Android speech and touch based smart wheel chair for physically disablities

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.

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

DELL

Typewritten Text

Android speech and touch based smart wheel chair for physically disablities

DELL

Typewritten Text

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.



• 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:



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.



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



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.



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



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.



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.



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

http://www.probots.co.in/articles/objectsensor_files/IR LED based Object Sensor.jpg



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.

http://www.probots.co.in/articles/objectsensor_files/IR LED and Photodiode based Obstacle sensor circuit.gif



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



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



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

http://en.wikipedia.org/wiki/File:2007-07-24_Piezoelectric_buzzer.jpg



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



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.



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.



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.



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



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



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



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.



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



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



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.



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



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.



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



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



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



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



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



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



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



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:



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



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



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



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



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.



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.