Gimbal - AbsoluteAstronomy.com

A gimbal is a pivoted support that allows the rotation of an object about a single axis. A set of two gimbals, one mounted on the other with pivot axes orthogonal, may be used to allow an object mounted on the innermost gimbal to remain immobile (i.e., vertical in the animation) regardless of the motion of its support. For example: on a ship, the gyroscope

Gyroscope

A gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum. In essence, a mechanical gyroscope is a spinning wheel or disk whose axle is free to take any orientation...

s, shipboard compasses, stoves, and even drink holders, typically use gimbals to keep them upright with respect to the horizon

Horizon

The horizon is the apparent line that separates earth from sky, the line that divides all visible directions into two categories: those that intersect the Earth's surface, and those that do not. At many locations, the true horizon is obscured by trees, buildings, mountains, etc., and the resulting...

despite the ship's pitching and rolling.

The "Cardan suspension" of a gimbal is named after the Italian

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

inventor Gerolamo Cardano

Gerolamo Cardano

Gerolamo Cardano was an Italian Renaissance mathematician, physician, astrologer and gambler...

(1501–1576), who described the device in detail, but did not claim its invention.

History

The gimbal was first invented by the Greek

Ancient Greece

Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

inventor Philo of Byzantium

Philo of Byzantium

Philo of Byzantium , also known as Philo Mechanicus, was a Greek engineer and writer on mechanics, who lived during the latter half of the 3rd century BC...

(280–220 BC). Philo described an eight-sided ink

Ink

Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...

pot with an opening on each side, which can be turned so that while any face is on top, a pen can be dipped and inked - yet the ink never runs out through the holes of the other sides. This was done by the suspension of the inkwell at the center, which was mounted on a series of concentric metal rings which remained stationary no matter which way the pot is turned.

The authenticity of Philo's description of a cardan suspension has been doubted by some authors on the ground that the part of Philo's Pneumatica which describes the use of the gimbal survived only in an Arabic translation of the early 9th century AD. Thus, the sinologist Joseph Needham

Joseph Needham

Noel Joseph Terence Montgomery Needham, CH, FRS, FBA , also known as Li Yuese , was a British scientist, historian and sinologist known for his scientific research and writing on the history of Chinese science. He was elected a fellow of the Royal Society in 1941, and as a fellow of the British...

suspected Arab interpolation

Interpolation (manuscripts)

An interpolation, in relation to literature and especially ancient manuscripts, is an entry or passage in a text that was not written by the original author...

as late as 1965. However, Carra de Vaux, author of the French translation which still provides the basis for modern scholars, regards the Pneumatics as essentially genuine. The historian of technology George Sarton (1959), too, asserts that it is safe to assume the Arabic version is a faithful copying of Philo's original, and credits Philon explicitly with the invention. So does his colleague Michael Lewis (2001). In fact, research by the latter scholar (1997) demonstrates that the Arab copy contains sequences of Greek letters which fell out of use after the time of Christ, thereby strengthening the case that it is a faithful copy of the Hellenistic original, a view recently also shared by the classicist Andrew Wilson

Andrew Wilson (classical archaeologist)

Andrew Ian Wilson is a British classical archaeologist and director of the Institute of Archaeology at the University of Oxford...

(2002).

The ancient

Ancient history

Ancient history is the study of the written past from the beginning of recorded human history to the Early Middle Ages. The span of recorded history is roughly 5,000 years, with Cuneiform script, the oldest discovered form of coherent writing, from the protoliterate period around the 30th century BC...

author Athenaeus Mechanicus, who flourished during the reign of Augustus

Augustus

Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...

(30 BC–AD 14), described the military use of a gimbal-like mechanism, calling it "little ape" (pithêkion): When preparing to attack coastal towns from the sea-side, military engineers used to yoke merchant-ships together to take the siege machines up to the walls. But to prevent the shipborne machinery from rolling around the deck in heavy seas, Athenaeus advises that "you must fix the pithêkion on the platform attached to the merchant-ships in the middle, so that the machine stays upright in any angle".

After antiquity

Ancient history

, gimbals remained widely known in the Near East

Muslim world

The term Muslim world has several meanings. In a religious sense, it refers to those who adhere to the teachings of Islam, referred to as Muslims. In a cultural sense, it refers to Islamic civilization, inclusive of non-Muslims living in that civilization...

. In the Latin West, reference to the device appeared again in the 9th century recipe book called the Little Key of Painting Mappae clavicula

Mappae clavicula

The Mappae clavicula is a medieval Latin text, a compilation containing recipes for a number of crafts including metalwork, dyeing and mosaic, as well as several recipes relevant to painting...

. The French

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

inventor Villard de Honnecourt

Villard de Honnecourt

Villard de Honnecourt was a 13th-century artist from Picardy in northern France. He is known to history only through a surviving portfolio of 33 sheets of parchment containing about 250 drawings dating from the 1220s/1240s, now in the Bibliothèque Nationale, Paris...

depicts a set of gimbals in his famous sketchbook (see right). In the early modern period, dry compasses were suspended in gimbals.

In China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

, the Han Dynasty

Han Dynasty

The Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...

(202 BC – AD 220) inventor Ding Huan created a gimbal incense burner

Censer

Censers are any type of vessels made for burning incense. These vessels vary greatly in size, form, and material of construction. They may consist of simple earthenware bowls or fire pots to intricately carved silver or gold vessels, small table top objects a few centimetres tall to as many as...

around AD 180. There is a hint in the writing of the earlier Sima Xiangru

Sima Xiangru

Sima Xiangru, also known as Ssu-ma Hsiang-ju was a Chinese writer. He was a minor official of the Western Han Dynasty, but was better known for his poetic skills, jiu business, and controversial marriage to the widow Zhuo Wenjun after both eloped...

(179–117 BC) that the gimbal existed in China since the 2nd century BC. There is mention during the Liang Dynasty

Liang Dynasty

The Liang Dynasty , also known as the Southern Liang Dynasty , was the third of the Southern dynasties in China and was followed by the Chen Dynasty...

(502–557) that gimbals were used for hinges of doors and windows, while an artisan once presented a portable warming stove

Stove

A stove is an enclosed heated space. The term is commonly taken to mean an enclosed space in which fuel is burned to provide heating, either to heat the space in which the stove is situated or to heat the stove itself, and items placed on it...

to Empress Wu Zetian

Wu Zetian

Wu Zetian , personal name Wu Zhao , often referred to as Tian Hou during the Tang Dynasty and Empress Consort Wu in later times, was the only woman in the history of China to assume the title of Empress Regnant...

(r. 690–705) which employed gimbals. Extant specimens of Chinese gimbals used for incense burners date to the early Tang Dynasty

Tang Dynasty

The Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...

(618–907), and were part of the silver

Silver

Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

-smithing tradition in China.

Inertial navigation

In inertial navigation, as applied to ships and submarines, a minimum of three gimbals is needed to allow an inertial navigation system

Inertial navigation system

An inertial navigation system is a navigation aid that uses a computer, motion sensors and rotation sensors to continuously calculate via dead reckoning the position, orientation, and velocity of a moving object without the need for external references...

(stable table) to remain fixed in inertial space, compensating for changes in the ship's yaw, pitch, and roll. In this application, the Inertial Measurement Unit

Inertial measurement unit

An inertial measurement unit, or IMU, is an electronic device that measures and reports on a craft's velocity, orientation, and gravitational forces, using a combination of accelerometers and gyroscopes. IMUs are typically used to maneuver aircraft, including UAVs, among many others, and...

(IMU) is equipped with three orthogonally mounted gyros to sense rotation about all axes in three-dimensional space. The gyro outputs drive motors controlling the orientation of the three gimbals as required to maintain the orientation of the IMU. In turn, angular measurement devices called "resolver

Resolver (electrical)

A resolver is a type of rotary electrical transformer used for measuring degrees of rotation. It is considered an analog device, and has a digital counterpart, the rotary encoder.-Description:...

s" mounted on the three gimbals provide the nine cosine values

Direction cosine

In analytic geometry, the direction cosines of a vector are the cosines of the angles between the vector and the three coordinate axes. Or equivalently it is the component contributions to the unit vector....

for the direction cosine matrix

Rotation representation (mathematics)

In geometry a rotation representation expresses a rotation as a mathematical transformation. In physics, this concept extends to classical mechanics where rotational kinematics is the science of describing with numbers the purely rotational motion of an object.According to Euler's rotation theorem...

needed to orient the ship.

Similar sensing platforms are used on aircraft.

In inertial navigation systems, gimbal lock

Gimbal lock

Gimbal lock is the loss of one degree of freedom in a three-dimensional space that occurs when the axes of two of the three gimbals are driven into a parallel configuration, "locking" the system into rotation in a degenerate two-dimensional space....

may occur when vehicle rotation causes two of the three gimbal rings to align with their pivot axes in a single plane. When this occurs, it is no longer possible to maintain the sensing platform's orientation.

Rocket engines

In spacecraft propulsion

Spacecraft propulsion

Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research. However, most spacecraft today are propelled by forcing a gas from the...

, rocket engine

Rocket engine

A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...

s are generally mounted on a pair of gimbals to allow a single engine to vector thrust about both the pitch and yaw axes; or sometimes just one axis is provided per engine. To control roll, twin engines with differential pitch or yaw control signals are used to provide torque about the vehicle's roll axis.

The word "gimbal" began as a noun. Most modern dictionaries continue to list it as such. Lacking a convenient term to describe the swinging movement of a rocket engine, engineers began also using the word "gimbal" as a verb. When a thrust chamber is swung by an attached actuator, the movement is referred to as "gimballed" or "gimballing". Official rocket documentation reflects this usage.

Photography and imaging

Gimbals are also used to mount every thing from small camera lenses to large photographic telescopes.

In portable photography

Photography

Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...

equipment single-axis gimbal heads are used in order to allow a balanced movement for camera and lenses. This proves useful in wildlife photography as well as in any other case where very long and heavy telephoto lenses are adopted: a gimbal head rotates a lens around its center of gravity, thus allowing for easy and smooth manipulation while tracking moving subjects.

Very large gimbal mounts in the form 2 or 3 axis altitude-altitude mounts are used in satellite photography for tracking purposes.

History

Inertial navigation

Rocket engines

Photography and imaging

See also