AUTOMATED METAL DETECTOR ROBOTIC VEHICLE WITH MANUAL CONTROL USING BLUETOOTH

SUBMITTED TO : SUBMITTED BY:MR.DEVENDRA GOYAL ABHINAV MAGGU(ASSTN. PROFFESOR RENUKA VERMAOF EELECTRICAL DEPARTMENT) VAIBHAV GUPTA EE 6TH SEMESTER

TABLE OF CONTENTS:• INTRODUCTION• ABOUT MICROCONTROLLER (ATMEGA8)• ABOUT MOTOR DRIVER I.C.• ABOUT PIR SENSORS• ABOUT METAL DETECTOR• WORKING OF METAL DETECTOR• BLUETOOTH MODULE(HC-05)• FURTURE ADAPTAITON• CONCLUSION• REFRENCES

What does our robot do ! The project is designed to develop a robotic vehicle that can

sense metals ahead of it on its path similar to sensing land mines. The robot is controlled by an android mobile with an App using Bluetooth technology. It has been provided with I.R sensor controlling the two dc motor of vehicle to avoid any obstacle in its path. It consists of a metal detector circuit consisting of an inductor coil sensing current changes which is interfaced to the control unit that alarms the user behind it about a suspected land mine ahead. The robot will move automatically while avoiding any rocks and other obstacle and search for metal in unknown locations as it detects any sign of metal it will immediately stop and a buzzer will start ringing.

INTRODUCTION……

• An obstacle avoiding refers to the ability of a robot to detect the obstacel in its way if there are any and thus make its own obstacel free path

• Metal detectors are devices that use electromagnetic fields to detect and signal the presence of metallic or ferromagnetic objects.

• In this robot we have used bluetooth connectivity (HC-05 module) to operate the metal detecting robot through an ANDROID APP.

• In this robot we use a microcontroller, motor driver I.C. ,PIR sensors ,metal detector circuit, bluetooth module(HC-05).

COMPONENTS OF ROBOT• AUTOMATION THROUGH PIR SENSOR AND

MOTOR DRIVER IC’S CONNECTED TO THE BOARD

• A BLUETOOTH DEVICE CONNECTED IN PARALLEL TO THE BOARD

• A METAL DETECTOR CIRCUIT

Microcontroller (ATmega8)…..• It is a micro computer chip which stores our programs executes them and takes

necessary action. The chip used here is Atmel popular AVR micro controller.

• It is a 8-bit single chip microcontroller.

Motor driver I.C.L293D……

• Whenever a robotics hobbyist talk about making a robot, the first thing comes to his mind is making the robot move on the ground. And there are always two options in front of the designer whether to use a DC Motor or a stepper motor.

• DC motors are always preferred over stepper motors.• In this part we will learn to interface a DC motor with a microcontroller. Usually

H-bridge is preferred way of interfacing a DC motor.• L293D is most used H-Bridge driver IC. H-bridge can also be made with the help

of transistors and MOSFETs etc.• Rather of being cheap, they only increase the size of the design board, which is

sometimes not required so using a small 16 pin IC is preferred for this purpose• L293 series of chips are power H-bridge motor drivers. The L293D chip is in 16-

pins dip packages, and has two h-bridge drivers. An H bridge is typically capable of running one DC motor bidirectional (forward, backwards, off), or two separate motors unidirectional (forward, off).

DC-Motors

PIN DIAGRAM OF L293D

PIR SENSORS• A passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared

(IR) light radiating from objects in its field of view. They are most often used in PIR-based motion detectors.

• The term passive in this instance refers to the fact that PIR devices do not generate or radiate any energy for detection purposes.

• This PIR sensors works as a obstacel avoider .• This sensors sense the raditions or obeject infront of this it sense and change the

path of robot.

Metal detector…….• The operation of metal detectors is based upon the principles of

electromagnetic induction. • When the magnetic field of the coil moves across metal, such as the

coin, the field induces eddy currents in the coin. • The single-coil detector is the one used in a real metal detector.• The eddy currents induce their own magnetic field, which generates an

opposite current in the coil, which induces a signal indicating the presence of metal.

• We can also use an inductive proximity sensor, which can detect only metal.

WORKING….. A metal detector is an electronic device.

An oscillator which produces AC current that passes through a coil producing an alternating magnetic field.

A part of the metal is near to the coil, eddy current will be induced in the metal

This produces a magnetic field of its own.

If another coil is used to measure the magnetic field.

The change in the magnetic field due to the metallic object can be detected.

The metal detectors are used to detect the weapons like guns, knives in the airports.

It is used in the construction industry to detect steel reinforcing bars in wires, concrete, pipes buried in floors and walls.

The main components a simple metal detector circuit are LC circuit, proximity sensor and the buzzer. The LC circuit is nothing but inductor and capacitor, which are connected in parallel.

The LC circuit activates the proximity sensor when it senses any metal close to it.

This sensor glow the LED and makes a buzzer.

When the LC circuit has any resonating frequency from any metal which is close to it

The electric field will be created, that will lead to induce current in the coil.

The change the signal in the flow of the signal through the coil.

A Variable resistor is used to change the value of the sensor, which is equal to the LC circuit.

When the metal is detected, the circuit will have changed signal.

This changed signal will be given to the proximity detector.

It will detect the change in the signal and react accordingly.

When the metal is detected by the coil, the o/p of the sensor will be of 1mA

SIMPLE CIRCUIT DIAGRAM Of METAL DETECTOR:

Metal detector with buzzer

BLUETOOTH MODULE• HC-05 module is an easy to use Bluetooth SPP (Serial Port Protocol)

module, designed for transparent wireless serial connection setup• Hardware Features: Typical -80dBm sensitivity , Up to +4dBm RF

transmit power , Low Power 1.8V Operation ,1.8 to 3.6V I/O , With edge connector

• Software Features: Default Baud rate: 38400, Data bits:8, Stop bit:1,Parity:No parity, Auto-connect to the last device on power as default.

• Permit pairing device to connect as default.• Auto-pairing PINCODE:”0000” as default• Auto-reconnect in 30 min when disconnected as a result of beyond

the range of connection

Serial Port Bluetooth Module (Master/Slave) : HC-05

Bluetooth with PIR sensor attached to ATmega8

Future Aspects• The automation done using PIR sensor and

manual control through Bluetooth can also be used in a household cleaning & mopping robot

• The use of GPS will give you the exact location if used , similarly the use of ultrasonic sensor instead of PIR will give more accurate result

• The range of metal detection could also be increased by increasing the no. of turns of coil

Conclusion

Thus we are able to detect metal with the following robot while avoiding obstacle and manual controlling through the phone.