it's a small Mechatronics Project which includes Programming , design. mechanic and electrical circuits

1. WHEELCHAIR GUIDED BY
VOICE COMMANDS

2.  Team Members :
Majd Khaleel
Sa’ed Daraghmeh
Alaa Dweekat
 Supervised By :
Dr. Aiman Al-Sharea
Dr.Nathir Rawashdeh

4. 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.

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

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

7. BLOCK DIAGRAM

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

9. 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.

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

11. SPEECH RECOGNITION CIRCUIT

12. 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).

13. SPEECH RECOGNITION CIRCUIT
HM2007 pin diagram

14. 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.

15. SPEECH RECOGNITION CIRCUIT
HM2007 pin diagram

16. SPEECH RECOGNITION CIRCUIT
SRC CONSTRUCTION

17. SPEECH RECOGNITION CIRCUIT
SRC CONSTRUCTION

18. SPEECH RECOGNITION CIRCUIT
TRAINING THE KIT:

19. 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.

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

21. DRIVE UNIT
Drive Unit consists of two main parts are :
I. Two geared DC series motors.
II. Transmission unit.
Belt

22. DRIVE UNIT
Why a DC Series Motor Was Chosen?
Very high speed at no load
High torque at low speed

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

24. 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 :
Direction Right motor Left motor
Forward ON ( CW ) ON ( CW )
Backward ON ( CCW ) ON ( CCW )
Right OFF ON ( CW )
Left ON ( CW ) OFF

25. DRIVE UNIT
Gearbox
 We use the gearbox to reduce the speed of the
motor and increase its torque.

26. 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 .

27. DRIVE UNIT
Transmission 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.

28. DRIVE UNIT
There are many types of belts :
Flat belt Circular belt V-belt

29. 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.

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

31. INTERFACING CIRCUIT

32. INTERFACING CIRCUIT
SRC
Joystick
+
- +
-

33. INTERFACING CIRCUIT
SRC
Joystick
+
-
+
-

34. INTERFACING CIRCUIT
Direction
Left Motor Right Motor
Transistor 1 Transistor 2 Transistor 3 Transistor 4
None 0 0 0 0
Forward 1 0 1 0
Reverse 0 1 0 1
Right 1 0 0 0
Left 0 0 1 0

35. INTERFACING CIRCUIT
Voice
NO NO NO
YES
NO NO

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

37. 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.