Inertial Navigation System (INS, Inertial Navigation System) is also called Inertial reference System. It is a kind of system which don’t depend on external information, nor to the external radiation energy (such as a radio Navigation) autonomous Navigation System. Its working environment including air, ground not only, still can be in water. The basic working principle of inertial navigation is based on Newton’s laws of mechanics, by measuring the acceleration of the carrier in the inertial frame of reference, it will integral time, and convert it into the navigation system, also it can get in the navigation system of the information such as speed, yaw Angle and position.
Belongs to calculate navigation mode of inertial navigation system, from a position of known points according to the movement of the body, it can be measured continuously course Angle and velocity calculated below point position, thus can continuously measure the current position of body movement. Gyroscope in the inertial navigation system is used to form a navigation system, stable accelerometer measurement axis in the coordinate system, and presents heading and attitude Angle; Accelerometer used to measure the acceleration in the movement of body, after an integral of time to get speed, speed through the distance of time points at a time.
Inertial navigation system has the following advantages: 1, It is not dependent on any external information, nor to the external radiation energy of autonomous system, therefore, good concealment, it is not affected by the outside electromagnetic interference; 2, It can be all-weather, full time job in the air, the earth’s surface and underwater; 3, It can provide position, velocity, heading and attitude Angle data, the navigation information good continuity and low noise;4, data update rate is high, short-term precision and good stability.
Its defect is: 1, The result of the navigation information through integration, positioning error increases over time, the long-term accuracy; 2, It needs longer initial alignment time before each use; 3, The price of the equipment is expensive; 4, It can’t give time information.