Human-Robot Interaction Based On Gesture Identification

Human Robotic Interaction Based On Gesture Identification
Dept. of ECE, SJCET, Palai 1
1. INTRODUCTION
Robots are artificial agents with capacities of perception and action in the
physical world often referred by researchers as workspace. Their use has been
generalized in factories but nowadays they tend to be found in the most
technologically advanced societies in such critical domains as search and rescue,
military battle, mine and bomb detection, scientific exploration, law enforcement,
entertainment and hospital care.
These new domains of applications imply a closer interaction with the user.
The concept of closeness is to be taken in its full meaning, robots and humans share
the workspace but also share goals in terms of task achievement. This close
interaction needs new theoretical models, on one hand for the robotics scientists who
work to improve the robots utility and on the other hand to evaluate the risks and
benefits of this new "friend" for our modern society.
Robots are poised to fill a growing number of roles in today‘s society, from
factory automation to service applications to medical care and entertainment. While
robots were initially used in repetitive tasks where all human direction is given a
priori, they are becoming involved in increasingly more complex and less structured
tasks and activities, including interaction with people required to complete those
tasks. This complexity has prompted the entirely new endeavour of Human-Robot
Interaction (HRI), the study of how humans interact with robots, and how best to
design and implement robot systems capable of interacting with humans. The
fundamental goal of HRI is to develop the principles and algorithms for robot systems
that make them capable of direct, safe and effective interaction with humans. Many
facets of HRI research relate to and draw from insights and principles from
psychology, communication, anthropology, philosophy, and ethics, making HRI an
inherently interdisciplinary endeavour.

A robot is a mechanical or virtual intelligent agent that can perform tasks
automatically or with guidance, typically by remote control. In practice a robot is
usually an electro-mechanical machine that is guided by computer and electronic
programming. Robots can be autonomous,semi-autonomous or remotely controlled.
The word robot first appeared in the play Rossum‘s Universal Robots by the Czech
writer Karel Čapek in 1920.
Robots are used in an increasingly wide variety of tasks such as vacuuming
floors, mowing lawns, cleaning drains, building cars, in warfare, and in tasks that are
too expensive or too dangerous to be performed by humans such as exploring outer
space or at the bottom of the sea. Robots range from humanoids such
as ASIMO and TOPIO to Nano robots, Swarm robots, Industrial robots, military
robots, mobile and serving robots The branch of technology that deals with robots is
robotics.
At present there are two main types of robots, based on their use: general-
purpose autonomous robots and dedicated robots. Robots can be classified by
their specificity of purpose. A robot might be designed to perform one particular task
extremely well, or a range of tasks less well. Of course, all robots by their nature can
be re-programmed to behave differently, but some are limited by their physical form.
With the advance in artificial intelligence, the research is focusing on one part
towards the safest physical interaction. But also on a socially correct interaction,
dependent on cultural criteria. The goal is to build an intuitive and easy
communication with the robot through speech, gestures, and facial expressions.
Dautenhan refers to friendly Human-robot interaction as "Robotiquette"
defining it as the "social rules for robot behaviour (a ‗robotiquette‘) that is
comfortable and acceptable to humans.
The robot has to adapt itself to our way of
expressing desires and orders and not the contrary. But every day environments such
as homes have much more complex social rules than those implied by factories or
even military environments.

2. HUMAN ROBOTIC INTERACTION
Human–robot interaction is the study of interactions between humans and
robots. It is often referred as HRI by researchers. Human–robot interaction is a
multidisciplinary field with contributions from HCI, artificial
intelligence, robotics, natural language understanding, and social sciences.
Human-robot interaction has been a topic of both science fiction and academic
speculation even before any robots existed. Because HRI depends on knowledge of
(sometimes natural) human communication, many aspects of HRI are continuations
of human communications topics that are much older than robotics per se.
The origin of HRI as a discrete problem was stated by 20th-century
author Isaac Asimov in 1941, in his novel I, Robot. He states the Three Laws of
Robotics as,
1. A robot may not injure a human being or, through inaction, allow a human
being to come to harm.
2. A robot must obey any orders given to it by human beings, except where such
orders would conflict with the First Law.
3. A robot must protect its own existence as long as such protection does not
conflict with the First or Second Law.
These three laws of robotics determine the idea of safe interaction. The closer
the human and the robot get and the more intricate is the relationship the more the
risk of a human being injured rises. Nowadays in advanced societies manufacturers
employing robots solve this issue by not letting human and robot share the workspace
at any time. This is achieved by the extensive use of safe zones and cages. Thus the

presence of humans is completely forbidden in the robot workspace while it is
working.
With the advances of artificial intelligence, the autonomous robots could
eventually have more proactive behaviours, planning their motion in complex
unknown environments. These new capabilities would have to keeping safety as a
primer issue and as second efficiency. To allow this new generation of robot, research
is being made on human detection, motion planning, scene reconstruction, intelligent
behaviour through task planning.
The basic goal of HRI is to define a general human model that could lead to
principles and algorithms allowing more natural and effective interaction between
humans and robots.Many in the field of HRI study how humans collaborate and
interact and use those studies to motivate how robots should interact with humans.
HRI has continued to be a topic of academic and popular culture interest. In
fact, real-world robots have come into existence long after plays, novels, and movies
developed them as notions and began to ask questions regarding how humans and
robots would interact, and what their respective roles in society could be. While not
every one of those popular culture works has affected the field of robotics research,
there have been instances where ideas in the research world had their genesis in
popular culture.
In I, Robot, the three laws were examined relative to commands that humans
give robots, methods for humans to diagnose malfunctions, and ways in which robots
can participate in society. The theoretical implications of how the three laws are
designed to work has impacted the way that robot and agent systems operate today,
even though the type of autonomous reasoning needed for implementing a system that
obeys the three laws does not exist yet.
On the other end of HRI research the cognitive modelling of the "relationship"
between human and the robots benefits the psychologists and robotic researchers the
user study are often of interests on both sides. This research endeavours part of
human society.

Philip K. Dick‘s novel Do Androids Dream of Electric Sheep (1968) is set in a
future world (originally in the late ‘90s) where robots (called replicants) mingle with
humans. The replicants are humanoid robots that look and act like humans, and
special tests are devised to determine if an individual is a human or a replicant. The
test is related to the Turing Test, in that both involve asking probing questions that
require human experiences and capacities in order to answer correctly. As is typical,
the story also featured a battle between humans and replicants.
George Lucas‘ Star Wars movies (starting in 1977) feature two robot
characters (C3P0 and R2D2) as key characters, which are active, intuitive, even
heroic. One of the most interesting features from a robot design point of view is that,
while one of the robots is humanoid in form (C3PO) and the other (R2D2) is not, both
interact effectively with humans through social, assistive, and service interactions.
C3P0 speaks, gestures, and acts as a less-than-courageous human. R2D2, on the other
hand, interacts socially only through beeps and movement, but is understood and
often preferred by the audience for its decisiveness and courage.
In the television show Star Trek: The Next Generation (1987-1994), an
android named Data is a key team member with super-human intelligence but no
emotions. Data‘s main dream was to become more human, finally mastering emotion.
Data progressed to becoming an actor, a poet, a friend, and often a hero, presenting
robots in a number of potentially positive roles.

Fig 2.1 An example of an HRI testbed: a humanoid torso on a mobile platform, and a
simulation of the same system.
The short story and movie The Bicentennial Man, features a robot who
exhibits human-like creativity, carving sculptures from wood. Eventually, he strikes
out on his own, on a quest to find like-minded robots. His quest turns to a desire to be
recognized as a human. Through cooperation with a scientist, he develops artificial
organs in order for him to bridge the divide between himself and other humans,
benefiting both himself and humanity. Eventually, he is recognized as a human when
he creates his own mortality.
These examples, among many others, serve to frame to scope of HRI research
and exploration. They also provide some of the critical questions regarding robots and
society that have become benchmarks for real-world robot systems.
Scholtz describes five roles that a human may have when interacting with a
robot: supervisor, operator, teammate, mechanic/programmer, and bystander. One or
more of these values would be assigned to the INTERACTION-ROLE classification.
A supervisory role is taken by a human when it needs to monitor the behavior
of a robot, but does not need to directly control it. For example, a supervisor of an

unmanned vehicle may tell the robot where it should move, then the robot plans and
carries out its task.
An operator needs to have more interaction with a robot, stepping in to
teleoperate the robot or needing to change the robot‘s behavior.
A teammate works with a robot to accomplish a task. An example of this
would be a manufacturing robot that accomplished part of an assembly while a
human worked on another part of the assembly of the item.
A mechanic or programmer needs to physically change the robot‘s hardware
or software.
A bystander does not control a robot but needs to have some understanding of
what the robot is doing in order to be in the same space. For example, a person who
walks into a room with a robot vacuum cleaner needs to be able to avoid the robot
safely.
2.1 HRI RESEARCH CHALLENGES
The study of HRI contains a wide variety of challenges, some of them of basic
research nature, exploring concepts general to HRI, and others of domain-specific
nature, dealing with direct uses of robot systems that interact with humans in
particular contexts. In this section, we overview the following major research
challenges within HRI: multimodal sensing and perception; design and human
factors; developmental and epigenetic robotics; social, service and assistive robotics;
and robotics for education.
Multi-Modal Perception
Real-time perception and dealing with uncertainty in sensing are some of the
most enduring challenges of robotics. For HRI, the perceptual challenges are
particularly complex, because of the need to perceive, understand, and react to human
activity in real-time.

The range of sensor inputs for human interaction is far larger than for most
other robotic domains in use today. HRI inputs include vision and speech, both major
open challenges for real-time data processing. Computer vision methods that can
process human-oriented data such as facial expression and gestures must be capable
of handling a vast range of possible inputs and situations. Similarly, language
understanding and dialog systems between human users and robots remain an open
research challenge. Tougher still is to obtain understanding of the connection between
visual and linguistic data and combining them toward improved sensing and
expression.
Design And Human Factors
The design of the robot, particularly the human factor concerns, is a key
aspect of HRI. Research in these areas draws from similar research in human-
computer interaction (HCI) but features a number of significant differences related to
the robot‘s physical real-world embodiment. The robot‘s physical embodiment, form
and level of anthropomorphism, and simplicity or complexity of design, are some of
the key research areas being explored.
Developmental/Epigenetic Robotics
Developmental robotics, sometimes referred to as epigenetic robotics, studies
robot cognitive development. Developmental roboticists are focused on creating
intelligent machines by endowing them with the ability to autonomously acquire
skills and information. Research into developmental/epigenetic robotics spans a broad
range of approaches. One effort has studied teaching task behavior using shaping and
joint attention, a primary means used by children in observing the behavior of others
in learning tasks. Developmental work includes the design of primitives for humanoid
movements, gestures, and dialog.
Social,Service And Assistive Robotics
Service and assistive robotics include a very broad spectrum of application
domains, such as office assistants, autonomous rehabilitation aids, and educational

robots. This broad area integrates basic HRI research with real-world domains that
required some service or assistive function. The study of social robots (or socially
interactive robots) focuses on social interaction, and so is a proper subset of problems
studied under HRI.
Educational Robotics
Robotics has been shown to be a powerful tool for learning, not only as a topic
of study, but also for other more general aspects of science, technology, engineering,
and math (STEM) education. A central aspect of STEM education is problem-
solving, and robots serve as excellent means for teaching problem-solving skills in
group settings. Based on the mounting success of robotics courses world-wide, there
is now is an active movement to develop robot hardware and software in service of
education, starting from the youngest elementary school ages and up. Robotics is
becoming an important tool for teaching computer science and introductory college
engineering.

3. PROPOSED WORK
In this project we have established a successful interaction between a human
and robot. This interaction has become possible by the hand gesture identification.
The gestures (left, right, forward and backward) made by the human hand are
identified and converted to electrical signals (voltage) by the accelerometer. The
accelerometer captures the motion in X,Y and Z directions and corresponding
voltages are produced which are transmitted to the receiver via a wireless
transmission method ,zigbee is used for this purpose. Zigbee is used because it is very
powerful and reliable method than other methods.
The receiver receives the signals transmitted and will generate some control
sequence to make corresponding motion in the autobot. The autobot is designed with
three wheels. Because three wheeled autobot controlling is easier and power saving
method than the four wheeled autobot. In this autobot the front wheel is free to move
in any direction and the two back wheels are connected to the shafts of two motors. A
wireless camera is provided in the receiver, so the autobot can be controlled by the
human by standing in a remote location. Camera gives the instant video in the
monitor which is placed in the transmitter section. So by seeing video a deaf and
dump person can control the autobot.

4. BLOCK DIAGRAMS
4.1 TRANSMITTER SECTION
Fig 4.1.2 Block Diagram Of Transmitter Section
Figure above shows the basic block diagram of the Human Robot Interaction
System. There are different ways to interact human with robot like sound, gesture,
touch etc. Here we are using the gesture method of interaction. For identifying the
gesture of the human hand we are using the accelerometer. Followed by the
accelerometer there is a processing unit which is a PIC microcontroller 16F876A.
Which is an advanced and high speed device. The output of the microcontroller is

transmitted through a wireless communication method called zigbee protocol. Which
is an advanced, high speed, reliable and accurate method is of wireless
communication than the other conventional wireless protocols.
The accelerometer here using is an analog accelerometer. It will detect the
motion corresponding to X, Y & Z directions. This device produces some analog
voltages corresponding to the motion. We cannot use these voltages in the analog
form so we have to convert the analog values to digital values. The analog values are
converted to digital format by the usage of an analog to digital converter which inside
the microcontroller.
In the microcontroller memory,there are some predefined ranges of values are
stored for each type of motion for X,Y & Z. When a motion occurs the controller
checks the value and compares it with the predefined range of values. If the value is
in that predefined range, the controller identifies that the motion is occurred in X or Y
or in Z direction. Then according to the accelerometer specification, for one motion
two co-ordinate values changes and other one will remain the same. So for the left,
right, front and back movements some values are taken experimentally and assigning
some range. If the output of accelerometer is in that range the controller will generate
a particular code corresponding to each motion i.e. 01 for left, 02 for right etc. These
codes are generated in the any of the port of controller as per the program. These
codes are transmitted through the zigbee transmitter.
The function of the controller is to initialize and monitor the stop count. Stop
count is the count which is given during the effective motion detection and code
generation process.

4.2 RECEIVER SECTION
Fig 4.2.3 Block Diagram Of Receiver Section
Figure above shows the receiver section of the Human Robot Interaction
System. When there is a motion occurs the transmitter detects the type of motion and
will generate and transmit codes corresponding to the type of motion. The zigbee
receiver receives the code and will produce another set of codes .These codes
determines the tasks to be performed for each command, ie. Some tasks are assigned
to each code. This is the main function of the 89C2051 microcontroller .It is a 20 pin
microcontroller with two ports. The controller then sends the codes to the main
controller of the autobot in a serial format. Then the controller in the receiver will
initialize a stop count. The stop count increments automatically and the device
continuously monitor the status of stop count. The code generation and sending

process will stop when the stop count reaches it‘s maximum value or there is another
motion occurred.
The controller of the autobot receives the code generated by the receiver
controller and will generate some sequence of codes to control the motor driver .The
motor driver is provided to interface the two motors with the controller and to provide
more power to the motors. It also helps to provide fast response. The motor driver can
control two motors at a time .It is having internal ESD protection and thermal shut
down, high noise immunity. According to the code received from the autobot
controller the motor driver will rotate the motor shaft in clockwise and anti clockwise
direction for the motion of robot .Thus the autobot motion occurs.
The autobot is a three wheeled device; two of them are connected to the dc
motors. The motor driver IC controls the movement of the motors. The front wheel is
free to move in any direction where as the other two wheels can move in clockwise
and anti-clockwise direction only. The three wheel concept reduces the power
requirement, power loss and increases the fast response. For a four wheeled autobot
four motors and two drivers IC‘s are required.

5. HARDWARE SECTION
5.1 CIRCUIT DIAGRAMS
5.1.1 TRANSMITTER SECTION
Fig 5.1.1.4 Circuit Diagram Of Transmitter Section

Figure shows the circuit diagram of transmitter of the Human Robot
Interaction System. The circuit diagram of power supply is shown on the top of the
figure. The voltage regulator IC 7805 is used to regulate the incoming power supply.
There is a power supply indicator also provided. The total system works with 5V
supply.
The transmitter parts mainly consist of an accelerometer. PIC microcontroller
and Zigbee transceiver. The accelerometer here using is ADXL 335 which is an
analog accelerometer. It detects the X, Y and Z directional motion of human hand and
will produce corresponding analog voltages. The system is more compatible with
digital voltages. So we need to convert the analog values in to digital format. The
ADXL 335 consists of 3 output pins for X, Y and Z outputs. For the analog to digital
conversion, the ADC in the PIC is used. The output pins of ADXL 335 are connected
to the 3 analog inputs of the PIC. i.e. pin 2, 3 and 4. The PIC converts the analog
value to digital value and compares the values with the predefined values stored in its
memory.
According to the specification of ADXL 335 for any motion the two co-
ordinate values changes and one value remains the same. For example, consider the
forward motion of the hand, X and Y co-ordinate value produces particular values
and Z remains in the previous value. For each motions, ie.forward, backward, left and
right the values for X,Y and Z co-ordinates are measured and stored in the
microcontroller memory.
When the motion occurs the accelerometer produces corresponding output.
The PIC compares those values with the values in its memory. If the comparison
satisfies, the PIC will produce a particular code and will send that code to receiver
through Zigbee transmitter. The Zigbee is connected to the transmitter and receiver
pins of PIC microcontroller.
The crystal oscillator is also provided to generate a clock frequency of
20MHz.

5.1.2 RECEIVER SECTION
Fig 5.1.2.5 Circuit Diagram Of Receiver Section

Figure shows the circuit diagram of receiver. The power supply is provided to
generate 5V supply. The voltage regulator IC 7805 is used.
The main component is 89C2051 microcontroller. It is a 20 pin
microcontroller with 2 ports and works with 12 MHz frequency. The Zigbee
receiver is connected to receiver pin of the microcontroller. The Zigbee receiver
receives some codes and controller monitors the code and for each code the controller
generates some other codes in the port P1. The port 1 is pulled up with a resistor
pack. And the output is connected to a latch IC 7417C573. And its output is applied
to the main controller of the autobot. The latch is used to provide the quick response.
5.1.3 AUTOBOT
Fig 5.1.3.6 Circuit Diagram Of Autobot

Figure shows the circuit diagram of autobot. The circuit diagram of the power
supply is shown in figure. There is a provision to give ac and dc supply to the device.
There is a bridge provided for ac supply. Commonly dc is giving to the device to
make it wireless. 7805 voltage regulator is used for providing 5V supply at the output.
PIC 18F4550 is the main controller used in the autobot. It is a USB
programmable microcontroller. It is an 8 bit microcontroller with flash programming
capability. The special codes generated by the receiver-microcontroller are applied to
the pins 27 to 30. The controller receives these codes and will give some commands
to the motor driver IC. The commands are saved in the memory of the main
controller. These commands gives instruction to the driver IC and it controls the
movement of motor and the wheels attached with the motor shaft. For making a left
turn, the motor at the right side should rotate in clockwise in full speed and the motor
at the left should remain in still condition. For making a right turn the left motor
should rotate in clockwise in full speed and right motor should remain in still
position. For the forward motion both motors should rotate in clockwise and in full
speed. For the reverse motion both the motors should rotate in anticlockwise
direction.
PIN 1 PIN2(INPUT) PIN7(OUTPUT) FUNCTION
HIGH LOW HIGH TURN
CLOCKWISE
HIGH HIGH LOW TURN ANTI
CLOCKWISE
HIGH LOW LOW STOP
HIGH HIGH HIGH STOP
LOW NOT APPLICABLE NOT APPLICABLE STOP
Table 5.1.1 L293D Operation modes

5.2 MAIN COMPONENTS
5.2.1 ACCELEROMETER
An accelerometer is a device that measures proper acceleration, also called the
four-acceleration. For example, an accelerometer on a rocket accelerating through
space will measure the rate of change of the velocity of the rocket relative to any
inertial frame of reference. However, the proper acceleration measured by an
accelerometer is not necessarily the coordinate acceleration (rate of change of
velocity). Instead, it is the acceleration associated with the phenomenon of weight
experienced by any test mass at rest in the frame of reference of the accelerometer
device. For an example where these types of acceleration differ, an accelerometer will
measure a value of g in the upward direction when remaining stationary on the
ground, because masses on earth have weight m*g. By contrast, an accelerometer in
gravitational free fall toward the center of the Earth will measure a value of zero
because, even though its speed is increasing, it is at rest in a frame of reference in
which objects are weightless.
Most accelerometers do not display the value they measure, but supply it to
other devices. Real accelerometers also have practical limitations in how quickly they
respond to changes in acceleration, and cannot respond to changes above a certain
frequency of change.
Single- and multi-axis models of accelerometer are available to detect
magnitude and direction of the proper acceleration (or g-force), as a vector quantity,
and can be used to sense orientation (because direction of weight changes),
coordinate acceleration (so long as it produces g-force or a change in g-force),
vibration, shock, and falling (a case where the proper acceleration changes, since it
tends toward zero). Micromachined accelerometers are increasingly present in
portable electronic devices and video game controllers, to detect the position of the
device or provide for game input.
Pairs of accelerometers extended over a region of space can be used to detect
differences (gradients) in the proper accelerations of frames of references associated

with those points. These devices are called gravity gradiometers, as they measure
gradients in the gravitational field. Such pairs of accelerometers in theory may also be
able to detect gravitational waves.
Physical Principles
An accelerometer measures proper acceleration, which is the acceleration it
experiences relative to freefall and is the acceleration felt by people and objects. Put
another way, at any point in space-time the equivalence principle guarantees the
existence of a local inertial frame, and an accelerometer measures the acceleration
relative to that frame. Such accelerations are popularly measured in terms of g-force.
An accelerometer at rest relative to the Earth's surface will indicate
approximately 1 g upwards, because any point on the Earth's surface is accelerating
upwards relative to the local inertial frame (the frame of a freely falling object near
the surface). To obtain the acceleration due to motion with respect to the Earth, this
"gravity offset" must be subtracted and corrections for effects caused by the Earth's
rotation relative to the inertial frame.
The reason for the appearance of a gravitational offset is Einstein's
equivalence principle, which states that the effects of gravity on an object are
indistinguishable from acceleration. When held fixed in a gravitational field by, for
example, applying a ground reaction force or an equivalent upward thrust, the
reference frame for an accelerometer (its own casing) accelerates upwards with
respect to a free-falling reference frame. The effects of this acceleration are
indistinguishable from any other acceleration experienced by the instrument, so that
an accelerometer cannot detect the difference between sitting in a rocket on the
launch pad, and being in the same rocket in deep space while it uses its engines to
accelerate at 1 g. For similar reasons, an accelerometer will read zero during any type
of free fall. This includes use in a coasting spaceship in deep space far from any mass,
a spaceship orbiting the Earth, an airplane in a parabolic "zero-g" arc, or any free-fall
in vacuum. Another example is free-fall at a sufficiently high altitude that
atmospheric effects can be neglected.

However this does not include a (non-free) fall in which air resistance
produces drag forces that reduce the acceleration, until constant terminal velocity is
reached. At terminal velocity the accelerometer will indicate 1 g acceleration
upwards. For the same reason a skydiver, upon reaching terminal velocity, does not
feel as though he or she were in "free-fall", but rather experiences a feeling similar to
being supported (at 1 g) on a "bed" of uprushing air.
Acceleration is quantified in the SI unit metres per second per second (m/s2
),
in the cgs unit gal (Gal), or popularly in terms of g-force (g).
For the practical purpose of finding the acceleration of objects with respect to
the Earth, such as for use in an inertial navigation system, a knowledge of local
gravity is required. This can be obtained either by calibrating the device at rest, or
from a known model of gravity at the approximate current position.
APPLICATION
Engineering
Accelerometers can be used to measure vehicle acceleration. They allow for
performance evaluation of both the engine/drive train and the braking systems.
Accelerometers can be used to measure vibration on cars, machines,
buildings, process control systems and safety installations. They can also be used to
measure seismic activity, inclination, machine vibration, dynamic distance and speed
with or without the influence of gravity. Applications for accelerometers that measure
gravity, wherein an accelerometer is specifically configured for use in gravimetry, are
called gravimeters.
Notebook computers equipped with accelerometers can contribute to the
Quake-Catcher Network (QCN), a BOINC project aimed at scientific research of
earthquakes.

Industry
Accelerometers are also used for machinery health monitoring to report the
vibration and its changes in time of shafts at the bearings of rotating equipment such
as turbines, pumps, fans, rollers, compressors, and cooling towers,. Vibration
monitoring programs are proven to warn of impending failure, save money, reduce
downtime, and improve safety in plants worldwide by detecting conditions such as
wear and tear of bearings, shaft misalignment, rotor imbalance, gear failure or bearing
fault which, if not attended to promptly, can lead to costly repairs. Accelerometer
vibration data allows the user to monitor machines and detect these faults before the
rotating equipment fails completely. Vibration monitoring programs are utilized in
industries such as automotive manufacturing, machine tool applications,
pharmaceutical production, power generation and power plants, pulp and paper, sugar
mills, food and beverage production, water and wastewater, hydropower,
petrochemical and steel manufacturing.
Building And Structural Monitoring
Accelerometers are used to measure the motion and vibration of a structure
that is exposed to dynamic loads. Dynamic loads originate from a variety of sources
including:
Human activities – walking, running, dancing or skipping
Working machines – inside a building or in the surrounding area
Construction work – driving piles, demolition, drilling and excavating
Moving loads on bridges
Vehicle collisions
Impact loads – falling debris
Concussion loads – internal and external explosions
Collapse of structural elements

Wind loads and wind gusts
Air blast pressure
Loss of support because of ground failure
Earthquakes and aftershocks
Measuring and recording how a structure responds to these inputs is critical
for assessing the safety and viability of a structure. This type of monitoring is called
Dynamic Monitoring.
Consumer Electronics
Fig 5.2.1.7 Galaxy Nexus, an example of a smart phone with a built-in accelerometer
Accelerometers are increasingly being incorporated into personal electronic
devices.
Motion Input
Some smartphones, digital audio players and personal digital assistants
contain accelerometers for user interface control; often the accelerometer is used to
present landscape or portrait views of the device's screen, based on the way the device
is being held.

Automatic Collision Notification (ACN) systems also use accelerometers in a
system to call for help in event of a vehicle crash. Prominent ACN systems include
Onstar AACN service, Ford Link's 911 Assist, Toyota's Safety Connect, Lexus Link,
or BMW Assist. Many accelerometer-equipped smartphones also have ACN software
available for download. ACN systems are activated by detecting crash-strength G-
forces.
Nintendo's Wii video game console uses a controller called a Wii Remote that
contains a three-axis accelerometer and was designed primarily for motion input.
Users also have the option of buying an additional motion-sensitive attachment, the
Nunchuk, so that motion input could be recorded from both of the user's hands
independently. Is also used on the Nintendo 3DS system.
The Sony PlayStation 3 uses the DualShock 3 remote which uses a three axis
accelerometer that can be used to make steering more realistic in racing games, such
as Motorstorm and Burnout Paradise.
The Nokia 5500 sport features a 3D accelerometer that can be accessed from
software. It is used for step recognition (counting) in a sport application, and for tap
gesture recognition in the user interface. Tap gestures can be used for controlling the
music player and the sport application, for example to change to next song by tapping
through clothing when the device is in a pocket. Other uses for accelerometer in
Nokia phones include Pedometer functionality in Nokia Sports Tracker. Some other
devices provide the tilt sensing feature with a cheaper component, which is not a true
accelerometer.
Sleep phase alarm clocks use accelerometric sensors to detect movement of a
sleeper, so that it can wake the person when he/she is not in REM phase, therefore
awakes more easily.
Orientation Sensing
A number of 21st century devices use accelerometers to align the screen
depending on the direction the device is held, for example switching between portrait

and landscape modes. Such devices include many tablet PCs and some smartphones
and digital cameras.
For example, Apple uses an LIS302DL accelerometer in the iPhone, iPod
Touch and the 4th and 5th generation iPod Nano allowing the device to know when it
is tilted on its side. Third-party developers have expanded its use with fanciful
applications such as electronic bobbleheads. The BlackBerry Storm phone was also
an early user of this orientation sensing feature.
Fig 5.2.1.8 Orientation Detection
The Nokia N95 and Nokia N82 have accelerometers embedded inside them. It
was primarily used as a tilt sensor for tagging the orientation to photos taken with the
built-in camera and later became available to other applications through a firmware
update.
As of January 2009, almost all new mobile phones and digital cameras contain
at least a tilt sensor and sometimes an accelerometer for the purpose of auto image
rotation, motion-sensitive mini-games, and to correct shake when taking photographs.

5.2.1.1 ANALOG ACCELEROMETER ADXL335
Fig 5.2.1.9 ADXL 335
The ADXL335 is a small, thin, low power, complete 3-axis accel-erometer
with signal conditioned voltage outputs. The product measures acceleration with a
minimum full-scale range of ±3 g. It can measure the static acceleration of gravity in
tilt-sensing applications, as well as dynamic acceleration resulting from motion,
shock, or vibration.
The user selects the bandwidth of the accelerometer using the CX, CY, and
CZ capacitors at the XOUT, YOUT, and ZOUT pins. Bandwidths can be selected to
suit the application, with a range of 0.5 Hz to 1600 Hz for the X and Y axes, and a
range of 0.5 Hz to 550 Hz for the Z axis.
The ADXL335 is available in a small, low profile, 4 mm × 4 mm × 1.45 mm,
16-lead, plastic lead frame chip scale package (LFCSP_LQ).

Functional Block
Fig 5.2.1.10 Functional Block Of ADXL 335
The ADXL335 is a complete 3-axis acceleration measurement system. The
ADXL335 has a measurement range of ±3 g mini-mum. It contains a polysilicon
surface-micromachined sensor and signal conditioning circuitry to implement open-
loop acceleration measurement architecture. The output signals are analog voltages
that are proportional to acceleration. The accelerometer can measure the static
acceleration of gravity in tilt-sensing applications as well as dynamic acceleration
resulting from motion, shock, or vibration.
The sensor is a polysilicon surface-micromachined structure built on top of a
silicon wafer. Polysilicon springs suspend the structure over the surface of the wafer
and provide a resistance against acceleration forces. Deflection of the structure is
meas-ured using a differential capacitor that consists of independent fixed plates and
plates attached to the moving mass. The fixed plates are driven by 180° out-of-phase
square waves. Acceleration deflects the moving mass and unbalances the differential
capacitor resulting in a sensor output whose amplitude is proportional to acceleration.

Phase-sensitive demodulation techniques are then used to determine the magnitude
and direction of the acceleration.
The demodulator output is amplified and brought off-chip through a 32 kΩ
resistor. The user then sets the signal bandwidth of the device by adding a capacitor.
This filtering improves measurement resolution and helps prevent aliasing.
For most applications, a single 0.1 μF capacitor, CDC, placed close to the
ADXL335 supply pins adequately decouples the accelerometer from noise on the
power supply. However, in applications where noise is present at the 50 kHz internal
clock frequency (or any harmonic thereof), additional care in power supply bypassing
is required because this noise can cause errors in acceleration measurement.
If additional decoupling is needed, a 100 Ω (or smaller) resistor or ferrite bead
can be inserted in the supply line. Additionally, a larger bulk bypass capacitor (1 μF
or greater) can be added in parallel to CDC. Ensure that the connection from the
ADXL335 ground to the power supply ground is low impedance because noise
transmitted through ground has a similar effect to noise transmitted through VS.
The ADXL335 has provisions for band limiting the XOUT, YOUT, and
ZOUT pins. Capacitors must be added at these pins to implement low-pass filtering
for antialiasing and noise reduction. The equation for the 3 dB bandwidth is
F−3 dB = 1/(2π(32 kΩ) × C(X, Y, Z))
or more simply
F–3 dB = 5 μF/C(X, Y, Z)
The tolerance of the internal resistor (RFILT) typically varies as much as
±15% of its nominal value (32 kΩ), and the bandwidth varies accordingly. A
minimum capacitance of 0.0047 μF for CX, CY, and CZ is recommended in all cases.
The ST pin controls the self-test feature. When this pin is set to VS, an
electrostatic force is exerted on the accelerometer beam. The resulting movement of
the beam allows the user to test if the accelerometer is functional. The typical change

in output is −1.08 g (corresponding to −325 mV) in the X-axis, +1.08 g (or +325 mV)
on the Y-axis, and +1.83 g (or +550 mV) on the Z-axis. This ST pin can be left open-
circuit or connected to common (COM) in normal use.
Never expose the ST pin to voltages greater than VS + 0.3 V. If this cannot be
guaranteed due to the system design (for instance, if there are multiple supply
voltages), then a low VF clamping diode between ST and VS is recommended.
The selected accelerometer bandwidth ultimately determines the measurement
resolution (smallest detectable acceleration). Filtering can be used to lower the noise
floor to improve the resolution of the accelerometer. Resolution is dependent on the
analog filter bandwidth at XOUT, YOUT, and ZOUT.
The output of the ADXL335 has a typical bandwidth of greater than 500 Hz.
The user must filter the signal at this point to limit aliasing errors. The analog
bandwidth must be no more than half the analog-to-digital sampling frequency to
minimize aliasing. The analog bandwidth can be further decreased to reduce noise
and improve resolution.
The ADXL335 noise has the characteristics of white Gaussian noise, which
contributes equally at all frequencies and is described in terms of μg/√Hz (the noise is
proportional to the square root of the accelerometer bandwidth). The user should limit
bandwidth to the lowest frequency needed by the application to maximize the
resolution and dynamic range of the accelerometer.
5.2.2 ZIGBEE
ZigBee is a specification for a suite of high level communication protocols
using small, low-power digital radios based on an IEEE 802 standard for personal
area networks. Applications include wireless light switches, electrical meters with in-
home-displays, and other consumer and industrial equipment that requires short-range
wireless transfer of data at relatively low rates. The technology defined by the ZigBee
specification is intended to be simpler and less expensive than other WPANs, such as
Bluetooth. ZigBee is targeted at radio-frequency (RF) applications that require a low

data rate, long battery life, and secure networking. ZigBee has a defined rate of 250
kbps best suited for periodic or intermittent data or a single signal transmission from a
sensor or input device. ZigBee based traffic management system have also been
implemented. The name refers to the waggle dance of honey bees after their return to
the beehive.
ZigBee is a low-cost, low-power, wireless mesh network standard. The low
cost allows the technology to be widely deployed in wireless control and monitoring
applications. Low power-usage allows longer life with smaller batteries. Mesh
networking provides high reliability and more extensive range. ZigBee chip vendors
typically sell integrated radios and microcontrollers with between 60 KB and 256 KB
flash memory.
ZigBee operates in the industrial, scientific and medical (ISM) radio bands;
868 MHz in Europe, 915 MHz in the USA and Australia, and 2.4 GHz in most
jurisdictions worldwide. Data transmission rates vary from 20 to 900 kilobits/second.
The ZigBee network layer natively supports both star and tree typical
networks, and generic mesh networks. Every network must have one coordinator
device, tasked with its creation, the control of its parameters and basic maintenance.
Within star networks, the coordinator must be the central node. Both trees and meshes
allows the use of ZigBee routers to extend communication at the network level.
ZigBee builds upon the physical layer and medium access control defined in
IEEE standard 802.15.4 (2003 version) for low-rate WPANs. The specification goes
on to complete the standard by adding four main components: network layer,
application layer, ZigBee device objects (ZDOs) and manufacturer-defined
application objects which allow for customization and favor total integration.
Besides adding two high-level network layers to the underlying structure, the
most significant improvement is the introduction of ZDOs. These are responsible for
a number of tasks, which include keeping of device roles, management of requests to
join a network, device discovery and security.

Fig 5.2.2.11 Zigbee Protocol Stack
ZigBee is not intended to support powerline networking but to interface with
it at least for smart metering and smart appliance purposes.
Because ZigBee nodes can go from sleep to active mode in 30 ms or less, the
latency can be low and devices can be responsive, particularly compared to Bluetooth
wake-up delays, which are typically around three seconds.Because ZigBee nodes can
sleep most of the time, average power consumption can be low, resulting in long
battery life.

Uses
ZigBee protocols are intended for embedded applications requiring low data
rates and low power consumption. The resulting network will use very small amounts
of power — individual devices must have a battery life of at least two years to pass
ZigBee certification.
Typical application areas include:
Home Entertainment and Control — Home automation, smart lighting,
advanced temperature control, safety and security, movies and music
Wireless Sensor Networks — Starting with individual sensors like
Telosb/Tmote and Iris from Memsic
Industrial control
Embedded sensing
Medical data collection
Smoke and intruder warning
Building automation
Device Types
There are three different types of ZigBee devices:
ZigBee coordinator (ZC): The most capable device, the coordinator forms the
root of the network tree and might bridge to other networks. There is exactly
one ZigBee coordinator in each network since it is the device that started the
network originally. It is able to store information about the network, including
acting as the Trust Center & repository for security keys.
ZigBee Router (ZR): As well as running an application function, a router can
act as an intermediate router, passing on data from other devices.
ZigBee End Device (ZED): Contains just enough functionality to talk to the
parent node (either the coordinator or a router); it cannot relay data from other
devices. This relationship allows the node to be asleep a significant amount of

the time thereby giving long battery life. A ZED requires the least amount of
memory, and therefore can be less expensive to manufacture than a ZR or ZC.
Protocols
The protocols build on recent algorithmic research (Ad-hoc On-demand
Distance Vector, neuRFon) to automatically construct a low-speed ad-hoc network of
nodes. In most large network instances, the network will be a cluster of clusters. It
can also form a mesh or a single cluster. The current ZigBee protocols support beacon
and non-beacon enabled networks.
In non-beacon-enabled networks, an unslotted CSMA/CA channel access
mechanism is used. In this type of network, ZigBee Routers typically have their
receivers continuously active, requiring a more robust power supply. However, this
allows for heterogeneous networks in which some devices receive continuously,
while others only transmit when an external stimulus is detected. The typical example
of a heterogeneous network is a wireless light switch: The ZigBee node at the lamp
may receive constantly, since it is connected to the mains supply, while a battery-
powered light switch would remain asleep until the switch is thrown. The switch then
wakes up, sends a command to the lamp, receives an acknowledgment, and returns to
sleep. In such a network the lamp node will be at least a ZigBee Router, if not the
ZigBee Coordinator; the switch node is typically a ZigBee End Device.
In beacon-enabled networks, the special network nodes called ZigBee Routers
transmit periodic beacons to confirm their presence to other network nodes. Nodes
may sleep between beacons, thus lowering their duty cycle and extending their
battery life. Beacon intervals depend on data rate; they may range from 15.36
milliseconds to 251.65824 seconds at 250 kbit/s, from 24 milliseconds to 393.216
seconds at 40 kbit/s and from 48 milliseconds to 786.432 seconds at 20 kbit/s.
However, low duty cycle operation with long beacon intervals requires precise
timing, which can conflict with the need for low product cost.

In general, the ZigBee protocols minimize the time the radio is on, so as to
reduce power use. In beaconing networks, nodes only need to be active while a
beacon is being transmitted. In non-beacon-enabled networks, power consumption is
decidedly asymmetrical: some devices are always active, while others spend most of
their time sleeping.
Except for the Smart Energy Profile 2.0, ZigBee devices are required to
conform to the IEEE 802.15.4-2003 Low-Rate Wireless Personal Area Network (LR-
WPAN) standard. The standard specifies the lower protocol layers—the (physical
layer) (PHY), and the (media access control) portion of the (data link layer (DLL)).
The basic channel access mode is "carrier sense, multiple access/collision avoidance"
(CSMA/CA). That is, the nodes talk in the same way that people converse; they
briefly check to see that no one is talking before they start. There are three notable
exceptions to the use of CSMA. Beacons are sent on a fixed timing schedule, and do
not use CSMA. Message acknowledgments also do not use CSMA. Finally, devices
in Beacon Oriented networks that have low latency real-time requirements may also
use Guaranteed Time Slots (GTS), which by definition do not use CSMA.
XBEE
Fig 5.2.2.12 XBEE

The XBee/XBee-PRO ZNet 2.5 OEM (formerly known as Series 2 and Series
2 PRO) RF Modules were engineered to operate within the ZigBee protocol and
support the unique needs of low-cost, low-power wireless sensor networks. The
modules require minimal power and provide reliable delivery of data between remote
devices.
Serial Communication
The XBee ZNet 2.5 OEM RF Modules interface to a host device through a
logic-level asynchronous serial port. Through its serial port, the module can
communicate with any logic and voltage compatible UART; or through a level
translator to any serial device (For example: Through a Digi proprietary RS-232 or
USB interface board).
UART Data Flow
Devices that have a UART interface can connect directly to the pins of the RF
module as shown in the figure below.
Fig 5.2.2.13 UART DATA FLOW
Data enters the module UART through the DIN (pin 3) as an asynchronous
serial signal. The signal should idle high when no data is being transmitted. Each data
byte consists of a start bit (low), 8 data bits (least significant bit first) and a stop bit

(high). The following figure illustrates the serial bit pattern of data passing through
the module.
Fig 5.2.2.14 UART data packet 0x1F (decimal number ʺ31ʺ) as transmitted through the RF
module Example Data Format is 8‐N‐1 (bits ‐ parity ‐ # of stop bits)
The module UART performs tasks, such as timing and parity checking, that
are needed for data communications. Serial communications depend on the two
UARTs to be configured with compatible settings (baud rate, parity, start bits, stop
bits, data bits).
5.2.3 PIC 18F4550
PIC 18F4550 is an 8 bit microcontroller having mainly five extra features.
1. Universal serial bus features
2. Power managed modes
3. Flexible oscillator structure
4. Peripheral highlights
5. Special microcontroller features
Universal Serial Bus Features
USB V2.0 Compliant
Low Speed (1.5 Mb/s) and Full Speed (12 Mb/s)

Supports Control, Interrupt, Isochronous and Bulk Transfers
On-Chip USB Transceiver with On-Chip Voltage Regulator
Special Microcontroller Features
C Compiler Optimized Architecture with Optional Extended
Instruction Set
100,000 Erase/Write Cycle Enhanced Flash Program Memory Typical
1,000,000 Erase/Write Cycle Data EEPROM
Memory Typical
Flash/Data EEPROM Retention: > 40 Years
Self-Programmable under Software Control
Priority Levels for Interrupts
8 x 8 Single-Cycle Hardware Multiplier
Extended Watchdog Timer (WDT):
- Programmable period from 41 ms to 131s
Programmable Code Protection
Single-Supply 5V In-Circuit Serial Programming™ (ICSP™) via Two
Pins
In-Circuit Debug (ICD) via Two Pins
5.2.4 PIC 16F876A
Main Features
- 8 channel Analog-to-Digital Converter (A/D)· Brown-out Reset (BOR)·
Analog Comparator module with: - Two analog comparators -
Programmable on-chip voltage reference (VREF) module - Programmable
input multiplexing from device inputs and internal voltage reference.
- Only 35 single word instructions to learn· All single cycle instructions
except for program branches, which are two-cycle· Operating speed: - 20
MHz clock input 200 ns instruction cycle· x 14 words of FLASH Program

Memory, x 8 bytes of Data Memory (RAM), x 8 bytes of EEPROM Data
Memory· Pinout compatible to other 40/44-pin PIC16CXXX and
PIC16FXXX microcontrollers.
- Low power, high speed FLASH/EEPROM technology Fully static design
Wide operating voltage range to 5.5V) Commercial and Industrial
temperature ranges Low power consumption
Special Microcontroller Features
100,000 erase/write cycle Enhanced Flash program memory typical
1,000,000 erase/write cycle Data EEPROM memory typical
Data EEPROM Retention > 40 years
In-Circuit Serial Programming™ (ICSP™) via two pins
Single-supply 5V In-Circuit Serial Programming
Watchdog Timer (WDT) with its own on-chip RC oscillator for
reliable operation
Programmable code protection
Power saving Sleep mode
5.2.5 89C2051 MICROCONTROLLER
The AT89C2051 is a low-voltage, high-performance CMOS 8-bit
microcomputer with 2K bytes of Flash programmable and erasable read-only memory
(PEROM). The device is manufactured using Atmel‘s high-density nonvolatile
memory technology and is compatible with the industry standard MCS-51 instruction
set. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel
AT89C2051 is a powerful microcomputer which provides a highly-flexible and cost-
effective solution to many embedded control applications. The AT89C2051 provides
the following standard features: 2K bytes of Flash, 128 bytes of RAM, 15 I/O lines,
two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex
serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In
addition, the AT89C2051 is designed with static logic for operation down to zero

frequency and supports two software selectable power saving modes. The Idle Mode
stops the CPU while allowing the RAM, timer/counters, serial port and interrupt
system to continue functioning. The power-down mode saves the RAM contents but
freezes the oscillator disabling all other chip functions until the next hardware reset.
5.2.6 L293D MOTOR DRIVER
The Device is a monolithic integrated high voltage, high current four channel
driver designed to accept standard DTL or TTL logic levels and drive inductive loads
(such as relays solenoids , DC and stepping motors) and switching power transistors.
To simplify use as two bridges each pair of channels is equipped with an enable input.
A separate supply input is provided for the logic, allowing operation at a lower
voltage and internal clamp diodes are included. This device is suitable for use in
switching applications at frequencies up to 5 kHz. The L293D is assembled in a 16
lead plastic package which has 4 center pins connected together and used for heat
sinking The L293DD is assembled in a 20 lead surface mount which has 8 center pins
connected together and used for heat sinking.
Features
1. 600ma output current capability per channel
2. 1.2a peak output current (non repetitive) per channel enable facility
3. Over temperature protection
4. Logical ‖0‖ input voltage up to 1.5 v
5. High noise immunity
6. Internal clamp diodes
5.2.7 SL74HC573
This device contains protection circuitry to guard against damage due to high
static voltages or electric fields. However, precautions must be taken to avoid
applications of any voltage higher than maximum rated voltages to this high-

impedance circuit. For proper operation, VIN and VOUT should be constrained to the
range.
GND (VIN or VOUT) VCC.
Features
The SL74HC573 is identical in pinout to the LS/ALS573. The device
inputs are compatible with standard CMOS outputs; with pull up
resistors, they are compatible with LS/ALSTTL outputs.
These latches appear transparent to data (i.e., the outputs change
asynchronously) when Latch Enable is high. When Latch Enable goes
low, data meeting the setup and hold time becomes latched.
Outputs Directly Interface to CMOS, NMOS, and TTL
Operating Voltage Range: 2.0 to 6.0 V
Low Input Current: 1.0 Ma
High Noise Immunity Characteristic of CMOS Devices

6. FLOWCHARTS
6.1 TRANSMITTER SECTION
Fig 6.1.15 Flowchart Of Transmitter Section

Figure above shows the flowchart of transmitter section of the Human- Robot
Interaction system. The accelerometer is the device used for making the human
interaction with robot. The accelerometer detects the gestures of human hand and it
converts the gestures to some electric voltages.ie the accelerometer detects the X,Y&
Z directional motions of the hand and converts these motions in to some voltages.
These voltages are decoded and transmitting to the robot at a remote location. This
information are transmitted through a wireless transmission method called zigbee,
which is one of the most effective wireless communication protocols. This is the basic
working of transmitting section.
At first all the devices are initialized, including the accelerometer, zigbee and
the code generating section. The accelerometer is so sensitive to detect the motions.
When there is a motion occurred, accelerometer detects the motion which is in X, Y
or in Z direction. The device will produce some output voltages. These voltages are
applied to a code generating circuit. The code generating circuit mainly consist of a
PIC micro controller 16F876A.This PIC contains analoge to digital converter. Before
the operation some ranges of values produced in the accelerometer corresponding to
the X, Y & Z motions are specified and stored in the microcontroller memory. When
there is a motion occurred the controller compares the values and if the values are in
the ranges which are specified in the memory. For each range of values the
microcontroller will generate a pre assigned code in any one of it‘s port, ie for eg. for
X &Y combination values the code is 01,for X&Z code is 02 and for Y&Z code is 03
etc.
So the controller checks the incoming values from the output pins of
accelerometer and will generate corresponding code if the values are in the predefined
range. Otherwise the device will not generate any code and waits for the occurance of
any motion.
After generating the predefined code the microcontroller sends these codes to
the remote location through a zigbee device, and will initialize a stop count. The stop
count will increment repeatedly till another motion is occurred. At the receiver there
are some tasks assigned to the codes which are transmitted. When another motion is
occurred the stop count will be reinitialize for that particular motion code. Consider if

there is no other motion occurred after an initialization of stop count, the controller
checks the count and if it reaches the defined count value the code generation will
stops. And the device will stop the working.
Here we are using the zigbee protocol; the zigbee is having a particular range.
Consider for a particular motion a particular code will be generate and consider the
task corresponding to the code is ―forward motion‖. If we are not trying to provide
the stop count the device will check for the another motion for a long time and the
robot at the receiver part will move continuously and will go out of the range of
zigbee and from our controllable range. And after this the change in the hand motion
at the transmitter will not convert in to the motion of robot. So if we are providing the
stop count the device will stop the operation when the counter reaches it‘s maximum
value and waiting for the any other movement.

6.2 RECEIVER SECTION
Fig 6.2.16 Flowchart Of Receiver Section

The receiver mainly consists of a zigbee receiver and a microcontroller
89C2051, which is the main controller of receiver. The receiver is fixed on an autobot
which is able to move in any direction according to the commands. The main
components of the autobot is PIC18F4550, a motor driver ic and two wheels
connected to dc motors. The front wheel is free to move in any direction.
During non operating condition ie, the device is not detecting any motion the
motors are in idle state. When a motion occurs the transmitter detects the motion and
sends the code corresponding to the motion. The zigbee receiver receives the code
and sends this data to microcontroller in te receiver circuit. The controller detects the
codes and generates some other codes corresponding to the received codes in any one
of it‘s port as per the program. This code determines the movement of the autobot.
Some tasks like left motion, right motion, forward motion, backward motion and stop
are assigned in the autobot controller to the codes of receiver-controller.
While seeing the code generated by the receiver controller the main controller
of autobot produces some sequence of codes to control the motor driver IC and the
driver IC controls the motion of motors like forward, backward etc. After this the PIC
microcontroller initializes a stop count and waits for the any other motion.
When another motion is detected the device reinitializes the stop count and the
code corresponding to that motion is generated and the main controller generates
corresponding sequence to control the motion of the motors and wheels of autobot
corresponding to that motion will be performed. If the motion is not changed the
device will check the stop count and if it is reached it‘s maximum allowable value
the operation of the device will stop.
The stop count concept helps us to keep our device in our control range .In the
receiver part we are using two controllers one for controlling the receiver and one for
controlling the autobot. There may be many complexity in programming the autobot
and receiver with one controller which will affect the sudden response of the autobot
with the commands in the form of gestures. By using two controllers we can control
the device more accurately without more interrupting the main controller of autobot.

7. PCB LAYOUTS
Fig 7.17 Component Layout Of Autobot

Fig 7.18 PCB Layout Of Autobot

Fig 7.19 PCB Layout Of Receiver

Fig 7.20 PCB Layout Of Transmitter

8. RESULT AND DISCUSSION
The project ―Human Robotic Interaction Based On Gesture Identification‖
was designed such that autobot can move in forward, backward, right side and left
side according to the motion of the hand. The main highlight of this project is the
ZIGBEE transceiver, which is used for the data transfer between the receiver and
transmitter. Movement of the hand is detected by the accelerometer which is attached
to the hand. This system can be used in home automation. This system also has a
camera in the receiver section. As a result autobot can be used for spy works. By the
usage of zigbee transceiver it is able to control the autobot from another location.
Fig 8.21 Prototype of Robot

9. ADVANTAGES AND DISADVANTAGES
9.1 ADVANTAGES
Ease of controlling.
Movement of autobot can be controlled by hand movements.
Fast response.
The module can be made into various forms as per the area of application.
User friendly- One need not to know about the robot, as they can control by
hand movement.
Efficient and low cost design.
9.2 DISADVANTAGES
Camera in the receiver section uses more power, so robot cannot run on
battery for long time.

10. APPLICATIONS
Robots are used for many services in our society. It extends from industrial
automation tools to medical care. Robots can be used in the hazardous areas where
the human can‘t reach.
A deaf and dumb person can also control the robot. So this system can be used
in home automation. The system can be used in industrial areas for fast operation and
ease of work.Giant machinery vehicles can be controlled by body movements.
In the mine industry, robots can be used before human workers for examining
the environment .By knowing the environmental conditions inside the mines
appropriate precautions can be taken.

11.FUTURE SCOPE
HIR is going to be an important military application in future. By translating
whole motions of a human body to a humanoid (human-like robot) we can make a
machine clone of human beings. And these robots can be used for military
applications. By this we can reduce human casualty as there is no direct involvement
of human beings, also the machine parts are not easily damaged as human organs
would be.
In medical area, doctors can treat patients in a remote location by sitting in
their own cabin under normal situation.

12.CONCLUSION
This project proposes an authoring method capable of creating and controlling
motions of industrial robots based on gesture identification. The proposed method is
simple, user-friendly, cost effective, and intelligent and facilitates motion authoring
of industrial robots using hand, which is second only to language in terms of means of
communication. The proposed robot motion authoring method is expected to provide
user-friendly and intuitive solutions for not only various industrial robots, but also
other types of robots including humanoids.

13. REFERENCES
1. N. K. Aaronson, C. Acquadro, J. Alonso, G. Apolone, D. Bucquet, M.
Bullinger, K.Bungay,S.Fukuhara, B. Gandek, S. Keller, D. Razavi and R.
Sanson-Fisher.International quality of life assessment (iqola) project. Quality
of Life Research, 1(5):349–351, Dec 2004.
2. P. Aigner and B. McCarragher. Shared control framework applied to a robotic
aid for the blind. Control Systems Magazine, IEEE, 19(2):40–46, April 1999.
3. D.Grollman,Jenkins. Learning elements of robot soccer from demonstration.
In Proceedings of theInternational Conference on Development and Learning
(ICDL), London, England, Jul 2007.
4. K. Gold and B. Scassellati. Learning about the self and others through
contingency. In AAAI Spring Symposium on Developmental Robotics,
Stanford, CA, March 2005.
5. P. H. Kahn, H. Ishiguro, B. Friedman, and T. Kanda. What is a human? –
Toward psychological benchmarksin the field of human-robot interaction. In
IEEE Proceedings of the International Workshop on Robot and Human
Interactive Communication (RO-MAN), Hatfield, UK, Sep 2006.

APPENDIX

Human-Robot Interaction Based On Gesture Identification

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