Radio control (often abbreviated to RC) is the use of

control signal In telecommunication, signaling is the use of signals for controlling communications. This may constitute an information exchange concerning the establishment and control of a telecommunication circuit and the management of the network. Classif ...

s transmitted by

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

to remotely control a device. Examples of simple radio control systems are

garage door opener A garage door opener is a motorized device that opens and closes a garage door controlled by switches on the garage wall. Most also include a handheld radio remote control carried by the owner, which can be used to open and close the door from a ...

s and

keyless entry system A remote keyless system (RKS), also known as keyless entry or remote central locking, is an electronic lock that controls access to a building or vehicle by using an electronic remote control (activated by a handheld device or automatically by ...

s for vehicles, in which a small handheld radio transmitter unlocks or opens doors. Radio control is also used for control of model vehicles from a hand-held

radio transmitter In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the ...

Industrial Industrial may refer to: Industry * Industrial archaeology, the study of the history of the industry * Industrial engineering, engineering dealing with the optimization of complex industrial processes or systems * Industrial city, a city dominate ...

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...

, and

scientific research The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific m ...

organizations make use of radio-controlled vehicles as well. A rapidly growing application is control of

unmanned aerial vehicle An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controller ...

s (UAVs or drones) for both civilian and military uses, although these have more sophisticated control systems than traditional applications.

History

The idea of controlling unmanned vehicles (for the most part in an attempt to improve the accuracy of torpedoes for military purposes) predates the invention of radio. The latter half of the 1800s saw development of many such devices, connected to an operator by wires, including the first practical application invented by German engineer

Werner von Siemens Ernst Werner Siemens (von Siemens from 1888; ; ; 13 December 1816 – 6 December 1892) was a German electrical engineer, inventor and industrialist. Siemens's name has been adopted as the SI unit of electrical conductance, the siemens. He foun ...

in 1870. Getting rid of the wires via using a new wireless technology, radio, appeared in the late 1890s. In 1897 British engineer Ernest Wilson and C. J. Evans patented a radio controlled torpedo or demonstrated remote radio control boats on the

Thames river The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...

(accounts of what they did vary). At an 1898 exhibition at

Madison Square Garden Madison Square Garden, colloquially known as The Garden or by its initials MSG, is a multi-purpose indoor arena in New York City. It is located in Midtown Manhattan between Seventh and Eighth avenues from 31st to 33rd Street, above Pennsylva ...

Nikola Tesla Nikola Tesla ( ; ,"Tesla"
''

Leonardo Torres y Quevedo Leonardo Torres y Quevedo (; 28 December 1852 – 18 December 1936) was a Spanish civil engineer and mathematician of the late nineteenth and early twentieth centuries. Torres was a pioneer in the development of the radio control and automated ...

introduced a radio based control system called the "''Telekino''" at the

Paris Academy of Science The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at th ...

. In the same year, he obtained a patent in France, Spain, Great Britain, and the United States. It was intended as a way of testing a dirigible of his own design without risking human lives. To avoid the expense of conceivably crashing his airship prototype he built his demonstration device into a boat. Unlike the previous systems, which carried out actions of the 'on/off' type, Torres device was able to memorize the signals received to execute the operations on its own and could carry out to 19 different orders. In 1906, in the presence of an audience which included the King of Spain, Torres demonstrated the invention in the

Port of Bilbao The Port of Bilbao is located on the Bilbao Abra bay, and along the Estuary of Bilbao, in Biscay ( Basque Country). The main facilities are in the Santurtzi and Zierbena municipalities, approximately 15 km (9.3 mi) west of Bilbao. Also ...

, guiding a boat from the shore with people on board. Later, he would try to apply the Telekino to projectiles and torpedoes but had to abandon the project for lack of financing. In 1904, ''Bat'', a

Windermere Windermere (sometimes tautologically called Windermere Lake to distinguish it from the nearby town of Windermere) is the largest natural lake in England. More than 11 miles (18 km) in length, and almost 1 mile (1.5 km) at its wides ...

steam launch, was controlled using experimental radio control by its inventor, ack Kitchen In 1909 the French inventor Gabet demonstrated what he called his "''Torpille Radio-Automatique''", a radio-controlled torpedo. In 1917, Archibald Low as head of the secret

RFC RFC may refer to: Computing * Request for Comments, a memorandum on Internet standards * Request for change, change management * Remote Function Call, in SAP computer systems * Rhye's and Fall of Civilization, a modification for Sid Meier's Civ ...

experimental works at

Feltham Feltham () is a town in West London, England, from Charing Cross. Historically part of Middlesex, it became part of the London Borough of Hounslow in 1965. The parliamentary constituency of Feltham and Heston has been held by Labour Party ...

, was the first person to use radio control successfully on an aircraft, an "Aerial Target". It was "piloted" from the ground by future world aerial speed record holder

Henry Segrave Sir Henry O'Neal de Hane Segrave (22 September 1896 – 13 June 1930) was an early British pioneer in land speed and water speed records. Segrave, who set three land and one water record, was the first person to hold both titles simultaneous ...

. Low's systems encoded the command transmissions as a countermeasure to prevent enemy intervention. By 1918 the secret D.C.B. Section of the Royal Navy's Signals School, Portsmouth under the command of Eric Robinson V.C. used a variant of the Aerial Target’s radio control system to control from ‘mother’ aircraft different types of naval vessels including a submarine.UK National Archives ADM 1/8539/253 Capabilities of distantly controlled boats. Reports of trials at Dover 28 - 31 May 1918 USS Iowa Radio Gear

During World War I American inventor John Hays Hammond, Jr. developed many techniques used in subsequent radio control including developing remote controlled torpedoes, ships, anti-jamming systems and even a system allowing his remote-controlled ship targeting an enemy ship's searchlights. In 1922 he installed radio control gear on the obsolete US Navy battleship USS ''Iowa'' so it could be used as a

target ship A target ship is a vessel — typically an obsolete or captured warship — used as a seaborne target for naval gunnery practice or for weapons testing. Targets may be used with the intention of testing effectiveness of specific types of ammunit ...

(sunk in gunnery exercise in March 1923). The Soviet

Red Army The Workers' and Peasants' Red Army (Russian: Рабо́че-крестья́нская Кра́сная армия),) often shortened to the Red Army, was the army and air force of the Russian Soviet Federative Socialist Republic and, after ...

used remotely controlled

teletank Teletanks were a series of wireless remotely controlled unmanned tanks produced in the Soviet Union in the 1930s and early 1940s so as to reduce combat risk to soldiers. They saw their first combat use in the Winter War, at the start of World Wa ...

s during the 1930s in the

Winter War The Winter War,, sv, Vinterkriget, rus, Зи́мняя война́, r=Zimnyaya voyna. The names Soviet–Finnish War 1939–1940 (russian: link=no, Сове́тско-финская война́ 1939–1940) and Soviet–Finland War 1 ...

against

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

and fielded at least two teletank battalions at the beginning of the

Great Patriotic War The Eastern Front of World War II was a theatre of conflict between the European Axis powers against the Soviet Union (USSR), Poland and other Allies, which encompassed Central Europe, Eastern Europe, Northeast Europe (Baltics), and Sou ...

. A teletank is controlled by radio from a control tank at a distance of 500–1,500 m, the two constituting a ''telemechanical group''. There were also remotely controlled cutters and experimental remotely controlled planes in the Red Army. The

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

World War One World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

development of their radio-controlled 1917 'Aerial Target' (AT) and 1918 'Distant Control Boat' (DCB) using Low's control systems led eventually to their 1930s fleet of "Queen Bee". This was a remotely controlled unmanned version of the de Havilland "

Tiger Moth The de Havilland DH.82 Tiger Moth is a 1930s British biplane designed by Geoffrey de Havilland and built by the de Havilland Aircraft Company. It was operated by the Royal Air Force (RAF) and other operators as a primary trainer aircraft. ...

" aircraft for

Navy fleet A fleet or naval fleet is a large formation of warships – the largest formation in any navy – controlled by one leader. A fleet at sea is the direct equivalent of an army on land. Purpose In the modern sense, fleets are usually, but not ...

gunnery firing practice. The "Queen Bee" was superseded by the similarly named '' Queen Wasp'', a purpose-built, target aircraft of higher performance.

Second World War

Radio control was further developed during World War II, primarily by the

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who used it in a number of

missile In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocke ...

projects. Their main effort was the development of radio-controlled missiles and

glide bomb A glide bomb or stand-off bomb is a standoff weapon with flight control surfaces to give it a flatter, gliding flight path than that of a conventional bomb without such surfaces. This allows it to be released at a distance from the target r ...

s for use against shipping, a target otherwise both difficult and dangerous to attack. However, by the end of the war, the ''

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

'' was having similar problems attacking Allied

bomber A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching aerial torpedo, torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped ...

s and developed a number of radio

command guided Command guidance is a type of missile guidance in which a ground station or aircraft relay signals to a guided missile via radio control or through a wire connecting the missile to the launcher and tell the missile where to steer to intercept its ...

anti-aircraft missile Anti-aircraft missiles are guided missiles designed to destroy or damage aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dy ...

s, none of which saw service. The effectiveness of the

's systems, primarily comprising the series of

Telefunken Telefunken was a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the ''Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ('General electricity company'). The name "Telefunken" ap ...

''Funk-Gerät'' (or FuG) 203 ''Kehl'' twin-axis, single joystick-equipped transmitters mounted in the deploying aircraft, and Telefunken's companion FuG 230 ''Straßburg'' receiver placed in the ordnance to be controlled during deployment and used by both the

Fritz X Fritz X was the most common name for a German guided anti-ship glide bomb used during World War II. ''Fritz X'' was the world's first precision guided weapon deployed in combat and the first to sink a ship in combat. ''Fritz X'' was a nickname us ...

unpowered, armored anti-ship bomb, and the powered Henschel Hs 293 guided bomb, was greatly reduced by

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

efforts to jam their radio signals, eventually with American assistance. After initial successes, the British launched a number of

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raids to collect the missile radio sets. Jammers were then installed on British ships, and the weapons basically "stopped working". The German development teams then turned to

wire guidance A wire-guided missile is a missile that is guided by signals sent to it via thin wires connected between the missile and its guidance mechanism, which is located somewhere near the launch site. As the missile flies, the wires are reeled out behi ...

once they realized what was going on, but the systems were not ready for deployment until the war had already moved to

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

. The German ''

Kriegsmarine The (, ) was the navy of Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war (1919–1935) of the Weimar Republic. The was one of three official branches, along with the a ...

'' operated ''FL-Boote'' (''ferngelenkte Sprengboote'') which were radio controlled

motor boats A motorboat, speedboat or powerboat is a boat that is exclusively powered by an engine. Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the internal combustion engine, the gea ...

filled with explosives to attack enemy shipping from 1944. Both the British and US also developed radio control systems for similar tasks, to avoid the huge anti-aircraft batteries set up around German targets. However, no system proved usable in practice, and the one major US effort, ''

Operation Aphrodite Aphrodite and Anvil were the World War II code names of United States Army Air Forces and United States Navy operations to use Boeing B-17 Flying Fortress and Consolidated PB4Y bombers as precision-guided munitions against bunkers and other har ...

'', proved to be far more dangerous to its users than to the target. The American Azon guided free-fall ordnance, however, proved useful in both the

European European, or Europeans, or Europeneans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine, the cuisines of Europe ...

and

CBI Theater China Burma India Theater (CBI) was the United States military designation during World War II for the China and Southeast Asian or India–Burma (IBT) theaters. Operational command of Allied forces (including U.S. forces) in the CBI was offi ...

s of World War II. Radio control systems of this era were generally electromechanical in nature, using small metal "fingers" or " reeds" with different

resonant Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied periodic force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscilla ...

frequencies each of which would operate one of a number of different

relay A relay Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts An automotive-style miniature relay with the dust cover taken off A relay is an electrically operated switch ...

s when a particular frequency was received. The relays would in turn then activate various actuators acting on 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 signals. The radio gear used to control the rudder function on the American-developed Azon guided ordnance, however, was a fully proportional control, with the "ailerons", solely under the control of an on-board gyroscope, serving merely to keep the ordnance from rolling. These systems were widely used until the 1960s, when the increasing use of solid state systems greatly simplified radio control. The electromechanical systems using

reed relay A reed relay is a type of relay that uses an electromagnet to control one or more reed switches. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them. Sealed in a long, nar ...

s 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 modulation, modern systems include 20 or more using

frequency modulation Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and Run-length limited#FM: .280. ...

Radio-controlled models

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

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...

s 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 An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...

' 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 with 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 required only 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 could interpret, using

pulse-width modulation Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discrete parts. The average value of voltage (and current) fed ...

(PWM). More recently, high-end

hobby A hobby is considered to be a regular activity that is done for enjoyment, typically during one's leisure time. Hobbies include collecting themed items and objects, engaging in creative and artistic pursuits, playing Sport, sports, or pursu ...

systems using

pulse-code modulation Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM Stream (comp ...

(PCM) features have come on the market that provide a

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

ized digital

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

-stream signal to the receiving device, instead of the earlier PWM encoding type. However, even with this coding, loss of transmission during flight has become more common, in part because of the ever more wireless society. Some more modern FM-signal receivers that still use "PWM" encoding instead can, thanks to the use of more advanced computer chips in them, be made to lock onto and use the individual signal characteristics of a particular PWM-type RC transmitter's emissions alone, ''without'' needing a special "code" transmitted along with the control information as PCM encoding has always required. In the early 21st century, 2.4 gigahertz

spread spectrum In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency dom ...

RC control systems have become increasingly utilized in control of model vehicles and aircraft. Now, these 2.4 GHz systems are being made by most radio manufacturers. These radio systems range in price from a couple thousand

dollar Dollar is the name of more than 20 currencies. They include the Australian dollar, Brunei dollar, Canadian dollar, Hong Kong dollar, Jamaican dollar, Liberian dollar, Namibian dollar, New Taiwan dollar, New Zealand dollar, Singapore dollar, U ...

s, all the way down to under US$30 for some. Some manufacturers even offer conversion kits for older digital 72 MHz or 35 MHz receivers and radios. As the emerging multitude of 2.4 GHz band spread spectrum RC systems usually use a "frequency-agile" mode of operations, like FHSS that do not stay on one set frequency any longer while in use, the older "exclusive use" provisions at model flying sites needed for VHF-band RC control systems' frequency control, for VHF-band RC systems that only used one set frequency unless serviced to change it, are not as mandatory as before.

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 In developmental psychology and moral, political, and bioethical philosophy, autonomy, from , ''autonomos'', from αὐτο- ''auto-'' "self" and νόμος ''nomos'', "law", hence when combined understood to mean "one who gives oneself one's ow ...

, 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 this point". Some of the most outstanding examples of remote radio control of a vehicle are the

Mars Exploration Rover NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rover ...

s such as

Sojourner A sojourner is a person who resides temporarily in a place. Sojourner may also refer to: * Sojourner Truth (1797–1883), abolitionist and women's rights activist * Albert Sojourner (1872–1951), member of the Mississippi House of Representative ...

Industrial radio remote control

Today radio control is used in industry for such devices as overhead cranes and switchyard

locomotive A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...

s. Radio-controlled teleoperators are used for such purposes as inspections, and special vehicles for disarming of

bomb A bomb is an explosive weapon that uses the Exothermic process, exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-t ...

s. Some remotely controlled devices are loosely called

robot A robot is a machine—especially one programmable by a computer—capable of carrying out a complex series of actions automatically. A robot can be guided by an external control device, or the control may be embedded within. Robots may be c ...

s, but are more properly categorized as teleoperators since they do not operate autonomously, but only under control of a human operator. An industrial radio remote control can either be operated by a person, or by a computer control system in a

machine to machine Machine to machine (M2M) is direct communication between devices using any communications channel, including wired and wireless. Machine to machine communication can include industrial instrumentation, enabling a sensor or meter to communicate th ...

(M2M) mode. For example, an automated warehouse may use a radio-controlled crane that is operated by a computer to retrieve a particular item. Industrial radio controls for some applications, such as lifting machinery, are required to be of a fail-safe design in many jurisdictions. Industrial remote controls work differently from most consumer products. When the receiver receives the radio signal which the transmitter sent, it checks it so that it is the correct frequency and that any security codes match. Once the verification is complete, the receiver sends an instruction to a

which is activated. The relay activates a function in the application corresponding to the transmitters button. This could be to engage an electrical directional motor in an

overhead crane An overhead crane, commonly called a bridge crane, is a type of crane found in industrial environments. An overhead crane consists of two parallel rails seated on longitudinal I-beams attached to opposite steel columns by means of brackets. ...

. In a receiver there are usually several relays, and in something as complex as an overhead crane, perhaps up to 12 or more relays are required to control all directions. In a receiver which opens a gate, two relays are often sufficient. Industrial remote controls are getting more and higher safety requirements. For example: a remote control may not lose the safety functionality in case of malfunction. This can be avoided by using redundant relays with forced contacts.

History

Second World War

Radio-controlled models

Modern military and aerospace applications

Industrial radio remote control

See also

Notes and references

Further reading