A Different Ride by Differently Abled Person(Eyeball Wheelchair)

SENGUNTHAR ENGINEERING COLLEGE

Mechanical Engineering Department

Tiruchengode-637205,

Nammakal (Dist),

Tamil Nadu.

(Approved by AICTE, New Delhi)

A different ride

By

Differently abled persons

[Eye ball Wheel chair]

By,

R.RAMESH KRISHNAN, T.MOHAMMED THARIQ,

Final Year, Final Year,

[email protected], [email protected],

C.N:9003808741. C.N:9585109876.

ABSTRACT:

To operate the wheel chair of a paralyzed patient using their eyeball movement using embedded system.

It is very difficult to understand the emotions of the paralyzed patients, care them and to move them according to their wish. To solve this problem this system is implemented.

The system consists of the eyeball sensor, which detects the movement of the eyeball of the paralyzed patient and sends the information to the microcontroller. The microcontroller processes the signals coming from the eyeball sensor and controls the wheel accordingly. The moments of the wheelchair that can be controlled by the microcontroller are forward, right and left.

When the eye moves to the left side the wheelchair moves to the

left side. When the eye moves to the right side the wheelchair moves to the right

side . When the eye looks straight wheelchair moves in forward direction. To control the action of the wheel chair motors are used. The motors are drive by the motor drivers.

The motors are coupled with the wheels and the wheels are attached to the wheelchair mechanism.

GENERAL BLOCK DIAGRAM:

EyeballSensor

Microcontroller

BufferBattery

Left Side Motor Driver

Right Side Motor Driver

Right MotorLeft Motor

Right WheelLeft Wheel

Wheel Chain Mechanism

MICRO CONTROLLER:

The difference

between

Microprocessor and

Micro controller is

Microprocessor can

only process with the

data, Micro controller

can control external

device.

That is if you want

switch “ON” or

“OFF” a device, you

need peripheral ICs to

do this work with

Micro controller you

can directly control the

device.

INTRODUCTION TO ATMEL MICROCONTROLLER:

SERIES: 89S51 Family, TECHNOLOGY: CMOS

The major Features of 8-bit Micro controller ATMEL

89S51:

8 Bit CPU optimized for control

applications

Extensive Boolean processing

(Single - bit Logic ) Capabilities.

On - Chip Flash Program Memory

On - Chip Data RAM

Bi-directional and Individually

Addressable I/O Lines

Multiple 16-Bit Timer/Counters

Full Duplex UART

Multiple Source / Vector / Priority

Interrupt Structure

On - Chip Oscillator and Clock

circuitry.

On - Chip EEPROM

SPI Serial Bus Interface

Watch Dog Timer

ANALOG TO DIGITAL CONVERTER:

ADC 0809 analog

to digital converter is a

successive

approximation type

analog to digital

converter. The

successive

approximation technique

uses a very efficient

code search strategy to

complete n-bit

conversion in just n-

clock periods. The

circuit uses a successive

approximation register to

find the required value

by trial and error. The

ADC0809 data

acquisition component is

a monolithic CMOS

device with an 8-bit

analog-to-digital

converter, 8-channel

multiplexer and

microprocessor

compatible control logic.

The converter features a

high impedance chopper

stabilized comparator, a

256R voltage divider

with analog switch tree

and a successive

approximation register.

Fig 5.7 Pin Diagram of ADC0809

OPERATION OF THIS CIRCUIT:

With the arrival

of START command,

the SAR sets the MSB

d1=1 with all other bits

to zero so that the trial

code is 10000000. The

output of the ADC is

now compared with

analog input. If input is

greater than the DAC

output then 10000000 is

less than the correct

digital representation.

The MSB is left at ‘1’

and the next lower

significant bit is made

‘1’ and further tested.

However, if input is less

than the DAC output,

then 10000000 is greater

than the correct digital

representation.

+- 1

0u

10

0n

22

0

CQ

X3

5A

IN0

IN1

IN2

IN3

IN4

IN5

IN6

IN7

d0

d1

d2

d3

d4

d5

d6

d7

START

ALE

EOC

O/P EN

CLK

ADDRESS

GND Vref (-)

ADC0809

A

N

A

L

O

G

I/P

+5V

Vcc Vref (+)

26

27

28

1

2

3

4

5

21

20

19

18

8

15

14

17

6

22

7

9

10

25

24

2313 16

11 1

A/D converter Circuit Diagram

CIRCUIT DESCRIPTION:

The output from the filter

is given to pin 26 of ADC

0809 shown in fig .The

address channels A,B,C

are grounded so that

channel 1 is enabled. The

digitized output from the

converter is given to

port 0 of micro

controller. The filter

capacitors in the circuit

remove the low and

high frequency noises.

The control signals

from the ADC are

given to port 2 of the

microcontroller. This

circuit follows the

principle of successive

approximation method

and when the start of

conversion goes high,

it marks the beginning

of the process and high

end of conversion

marks the end of it.

LIGHT DEPENDENT RESISTOR (LDR):

LDRs or Light

Dependent Resistors are

very useful especially in

light/dark sensor circuits.

Normally the resistance

of an LDR is very high,

sometimes as high as

1000 000 ohms, but

when they are

illuminated with light

resistance drops

dramatically.

A photoresistor

or light dependent

resistor or cadmium

sulfide (CdS) cell is a

resistor whose resistance

decreases with

increasing incident light

intensity. It can also be

referred to as a

photoconductor.

A photoresistor is

made of a high

resistance

semiconductor. If light

falling on the device is

of high enough

frequency, photons

absorbed by the

semiconductor give

bound electrons enough

energy to jump into the

conduction band. The

resulting free electron

(and its hole partner)

conduct electricity,

thereby lowering

resistance.

LCD DISPLAY:

Liquid crystal cell

displays (LCDs) are used

in similar applications

where LEDs are used.

These applications are

display of display of

numeric and

alphanumeric characters

in dot matrix and

segmental displays.

LCDs are of two types:

I. Dynamic

scattering type

II. Field effect

type

The construction of a

dynamic scattering

liquid crystal cell.

The liquid crystal

material may be one

of the several

components, which

exhibit optical

properties of a crystal

though they remain

in liquid form. Liquid

crystal is layered

between glass sheets

with transparent

electrodes deposited

on the inside faces.

When a

potential is applied

across the cell,

charge carriers

flowing through the

liquid disrupt the

molecular alignment

and produce

turbulence. When the

liquid is not

activated, it is

transparent. When

the liquid is activated

the molecular

turbulance causes

light to be scattered

in all directions and

the cell appeas to be

bright.

This phenomenon is

called dyanamic

scattering.

The

construction of a

field effect liquid

crystal display is

similar to that of the

dynamic scattering

type,with the

exception that two

thin polarizing

optical filters are

placed at the inside

of each glass sheet.

The liquid crystal

material in the field

effect cell is also of

different type from

employed in the

dynamic scattering

cell. The material

used is twisted

nemayic type and

actually twists the

light passing through

the cell when the

latter is not

energised.

Liquid crystal cells are

of two types:

i. Transmittive type

ii. Reflective

type

In the

transmittive type cell,

both glass sheets are

transparent, so that light

from a rear source is

scattered in the forward

direction when the cell is

activated.

OVER ALL CIRCUIT

DIAGRAM:

OPERATI

ON:

LEFT

MOMEMEN

T:

The person who

used that wheel chair

should wear the glass,

in that glass consist

three LDR and two

LED. The LED

transmits some light in

your eyes. Normally

the whight color

absorb and reflect the

light energy, but black

color only absorbs the

light energy doesn’t

reflect. If that person

see left side means that

left LDR gets less

intensity compare to

other two

LDRS,because the

person’s eye ball in

front of left LDR.

According to

LDR working

principle,

I α 1/R

Due to less

intensity in left LDR

that LDR has high

resistance value.In

LDR transmits the

analog value at high

resistance only.So,that

particular analog

voltage send to the

ADC,that covets

analog to

digital.Because before

that process we set

some initial digital

values depends on your

eye intensity level,how

means if that person

change eye ball

position the display

shows some value.

That value has been

stored by using the

enter

switch .Afterwards

make some

adjustments by using

min and max switch,

because avoid the

lightening errors.

Now the output

of ADC and the

display setting value

both are digital values,

these two inputs are

given to the

microcontroller. The

microcontroller

performs the

comparision process it

will compare both the

values.If the output of

ADC coincidence with

left value of diplay

setting,it produded the

output.The output of

microcontroller is

given to left motor

drive because left

value is match.

Now the the left

motor drive output is

given to left side

motor,so the left wheel

rotates backward

direction.But the right

motor rotates forward

direction.So the wheel

now moves towards

left direction.

RIGHT

MOMEMENT:

The the person

who used that wheel

chair should wear the

glass, in that glass

consist three LDR and

two LED.The LED

transmits some light in

your eyes.Normally the

whight colour absorb

and reflect the light

energy,but black

colour only obsorbs the

light energy doesn’t

reflect.If that person

see right side means

that right LDR gets

less intensity compare

to other two

LDRS,because the

person’s eye ball in

front of right LDR.

According to

LDR working

principle,

I α 1/R

Due to less

intensity in right LDR

that LDR has high

resistance value.In

LDR transmits the

analog value at high

resistance only.So,that

particular analog

voltage send to the

ADC,that covets

analog to

digital.Because before

that process we set

some initial digital

values

depends on your eye

intensity level,how

means if that person

change eye ball

position the display

shows some value.That

value has been stored

by using the enter

switch .Afterwards

make some adjesments

by using min and max

switch,because avoid

the lightening errors.

Now the output

of ADC and the

display setting value

both are digital

values,these two inputs

are given to the

microcontroller.The

microcontroller

performs the

comparision process it

will compare both the

values.If the output of

ADC coincidence with

right value of diplay

setting,it produded the

output.The output of

microcontroller is

given to right motor

drive because right

value is match.

Now the the

right motor drive

output is given to right

side motor,so the right

wheel rotates backward

direction.But the right

motor rotates forward

direction.So the wheel

now moves towards

right direction.

FRONT

MOVEMENT:

The person looks

straight means middle

LDR gets the less

intensity,because your

eye ball in front of

middle

LDR.According LDR

working principle,

I α 1/R

In that the

resistance value is high

because of less

intensity.So that

middle LDR only

transmits the analog

voltage to the

ADC,that ADC

converts analog to

digital.Because the

presetting front value

is also digital

value.The ADC and

the DISPLAY output

both are given the

input of

microcontroller.The

microcontroller

compares both the

ADC and DISPLAY

values.If front value is

match.So the supply is

given to both the left

and right motor.The

left motor produces the

torque,the left wheel

rotates.Same as the

right motor produces

the torque,the right

wheel rotates.Now

finally the moves

towards the forward

direction without any

other movements.

STOP:

The person closed

the eyes means no one

LDR gets the reflects.

So the motor drives

also cannot gets the

supply.So now the

wheel chair is at the

stop position.

FEATURES:

The cost of this

product is very

less compare to

remote

controlled wheel

chair.

Once purchase

this product use

life long .

If it useful for

all kind of

people because

change the

presetting value

is very easy.

Improve the

disable people

self-

confidence,beca

use they move

theirself. No

others help.

Output is more

accuracy

compare to

remote

controlled wheel

chairs.

Simple

construction

apart from

wheelchair

additionally we

need one circuit

board and two

DC series

motors.

CONCLUSION:

By using our project To operate the wheel chair of a paralyzed patient using

their eyeball movement using embedded system.The paralyzed patients, care them and

to move them according to their wish. To solve this problem this system is implemented.

The system consists of the eyeball sensor, which detects the movement of the eyeball of the paralyzed patient and sends the information to the microcontroller.the microcontroller processes the signals coming from the eyeball sensor and controls the wheel accordingly. The moments of the wheelchair that can be controlled by the microcontroller are forward, right and left.