09-03-2011, 11:14 AM
Presented By
D.SPARSHA
G.VANDANA
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Remote Controlled Metal Detecting Robot with Remote Image Transmission
ABSTRACT
Path Finder was sent to Mars in 1998. This was achievement a great which detected the secrets of “Mars”. This project deals with RF controlled robot. This robot prototype for the “Path Finder”.
This robot is controlled by a RF remote. This can be moved forward and reverse direction using geared motors of 60RPM. Also this robot can take sharp turnings towards left and right directions. This project uses AT89S52 MCU as its controller. A high sensitive induction type metal detector is designed using colpitts oscillator principle and fixed to this robot. Also a wireless camera with voice is interfaced to the kit.
When the robot is moving on a surface, the system produces a beep sound when metal is detected. This beep sound will be transmitted to remote place. Simultaneously the images around the robot will be transmitted to remote place. User can monitor the images and metal detection alarms on Television.
The RF modules used here are STT-433 MHz Transmitter, STR-433 MHz Receiver, HT640 RF Encoder an HT648 RF Decoder. he three switches are interfaced to the RF transmitter through RF Encoder. The encoder continuously reads the status of the switches, passes the data to the RF transmitter and the transmitter transmits the data.
This project uses 9V battery. This project is much useful for mines detection and surveillance applications
PROJECT OVERVIEW
The aim of this project is to control the operation of movement of a remote controlled robot to detect metals and to view the images surrounding the robot.
The main objectives of this project are to use radio frequency bands.
The movement of robot is controlled by the transmission of signals through air.
The receiver senses these signals from the air..
This mini project makes use of the transmitter and receiver at 433MHz that is available at low cost hence making it very complicated.
The Radio Frequency based control proves to be more advantageous compared to the Infrared Red based control that limits the operating range to only a few meters of distance.
When the robot is moving on a surface, the system produces a beep sound when metal is detected. This beep sound will be transmitted to remote place. Simultaneously the images around the robot will be transmitted to remote place. User can monitor the images and metal detection alarms on Television.
CHAPTER 2
WIRELESS COMMUNICATION
Wireless communication, as the term implies, allows information to be exchanged between two devices without the use of wire or cable. A wireless keyboard sends information to the computer without the use of a keyboard cable; a cellular telephone sends information to another telephone without the use of a telephone cable. Changing television channels, opening and closing a garage door, and transferring a file from one computer to another can all be accomplished using wireless technology. In all such cases, information is being transmitted and received using electromagnetic energy, also referred to as electromagnetic radiation. One of the most familiar sources of electromagnetic radiation is the sun; other common sources include TV and radio signals, light bulbs and microwaves.
2.1. Radio Frequency-its necessity
Radio frequency is a frequency or rate of oscillation within the range of about 3Hz to 300 GHz. This range corresponds to frequency of alternating current electrical signals used to produce and detect radio waves.Since most of this range is beyond the vibration rate the most mechanical systems can respond to, RF usually refers to oscillations in electrical circuits. RF is widely used because it does not require any line of sight, less distortions and no interference. Examples include, Cordless and cellular telephone, radio and television broadcast stations, satellite communications systems, and two-way radio services all operate in the RF spectrum.
2.1.1. Brief Description of RF
Radio frequency (abbreviated RF) is a term that refers to alternating current (AC) having characteristics such that, if the current is input to an antenna, an electromagnetic (EM) field is generated suitable for wireless broadcasting and/or communications. These frequencies cover a significant portion of the electromagnetic radiation spectrum, extending from nine kilohertz (9 kHz),the lowest allocated wireless communications frequency (it's within the range of human hearing), to thousands of gigahertz(GHz).
When an RF current is supplied to an antenna, it gives rise to an electromagnetic field that propagates through space. This field is sometimes called an RF field; in less technical jargon it is a "radio wave." Any RF field has a wavelength that is inversely proportional to the frequency.
As the frequency is increased beyond that of the RF spectrum, EM energy takes the form of infrared (IR), visible, ultraviolet (UV), X rays, and gamma rays. ), X rays, and gamma rays. Many types of wireless devices make use of RF fields.Some wireless devices operate at IR or visible-light frequencies, whose electromagnetic wavelengths are shorter than those of RF fields.
2.1.2. Properties of Radio Frequency
Electrical currents that oscillate at RF have special properties not shared by direct current signals:
1. One such property is the ease with which it can ionize air to create a conductive path through air. This property is exploited by 'high frequency' units.
2. Another special property is an electromagnetic force that drives the RF current to the surface of conductors, known as the skin effect.
