Research on Rotation Scheme of Hybrid Inertial Navigation System with Three Rotating Axes

Hybrid inertial navigation system with three rotating axes involves the advantages of platform navigation system, strapdown navigation system and rotatory inertial navigation systems, which can improve navigation and positioning accuracy substantially. A comprehensive study of the error propagation properties and error compensation mechanism of rotatory inertial navigation system is conducted. On the basis of this theory, combined with the analysis of the traditional rotation scheme, a reasonable scheme of system error compensation based on the geographical coordinate system is determined. The rotation scheme relative to the geographic frame cannot eliminate the coupling items between the errors of the gyroscope and the Earth rotation, then a three-axis rotation scheme relative to inertial frame is proposed. The simulation is conducted to verify the rotation scheme, and the results are compared with the rotation scheme relative to the geographical frame. Results show that the inertial frame modulation scheme can reduce the navigation error caused by coupling items between the errors of the gyroscope and the Earth rotation obviously.