VOICE CONTROLLED WHEELCHAIR PROJECT GUIDE: Mr. RAJESH M.V Sr. LECTURER IN ELECTRONICS & COMM PROJECT CO-ORDINATOR: Mrs. JIBI JOHN Sr. LECTURER IN ELECTRONICS & COMM Website: Team Members NISHA M.S. ECU032/48 SAPNA VASUDEVAN ECU032/32 TINTU 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 ICMICROCONTROLLER DRIVER CIRCUIT RIGHT MOTOR BATTERY CHARGER 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 SideSoldering 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=15s s=ut+0.5at2 therefore, a=0.047m/s2 v=0.705m/s Trial 2- m=40kg s=5.321m t=14s s=ut+0.5at2 therefore, a=0.054m/s2 v=0.7601m/s Trial 3-m=40kg s=5.321m t=7s s=ut+0.5at2 therefore, a=0.21m/s2 v=1.52m/s

MOTOR CALCULATIONS R=0.3m a=0.21 m/s2 (maximum possible practically) v (max)=2m/s m=100kg taken F= ma + μN= *900=57N note:0.02 is the frictional co- efficient for a smooth surface is the roughest possible.900N is taken as a std value P=F*v (max)=114W,both motors….57W one motor…… Τ = F* R=57*0.3=17.1Nm To find rpm of motor t=7s s=5.321m v=1.52 rpm=(s*60)/(2*3.14*R*t)=26rpm now, s=5.321m v=v (max)=2m/s from v2=2as, a=0.375m/s2 from, v=at, we get t= 5.5s Therefore, rpm=(s*60)/(2*3.14*R*t)=31rpm finally, 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.

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