The emergence of inertial navigation is relatively early, and it uses a purely computational method to navigate and position. Even in today’s wide application of satellite navigation such as GPS and Beidou, inertial navigation still occupies a firm place in many navigation systems.
1.The theoretical basis of inertial navigation When it comes to the theoretical basis of inertial navigation, we have to mention Newton’s contribution to inertial navigation. Two important tools used in inertial navigation: Newton’s second law and calculus are inextricably linked with Newton. Newton’s second law tells us: dv/dt=a, and the relationship between distance and time is also obvious: ds/dt=v, which links distance and acceleration together. Neither the distance nor the speed can be measured directly, but the acceleration can, as long as there is acceleration, the distance at every moment can be known. But the reality is not one-dimensional, but three-dimensional space. How to do it? At this time, we need to know the change of the angle. Therefore, we also need an angular accelerometer (gyroscope). The invention of the gyroscope is also inseparable from the credit of Newton. It was he who studied the mechanics of high-speed rotating rigid bodies that provided the theoretical research on the invention of the gyroscope for future generations. The gyroscope plus the accelerometer is the sensor part of the inertial navigation. In this way, the motion path is linked to the two quantities of acceleration and angular acceleration that can be measured by the sensor. Inertial navigation is to measure these two instantaneous variables, and after a series of formula operations, the motion path can be completely calculated.
2.Advantages of inertial navigation
1) Inertial navigation positioning does not require external information. Inertial navigation can be said to be an old antique, but its status is still unshakable today. Whether it is satellite navigation or radio navigation, it is limited by external information. Once the satellites are unavailable and there is no navigation station, then these navigation systems are completely paralyzed. But inertial navigation does not need to rely on external information at all. The initial data it uses for calculation comes from itself, and it is neither affected by external interference, nor does it send any signals, let alone any other equipment. Therefore, inertial navigation is mostly used in military affairs.
2) Continuity of Inertial Navigation and Positioning Other navigation and positioning systems are positioned one by one, but the position of inertial navigation is a continuous curve, which is also a major advantage.
3) There are certainly limitations of inertial navigation. Compared to other navigation, inertial navigation has a limitation: accumulated error. The operations of the MCU are all quantified, and errors are inevitable. Inertial navigation is a continuous calculation, and the accumulated errors sometimes reach an unacceptable level. The solution to this problem is usually compensation and correction: readjust every once in a while. Correct the position, velocity, and angular velocity.
Application Prospects of Inertial Navigation Inertial navigation is more commonly used now, combining inertial navigation with GPS and Beidou satellite navigation to make combined navigation for use. For example, the GPS/Beidou + inertial navigation integrated vehicle integrated navigation system of Tiangong measurement and control.