Analysis and experiment of error restraint principle in an inertial navigation system with inertial sensors rotation

This research developed a new inertial navigation system INS with two inertial measurement units IMU rotating bi-directionally around the vertical and longitudinal body axis respectively. Theoretical analysis and simulation of the proposed rotation INS RINS were presented, which demonstrated that RINS could attenuate positioning errors caused by random constant and time-related components of sensor errors, whereas it did not perform better in modulating white noise component. It also showed that in RINS, utilising inertial sensors with longer relation time and increasing rotation rate are more beneficial. In addition, bi-directional rotation could acquire better result than that unidirectional rotation. Moreover, an experimental RINS prototype with gyroscope drifts of 0.05°/h and accelerometer biases of 50 ug was built. The vehicle tests showed that RINS can achieve positioning accuracy of less than 3 n miles during 8 h 0.3 n mile/h, CEP, more than 10 times improvement than strapdown INS with the same inertial sensors.