Research on the technology of rotational motion for FOG strapdown inertial navigation system

In order to improve the accuracy of strapdown inertial navigation system, the constant drift of gyro and the bias of accelerometer in inertial measurement unit (IMU) will be translated into periodic signal by the rotation of IMU, and the undesirable effects of constant drifts of inertial components can be eliminated by integral operations. The uniaxial unidirectional and reciprocating rotary compensation methods are listed in this paper, and the uniaxial rotary compensation principle is also derived. According to the scale error and the installation error of inertial components, the error characteristics of two rotation modes are analysed and simulated. Simulation results show that, the unidirectional rotation mode of IMU will lead to navigational errors due to the existence of scale factor, whereas such errors can be avoided in IMU reciprocating rotation mode.