International Journal of Engineering Trends and Technology (IJETT) – Volume 7 Number 3- Jan 2014
Handy Hand
M.V.S.Praveen#1, K.Vasavi*2, B.Santosh Sarma#3
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Student & Electronics and Instrumentation & GITAM University
Visakhapatnam, Andhra Pradesh, India
Abstract—Robotics is the branch of technology that deals with the
design,
construction,
operation,
structural
disposition,
manufacture and application of robots and computer systems for
their control, sensory feedback, and information processing. The
word ‘Robotics’ means the study of robots was coined by Isaac
Asimov. Robotics involves elements of mechanical and electrical
engineering, as well as control theory, computing and now
artificial intelligence. Robotics technology has matures to a point
where these have many research and industrial application.
Robots have been used to replace people in production line and
are ideally suited for repetitive work. The Robot Institute of
America defines a robot as “A Programmable multifunctional
manipulator designed to move material, parts and tools of
specialized device through variable programmed of variety of
tasks”. So we made a robotic hand called “HANDY HAND” which
is attached to handicap people. The essential part of the robotic
arm is relay based brick capable of driving a DC Motor and IR
sensors. This paper explains the method of interfacing the robotic
hand with DC motors, relays and IR sensor which can grab and
release less weight objects without any programming.
Keywords—DC Motors, IR Sensors, Relay, LIMIT Switch,
LITHIUM ION POLYMER Battery.
I. INTRODUCTION
A branch of technology that deals with a robot is Robotics. A
robotics is a mechanical or virtual intelligent agent that can
perform tasks automatically or with guidance, typically by
remote controlled. In practice a robot is usually an electro
mechanical machine that is guided by computer, and electronic
programming robot can autonomous or semi autonomous. The
word robot first appeared in the play Rossum’s universal robots
by the Czech writer Karelcapek in 1920.Robots are used in an
increasingly wide variety of tasks such as vacuuming floors,
mowing lawns, cleaning drains, building cars, in warfare, 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, military robots, mobile and
servicing robots. There is no consensus on which machines
qualify as robots but there is general agreement among experts,
and the public, that robot tend to do some of the tasks such as
move around, operate a mechanical limb, sense and manipulate
their environment, and exhibit intelligent behavior especially
which mimics human or other animals. There is no particular
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definition of a robot. According to the Encyclopedia Britannica
robot is “any automatically operated machine that replaces
human effort, though it may not resemble human being in
appearance or perform functions in a human like manner”.
Merriam Webster describes a robot as a “mechanical that looks
like a human being and performs various complex acts (as
waling or talking )of a human being”, or a “device that
automatically performs complicated often repetitive tasks”, or a
“mechanism guided by automatic controls”.
So based on these criteria we inspired to make a robot which
is helpful for handicap people. The main task is to open and
close the hand via motor by using relay and IR sensor. It is a
mechanical robotic arm which is functioned by sensors, with
similar functions to a human arm.
II. SYSTEM ANALYSIS
The main objective of this robot is to help the handicap
people by fixing a robotic arm. This robotic arm is mainly
controlled by the TR sensors via DC motor by stretchable
fingers which can bend easily. And it completely looks like a
Human Hand.
A. BLOCK DIAGRAM
8051
SENSOR-
LIMIT
SWITCH
Micro
SENSOR2
RELAY
Control
ler
DC
MOTOR
Fig.1 Block diagram of Handy Hand
The above block diagram shows the overall co-ordination of
the robot. The robot structure consists of motors, relay circuits
i.e. dual coil 12v dc relay board and IR sensors. Two IR sensors
are used. Whenever the voltage enters into the motor, the
sensors senses and rotates in clockwise direction for closing
purpose and in anticlockwise direction for opening purpose.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 7 Number 3- Jan 2014
A.
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 Dallas Semi/Maxim
HARDWARE REQUIRED
8051 Microcontroller
IR Sensors (Infra Red Sensor)
Relays
LIMIT Switch
DC Motor
This robot is built with P89V51RD2 microcontroller which
manufactured from Philips Company.
The 8051 is an 8-bit processor, meaning that the CPU can work
on only 8 bits of data at a time. Data larger than 8 bits has to be
broken into 8-bit pieces to be processed by the CPU. The 8051
is also referred as “system on chip”.
B. SOFTWARE REQUIRED
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EXT
INTERRUPTS
Embedded C programming
Keil C compiler
Flash Magic
On chip
ROM
for
progra
m code
INTERRUPT
CONTROL
III. HARDWARE DESCRIPTION
ETC
On chip
RAM
TIMER 1
CPU
A. 8051 MICROCNTROLLER
A microcontroller is a small, low-cost and self contained
computer-on-a-chip that can be used as an embedded system. A
few microcontrollers may utilize four-bit expressions and work
at clock rate frequencies, which usually include:
BUS
CONTROL
OSC
4 I/O PORTS
P0 P1 P2 P3
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An 8 or 16 bit microprocessor.
A little measure of RAM.
Programmable ROM and flash memory.
Parallel and serial I/O.
Timers and signal generators.
Analog to Digital and Digital to Analog conversion
8051 Family
AVR microcontroller Family
PIC microcontroller Family
ARM Family
Intel
Atmel
Philips
Infineon
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TXD RXD
The 8051 has following features. They are:
TABLE 1: FEATURES OF 8051
FEATURES
QUANTITY
ROM
4K bytes
RAM
128 bytes
I/O PORTS
32
TIMERS
2
SERIAL PORT
1
INTERRUPT SOURCES
6
There are minimum six requirements for proper operation of
microcontroller. Those are:
In 1981, Intel Corporation introduced an 8-bit
microcontroller called the 8051.The 8051 family has largest
number of diversified (multiple sources) suppliers, which were
originated by Intel, and several companies which include:
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SERIAL
PORT
Fig 2. 8051 microcontroller Block diagram
Microcontrollers usually must have low-power
requirements since many devices they control are batteryoperated.
Microcontrollers are used in many consumer electronics,
car engines, and computer peripherals and test or measurement
equipment. And these are well suited for long lasting battery
applications.
The dominant parts of microcontrollers being used now
a day are implanted in other apparatus. There are many types of
micro controller families that are available in the market. Those
are:
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TIMER 0
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Power supply section
Pull-ups for ports (it is must for PORT0)
Reset circuit
Crystal circuit
ISP circuit (for program dumping)
EA/VPP pin is connected to VCC.
PORT0 is open collector that’s why we are using pull-up
resistor which makes PORT0 as an I/O port. Reset circuit is
used to reset the microcontroller. Crystal circuit is used for the
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International Journal of Engineering Trends and Technology (IJETT) – Volume 7 Number 3- Jan 2014
microcontroller for timing pluses. In this project we are not
using external memory that’s why EA/VPP pin in the
microcontroller is connected to VCC that indicates internal
memory is used for this application.
It is a 40pin microcontroller with VCC of 5V connected to
pin 40 and VSS at pin 20 which is kept 0V. And there are input
and output ports from P1.0 – P1.7 and which having open drain
feature. Port3 has got extra features. Pin36 has open drain
condition and pin17 has internally pulled up transistor inside
the microcontroller. When we apply logic 1 at port1 then we
get logic 1 at port21 and vice versa. The programming of
microcontroller is dead complicate. Basically we write a
program in C language which is next converted to machine
language understand by the microcontroller. A RESET pin is
connected to pin9, connected with a capacitor. When the switch
is ON, the capacitor starts charging and RST is high. Applying
a high to the reset pin resets the microcontroller. If we apply
logic zero to this pin, the program starts execution from the
beginning.
Fig 3. IR SENSOR
The basic idea is to make use of IR LEDS to send the
infrared waves to the object. Another IR diode of the same type
is to be used to detect the reflected wave from the object. The
diagram is shown below.
B.IR SENSORS
A Sensor converts the physical parameter (for example:
temperature, blood pressure, humidity, speed, etc) into a signal
which can be measures electrically. Sensors are sophisticated
devices that are frequently used to detect and respond to
electrical or optical signals. There are certain features which
have to be considered when we choose a sensor. There are:
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Accuracy
Environment condition-usually has limits for
temperature/humidity
Range-Measurement limit or sensor
Calibration- Essential for most of the measuring
devices as the readings changes with time.
Resolution- Smallest increment detected by the
sensor
Cost
Repeatability- The reading that varies is repeatedly
measured under the same environment.
Fig 4 Basic Idea of IR Sensor
The transmitter part of the sensor is an Infrared (IR) Led
which transmits continuous IR rays to be received by an IR
receiver. The output of the receiver varies depending upon its
reception of IR rays. Since this variation cannot be analyzed as
such, therefore this output can be fed to a comparator. Here
operational amplifier (op-amp) of LM358 is used as
comparator.
When the IR receiver does not receive signal the potential at
the inverting input goes higher than that at non-inverting input
of the comparator. Thus the output of the comparator goes low
and LED does not glow. When the IR receiver receives signal
the potential at the inverting input goes low. Thus the output of
the comparator goes high and the LED starts glowing.
C. RELAYS
Some commonly used sensors along with their principle and
applications are temperature sensors, IR sensor, and UV sensor.
In order to fulfill our requirement, IR sensor is required.
IR sensor devices detect infrared wavelengths, or light made
up of electronic radiation with wavelength between 0.7 to 1000
microns, a system of measurement equal to one millionth of a
meter. This wavelength range makes up the infrared band,
which emits radiation temperatures detectable by IR sensors.
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Relay is an electromagnetic device which is used to isolate
two circuits electrically and connect them magnetically. They
are very useful devices and allow one circuit to switch another
one while they are completely separate. They are often used to
interface an electronic circuit (working at a low voltage) to an
electrical circuit which works at very high voltage. For
example, a relay can make a 5V DC battery circuit to switch a
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230V AC mains circuit. Thus a small sensor circuit can drive,
say, a fan or an electric bulb.
placed. The door, when gets fully opened, will depress the limit
switch lever and thus the control circuit of motor becomes
incomplete and the motor stops.
E. LIPO BATTERY
Lithium-ion polymer batteries (LIPO) are rechargeable
batteries. LIPO batteries are usually composed of several
identical secondary cells in parallel to increase the discharge
current capability. They offer high discharge rates and a high
energy storage/weight ratio.
Fig 5 Basic circuit of Relay
These device is consist of a coil of wire is covered with an
iron core. When electricity is applied to a V1 & V2 means coil
of wire it becomes magnetic, hence the term electro magnet.
The A, B & C terminals are SPDT Switch controlled by an
electro magnet. When electricity is applied to v1 & v2, the
electromagnet acts upon the SPDT switch so that the B, C
terminals are connected. When the electricity is disconnected,
then A, C terminals are connected. If electricity is
disconnected, some current is present in that coil. During turn
off the reverse EMF doesn’t worked means, we are using
flywheel diode. This diode doesn’t allow the current in the
previous block.
D. LIMIT SWITCH
Fig
7. LITHIUM ION POLYMER
F. ACRYLIC SHEET
Acrylic sheet is a material with unique physical properties
and performance characteristics. It weighs half as much as the
finest optical glass yet is equal to it in clarity and is up to 17
times more impact resistant. Acrylic sheet is made in over 250
colors, in thickness from 0.30 to 4.25 and can transmit
ultraviolet light or filer it out, as required.
A mechanical Limit Switch interlocks a mechanical motion
or position with an electrical circuit. A good starting point for
limit switch selection is contact arrangement. The most
common limit switch is the single-pole contact block wit one
NO and one NC set of contacts. However, limit switches are
available with up to four poles.
Fig
8. Acrylic Sheets
G. FIRM PLASTIC
Fig 6. LIMIT SWITCH
A limit switch is an electromechanical device. It is placed in
the control circuitry of a machine system. For example-A motor
is used to open a door. At the end of the door, a limit switch is
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Plastic sheeting is the popular substitute for still in global
market. Plastic sheets are very firm and strong to accommodate
all tasks, from house furniture t roofing purpose. So we used
firm plastic for covering the side body parts with thickness of
4mm,it looks like a fabricated .
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H. SURGICAL BAND
We used the surgical band for stability for elbow joint range
of motion usually remains near normal. This orthopedically
designed support is an innovative and unique device,
scientifically designed to air in the relief and prevention of
pain.
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A project manager
A make facility
Tool configuration
Editor
A powerful debugger
I. DC MOTORS
An electric motor is an electromechanical device that
converts electrical energy into mechanical energy. Most electric
motors operate through the interaction of magnetic fields and
current carrying conductors to generate force.
A DC motor is an electric motor that runs on direct current
(DC) electricity. DC motors were used to run machinery, often
eliminating the need for a local steam engine or internal
combustion engine. Dc motors can operate directly from
rechargeable batteries, providing the motive power for the first
electric vehicles.
Fig. 10 IDE Window
C. Flash Magic:
Flash Magic is a tool which used to program hex code in
EEPROM of micro-controller. It is a freeware tool. It only
supports the micro-controller of Philips and NXP. You can
burn a hex code into those controllers which supports ISP (in
system programming) feature.
Fig 9. DC MOTOR
DC motors are found in applications as small as toy and disk
drives, or in large sizes to operate still rolling mills and paper
machines. Modern Dc motors are nearly always operated in
conjunction with power electronic devices.
IV.SOFTWARE REQUIREMENT
A. Kiel-C Compiler:
Many companies provide the 8051 assembler, some of them
provide shareware version of their product on the Web, Kiel is
one of them. We can download them from their Websites.
However, the size of code for these shareware versions is
limited and we have to consider which assembler is suitable for
our application.
B. Kiel U Vision2:
This is an IDE (Integrated Development Environment) that
helps you write, compile, and debug embedded programs. It
encapsulates the following components:
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Fig. 11. Flash Magic Window
V. HANDY HAND OPERATION
There will be a two sensors, one is at centre, and another
facing towards the bottom of the hand. After completion of
first sensor task, the second sensor performs its task. And as
we know that the black object is for attracting and white
object is for reflecting, based on this principle the complete
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International Journal of Engineering Trends and Technology (IJETT) – Volume 7 Number 3- Jan 2014
sensors works. The entire operation is made on relay board,
digital IC circuits
Fig 13.CIRCUIT DIAGRAM
Fig 12. FLOW CHART
A motor is DC motor of 1kg torque and 100 rpm. When
power supply is ON, motor remains constant. When we place
an object over the first sensor i.e.S1,it gets sense (S1=1), and
the motor rotates in anticlockwise direction and hand will close.
If it doesn’t sense, the motor mechanism remains in constant.
While closing an object, the limit switch gets triggered
(Switch=1) and hence the motor gets stop. When placing the
object, the second sensor i.e.S2 get sense (S2=1), the motor
rotates in clockwise direction and hand opens. If it doesn’t
sense the motor remains constant.
Threading mechanism is used for closing and opening the
hand. The whole operation is performed by 12V relay circuit
board which can operate several circuits with one signal by
giving power supply from LIPO battery which has high charge
and less weight ratio.
A relay consists of 5 terminals-VCC, GND, Normal open
(NO),Normal Close(NC) and Common(C).For rotation of
motor in both clockwise and anticlockwise direction, we
require two relays. The common terminals of both the relays
are connected to the motor polarities. The NC and NO
terminals of second relay is given power supply. The NC and
NO terminals of first relay is connected to the limit switch. The
limit switch allows the hand to hold the object perfectly. It has
three terminals NC, COMMON(C), NO. Normal close (NC) is
connected to the first relay NC terminal and common is given
to power supply. Whenever the limit switch is triggered, the
first relay gets stopped and the motor stops to rotate in one
direction.
VI. RESULTS
A. SIDE VEIW OF HANDY HAND
A. CIRCUIT DIAGRAM
The above circuit diagram shows the basic operation of
Handy hand, which has IR sensors, relay, motor and limit
switch.
IR sensors always emit the light. It consists of transmitter
and receiver. When we place an object or any obstacle near the
transmitter, it get reflected and received by the receiver. The
output of the sensor is high and it is given to the relay.
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Fig 14. Side view of Handyhand
This is the side view of the arm which consists of a surgical
band so that it gives the stability to the arm. This arm is very
flexible and secure to the people who use it and it is covered
with complete firm plastic.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 7 Number 3- Jan 2014
B. CLOSING THE OBJECT
inconvenient and increased the design cost and development
period. Our future work includes the implementation of
additional applications, the refinement of our implementation,
especially using the solar panels, we can develop voltage by
own due to thermal energy. And using the IR proximity sensors
we can further reduce the complexity of circuits.
We see a lot of people who are born without hands. They
may have one hand or not even that. These handicap people
have to face many problems while doing their tasks. So, with
our “HANDY HAND” arm we can help the handicap people
with low price. The main advantage is we don’t need any
surgery to nervous system.
Fig 15. Closing the object
The figure shows the image of catching the object, when
closing, the limit switch gets triggers and stops the motor
rotation.
C. RELEASING OBJECT
VIII. REFERNCES
[1]. Muhammad Ali Mazidi and Janice Gillispie Mazidi, the
8051 Microcontroller and Embedded Systems by, Pearson
Education.
[2]. Kenneth B. Rexford and Peter R. Giuliani (2002).Electrical
control of machines (6th ed.). Cengage Learning .p. 58. ISBN
978-0-7668-6198-4.
[3]. Wikipedia.org/wiki/relay
[4]. Reusch, William (1999).”Infrared Spectroscopy”. Michigan
State Univesity.Retrieved 2006-10-27.
[5]. Rchelicopterfun.com/rc-lipo-batteries.html
[6]. “Toshiba to Launch Innovative Rechargeable Battery
Business” (Press release). Toshiba. 11 December
2007.Retrieved 25 June 2009
Fig 16. Releases the object
When the second sensor senses the motor rotate in anti
clockwise direction, then the motor releases the object.
VII. CONCLUSION AND FUTURE SCOPE
In this design, we used Philips 8051 microcontroller and Keil
C - Compiler helped us see the powerful design technologies of
software and hardware systems. Most traditional circuit designs
are composed of hardware components building on a
printed circuit board (PCB), we used same. If errors are found
or the system needs to be improved or upgraded, the PCB must
be redesigned. Adjusting and modifying the PCB is very
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