Radio Controller (often abbreviated to RC) is the use of control signals transmitted by radio to remotely control a device. Examples of simple radio control systems are garage door openers and keyless entry systems 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. Industrial, military, and scientific research organizations make use of radio-controlled vehicles as well. A rapidly growing application is control of unmanned aerial vehicles (UAVs or drones) for both civilian and military uses, although these have more sophisticated control systems than traditional applications.
Today radio control is used in industry for such devices as overhead cranes and switchyard locomotives. Radio-controlled teleoperators are used for such purposes as inspections, and special vehicles for disarming of bombs. Some remotely controlled devices are loosely called robots but are more properly categorized as teleoperators since they do not operate autonomously, but only under control of a human operator. Radio 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 otherwise both difficult and dangerous to attack. However, by the end of the war, the Luftwaffe was having similar problems attacking Allied bombers and developed a number of radio command guided anti-aircraft missiles, none of which saw service. The effectiveness of the Luftwaffe’s systems, primarily comprising the series of Telefunken Funk-Gerät (or FuG) 203 Kehl twin-axis, single joystick-equipped transmitters mounted in the deploying aircraft, and Telefunken’s companion Fug 230 Strasburg receiver placed in the odnance to be controlled during deployment and used by both the Fritz X unpowered, armored anti-ship bomb, and the powered Henschel Hs 293 guided bomb, was greatly reduced by British efforts to jam their radio signals, eventually with American assistance. After initial successes, the British launched a number of commando 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 once they realized what was going on, but the systems were not ready for deployment until the war had already moved to France.
The German Kriegsmarine operated FL-Boote (ferngelenkte Sprengboote) which were radio-controlled motorboats 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, 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 and CBI Theaters of World War II.
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 (sunk in gunnery exercise in March 1923).
The Soviet Red Army used remotely controlled tele tanks during the 1930s in the Winter War against Finland and fielded at least two tele tank battalions at the beginning of the Great Patriotic War. A tele tank 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.
