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EYEBALL CONTROLLED WHEEL CHAIR ROBOT FOR DISABLE PEOPLE

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EYEBALL CONTROLLED WHEEL CHAIR  ROBOT FOR  DISABLE  PEOPLE Powered By Docstoc
					           EYEBALL CONTROLLED WHEEL CHAIR ROBOT FOR
                        DISABLE PEOPLE
                             -Upcoming product for disable

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:




        Eyeball                         Microcontroller
        Sensor




      Battery                               Buffer




                Left Side Motor                           Right Side Motor
                Driver                                    Driver




                   Left Motor                               Right Motor




                   Left Wheel                               Right Wheel




                                  Wheel Chain Mechanism
MICRO CONTROLLER:

The difference between Microprocessor and Micro controller is “OFF” a device, you need peripheral ICs to do this work
Microprocessor can only process with the data, Micro with Micro controller you can directly control the device.
controller      can       control       external      device.
That is if you want switch “ON” or

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:

ADC0809 data acquisition component is a monolithic                    converter features a high impedance chopper
      CMOS device with an 8-bit analog-to-digital                     stabilized comparator, a 256R voltage divider
      converter,   8-channel    multiplexer    and                    with analog switch tree and a successive
      microprocessor compatible control logic. The                    approximation register.




                      Fig 5.7 Pin Diagram of ADC0809

    OPERATION OF THIS CIRCUIT:
                                                                 10000000 is less than the correct digital representation.
                                                           Wi    The MSB is left at ‘1’ and the next lower significant bit is
    th the arrival of START command, the SAR sets the MSB        made ‘1’ and further tested. However, if input is less than
    d1=1 with all other bits to zero so that the trial code is   the DAC output, then 10000000 is greater than the correct
    10000000. The output of the ADC is now compared with         digital representation.
    analog input. If input is greater than the DAC output then
                                                                   +5V




                                                                                                               22 0
                                                                                              - +
                                                                                       10 u




                                                                                                     10 0n




                                                                                                                      CQX3 5A
                                      Vc c                         Vref (+)
                                             11                1
                           I N0        26                          21            d0
                    A
                           I N1        27                          20            d1
                    N
                           I N2        28                          19            d2
                    A
                           I N3        1                           18            d3
                    L
                           I N4        2                           8             d4
                    O
                           I N5        3                           15            d5
                    G
                           I N6        4                           14            d6
                    I /P
                           I N7        5                           17            d7

                                                  AD C 080 9       6             STAR T
                                                                   22            AL E
                                                                   7             EOC
                                                                   9             O/P EN
                                                                   10            C LK



                                                                  25
                                                                  24                           AD D R ESS
                                         13                    16 23
                                      GND                          Vref (-)




              A/D converter Circuit Diagram
  CIRCUIT DESCRIPTION:

  The output from the filter is given to pin 26 of                            control signals from the ADC are given to port 2 of
ADC 0809 shown in fig .The address channels A,B,C                             the microcontroller. This circuit follows the principle
are grounded so that channel 1 is enabled. The                                of successive approximation method and when the
digitized output from the converter is given to port 0                        start of conversion goes high, it marks the beginning
of micro controller. The filter capacitors in the circuit                     of the process and high end of conversion marks the
remove the low and high frequency noises. The                                 end of it.

  LIGHT DEPENDENT RESISTOR (LDR):

         LDRs or Light Dependent Resistors are very                                applications are display of display of numeric and
  useful especially in light/dark sensor circuits. Normally                        alphanumeric characters in dot matrix and segmental
  the resistance of an LDR is very high, sometimes as                              displays.
  high as 1000 000 ohms, but when they are illuminated
  with light resistance drops dramatically.                                           LCDs are of two types:

         A photoresistor or light dependent resistor or                             I. Dynamic scattering type
  cadmium sulfide (CdS) cell is a resistor whose                                   II. Field effect type
  resistance decreases with increasing incident light
  intensity. It can also be referred to as a photoconductor.                          The construction of a dynamic scattering liquid
         A photoresistor is made of a high resistance                            crystal cell. The liquid crystal material may be one of
    semiconductor. If light falling on the device is of high                     the several components, which exhibit optical properties
    enough frequency, photons absorbed by the                                    of a crystal though they remain in liquid form. Liquid
    semiconductor give bound electrons enough energy to                          crystal is layered between glass sheets with transparent
    jump into the conduction band. The resulting free                            electrodes deposited on the inside faces.
    electron (and its hole partner) conduct electricity,                             When a potential is applied across the cell, charge
    thereby lowering resistance.                                                 carriers flowing through the liquid disrupt the molecular
                                                                                 alignment and produce turbulence. When the liquid is
    LCD DISPLAY:                                                                 not activated, it is transparent. When the liquid is
     Liquid crystal cell displays (LCDs) are used in                             activated the molecular turbulance causes light to be
    similar applications where LEDs are used. These
scattered in all directions and the cell appeas to be               nemayic type and actually twists the light passing
bright.                                                             through the cell when the latter is not energised.
     This phenomenon is called dyanamic scattering.                 Liquid crystal cells are of two types:
          The construction of a field effect liquid crystal           i. Transmittive type
  display is similar to that of the dynamic scattering                 ii.      Reflective type
  type,with the exception that two thin polarizing                          In the transmittive type cell, both glass sheets
  optical filters are placed at the inside of each glass            are transparent, so that light from a rear source is
  sheet. The liquid crystal material in the field effect            scattered in the forward direction when the cell is
  cell is also of different type from employed in the               activated.
  dynamic scattering cell. The material used is twisted

OVER ALL CIRCUIT DIAGRAM:




OPERATION:                                                       depends on your eye intensity level,how means if that
LEFT MOMEMENT:                                                   person change eye ball position the display shows
              The the person who used that wheel chair           some value.That value has been stored by using the
should wear the glass, in that glass consist three LDR           enter switch .Afterwards make some adjesments by
and two LED.The LED transmits some light in your                 using min and max switch,because avoid the
eyes.Normally the whight colour absorb and reflect               lightening errors.
the light energy,but black colour only obsorbs the                           Now the output of ADC and the display
light energy doesn’t reflect.If that person see left side        setting value both are digital values,these two inputs are
means that left LDR gets less intensity compare to               given to the microcontroller.The microcontroller performs
other two LDRS,because the person’s eye ball in                  the comparision process it will compare both the values.If
front of left LDR.                                               the output of ADC coincidence with left value of diplay
              According to LDR working principle,                setting,it produded the output.The output of
                     I α 1/R                                     microcontroller is given to left motor drive because left
  Due to less intensity in left LDR that LDR has high            value is match.
resistance value.In LDR transmits the analog value at         left side motor,so the left wheel rotates backward
high resistance only.So,that particular analog voltage        direction.But the right motor rotates forward
send to thADC,that covets analog to digital.Because           direction.So the wheel                Now the the left
before that process we set some initial digital values
motor drive output is given to now moves towards          backward direction.But the right motor rotates
left direction.                                           forward direction.So the wheel now moves towards
                                                          right direction.
RIGHT MOMEMENT:                                           FRONT MOVEMENT:
              The the person who used that wheel chair          The person looks straight means middle LDR gets
should wear the glass, in that glass consist three LDR    the less intensity,because your eye ball in front of
and two LED.The LED transmits some light in your          middle LDR.According LDR working principle,
eyes.Normally the whight colour absorb and reflect                  I α 1/R
the light energy,but black colour only obsorbs the              In that the resistance value is high because of less
light energy doesn’t reflect.If that person see right     intensity.So that middle LDR only transmits the analog
side means that right LDR gets less intensity compare     voltage to the ADC,that ADC converts analog to
to other two LDRS,because the person’s eye ball in        digital.Because the presetting front value is also digital
front of right LDR.                                       value.The ADC and the DISPLAY output both are
              According to LDR working principle,         given the input of microcontroller.The microcontroller
                                    I α 1/R               compares both the ADC and DISPLAY values.If front
              Due to less intensity in right LDR that     value is match.So the supply is given to both the left
LDR has high resistance value.In LDR transmits the        and right motor.The left motor produces the torque,the
analog value at high resistance only.So,that particular   left wheel rotates.Same as the right motor produces the
analog voltage send to the ADC,that covets analog to      torque,the right wheel rotates.Now finally the moves
digital.Because before that process we set some           towards the forward direction without any other
initial digital values                                    movements.
                                                          STOP:
depends on your eye intensity level,how means if that          The person closed the eyes means no one LDR gets
person change eye ball position the display shows         the reflects. So the motor drives also cannot gets the
some value.That value has been stored by using the        supply.So now the wheel chair is at the stop position.
enter switch .Afterwards make some adjesments by
using min and max switch,because avoid the                FEATURES:
lightening errors.                                                  The cost of this product is very less compare
               Now the output of ADC and the              to remote controlled wheel chair.
display setting value both are digital values, these                Once purchase this product use life long .
two inputs are given to the microcontroller. The                    If it useful for all kind of people because
microcontroller performs the comparision process it       change the presetting value is very easy.
will compare both the values.If the output of ADC                   Improve      the    disable    people    self-
coincidence with right value of diplay setting,it         confidence,because they move theirself. No others help.
produded the output.The output of microcontroller is                Output is more accuracy compare to remote
given to right motor drive because right value is         controlled wheel chairs.
match.                                                              Simple construction apart from wheelchair
                Now the the right motor drive output      additionally we need one circuit board and two DC
is given to right side motor,so the right wheel rotates   series motors.

				
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