Abstract
In recent survey more than eleven thousand people are suffering from full
disablement or partial disablement due to severe damage to brain, nervous system, of
internal spinal injuries caused during accident or over dosage of medicines. Few diseases
cannot be cured, because of which people suffer from lack of confidence to lead their life
due to dependency. On other side people can’t do daily routine, hence both the patient
and care taker suffer mentally and physically. Now a day’s people are in busy life style
they hire a guardian or care taker to look after these people. By considering all the facts,
this project was proposed to design a prototype of the wheel chair.
This prototype functions with two modes; one is by recognizing the verbal
command and another one by touching the mobile switch app. The module controls the
course of the wheel chair by the user or guardian or caretaker using command or switch.
The system uses android designed application to communicate with the wheel chair using
Bluetooth. The infrared sensor is used to detect the obstacle during the course of collision.
The system contains temperature sensor to monitor the temperature of the disabled person
which will be helpful in unhealthy condition.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 1
Chapter 1
INTRODUCTION
People who are unable to walk are using wheel chair, exert great amount of energy using
physical strength to turn and steel the wheels. With verbal being their guide the disabled would
save energy and could use their hands and arms for other activities. Controlling an object with
verbal is of great use for the disabled person to lead their life without depending on others.
Patient intricate in physical wounds and inabilities with mental quality battle to overcome
places utilizing the traditional hand controlled wheelchair. This anticipates empowers a
framework for computerized movement which can be controlled by any smartphone. The
primary idea required in this anticipates is smartphone, which has an android as an operating
system (OS). Android has an inbuilt speech processing and Bluetooth transceiver for
communication. The second principle piece of this framework design has atmega8
microcontroller, which drives the different headings of the dc motor for directional development
of wheelchair.
1.1 Motivation
In India 120 million individuals crippled [6] and up to forty-one percent are special abled.
Quantity of incapacitated individuals is expanding because of an accidents and the disorder like
loss of motion. In the event that a man is physically impeded, he is dependent to other individual
for the daily routines transport, nourishment and so forth. Motor disability is a condition that
influences individual's capacity to do motor errand, for example, moving and controlling items.
A man with motor handicap may utilize the assistive innovation (AT) gear like wheelchair, so to
make physically incapacitated individual free. On this ground the assistive innovation gear is
manufactured and makes the disabled person to self-subordinate for movement reason.
1.2 Objectives
• To control the movement of the prototype wheelchair by voice & switch and display the
movement with the assistance of LCD.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 2
• To interface an IR module and piezoelectric buzzer to identify the obstruction close to the
wheelchair and give awareness of hindrance to the user or guardian or care taker.
• To interface a temperature sensor to monitor the temperature of the disabled person.
1.3 Problem statement
The physically able and the aged individuals with problem in movement are rising. There
are patients who have lost the control of one arm and one leg or both arms and legs, as a
consequence of larger amount spinal cord harm or cerebrum and nervous system issue. The
present wheelchairs don't have blend of innovation like voice controlled and switch controlled
wheelchair. There are two sorts of wheelchair which are available in the commercial sector like
hand worked and joystick worked wheelchairs. Because of physical weakness, they can't control
the wheelchairs appropriately by utilizing their hands.
1.4 Approach to the solution
Android based switch and voice controlled wheelchair contains two modules: Transmitter
unit and Receiver unit. Transmitter unit is an android phone which has switch application and
speech application. Recipient unit is set on the wheelchair side. From the android phone the
movement of the developed wheelchair is controlled. Depending upon the command given from
the android phone to the receiver unit put on the wheelchair, required action will be taken and
course is shown on the liquid crystal display (LCD) along with the temperature of the individual.
The receiver unit comprises of Atmega8 microcontroller, Bluetooth module, Infrared (IR)
module, LCD, Temperature sensor and piezoelectric buzzer. At the receiver unit microcontroller
receives the command from the smart phone, process the received data and sends the appropriate
control signal to the DC motor through motor driver. The movement of the wheelchair is shown
on the LCD. If there is an obstacle present in the way of wheelchair, it is identified by IR module
and displays "Obstacle Detected" on LCD and also by making sound through piezoelectric
buzzer.
1.5 Organization of the report
The report is organized as follows:
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 3
Chapter 2 portrays the work done related to the topic Android based Switch and Voice controlled
Wheelchair.
Chapter 3 explains about various hardware components and software tools required.
Chapter 4 gives the explanation of flowcharts, design and implementation of Android based
switch and voice controlled wheelchair.
Chapter 5 depicts the consequences of different test made to check for the unwavering quality of
Android based switch and voice controlled wheelchair.
Chapter 6 gives the information about conclusion and scope for future work.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 4
Chapter 2
LITERATURE SURVEY
This chapter gives review of literatures referred from various IEEE papers and other
papers published in different journals.
2.1 Voice controlled wheelchair [1]
In this anticipate the individual can control the wheelchair by voice. Voice recognition
module has to be incorporated to the remote system. At first the voice command is stored in the
data base with the function keys. Remotely the information voice commands are transmitted. The
received voice command is sampled and recognized in speech framework where the speech is
recognized and coordinated by current specimen in the stored records. The voice recognition unit
perceives the voice and gives the information to control unit. The microcontroller processes the
received information and switches the movement of motor through driver circuit. This
framework keeps away from impediment with the assistance of obstacle avoider circuit.
2.2 Voice operated wheelchair [2]
This anticipates is the voice worked wheelchair for impeded individual, guided by using
assistance of verbal order from disabled individual. The prototype is battery fueled wheelchair
with DC motors. The verbal order given to the android mobile and changed over into the content
and this content is given to the microcontroller. The microcontroller controls the course of the
wheelchair by means of Bluetooth module. This anticipates utilizes IR framework to identify the
hindrance in the method for wheelchair. This wheelchair gives free development to the crippled
individual.
2.3 Voice based direction and speed control of wheelchair for physically challenged using
Arduino [3]
In this module information is given to the Arduino which is a microcontroller and used to
control the movement of wheelchair by means of two ways/modes. To begin with route is with
the assistance of verbal order and second way is with the assistance of a touch screen. The
HM2007 is utilized for speech identification purpose. A switch is utilized to change between two
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 5
information modes. The Arduino microcontroller controls the movements of wheelchair rely on
upon the info signal received from any two modes. For the movement of wheelchair two DC
motors are utilized.
2.4 Voice operated intelligent wheelchair [4]
In this paper, it utilizes Matlab programming for audio sampling and decision making.
The processed information passed on to the ARM processor and depending on the decision
obtained movement of wheelchair is done by controlling DC motor. The input to the Matlab is
furnished with the assistance of mic, as indicated by information signal; microcontroller will
decides the movement of the DC motors.
2.5 Design and modeling of voice controlled wheelchair incorporated with home
automation [5]
This anticipates portrays the outline of a voice controlled wheelchair and home
apparatuses utilizing installed embedded framework. The voice recognition processor HM2007
is utilized to perceive the voice. The course of the wheelchair can chose utilizing the
predetermined voice command or switch. In this framework the individual sitting in the
wheelchair can work the home apparatuses i.e. exchanging ON and OFF through voice
commands without movement. This framework lessen the production cost as well as will give
extraordinary result with different sorts of electrical wheelchair.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 6
Chapter 3
HARDWARE AND SOFTWARE REQUIREMENTS
This part gives insights about different hardware components and software utilized as a part of
execution of Android based voice empowered wheelchair.
3.1 Hardware Requirements
Android based voice enabled wheelchair requires the following hardware components:
ATMEGA8 microcontroller
IR Module
16x2 LCD
Motor Driver L293D
Bluetooth Module
Temperature Sensor LM35
Piezoelectric buzzer
The following segments describe the utilization of hardware and software components in our
prototype.
3.1.1 Atmega8 Microcontroller
For any embedded framework microcontroller is the heart. In this anticipate Atmega8
microcontroller is being utilized. Atmega8 is an elite, low power AVR 8-bit microcontroller.
Atmega8 microcontroller worked in three distinct modes.
Active: 3.6mA
Idle mode: 1.0mA
Power-down mode: 0.5µA
In this model Atmega8 microcontroller assumes a principle part, where it takes the
framework control both checking and mechanization. Here the whole function will be taken care
of concerning client characterized command. The command received from the android phone of
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 7
client will be sent through remote module like Bluetooth. Once the command got from the
transmitter, it will be analyzed, based on that the controller takes the required action.
Fig.3.1: Overview of ATmega8 Microcontroller
The Atmega8 microcontroller shown in Fig.3.1 contains General Purpose Input Output
(GPIO), Universal Asynchronous Receiver Transmitter (UART) and Analog to Digital (ADC)
blocks.
GPIO:
The GPIO pin is a multiplexed pin which can either send or receive the information or
can be configured as UART, interrupt, PWM or analog channel. There are four ports in atmega-8
port A, B, C, D to do general input or output operation specified by port direction setting register
or special purpose register. It can be enabled to use UART, PWM, ADC etc by enabling this
register disables the general input and output operation Fig.3.2 shows the specific registers used
for a single port.
Fig.3.2: Different port operation
If the port direction setting register is set to logic high the corresponding port is configured as
output, if it is set to logic low then it‟s configured as input.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 8
UART:
In most of the embedded microcontroller UART is used to convert the parallel data into
serial and serial into parallel, to be sent one by one for the long range. Most of the controller
supports the multi-processor communication and three modes of communication full duplex
mode can only be done with the help of inbuilt serial interrupt. Two communication can be done
one is synchronous mode another is asynchronous, this mode is known as independent mode.
The clock generated by internal baud rate generator gives the required clock for communication.
The general format of communication consist of one start bit usually not used, one stop bit in-
between eight bit data and a parity bit to check the error during transmission or reception of
packet. Fig.3.3 shows the time diagram of UART for communication.
Fig.3.3: Asynchronous data transfer timing diagram
ADC:
In normal most information is analog, whether it is temperature, pressure, voltage, and so
forth. Their variety is constantly analog in nature. The received information (Temperature) must
be processed. However the analog signal processing is deficient in terms of accuracy, speed and
desired output. Hence, we change them to digital form using an ADC.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 9
A sensor detects any physical parameter like temperature and converted into a
proportional simple analog electrical signal. The sensor furnish with analog yield, however a
microcontroller is a computerized one, subsequently we require an ADC. The Atmega8
microcontroller contains inbuilt an ADC. For processing, this analog signal is converted into a
digital signal using an ADC. This computerized signal is then given to the Microcontroller
(MCU) and is computed as needed. The computed information (Temperature) is shown on the
LCD.
3.1.2 IR Module
The basic idea is to transmit infrared light through IR-LEDs; which is then reflected by
any object as shown in Fig.3.4.
Fig.3.4: Basic function of module
3.1.3 IR Obstacle Sensor
This board can be used in two modes/ways: obstacle sensor and IR signal receiver and
transmitter.
Fig.3.5: IR module
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 10
3.1.4 Working of IR sensor
The sensor consists of an IR detector, picks up the incoming IR rays and signals the
presence of the object. The circuit works on 5V. It consists of an IR LED shown in Fig.3.6
connected through a 320 ohms resistor. The IR photodiode is connected in reverse bias and
forms a voltage divider with the 10K resistor. The potentiometer is used to set the threshold for
the sensor; it can be used to vary the range of the sensor. The red led is used to indicate the
presence of an object.
Fig.3.6: IR module schematic
When no IR light falls on the photodiode, the voltage at the inverting input (pin 3) of the LM358
is around 0.7V to 0.9V. When the IR rays fall on the photodiode, this voltage goes up to 3.5V to
4V. The LM358 constantly compares the voltage at pin 3 with the threshold voltage at the non-
inverting input (pin 2). If the voltage at pin 3 is greater, the output will be driven high switching
on the signal LED.
3.1.5 LCD16x2
The Liquid crystal display (LCD) Screen is an electronic showcase and has broad variety
of uses. These modules are superior more than 7 portions and added multi fragment LEDs. The
LCD can easily programmable; have no detention of showing distinctive characters. A 16x2
LCD shown in Fig.3.7 surmises it can demonstrate 16 characters for each line. In this each
character is in 5x7 pixel frameworks. This LCD has 2 registers i.e., Cmd and Data.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 11
Fig 3.7: Pin diagram of LCD display
The Cmd register stores guidelines that are given to LCD. The data register stores the
information that is visible on LCD.
Table.1: Pin function of LCD
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 12
3.1.6 Bluetooth Module
Bluetooth serial module is utilized for changing over serial port to Bluetooth. This
module works in two modes: master and slave. In the event that two MCUs need to speak with
each other, one interfaces with Bluetooth master while the other one associates with slave. Their
association can be assembled once the pair is made. At this point when MCU has Bluetooth slave
module, it can communicate with Bluetooth connector of advanced mobile phones and there is a
virtual correspondence serial port line amongst MCU and smart phone.
Bluetooth Serial modules shown in Fig.3.8 operation needn't bother with a drive and can speak
with the other Bluetooth gadget, which has the serial. Be that as it may, correspondence between
two Bluetooth modules requires no less than two conditions:
The communication must be between master and slave.
The password must be correct.
Fig.3.8: Bluetooth module HC-05
3.1.7 Temperature Sensor LM35
The LM35 is an accuracy incorporated circuit temperature gadget with a yield voltage
directly corresponding to the Centigrade temperature. Its low yield impedance, direct yield and
exact inalienable alignment makes interfacing to controller is simple. The LM35 is utilized with
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 13
single force supply. The LM35 draws just 60µA from the supply; it has low self-warming of
under 0.1ºC.
In this project temperature LM35 is used to measure the temperature of person while
moving on wheelchair. It will be helpful to monitor the health of disabled person.
3.1.8 Piezoelectric buzzer
A ringer or beeper is a sound flagging gadget, which might be mechanical,
electromechanical, or electronic.
Electromechanical
Early gadgets depended on an electromechanical framework indistinguishable to an
electric ringer without the metal gong. So also, a transfer might be associated with intrude on its
own inciting current, bringing on the contacts to buzz. Regularly these units were tied down to a
divider or roof to utilize it as a sounding board.
Electronic
Fig.3.9: Piezoelectric disk beeper
Piezoelectric material is fabricated to a diaphragm which in turn bend forth and back
causing an oscillation, when corresponding signal is given by a device to drive to generate
audible information.
3.1.9 Max232
Most of the microcontroller and microprocessor are complementary metal oxide
semiconductor (CMOS) and mainly operates at logic level five volt and zero as logic high and
logic low if this system wants to communicate with other transistor-transistor-logic (TTL) or
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 14
CMOS device of different logic level there may be chance of failure in communication due to
different logic levels and may be chance of getting damaged due to high voltage level. Hence the
RS232 standard is been used but the major problem once again is logic levels. For this reason a
IC maxima 232 is used which consist of voltage inverting and doubling done with the help of
four 0.1 microfarad ceramic disc capacitor connected to pin1 and 3, pin2 and vcc, pin 4 and 5,
pin 6 and ground as shown in Fig.3.10. Each max 232 can communicate with the two devices of
different logic level usually DB-9 connector is used to do the physical connection between
sender and receiver DB-9 consist of 9 pins upper row consist 5 pins in which pin2 is either
sender or receiver. Depending on type of connector, pin3 is either sender or receiver from there
5th
pin is ground which is a mandatory connection to be done for successful connection. The rest
of the pins are known as handshaking signal for multiprocessor communication.
3.1.10 Internal Structure of Max232
MAX232 requires four capacitors ranging from 1 to 10μF. The most widely used value
for these capacitors is 10μF.
Fig.3.10: Pin diagram of MAX232
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 15
3.1.11 Voltage regulator
To give the correct voltage to the circui not intend to damage the controller a set of five
volt regulators are used. Which can power up the corresponding device, as the motor runs form 9
volt to 12volt. There is no need of reducing the incoming voltage, to do with this 7805 constant
5volt 1 amp load driving capability and input range from 6 to 36 voltage is used. It has three
terminal pin. One is input pin, two is common pin and three is output from where constant 5 volt
is supplied to the devices. In order to keep the constant supply without thermal run away
additional heat desipater must be attached to the device
Fig.3.11: Voltage Regulators (7805)
Usually monolithic voltage regulator is available as 3 terminals IC7805 as shown in Fig.3.11.
The 3 terminals are denoted as IN (input), COM (common), OUT (output). This +5V regulator is
useful in power up to 500mw.It must have a heat sink for high current. A 1µf high quality and
tantalum capacitor should be placed from output to ground for stability. By using this regulator
circuit we are deriving 5v from 12v battery.
3.1.12 Gear Dc Motor
At whatever point a mechanical autonomy specialist discuss making a robot, the primary
thing rings a bell is making the robot precede onward the ground. What's more, there are
constantly two choices before the architect need to utilize a DC or stepper motor. With regards to
speed, weight, size, cost. DC motors are constantly favored over stepper motor. There are
numerous things which can be done when dc motors are connected with microcontroller. For
instance rate of motor can be controlled.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 16
Fig.3.12: Internal architecture of dc motor
As dc motor don‟t have much torque to drive a payload with desired rpm. To avoid this problem
sets of gear are used to drive the motor, which consist of driver gear idle linking gear and driven
gear, which will be connected to shaft of the motor and then it can be connected to wheel to drive
the pay load.
Fig.3.13: Gear combination
3.1.13 Dual H-Bridge Motor Driver L293D
L293D is a double H-Bridge motor driver. This IC can drive two dc motors in both
directions with fix course of movement by interfacing all I/O to microcontroller and up to four
motors can be controlled in fixed direction. This driver has yield current of 600mA and up to
1.2A for every line connected to motors. Mainly this IC has internal freewheeling diode, which
protects from back emf generated during the rotation and works with wide input from 4.5v to
36v. In the Fig. 3.14 to connect a single motor to driver and to microcontroller o/p1 and o/p2 are
connected to motor i/p pin A, B and EN will be connected to microcontroller.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 17
Fig.3.14: Connection diagram L293D to motor and input function
The direction signal will be given to A and B input, EN signal must be high. Additionally vcc1
must be connected to 5volts, vcc2 must be connected to 12 volt and all four ground additional
pull of 10k must be connected to i/o line of microcontroller to ensure the perfect operation of
driver.
3.1.14 Battery
Power bank are major source to run the prototype, here 12volt 1.2ampere/hour sealed
lead acid battery is used to give constant supply for continuous operation of the system.
Compared to conventional lead acid battery this bank won‟t spill the acid and no need to put
distilled water an additional charger need to charge the battery. The voltage 14.1 volts is knows
as full battery and 10 volts is known as low battery voltage, discharging the battery beyond the
level make the battery unusable. Additional voltage reducer IC 7805 must be used to drive the
digital part.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 18
3.2 Software Requirements
Android based voice enabled wheelchair requires the following software.
AVR Studio
Sina programmer
Eclipse
3.2.1 AVR Studio
Atmel® AVR Studio® 5 is the Integrated Development Environment (IDE) for creating
and troubleshooting implanted Atmel AVR® applications. The AVR Studio 5 IDE gives you a
consistent and simple to-use environment to compose, construct, and troubleshoot your C/C++
and constructing agent code. Which is utilized to produce a hex document, it is to composed to
microcontroller with an assistance of developer and developer programming.
Fig.3.15: Shows Front View of AVR Studio Version 5
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 19
Steps involved to code and generate hex file:
Step1: Create a new project
Fig.3.16: Screenshot of AVR studio for create a New Project
Step2: Select the target device, in Fig.3.17 Atmega8 device is selected.
Fig.3.17: Screenshot of selection of the Target Device for which the Hex File is to be
generated
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 20
Step3: Write the C code.
Fig.3.18: Screenshot of write Code with C
Step4: click on run compile, no errors result.
Step5: build target generate hex file.
3.2.2 Sina Programmer
Fig.3.19: Screenshot of front view of Sina Programmer
Sina Programmer is burner programming with straightforward client likewise
consolidates an AVR Fuse mini-computer. It utilizes enhanced AVRDUDE 5.10 and the
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 21
accessible ports and baud rate choice is conceivable. It is a standalone basic programming and no
establishment is select the IC sort as ATmega16 and set the Programmer to USB asp and port to
USB (as seen at the base of window).Click on browse, under Hex File find the .Hex document.
3.2.3 Eclipse
The Eclipse Platform shown in Fig.3.20 is intended for building integrated development
environments (IDEs) utilized as a part of PC programming. It comprises of base workspace and
an extensible module framework. Eclipse is composed in Java and its essential application is for
creating java applications. The Eclipse software development kit (SDK), it incorporates the java
development tools. Clients can extend its abilities by installing plug-ins development toolbox for
other programming dialects, and can compose and contribute their own particular modules.
Eclipse utilizes modules to give all the usefulness inside and on top of the runtime structure.
Fig.3.20: Architecture of Eclipse Platform
Furthermore the eclipse platform is extended using other programming lingos, for instance, C
and Python. The module structure allows the eclipse platform stage to work with typesetting
lingos like LaTex and frameworks organization applications, for instance, telnet and database
organization systems.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 22
Chapter 4
METHODOLOGY
Android based voice controlled wheelchair consists of transmitter unit and receiver unit.
They are connected together wirelessly. This chapter describes the working principle and
flowchart of the system.
4.1 Smart phone and processing
Smart phone and processing (transmitting unit) shown in Fig.4.1 running on android
operating system with Linux kernel used to do two process, in first process a touch screen based
app with a api for Bluetooth radio and stack enabled app communicates with touch screen api to
determine the action to be performed. When user touch corresponding button, after that packet
will be sent to Bluetooth for wireless transfer of data to wheel chair here smart phone Bluetooth
Fig.4.1: Transmitting Unit
ANDROID
OPERATING
SYSTEM
TOUCH
PANNEL
SPEECH INPUT
CONDENSER
MIC
SPEECH
RECOGNIZING
AND
PROCESSING
APK
BLUE
TOOTH
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 23
acts as master and wheel chair Bluetooth acts as slave which automatically pair in open
discovery mode with password. Second process based speech recognizing Google speech
recognizer; this speech will be sampled and processed using predetermined api. In android after
comparison a character will be generated to the corresponding voice command and same will be
sent to wheel chair via Bluetooth.
4.2 Receiving Unit
This module consist of atmega-8 microcontroller which perform all the controlling and
monitoring operation for the corresponding command received by UART through Bluetooth and
sensor to change the course of the wheel chair in case of obstacle. Atmega-8 operating at
16MHZ with flashes ROM of 8KB and RAM of 2KB. The LCD gives visible information to the
corresponding caretaker regarding the temperature of the patient obtained by conversion from
analog to digital from LM35 analog temperature sensor. The IR sensor does the part of collision
avoidance and course diversion. The two 60 rpm geared dc motor is used to give course to the
wheel chair. The mobility operation which is driven by the microcontroller with the help of
L293D h-bridge motor.
Fig.4.2: Receiving unit
LCD16X2
ATMEGA-8
MICROCONTROLLER
L293D H-BRIDGE
MOTOR DRIVER
MOTOR1 MOTOR2
38 KHZ IR
SENSOR
LM35
TEMPERATURE
SENSOR
HC-05
BLUEETOOTH
MODULE
BUZZER
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 24
The buzzer is used to provide audible 3KHz sound in case of any collision and mainly HC-05
Bluetooth does the transmission and reception. The bridge part wireless to receive the specific
command given by the user either by touch or voice input.
4.3 Differential drive to control wheel chair movement
By utilizing two motor, wheel chair can be coursed in coveted way. This guiding system of
wheel chair is called as differential drive as shown in Fig.4.3.
Fig.4.3: Differential Drive Mechanism of wheel chair
Differential motor drive does the controlling of wheel chair in desired direction. If both the
motors are rotating in forward direction the chair move in straight direction, if both motor rotates
in reverse course means wheel chair will go in reverse course. If left motor revolves in forward
direction and right motor rotates in reverse direction then wheel chair turns to right side. If right
motor revolves in forward course and left motor in reverse course means left turn. If both motor
halts means wheel chair will stop.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 25
Table 2: Wheel chair direction table
Motor1(L) Motor2(R) Wheel chair Course
FWD FWD FWD
REV FWD LFT
FWD REV RIG
REV REV REV
Note: FWD (FORWARD), REV (BACKWARD), LFT (LEFT), RIG (RIGHT)
4.4 Circuit Diagram of the system
In this circuit Atmega-8 is used to course the direction of the wheel chair as per the
command given by the client. These commands are received by Bluetooth HC-05 connected to
RXD and TXD pin of microcontroller configured as UART operating at nine thousand six
hundred baud rate, eight bit data, one stop bit, no start and no parity. Any command sent by the
client will be received through UART and then processed.
Fig.4.4: Hardware connection diagram of the prototype
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 26
The temperature sensor LM35 is connected to ADC1 pin of microcontroller to perform analog to
digital conversion of temperature for continuous monitoring the patient health status. In built
ADC does 12bit conversion resolution by successive approximation method. The converted
result will be stored in ADC result register ADCH and ADCL; internal VREF is used to perform
the conversion operation. The 38 KHz IR sensor is used to detect hindrance in the course of the
wheel chair and it diverts the direction of chair. IR sensor is equipped with IR emitting LED
which send infrared light and photo diode which receives the infrared reflected back from the
obstacle. Here photo diode is connected in reverse bias when infrared light falls on junction of
diode, the electrons moves from p to n making the voltage flow additional 50 K pot is used to
adjust the sensing range of IR sensor. The 3 KHz pizeo electric buzzer is used to generate the
audible warning information when wheel chair moves in collision course to avert the user. Two
12volt 60 rpm geared dc motor is used to move the chair in desired direction driven by L293D h-
bridge motor driver as dc motor is analog mechanical and works at 12 volt consuming 200to 300
mA of current. It mainly generates back emf while in motion if this motor is directly connected
to microcontroller, hence controller will get damaged, because its digital operates at 5volt and
can supply maximum of 40mA source current per input and output. So L293D gets the
information from microcontroller and change the course of wheel chair. The 16x2 LCD display
connected to pb0, pb1, pb2, pb3 in four bit mode and rs pin of LCD is connected to pd5, r/w is
connected to pd6 and enable is connected to pd7 of microcontroller.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 27
4.3 Flow Chart of the system
i) Speeech process with android
The flow chart shown in below describes the process of sytem when verbal input is given to
smart phone and depending on the speech command the course flow of the wheel chair changes
as represented in the Fig.4.5.
NO
YES
YES
NO
START
RUN SPEECH APP
INITIALIZE BLUETOOTH FOR
PACKET TRANSFER
RUN SPEECH ENGINE
IF SPEECH
INPUT
DETECTED
IF
COMMAND
IS FOWARD
SEND „F‟ TO
WHEEL CHAIR
A
C
B
PROCESS THE
SPEECH
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 28
YES
NO
YES
NO
YES
NO
YES
NO
Fig.4.5: Flow chart of speech processing
SEND „B‟ TO
WHEEL CHAIR
IF
COMMAND
IS LEFT
SEND „L‟ TO
WHEEL CHAIR
A
B
C
IF
COMMAND
IS
BACKWARD
IF
COMMAND
IS RIGHT
SEND „R‟ TO
WHEEL CHAIR
IF
COMMAND
IS STOP
SEND „S‟ TO
WHEEL CHAIR
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 29
ii) Touch control flow
NO
YES
YES
NO
Fig.4.6 describes the process of the system when switch input is given to the smart phone.
Depending on the switch command the course flow of the wheel chair changes as depict in the
above flow chart.
RUN TOUCH APP
INITIALIZE BLUETOOTH FOR
PACKET TRANSFER
RUN SCREEN SCAN PROCESS
IF TOUCH
INPUT
DETECTED
IF
COMMAND
IS FOWARD
SEND „F‟ TO
WHEEL CHAIR
A
C
B
PROCESS THE
POSITION
START
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 30
YES
NO
YES
NO
YES
NO
YES
NO
Fig. 4.6: Flow chart of touch control
SEND „B‟ TO
WHEEL CHAIR
IF
COMMAND
IS LEFT
SEND „L‟ TO
WHEEL CHAIR
A
B
C
IF
COMMAND
IS
BACKWARD
IF
COMMAND
IS RIGHT
SEND „R‟ TO
WHEEL CHAIR
IF
COMMAND
IS STOP
SEND „S‟ TO
WHEEL CHAIR
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 31
iii) Wheelchair control flow
NO
YES
YES
NO
Fig. 4.7 describes the overall process of the prototype of the wheel chair.
INITIALIZE INPUT AND OUTPUT
AND ADC
INITIALIZE UART AT 9600
BAUDRATE 8BIT DATA ONE STOP
BIT NO START NO PARITY
IF
COMMAND
RECIVED
IF
COMMAND
IS „F‟
MOVE
WHEELCHAIR
FORWARD
A
C
E
PROCESS THE
COMMAND
START
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 32
YES
NO
YES
NO
YES
NO
YES
NO
MOVE
WHEELCHAIR
REVERSE
IF
COMMAND
IS „L‟
MOVE
WHEELCHAIR LEFT
A
B
C
IF
COMMAND
IS „B‟
IF
COMMAND
IS „R‟
MOVE
WHEELCHAIR
RIGHT
IF
COMMAND
IS STOP
STOP WHEELCHAIR
D
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 33
YES
NO
NO NO
YES
Fig.4.7: Flow chart of wheel chair control
MOVE
WHEELCHAIR TO
RIGHT
E
D
IF IR SENSOR
ACTIVE
WAIT UNTILL
CONVERSION
COMPLETE
B
START ADC
CONVERSION
READ AND
CONVERT DIGITAL
VALUE TO
TEMPERATURE
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 34
Chapter 5
RESULTS AND DISCUSSION
In present days looking after the old people, patient or physically disabled and
quadriplegics is very difficult in major cities as well as in small towns because of this people
who are ill loose there hope of living. Because of dependency and some people may afford a care
taker to look after the peoples. Who are ill, this project compromises by making the ill to do of
their little work by own and make them, they are not dependent by using the android smart phone
with app running to control the wheel chair either by giving speech command by patient itself or
by touch control by other persons. This wheel chair as shown in Fig.5.1 is equipped with IR
sensor to detect obstacle and divert it and a temperature sensor to monitor temperature of patient.
Fig.5.1: Prototype of the wheel chair
The signal acquired and processed for the speed control is as described in below steps:
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 35
Step-1:
Fig.5.2 shows the touch based user interface for controlling the course of the wheel chair. When
user gives input by clicking open, the course of the wheel chair controlled by different option
such as FWD, REV, LFT, and RIG. If the user wants to halt the wheel chair, he can click close,
so that the movement of the wheel chair stopped.
Fig.5.2: Screen shot of touch user control app
Step-2:
Fig.5.3 shows the screenshot of verbal control app provides voice command based movement of
wheel chair. User need to turn on the internet and give specific voice command which will be
processed and matched by inbuilt algorithm of android. It sends specific command over
Bluetooth to control the movement of the wheel chair.
Fig.5.3: Verbal control app
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 36
Step-3:
In this step user has sent a command to move the wheel chair in forward direction the letter „F‟
will be sent by the android to wheel chair to move in forward direction Fig.5.4 shows the display
“FORWARD” on LCD for the received command „F‟ for forward direction and patient
temperature (room temperature) will be monitored continuously.
Fig.5.4: Screenshot of forward movement
Step-4:
In this step user has sent a command to move the wheel chair in reverse direction the letter „B‟
will be sent by the android to wheel chair to move in backward direction Fig.5.5 shows the
display “BACKWARD” on LCD for the received command „B‟ for backward direction and
patient temperature (room temperature) will be monitored continuously.
Fig.5.5: Screenshot of backward movement
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 37
Step-5:
In this step user has sent a command to move the wheel chair towards right direction the letter
„R‟ will be sent by the android to wheel chair to move towards right direction Fig.5.6 shows the
display “RIGHT” on LCD for the received command „R‟ for right turn and patient temperature
(room temperature) will be monitored continuously.
Fig.5.6: Screenshot of right turn
Step-6:
In this step user has sent a command to move the wheel chair towards left direction the letter „L‟
will be sent by the android to wheel chair to move towards left direction fig.5.7 shows the
display “LEFT” on LCD for the received command „L‟ for left turn and patient temperature
(room temperature) will be monitored continuously.
Fig.5.7: Screenshot of left turn
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 38
Step-7:
In this step IR sensor mounted on wheel chair detects the collision. If the patient forgets to stop
or issue the next command, then automatically wheel chair will turn to right and buzzer will be
turned on to give audible warning information shown in Fig.5.8 to patient or care taker.
Fig.5.8: Screenshot of Obstacle detection
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 39
Chapter 6
CONCLUSION AND SCOPE FOR FUTURE WORK
This part gives the conclusion drawn from the proposed work and the extension for future work.
6.1 Conclusion
This prototype pays to the self-dependency of physically challenged, handicapped and
paralyzed and aged people. This reduces the manual effort for attaining and distinguishing the
command for controlling the motion of a wheelchair by specified commands. Further that, the
improvement of this model is finished with less cost and reasonable. This wheelchair can be
utilized to help abled individuals and matured individuals particularly the individuals who are
not able to move.
This system is made highly efficient and effective. The setup for maintaining the
wheelchair will be a onetime investment for any real life application. The motor drive and
control arrangement of the model astute wheelchair has been exhibited. The android based voice
and switch controlled wheelchair will bring more comfort for the disabled individuals, also the
wheelchair has function of rotating wheelchair by some defined angle that will be very useful for
the user for taking left or right turn. The obstacle detection is incorporated in this project for
safety of disabled person. Further, the temperature sensor is incorporated in this prototype to
monitor the temperature of the user during unhealthy condition. This project is also helpful for
the people like visually impaired, hearing impaired and orthopedic disable person those who are
not able to move. Visually impaired person can use voice to control the movement of wheelchair
and hearing impaired person can use switch to control the operation of wheelchair.
6.2 Scope for future work
The range of automation could be increased by using long range wireless modules like
Wi-Fi, Zigbee etc.
The pulse rate monitoring unit could be incorporated to this prototype, to measure pulse
rate of a person along with temperature.
Android Based Switch and Voice Controlled Wheel Chair
Department of ECE, SJCE, Mysuru 40
REFERENCES
[1] Krishna Pal Tiwari, Kranti Kumar Dewangan, “Voice Controlled Autonomous Wheelchair”,
“International Journal of Science and Research” Volume 3, Issue 5, May 2013.
[2] Jayesh K. Kokate, A. M. Agarkar, “Voice operated wheelchair”, “International Journal of
research in engineering and technology” Volume 3, Issue 2, Feb-2014.
[3] M.Prathyusha, K. S. Roy, Mahaboob Ali Shaik, “Voice and Touch Screen Based Direction
and Speed Control of Wheel Chair for Physically Challenged Using Arduino” , “ International
Journal of Engineering Trends and Technology (IJETT)” , Volume 4, Issue4, April 2013.
[4] Ms. S. D. Suryawanshi , Mr. J. S. Chitode , Ms. S. S. Pethakar, “Voice Operated Intelligent
Wheelchair”, “ International Journal of Advanced Research in Computer Science and Software
Engineering” Volume 3, Issue 5, May 2013.
[5] Anoop K. J, Inbaezhilan, “Design and Modeing of Voice Controlled Wheelchair Incorporated
with Home Automation”, “Journal of Advanced Research in Electrical, Electronics and
Instrumentation Engineering”, Volume 3, Special issue 2, April 2014.
[6] Richard Simpson, “Smart Wheelchairs: A literature Survey”, “Journal of Rehabilitation
Research & Development”, Volume 42, Number 4, Pages 423–436 July/August 2005.
[7] http://www.who.int/mediacentre/news/notes/2013/disability_and _development_20130920/en
[8] htttp://www.allldatasheet.com/atmega8.
Top Related