VOICE COMMAND WHEEL CHAIR

BRIEF INTRODUCTION TO VOICE COMMAND WHEEL CHAIR

Voice recognition wheel chair is characterized by the ability of the system to perform various desirable tasks as recommened by the user. Nowadays, the appliances that are available in the market are gaining popularity due to the advancement in technology and ease in use. Thus, the controlling of such devices is getting more and more familiar. From long time ago mostly the controlling is done manually by the use of joysticks but as time passed the invention and innovation has made possible that we can operate the instruction as recommended by the user him/herself by the voice command. This has been a boon to the physically handicapped people.

HOW IS VOICE RECOGNIZED ?

This concept is more alike a comparison of between the source and the data stored in memory (the voice stored during the training process). The way of this concept function is when a user speaks out some command, the voice is captured through microphone as the input devices. Once the voice is captured, that will convert the analog (voice) to digital (binary signal). Later, the input voice is compared with the data stored in the memory early before the testing. The output of the comparison is the voice matched with any of the command trained and certain signal is produce as the input to the controlling system.

GENERAL METHODOLOGY AND OVERALL DIAGRAM.

The main attraction of this project is the operation of wheel chair by voice command of the user. Microcontroller along with voice recognition chip (HM 20007) is used as intelligent device for the wheel chair. Two mechanisms are used for driving the wheel chair in case of failure of one. The second mechanism to drive the wheel chair is electrically by using a joystick. Due to two operating mechanisms, in case command is received by the microcontroller from both the source then ambiguity error occurs. Thus to avoid the state of ambiguity error a relay or a simple switch is used to keep the one of the mechanism in off state.

Microphone is used as the input device for the voice which is fed to HM 2007 which is mounted on specially designed HM 2007’s kit that is used as interfacing device between the IC and the microcontroller. Series of speech recognition training is given to the IC so that the commands can be recognized by the IC during the operation hours.

The controlling input is from the voice command given by the user. This voice is then decoded by the HM2007 speech recognition circuit. In microcontroller, it receives the signal from the HM2007 speech recognition circuit. Besides that, the existence of the other component such as LCD is used to display the various instructions and by the help of sensor its distance from the obstacle can be seen on the LCD.