Inertial navigation is a navigation technology that uses inertial sensitive components or devices on the carrier to measure the carrier's motion acceleration and angular velocity, and calculate the carrier's position, velocity, and attitude angle. Inertial navigation is widely used in aerospace, rail transit, automatic driving, portable positioning terminals and other fields.

The equipment that makes up the inertial navigation system is installed in the carrier. It does not rely on external information, does not radiate energy to the outside world, and is not easily disturbed. It is an autonomous navigation system.


An inertial navigation system usually consists of an inertial measurement device, a computer, a control display, etc. Inertial measurement devices include accelerometers and gyroscopes, also known as inertial measurement units (IMUs). The 3 degrees of freedom gyroscopes are used to measure the 3 rotational motions of the carrier; the 3 accelerometers are used to measure the acceleration of the 3 translational motions of the carrier. The computer calculates the speed and position data of the carrier based on the measured acceleration signals. The control display shows various navigation parameters.

According to the installation method of the inertial measurement unit on the carrier, it is divided into a platform inertial navigation system (the inertial measurement unit is installed on the platform of the inertial platform) and a strapdown inertial navigation system (the inertial measurement unit is directly installed on the carrier) ; The latter saves the platform, the working conditions of the instrument are not good (affecting the accuracy), and the calculation workload is heavy.

Inertial navigation system is a kind of dead reckoning navigation. That is, the position of the next point is calculated from the position of a known point according to the continuously measured course angle and speed of the carrier, so the current position of the moving body can be continuously measured. The gyroscope in the inertial navigation system is used to form a navigation coordinate system to stabilize the measurement axis of the accelerometer in this coordinate system, and to give the heading and attitude angle; the accelerometer is used to measure the acceleration of the moving body through an integral of time The speed is obtained, and the distance can be obtained by integrating the speed with time.