NATIONAL INSTITUTE OF TECHNOLOGY MANIPUR

(An Autonomous Institution, Under MHRD, INDIA)

Submitted by:

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Under the guidance of:

METAL DETECTION ROBOT WITH COLLISION AVOIDANCE

OVERVIEW

Objective

Proposed system

Module description

Hardware and software requirements

Expected output

Advantages and Disadvantages

References

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OBJECTIVE

The main objective of our project is to build a robotic vehicle that

can sense metals ahead of it.

To search interesting stuff from where people are not able to reach.

To provide safety to the bomb disposal squad .

An obstacle sensor is used protect the robot from collision.

Ability to work in any hostile environment.

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PROPOSED SYSTEM

This project is divided into modules for better understanding of the

circuit . The modules include

Arduino UNO Microcontroller Board

Motor Control Driver

Metal Detector

Ultrasonic Sensors

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BLOCK DIAGRAM5

Arduino UNO Microcontroller Board 6

Microcontroller

It is a smaller computer.

Has on-chip RAM, ROM, I/O ports...

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Arduino UNO Microcontroller

Microcontroller ATmega328

Operating Voltage 5V

Pin Count 28

Input Voltage (recommended) 7-12V

Digital I/O Pins 14 (of which 6 provide PWM output)

Analog Input Pins 6

Current per I/O Pin 40 mA

Current for 3.3V Pin 50 mA

Flash Memory 32 KB (of which 0.5 KB used by boot loader)

SRAM 2 KB

EEPROM 1 KB

Clock Speed 16 MHz

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Motor Control Driver

Motor Shield is a dual full-bridge driver designed to drive DC

motors.

It control the speed and direction of each DC motors

independently using the microcontroller .

It uses L293D IC to control the motor.

The Motor Shield is powered only by an external power supply of

5V to 12V.

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MOTOR DRIVER L293D

L293D is a dual H-bridge motor driver integrated circuit

(IC).

Motor drivers act as current amplifiers since they take a low-

current control signal and provide a higher-current signal.

This higher current signal is used to drive the motors.

L293D contains two inbuilt H-bridge driver circuits. In its

common mode of operation, two DC motors can be driven

simultaneously, both in forward and reverse direction.

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Operation of Motor Driver

L293D has 2 set of arrangements where one set has input

1, input 2, output 1 and output 2 and other set has

input 3, input 4, output 3 and output 4, according to

block diagram if pin no 2 & 7 are high then pin no 3 & 6

are also high.

If enable 1 and pin number 2 are high leaving pin

number 7 as low then the motor rotates in forward

direction, vice-versa for reverse direction.

If enable 2 and pin number 10 are high leaving pin

number 15 as low then the motor rotates in forward

direction, vice-versa for reverse direction.

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Metal detector

The operation of metal detectors is based upon the principles

of electromagnetic induction.

The single-coil detector is the one used in a real metal

detector.

A pulsing current is applied to the coil, which then induces a

magnetic field.

When the magnetic field of the coil moves across metal, such

as the coin, the field induces eddy currents in the coin.

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.

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Ultrasonic Sensor

Ultrasonic sensors generate high frequency sound

waves and evaluate the echo which is received

back by the sensor.

It measures the time interval between sending the

signal and receiving the echo to determine the

distance to an object.

It detects the distance of the closest object in front of

the sensor (from 2 cm up to 3m).

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Ultrasonic Sensor

The 5V pin of the Ultrasonic sensor is connected

to the 5V pin on the Arduino.

The GND pin is connected to the GND pin.

The SIG (signal) pin is connected to digital pin 7

on the Arduino.

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Expected Outcome

The Robot will be able to moves in all four directions:

Right, Left, Front, Back .

The Ultrasonic Sensor will detects the obstacle and avoids collision.

The Robot will be able to sense metal ahead of it.

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ADVANTAGES

Provide safety to the bomb disposal squad by providing an extra line of defense.

Consistency of performance.

24/7 continuous working.

Reduced amount of operator errors.

Can be made to perform even the most dangerous tasks without concern.

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DISADVANTAGES

Precise programming needed (time, training)

New products require complete reprogramming.

Complex and expensive equipment to buy and install.

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Application

Detecting hidden landmines.

It can be use for treasure hunt.

Can be used by the bomb disposal Squad.

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Reference

http://arduino.cc/en/Main/arduinoBoardUno

http://arduino.cc/en/Main/ArduinoMotorShieldR3

http://en.wikipedia.org/wiki/Metal_detector

http://www.atmel.com/devices/atmega328.aspx

www.ti.com/lit/ds/symlink/l293d.

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