Metal Detector Robotic Vehicle

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Introduction

Here is a war field land rover that alerts on sensing planted land mine ahead controlled remotely using the RF mode primarily.

The RF remote control has the advantage of adequate range (up to 200 meters with proper antennae) besides being Omni-directional.

On the other hand, an IR remote would function over a limited range of about 5 meters, and the remote transmitter has to be oriented towards the receiver module quite precisely.

However, the cost involved in using RF modules is much higher than of IR components and as such, we have included the replacement alternative of RF modules with their IR counterparts for using the IR remote control.

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Transmitter






Receiver






Working Process

The project uses HT12E Encoder which converts 4 bit data to serial output which is then fed to the RF module for transmitting the same to be received by the receiver of RF module.

Then the output of which is fed to HT12D the serial decoder IC, next the output of which is fed to controller pin 1-4.

The transmitting end MC is connected to a set of pushbutton switches. Thus, while a particular button is pressed the program executed delivers corresponding 4-bit data that are then transmitted serially.

The data so received at the receiver end of port 1 operates the motor through motor driver IC L293D as required being interfaced from the Microcontroller output port 2.






The transmitter is powered by a 6v battery in series with a silicon diode to develop finally required voltage for microcontroller circuit.

The receiver is powered by a 12v battery in series with a silicon diode to protect the circuits from the accidental reverse battery connection.

5V DC out of the 12V available from regulator IC 7805 is fed to the controller, decoder, and the motor driver IC L293D pin 8 for the operation of the motor.

A metal detector circuit is used that uses a tuned circuit comprising of a coil.

Working Process (Continue…)






Two capacitor’s C2 and C3 determining a particular resonant frequency of the oscillator by Q4. The sensitivity of which is adjusted by a potentiometer of 5k.

The output of this resonant circuit is fed to Q2 which quarter in emitter follower configuration with appropriate filtering to forward bias Q3 that forces Q4 to be not in condition stage thus the buzzer connected from positive supply to the collector of Q4 does not get any power so doesn’t sound.

While any metal object is encountered by the coil the resonance frequency drifts away that remove’s the drive voltage to Q3, which in turn switches on the Q4 for the buzzer to get power and sound accordingly together with the L, LED growing to indicate the presence of the metallic object.

Working Process (Continue…)






8K Bytes of In-System Programmable (ISP) Flash

Memory.

4.0V to 5.5V Operating Range.

Crystal Frequency 11.0592MHZ.

Three-level Program Memory Lock.

256 x 8-bit Internal RAM.

32 Programmable I/O Lines.

Three 16-bit Timer/Counters.

AT89S52

Micro controller






CPU

On-chip RAM

On-chip ROM for program code

4 I/O Ports

Timer 0

Serial PortOSC

Interrupt Control

External interrupts

Timer 1

Timer/Counter

Bus Control

TxD RxDP0 P1 P2 P3

Address/Data

Counter Inputs

Block diagram of MC






MC components explanation

ROM:

A code of 4K memory is incorporated as on-chip ROM in 8051.

RAM:

The 8051 microcontroller is composed of 128 bytes of internal RAM.

Interrupt Control:

An event which is used to suspend or halt the normal program execution for a temporary period of time in order to serve the request of another program or hardware device is called an interrupt.







Parallel Input/Output Ports:

PORT P0: When there is no external memory present, this port acts as a general purpose input/output port.

PORT P1: This port is used for various interfacing activities.

PORT P2: This port can be used as a general purpose port when there is no external memory but when external memory is present it works in conjunction with PORT PO as an address bus.

PORT P3: PORT P3 behaves as a dedicated I/O port.







Address Bus:

A bus is group of wires using which data transfer takes place from one location to another within a system.

Timers and Counters:

Synchronization among internal operations can be achieved with the help of clock circuits which are responsible for generating clock pulses.

Internal operations can be synchronized using clock circuits which produce clock pulses.






Pin diagram of 8052






8052 pin diagram explanation

Port 0(p0.0 to p0.7):

It is 8-bit bi-directional I/O port. It is bit/ byte addressable. During external memory access, it functions as multiplexed data and low-order address bus AD0-AD7.

Port 1 (p1.0 to p1.7):

It is 8-bit bi-directional I/O port. When logic '1' is written into port latch then it works as input mode. It functions as simply I/O port and it does not have any alternative function.






8052 pin diagram explanation

Port 2 (p2.0 to p2.7):

It is 8-bit bi-directional I/O port. It is bit/ byte addressable.

Port 3(p3.0 to port 3.7):

It is 8-bit I/O port. In an alternating function each pins can be used as a special function I/O pin.

RESET:

It is active high I/P signal. It should be maintained high for at least two machine cycle while oscillator is running then 8051 microcontroller resets.






Motor driver IC

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.






Motor driver ic diagram






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.

If enable 2 and pin number 10 are high leaving pin number 15 as low then the motor rotates in forward direction.






30 pF

30 pF

8.2 K

10 uF+

11.0592 MHz

EA/VPPX1

X2

RST

31

19

18

9

Power on Reset circuit






The circuit uses HT 12E, HT 12D encoder and decoder.

433MHz ASK transmitter and receiver is used for the remote control.

RF remote control






Range in open space(Standard Conditions) : 100 Meters RX Receiver Frequency : 433 MHz RX Typical Sensitivity : 105 Dbm RX Supply Current : 3.5 mA RX IF Frequency : 1MHz Low Power Consumption Easy For Application RX Operating Voltage : 5V TX Frequency Range : 433.92 MHz TX Supply Voltage : 3V ~ 6V TX Out Put Power : 4 ~ 12 Dbm

Features of RF






The HT 12E Encoder ICs are series of CMOS LSIs for Remote Control system applications. They are capable of Encoding 12 bit of information which consists of N address bits and 12-N data bits.

The HT 12D ICs are series of CMOS LSIs for remote control system applications.

This ICs are paired with each other. For proper operation a pair of encoder/decoder with the same number of address and data format should be selected.

The Decoder receive the serial address and data from its corresponding decoder, transmitted by a carrier using an RF transmission medium and gives output to the output pins after processing the data.

RF encoder & decoder






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.

Metal detector






Software requirements

Keil an ARM Company makes C compilers, macro assemblers, real-time kernels, debuggers, simulators, integrated environments, evaluation boards, and emulators for ARM7/ARM9/Cortex-M3, XC16x/C16x/ST10, 251, and 8051 MCU families.

Compilers are programs used to convert a High Level Language to object code. Desktop compilers produce an output object code for the underlying microprocessor, but not for other microprocessors.






Advantages

The detection and removal of landmines can be achieved by using metal detection robot.

This Metal Detector Robotic Vehicle System is used for locating and detecting landmines very effectively and efficiently.

This system can be operated easily.

It is used for finding the landmines in a short period, a necessary worldwide concern at present.

It can move on natural ground surfaces including roads and tracks in a same manner to a human operator.

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Conclusion

The Metal Detector Robotic Vehicle is used to find the landmine when the robot moves on the earth.

The main purpose of this system is to detect and remove the landmines in a short span of time and sense the metals ahead of it.

This project can be improved by mounting a wireless camera on the robot, and the operator can control the movement of the robot easily by visualizing it on a screen.

http://www.edgefxkits.com/metal-detector-robotic-vehicle





Metal Detector Robotic Vehicle

Engineering

Transcript of Metal Detector Robotic Vehicle