VOICE CONTROLLED WHEELCHAIR

PROJECT GUIDE: Mr. RAJESH M.VSr. LECTURER IN ELECTRONICS & COMM

PROJECT CO-ORDINATOR: Mrs. JIBI JOHNSr. LECTURER IN ELECTRONICS & COMM

Website: www.techtriks.wordpress.com

Team MembersNISHA M.S. ECU032/48SAPNA VASUDEVAN ECU032/32TINTU MARY SCHARIH ECU032/SENTHIL KUMAR ECU032/PRIYANKA SUSAN GEORGE ECU032/

AIM:

The project aims at controlling a wheelchair by means of human voice.

PIC 16F877 is the brain of the control circuit.

The voice recognition is done by HM2007.

DC motors are used to drive the wheelchair.

The driving mechanism used is chain drive.

Two 12V,32Ah maintenance-free, lead acid batteries are used.

BLOCK DIAGRAM

MIC

VOICE RECOGNITION IC MICROCONTROLLER

DRIVER CIRCUIT

RIGHTMOTOR

BATTERYCHARGER

BATTERY

LEFT MOTOR

DRIVER CIRCUIT

SPEED &DIRECTION CONTROL

RESET

VOICE RECOGNITION CIRCUIT

FEATURES OF HM2007

It is a 48 pin DIP IC.

Speaker independent mode was used.

Maximum of 40 words can be recognized

Each word can be maximum 1.92sec long.

Microphone can be connected directly to the analog input.

64K SRAM, two 7 segment displays and their drivers were connected.

PIN DIAGRAM

HM6264

CIRCUIT DIAGRAM

TRAINING PROCESS:

VOICE TRAINING Make WAIT pin HIGH for training mode. Clear the memory by pressing 99 *. Enter the location number to be trained. After entering the number the LED will turn

off. Number will be displayed on the display. Next press # to train.

The chip will now listen to the voice input and LED will turn ON.

Now, speak the word you want to train into the microphone.

The LED should blink momentarily. This is the sign that the voice has been

accepted. Continue doing this for different words.

VOICE RECOGNITION Repeat the trained word into the microphone. If word is rightly recognized, the correct

location is displayed. The error codes are: 55- word too long. 66-word too short. 77-word no match.

PCB- Key Board

Component Side Soldering Side

Voice Recognition Circuit on Bread Board

• The circuit worked well on bread board• PCB Design is over.• Soldering remaining

Problems Encountered:

There were many basic mistakes in the the application circuit in the datasheet itself.

The CHIPSELECT of SRAM(PIN26)is an active high input, we tied it to ground through a capacitor and resistor as indicated in the application circuit.

Interfacing of 74LS373 with HM6264-Many Wrong Connections.

Interfacing 74LS47 with 74LS373-Many Wrong connections

One of the common anode 7-segment drivers was damaged.

MOTORS AND BATTERIES:

After calculations the following motor specifications were arrived at: 57W, 17.1Nm, 30 rpm.

The motor procured from AGNI MOTOR,BANGLORE has the following specifications:120W,9.8Nm,60 rpm with no load.

Two 12V,32Ah lead acid AMARON batteries were purchased

Power calculations

Trial1- m=40kg s=5.321m

t=15ss=ut+0.5at2therefore, a=0.047m/s2

v=0.705m/s Trial 2- m=40kg s=5.321m

t=14ss=ut+0.5at2therefore, a=0.054m/s2

v=0.7601m/s

•Trial 3-m=40kgs=5.321mt=7ss=ut+0.5at2therefore, a=0.21m/s2v=1.52m/s

MOTOR CALCULATIONS

R=0.3ma=0.21 m/s2 (maximum possible practically)v (max)=2m/sm=100kg takenF= ma + μN=21+0.04*900=57Nnote:0.02 is the frictional co- efficient for a smooth surface..0.04 is the roughest possible.900N is taken as a std valueP=F*v (max)=114W,both motors….57W one motor……Τ = F* R=57*0.3=17.1Nm

To find rpm of motort=7ss=5.321mv=1.52rpm=(s*60)/(2*3.14*R*t)=26rpmnow,s=5.321mv=v (max)=2m/sfrom v2=2as, a=0.375m/s2from, v=at, we get t= 5.5sTherefore, rpm=(s*60)/(2*3.14*R*t)=31rpmfinally, each motor should at least be 60W,100rpm

Flowchart

THINGS TO DO:

Programming of PIC16F877

Motors to be coupled to the wheel chair by chain drive mechanism.

Design of the speed and direction control circuit.

Design of battery charger.

THANK YOU