(often abbreviated to
or simply RC
) is the use of
radio signals to remotely control
device. The term is used frequently to refer to the control of
hand-held radio transmitter
, and scientific research
[traffic] use of radio-controlled vehicles as well.
In 1898 at
an exhibition at Madison Square Garden Nikola Tesla
demonstrated a small boat which could apparently obey commands from
the audience but was in fact controlled by Tesla interpreting the
verbal requests and sending appropriate frequencies to tuned
circuits in the boat.
He was granted a US patent
on this invention on November 8
In 1903, the Spanish engineer Leonardo Torres y Quevedo
presented the "Telekino
" at the Paris Academy of Science,
and was granted a patent in France, Spain, Great Britain and the
United States. In 1904, Bat, a Windermere steam launch, was controlled using experimental
radio control by its inventor, Jack
In 1909 the French inventor Gabet
demonstrated what he called his "Torpille
", a radio controlled torpedo
In 1917, Archibald Low
as head of the RFC
Experimental Works, was the first
person to use radio control successfully on an aircraft.In the
1920s, various radio-controlled ships were used for naval artillery
target practice.The Soviet Red Army
used remotely controlled teletanks during
1930s in the Winter War against Finland and fielded
at least two teletank battalions at the beginning of the Great Patriotic War.
is controlled by radio from a control tank at a distance of
500–1,500 meters, the two constituting a telemechanical
. There were also remotely controlled cutters Iand
experimental remotely controlled planes in the Red Army.
1930s Britain developed the radio controlled Queen Bee, a remotely
controlled unmanned Tiger Moth aircraft for a fleet's gunnery firing practice.
was superseded by the similarly named
, a later,
purpose built, target aircraft of higher performance.
Military applications in the Second World War
control was further developed during World War II, primarily by the
Germans who used it in a number of missile projects.
Their main effort was the
development of radio-controlled missiles and glide bombs
for use against shipping, a target
that is otherwise both difficult and dangerous to attack. However
by the end of the war the Luftwaffe
having similar problems attacking Allied bombers
, and developed a number of radio-controlled
anti-aircraft missiles, none of which saw service.
effectiveness of the Luftwaffe systems was greatly reduced by
British efforts to
jam their radio signals.
After initial successes, the
British launched a number of commando
to collect the missile radio sets. Jammers were then installed on
British ships, and the weapons basically "stopped working".
development teams then turned to wire guidance once they realized what
was going on, but these systems were not ready for deployment until
the war had already moved to France.
The German Kriegsmarine
FL-Boote (ferngelenkte Sprengboote) which were radio controlled
filled with explosives to
attack enemy shipping from 1944.
Both the British and US also developed radio control systems for
similar tasks, in order to avoid the huge anti-aircraft batteries
set up around German targets. However, none of these systems proved
usable in practice, and the one major US effort, Project
, proved to be far more dangerous to its users than
to the target.
Radio control systems of this era were generally electromechanical
in nature, using small metal "fingers" or "reeds" with different
frequencies each of which would
operate one of a number of different relays
when a particular frequency was received. The relays would in turn
then activate various actuators
the control surfaces of the missile. The controller's radio
transmitter would transmit the different frequencies in response to
the movements of a control stick; these were typically on/off
These systems were widely used until the 1960s, when the increasing
use of solid state
greatly simplified radio control. The electromechanical systems
using reed relays were replaced by similar electronic ones, and the
continued miniaturization of electronics allowed more signals,
referred to as control channels
, to be packed into the
same package. While early control systems might have two or three
channels using amplitude
, modern systems include 20 or more using frequency modulation
The first general use of radio control systems in models started in
the early 1950s with single-channel self-built equipment;
commercial equipment came later. The advent of transistors
greatly reduced the battery
requirements, since the current requirements at low voltage were
greatly reduced and the high voltage battery was eliminated. In
both tube and early transistor sets the model's control surfaces
were usually operated by an electromagnetic escapement
controlling the stored energy in a rubber-band loop, allowing
simple on/off rudder control (right, left, and neutral) and
sometimes other functions such as motor speed.
Crystal-controlled superheterodyne receivers
better selectivity and stability made control equipment more
capable and at lower cost. Multi-channel developments were of
particular use to aircraft, which really needed a minimum of three
control dimensions, (yaw, pitch and motor speed) as opposed to
boats, which can get away with two or one.
As the electronics revolution took off, single-signal channel
circuit design became redundant, and instead radios provided
proportionally coded signal streams which a servomechanism
More recently, high-end hobby
features have come on the market that provide a computerized digital
-stream signal to the receiving device,
instead of analog type pulse modulation. However, even with this
coding, loss of transmission during flight has become more common
in part because of the ever more wireless society.
In the early 21st century, 2.4 gigahertz transmissions have become
increasingly utilized in high-end control of model vehicles and
aircraft. Now, these 2.4 gigahertz systems are being made by most
radio manufacturers. The radios range from a couple thousand
dollars, all the way down to under $30 for some import systems.
Some manufacturers even offer conversion kits for older digital
72Mhz band radios.
Modern military and aerospace applications
Remote control military applications are typically not radio
control in the direct sense, directly operating flight control
surfaces and propulsion power settings, but instead take the form
of instructions sent to a completely autonomous
, computerized automatic pilot
. Instead of a "turn left" signal
that is applied until the aircraft is flying in the right
direction, the system sends a single instruction that says "fly to
Some of the most outstanding examples of remote radio control of a
vehicle are the Mars Exploration
such as Sojourner
Today radio control is used in industry for such devices as
. Radio-controlled teleoperators
are used for such purposes as
inspections, and special vehicles for disarming of bombs
. Some remotely-controlled devices are loosely
, but are more properly
categorized as teleoperators since they do not operate
autonomously, but only under control of a human operator.
Notes and References
- Fort Smith Flightmasters: Radio Control Systems (Part
2) with illustrations of an early installation and descriptions
of various escapements.