Inertial Navigation

Inertial Navigation 

a method of determining the coordinates and parameters of motion of various objects, such as ships, aircraft, and missiles, and of controlling their motion. It is based on the properties of the inertia of bodies and is autonomous, that is, it does not require external reference points or signals. The conventional methods of solving navigational problems are based on the use of external reference points or signals, such as stars, beacons, and radio signals. In principle these methods are rather simple, but in many cases they do not have the required accuracy, especially at high rates of motion (for example, during a space flight), and they cannot always be performed because of the lack of visibility or the existence of radio interference. The necessity of devising navigation systems lacking these shortcomings was the reason for the appearance of inertial navigation.

The development of the principles of inertial navigation dates to the 1930’s. A major contribution was made in the USSR by B. V. Bulgakov, A. Iu. Ishlinskii, E. B. Levental’, and G. O. Fridlender and abroad by the German scientist M. Schuler and the American scientist C. Draper. The principles of inertial navigation are based on the laws of mechanics, which were formulated by Newton and to which the motion of bodies with respect to an inertial frame of reference (for motion within the solar system, with respect to the stars) conforms.

The essence of inertial navigation is the determination, by means of instruments and devices mounted on a moving object, of the object’s acceleration and, on this basis, of the location (coordinates) of the object and its course, velocity, and path traversed, as well as the determination of the parameters necessary for the stabilization of the object and the automatic control of its motion. This is accomplished by means of accelerometers, which measure the accelerations of the object; electronic computers, which find the object’s velocity, coordinates, and other parameters of motion on the basis of accelerations (by integration); and gyroscopic devices, which reproduce the reference system within the object (for example, by means of a gyrostabi-lized platform) and which make it possible to determine the angles of rotation and inclination of the object, which are used to stabilize it and control its motion.

The practical realization of inertial navigation methods entails considerable difficulties that necessitate high accuracy and reliability of all devices with given weights and dimensions. These difficulties can be surmounted by designing special technical equipment—an inertial navigation system. The advantages of the methods of inertial navigation are their high accuracy, autonomy, and noise resistance and the possibility of complete automation of all navigation processes. As a result, inertial navigation methods are becoming increasingly widely used in solving the navigational problems of surface ships, submarines, aircraft, and spacecraft.

REFERENCES

Andreev, V. D. Teoriia inertsial’noi navigatsii. Moscow, 1966.
Broxmeyer, C. F. Sistemy inertsial’noi navigatsii. Leningrad, 1967. (Translated from English.)
Ishlinskii, A. Iu. Mekhanika giroskopicheskikh sistem. Moscow, 1963.
Ishlinksii, A. Iu. Inertsial’noe upravlenie ballisticheskimi raketami. Moscow, 1968.
Rivkin, S. S. Teoriia giroskopicheskikh ustroistv. part 2. Leningrad, 1964.
Fridlender, G. O. Inertsial’nye sistemy navigatsii. Moscow, 1961.
Iakushenkov, A. A. Osnovy inertsial’noi navigatsii. Leningrad, 1963.
Sliv, E. I. Prikladnaia teoriia inertsial’noi navigatsii. Leningrad, 1972.

S. S. RIVKIN