wheelchair guided by voice commands

WHEELCHAIR GUIDED BY VOICE COMMANDS

Team Members :

Majd Khaleel Sa’ed Daraghmeh

Alaa Dweekat

Supervised By :

Dr. Aiman Al-Sharea Dr.Nathir Rawashdeh

AIM OF THE PROJECT

To control the movement of a manual wheelchair by means of human voice, it helps disabled and elderly persons, since it does not need any body stress, and just depends on what disabled person says.

OUTLINES Block Diagram. Parts of The Project Speech Recognition Circuit. Drive Unit. Interfacing Circuit. Conclusion.

Block Diagram. Parts of The Project. Speech Recognition Circuit. Drive Unit. Interfacing Circuit. Conclusion.

BLOCK DIAGRAM

Block Diagram. Parts of The Project Speech Recognition Circuit. Drive Unit. Interfacing Circuit. Conclusion.

PARTS OF THE PROJECT Wheelchair. SRC. PIC16F877A. Two DC geared motors. 12V-Battery (For motors). 9V-Battery (For SRC & PIC microcontroller). 4 Relays. Joystick. Microphone. Belts.

Parts of The Project Block Diagram. Speech Recognition Circuit. Drive Unit. Interfacing Circuit. Conclusion.

SPEECH RECOGNITION CIRCUIT

SPEECH RECOGNITION CIRCUIT This circuit is trained to recognize definite

required words, and it can be programmed in any spoken language, and even non spoken languages.

The heart of the circuit is the HM2007 Speech Recognition Integrated Circuit.

This I.C. can provide two methods for recognizing a WLEN pin on the main circuit board selects either the 0.96 second word length (40 word) or the 1.92 second word length (20 word).

SPEECH RECOGNITION CIRCUITHM2007 pin diagram

SPEECH RECOGNITION CIRCUIT

The HM2007 stores the "trained" word patterns used for recognition in external memory.

Speech recognition is classified into two categories, speaker dependent and speaker independent.

This chip has two operational modes: Manual mode and CPU mode.

SPEECH RECOGNITION CIRCUITHM2007 pin diagram

SPEECH RECOGNITION CIRCUITSRC CONSTRUCTION

SPEECH RECOGNITION CIRCUITTRAINING THE KIT:

SPEECH RECOGNITION CIRCUIT Testing :

When repeating a trained word into the microphone. The number of the word should be displayed on the digital display.

Clearing the memory :To erase a single word space press the

number of the word you want to clear, then press the "*“ (clear) key.

To erase all the words in the RAM memory (Training) press "99" on the keypad then press the "*" (clear) key.

DRIVE UNITDrive Unit consists of two main parts are :

I. Two geared DC series motors.II. Transmission unit.

Belt

DRIVE UNIT Why a DC Series Motor Was Chosen?

Very high speed at no load

High torque at low speed

DRIVE UNITIn series motor the flux (Ф) is a function of armature current ( Ia), and it is proportional to (Ia).

DRIVE UNIT we use two motors in which every motor is

attached to its own wheel and this allow us to move the chair in different direction as shown below :

DirectionRight motorLeft motorForwardON ( CW )ON ( CW )

BackwardON ( CCW )ON ( CCW )RightOFFON ( CW )LeftON ( CW )OFF

DRIVE UNITGearbox We use the gearbox to reduce the speed of

the motor and increase its torque.

DRIVE UNIT We use helical gear, because The load in

helical gear is distributed over several teeth.

Gearbox ratio equal 0.08

Velocity of the motor 4000 rpm using the gearbox become 320 rpm .

DRIVE UNITTransmission Unit The belt used to transmit power from one

shaft to another by means of pulleys which rotate at same speed. The amount of power transmitted depends upon the following factors:

I. The velocity of the belt.II. The tension under which the belt is placed on

the pulleys.III.The arc of contact between the belt and the

smaller pulley.IV.The condition under which the belt is used.

DRIVE UNITThere are many types of belts :

Flat belt Circular belt V-belt

DRIVE UNIT We use V-belt because it is mostly used in

the factories and workshops. The V-belt has a positive drive because the

slip between the belt and the pulley groove is negligible. The power transmitted by V-belt is more than that of the flat belt for the same coefficient of friction.

INTERFACING CIRCUIT

INTERFACING CIRCUIT

SRC

Joystick+

- +

-

INTERFACING CIRCUIT

SRC

Joystick

+

-

+

-

INTERFACING CIRCUIT

DirectionLeft MotorRight Motor

Transistor 1Transistor 2Transistor 3Transistor 4

None0000

Forward1010

Reverse0101

Right1000

Left0010

INTERFACING CIRCUIT

Voice

NO NO NO

YES

NO NO

CONCLUSION

Speech can be one of the desirable interface means for wheelchairs.

When this project used by disabled person, he will be more comfortable, and self-dependent in his life.

There is possibility to run the chair at different speeds and choose between joystick and voice control methods.

wheelchair guided by voice commands

Engineering