall over).However, this
is not exactly how a human walks, and the difference is quite apparent to human
observers, some of whom have pointed out that ASIMO walks as if it needs the

lavatory. ASIMO's walking algorithm is not static, and some dynamic balancing is
used (See below). However, it still requires a smooth surface to walk on.
• Hopping: Several robots, built in the 1980s by Marc Raibert at the MIT Leg
Laboratory, successfully demonstrated very dynamic walking. Initially, a robot
with only one leg, and a very small foot, could stay upright simply by hopping. The
movement is the same as that of a person on a pogo stick. As the robot falls to
one side, it would jump slightly in that direction, in order to catch itself. Soon, the
algorithm was generalised to two and four legs. A bipedal robot was
demonstrated running and even performing somersaults.[ A quadruped was also
demonstrated which could trot, run, pace and bound. For a full list of these robots,
see the MIT Leg Lab Robots page.
• Dynamic Balancing: A more advanced way for a robot to walk is by using a
dynamic balancing algorithm, which is potentially more robust than the Zero
Moment Point technique, as it constantly monitors the robot's motion, and places
the feet in order to maintain stability. This technique was recently demonstrated
by Anybots' Dexter Robot, which is so stable, it can even jump.
• Passive Dynamics: Perhaps the most promising approach utilises passive
dynamics where the momentum of swinging limbs is used for greater efficiency. It
has been shown that totally unpowered humanoid mechanisms can walk down a
gentle slope, using only gravity to propel themselves. Using this technique, a
robot need only supply a small amount of motor power to walk along a flat
surface or a little more to walk up a hill. This technique promises to make walking
robots at least ten times more efficient than ZMP walkers, like ASIMO.

Other methods of locomotion

RQ-4 Global Hawk Unmanned Aerial Vehicle

• Flying: A modern passenger airliner is essentially a flying robot, with two humans
to manage it. The autopilot can control the plane for each stage of the journey,
including takeoff, normal flight and even landing. Other flying robots are
uninhabited, and are known as Unmanned Aerial Vehicles (UAVs). They can be
smaller and lighter without a human pilot onboard, and fly into dangerous territory
for military surveillance missions. Some can even fire on targets under
command. UAVs are also being developed which can fire on targets
automatically, without the need for a command from a human. However these
robots are unlikely to see service in the foreseeable future because of the
morality issues involved. Other flying robots include cruise missiles, the Entomopter
and the Epson micro helicopter robot.

Two robot snakes. Left one has 64 motors (with 2 degrees of freedom per
segment), the right one 10.

• Snaking: Several snake robots have been successfully developed. Mimicking the
way real snakes move, these robots can navigate very confined spaces, meaning
they may one day be used to search for people trapped in collapsed buildings.
The Japanese ACM-R5 snake robot can even navigate both on land and in
water.
• Skating: A small number of skating robots have been developed, one of which is
a multi-mode walking and skating device, Titan VIII. It has four legs, with
unpowered wheels, which can either step or roll. Another robot, Plen, can use a
miniature skateboard or rollerskates, and skate across a desktop.
• Swimming: It is calculated that when swimming some fish can achieve a
propulsive efficiency greater than 90%. Furthermore, they can accelerate and
manoeuver far better than any man-made boat or submarine, and produce less
noise and water disturbance. Therefore, many researchers studying underwater
robots would like to copy this type of locomotion. Notable examples are the Essex
University Computer Science Robotic Fish, and the Robot Tuna built by the Institute
of Field Robotics, to analyse and mathematically model thunniform motion.

Human interaction

Kismet (robot) can produce a range of facial expressions.

If robots are to work effectively in homes and other non-industrial environments, the
way they are instructed to perform their jobs, and especially how they will be told to stop
will be of critical importance. The people who interact with them may have little or no
training in robotics, and so any interface will need to be extremely intuitive. Science
fiction authors also typically assume that robots will eventually communicate with
humans by talking, gestures and facial expressions, rather than a command-line
interface. Although speech would be the most natural way for the human to
communicate, it is quite unnatural for the robot. It will be quite a while before robots
interact as naturally as the fictional C3P0.

• Speech recognition: Interpreting the continuous flow of sounds coming from a
human (speech recognition), in real time, is a difficult task for a computer, mostly
because of the great variability of speech. The same word, spoken by the same
person may sound different depending on local acoustics, volume, the previous
word, whether or not the speaker has a cold, etc.. It becomes even harder when
the speaker has a different accent. Nevertheless, great strides have been made
in the field since Davis, Biddulph, and Balashek designed the first "voice input
system" which recognized "ten digits spoken by a single user with 100%
accuracy" in 1952. Currently, the best systems can recognise continuous, natural
speech, up to 160 words per minute, with an accuracy of 95%.
• Gestures: One can imagine, in the future, explaining to a robot chef how to
make a pastry, or asking directions from a robot police officer. On both of these
occasions, making hand gestures would aid the verbal descriptions. In the first
case, the robot would be recognising gestures made by the human, and perhaps
repeating them for confirmation. In the second case, the robot police officer
would gesture to indicate "down the road, then turn right". It is quite likely that
gestures will make up a part of the interaction between humans and robots. A
great many systems have been developed to recognise human hand gestures.
• Facial expression: Facial expressions can provide rapid feedback on the
progress of a dialog between two humans, and soon it may be able to do the
same for humans and robots. A robot should know how to approach a human,

judging by their facial expression and body language. Whether the person is
happy, frightened or crazy-looking affects the type of interaction expected of the
robot. Likewise, a robot like Kismet can produce a range of facial expressions,
allowing it to have meaningful social exchanges with humans.
• Personality: Many of the robots of science fiction have personality, and that is
something which may or may not be desirable in the commercial robots of the
future. Nevertheless, researchers are trying to create robots which appear to
have a personality: i.e. they use sounds, facial expressions and body language to
try to convey an internal state, which may be joy, sadness or fear. One
commercial example is Pleo, a toy robot dinosaur, which can exhibit several
apparent emotions.

Control

A robot-manipulated marionette, with complex control systems

The mechanical structure of a robot must be controlled to perform tasks. The
control of a robot involves three distinct phases - perception, processing and action
(robotic paradigms). Sensors give information about the environment or the robot itself
(e.g. the position of its joints or its end effector). This information is then processed to
calculate the appropriate signals to the actuators (motors) which move the mechanical
structure.

The processing phase can range in complexity. At a reactive level, it may
translate raw sensor information directly into actuator commands. Sensor fusion may
first be used to estimate parameters of interest (e.g. the position of the robot's gripper)
from noisy sensor data. An immediate task (such as moving the gripper in a certain
direction) is inferred from these estimates. Techniques from control theory convert the
task into commands that drive the actuators.

At longer time scales or with more sophisticated tasks, the robot may need to build and
reason with a "cognitive" model. Cognitive models try to represent the robot, the world,
and how they interact. Pattern recognition and computer vision can be used to track
objects. Mapping techniques can be used to build maps of the world. Finally, motion
planning and other artificial intelligence techniques may be used to figure out how to
act. For example, a planner may figure out how to achieve a task without hitting
obstacles, falling over, etc.

Control systems may also have varying levels of autonomy. Direct interaction is
used for haptic or tele-operated devices, and the human has nearly complete control
over the robot's motion. Operator-assist modes have the operator commanding
medium-to-high-level tasks, with the robot automatically figuring out how to achieve
them. An autonomous robot may go for extended periods of time without human
interaction. Higher levels of autonomy do not necessarily require more complex
cognitive capabilities. For example, robots in assembly plants are completely
autonomous, but operate in a fixed pattern.

Dynamics and kinematics

The study of motion can be divided into kinematics and dynamics. Direct
kinematics refers to the calculation of end effector position, orientation, velocity and
acceleration when the corresponding joint values are known. Inverse kinematics refers
to the opposite case in which required joint values are calculated for given end effector
values, as done in path planning. Some special aspects of kinematics include handling
of redundancy (different possibilities of performing the same movement), collision
avoidance and singularity avoidance. Once all relevant positions, velocities and
accelerations have been calculated using kinematics, methods from the field of
dynamics are used to study the effect of forces upon these movements. Direct
dynamics refers to the calculation of accelerations in the robot once the applied forces
are known. Direct dynamics is used in computer simulations of the robot. Inverse
dynamics refers to the calculation of the actuator forces necessary to create a
prescribed end effector acceleration. This information can be used to improve the
control algorithms of a robot.

In each area mentioned above, researchers strive to develop new concepts and
strategies, improve existing ones and improve the interaction between these areas. To
do this, criteria for "optimal" performance and ways to optimize design, structure and
control of robots must be developed and implemented.

Conclusion

Thus we conclude that, Robotics is powerful weapon in the field of recent computer
technologies. The art of every action of humans is made possible with the field of
Robotics.The six – sensed humans were about to build robots wit six-senses where
they can have their own intelligence.
By:-

superVAR

Robotic

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