15-06-2013, 04:51 PM
Cell Phone Operated Robot
Cell Phone.pdf (Size: 1.12 MB / Downloads: 41)
INTRODUCTION :
Radio control (often abbreviated to R/C or
simply RC) is the use of radio signals to remotely control a
device. The term is used frequently to refer to the control of
model vehicles from a hand-held radio transmitter. Industrial,
military, and scientific research organizations make [traffic]
use of radio-controlled vehicles as well.
A remote control vehicle is defined as any
mobile device that is controlled by a means that does not
restrict its motion with an origin external to the device. This is
often a radio control device, cable between control and
vehicle, or an infrared controller. A remote control vehicle
(Also called as RCV) differs from a robot in that the RCV is
always controlled by a human and takes no positive action
autonomously.
One of the key technologies which underpin this
field is that of remote vehicle control. It is vital that a vehicle
should be capable of proceeding accurately to a target area;
maneuvering within that area to fulfill its mission and
returning equally accurately and safely to base.
HISTORY OF REMOTE CONTROLLED VEHICLES:
The First Remote Control Vehicle /
Precision Guided Weapon :
This propeller-driven radio controlled boat,
built by Nikola Tesla in 1898, is the original prototype of all
modern-day uninhabited aerial vehicles and precision guided
weapons. In fact , all remotely operated vehicles in air, land or
sea. Powered by lead-acid batteries and an electric drive
motor, the vessel was designed to be maneuvered alongside a
target using instructions received from a wireless remotecontrol
transmitter. Once in position, a command would be
sent to detonate an explosive charge contained within the
boat's forward compartment. The weapon's guidance system
incorporated a secure communications link between the
pilot's controller and the surface-running torpedo in an effort
to assure that control could be maintained even in the
presence of electronic countermeasures. To learn more about
Tesla's system for secure wireless communications and his
pioneering implementation of the electronic logic-gate circuit
read ‘Nikola Tesla — Guided Weapons & Computer
Technology’, Tesla Presents Series Part 3, with commentary by
Leland Anderson.
TECHNOLOGY USED :
Dual-Tone Multi-Frequency (DTMF)
Dual-tone multi-frequency (DTMF) signaling is
used for telecommunication signaling over analog telephone
lines in the voice-frequency band between telephone handsets
and other communications devices and the switching center.
The version of DTMF used for telephone tone dialing is known
by the trademarked term Touch-Tone (canceled March 13,
1984), and is standardized by ITU-T Recommendation Q.23. It
is also known in the UK as MF4. Other multi-frequency
systems are used for signaling internal to the telephone
network.
As a method of in-band signaling, DTMF tones
were also used by cable television broadcasters to indicate the
start and stop times of local commercial insertion points
during station breaks for the benefit of cable companies. Until
better out-of-band signaling equipment was developed in the
1990s, fast, unacknowledged, and loud DTMF tone sequences
could be heard during the commercial breaks of cable
channels in the United States and elsewhere.
Telephone Keypad
The contemporary keypad is laid out in a 3×4
grid, although the original DTMF keypad had an additional
column for four now-defunct menu selector keys. When used
to dial a telephone number, pressing a single key will produce
a pitch consisting of two simultaneous pure tone sinusoidal
frequencies. The row in which the key appears determines the
low frequency, and the column determines the high frequency.
For example, pressing the '1' key will result in a sound
composed of both a 697 and a 1209 hertz (Hz) tone. The
original keypads had levers inside, so each button activated
two contacts. The multiple tones are the reason for calling the
system multifrequency. These tones are then decoded by the
switching center to determine which key was pressed.