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Project Presentation 

Department of Electronics & Communication

Engineering

 

Voice controlled wheel-chair 

 

Group members: Project guide:

Shivam upadhyay Mr. Vibhu Srivastava

Rohit Katiyar

Vijay Sharma

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Introduction Block diagram of voice controlled wheel chair Specifications Microcontroller-PIC16F877 RF 434MHz Tx-Rx Motor driver H-bridge DC-motors Relay Conclusion Reference

CONTENTS

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Voice Controlled Wheel chair is a mobile robot whose

motions can be controlled by the user by giving specific

voice commands.

The speech recognition software running on a PC is capable

of identifying the 5 voice commands ‘Run’, ‘Stop’, ‘Left’,

’Right’ and ‘Back’ issued by a particular user.

INTRODUCTION

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BLOCK DIAGRAM OF VOICE CONTROLLED WHEEL CHAIR

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Microcontroller : PIC16F877 RF 434MHz Tx-Rx Motor driver circuit

H-bridge using MOSFET DC motors : (Options) Gear driven

Chain driven Relay Battery

SPECIFICATIONS

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Operating speed: DC - 20 MHz clock input DC - 200 ns instruction cycle Up to 8K x 14 words of FLASH Program Memory, Up to 368 x 8 bytes of Data Memory (RAM) Up to 256 x 8 bytes of EEPROM Data Memory Up to 8K x 14 words of FLASH Program Memory, Up to 368 x 8 bytes of Data Memory (RAM) Up to 256 x 8 bytes of EEPROM Data Memory

MICROCONTROLLER : PIC16F877

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Functions :

Processes data Provides control voltages to motor.

Contd…

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RF 434MHz Tx-Rx

This transmitter Transmit and receive the signal at 434 MHz frequency.

This radio frequency (RF) transmission system employs Amplitude Shift Keying (ASK) with transmitter/receiver (Tx/Rx) pair operating at 434 MHz

The transmitter module takes serial input and transmits these signals through RF.

The transmitted signals are received by the receiver module placed away from the source of transmission.

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Lost cost 433.92MHz receiver module Low working voltage. Low current 5.7mA. High sensitive -116dBm.

Key features of RF 434MHz Tx-Rx :

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H-BRIDGE:

H bridge circuit is use for controlling the DC motors.

MOTOR DRIVER

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The H-bridge arrangement is generally used to reverse the polarity of the motor.

It can also be used to 'brake' the motor, where the motor comes to a sudden stop, as the motor's terminals are shorted.

It also let the motor 'free run' to a stop, as the motor is effectively disconnected from the circuit.

Working of H-BRIDGE

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The following table summarizes operation, with S1-S4 corresponding to the below diagram:

Contd…

S1 S2 S3 S4 RESULT

1 0 0 1 Motor moves right

0 1 1 0 Motor moves left

0 0 0 0 Motor free runs

0 1 0 1 Motor brakes

1 0 1 0 Motor brakes

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An electric motor converts electrical energy into mechanical motion.

DC motors drives the wheels of wheel chair.

DC MOTORS

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Working of DC motor :

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The different direction of motions possible is: Forward: Both the motors in forward direction Reverse: Both the motors in the reverse direction Left: Left motor stopped/Right motor in the forward

direction Right: Right motor stopped/Left motor in the forward

direction In turn: The motors are in the opposite direction

Contd…

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Relays are remote control electrical switches that are controlled by another switch, such as a horn switch or a computer as in a power train control module.

Relays allow a small current flow circuit to control a

higher current circuit.

Relays are either Normally Open or Normally Closed.

RELAY

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Normally open relays have a switch that remains open until energized (ON).

In energized ON, current flowing through the control circuit coil (pins 1 and 3) creates a small magnetic field which causes the switch to close, pins 2 and 4.

The switch, which is part of the load circuit, is used to control an electrical circuit that may connect to it.

Current now flows through pins 2 and 4 shown in RED, when the relay in energized.

NORMALLY OPEN RELAYS :

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When the relay control coil is NOT energized, the relay switch contacts are closed, completing the circuit through pins 2 and 4.

When the control coil is energized, the relay switch contacts opens, which breaks the circuit open and no continuity exists between pins 2 and 4.

NORMALLY CLOSED RELAYS:

Normally Open (NO) Normally Closed (NC)

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A speech recognition application is used through VB for recognizing a voice command and performing the required operation.

Visual Basic (VB) is a third-generation event driven programming language and associated development environment from Microsoft and its programming model.

Visual Basic was derived from BASIC and enables the rapid application development (RAD) of graphical user interface (GUI) applications.

VISUAL BASIC FOR SPEECH RECOGNITION:

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Visual basic provides an important Microsoft speech to text converting tool.

This tool plays the most important role in converting a user’s speech command into text and send respective signal to the microcontroller to perform the required operation.

Contd…

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Circuit diagram of power supply:

CIRCUIT DIAGRAM:

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Circuit diagram for microcontroller:

Contd…

U 1

1

910

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234567

2122232425262728

1112131415161718

MC LR /V PP

O SC 1 /C LK INO SC 2 /C LKO U T

VD D

R A 0 /AN 0R A 1 /AN 1R A 2 /AN 2R A 3 /AN 3 /VR E FR A 4 /TO C K IR A 5 /S S /AN 4

R B 0 / IN TR B 1R B 2R B 3R B 4R B 5R B 6R B 7

R C 0 /T1O SO /T1C K IR C 1 /T1O S IR C 2 /C C P 1

R C 3 /SC K /SC LR C 4 /SD I /S D A

R C 5 /SD OR C 6R C 7

Crystal Ocs 4Mhz

RF Receiver

5V

R 14 . 7K

Motor1

5V

Motor2

SW 15V

PIC16F72

5V

5V

VC C

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The goal of this project was to develop a speech controlled wheelchair application for the handicapped and physically paralyzed patients.

The goals were fulfilled with quite good results.

In this case Visual Basic was used, a programming language that is easy to learn and use but yet powerful enough to make wheelchair control systems.

Still much of the performance results depend on the speech recognition programming, which hopefully will improve further.

CONCLUSION

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www.electronics4u.com www.projectsabtsracts.com www.techtriks.wordpress.com www.ideaprojects.com www.datasheetcatalogue.com www.alldatasheets.com

REFERENCE

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THANK YOU