Abstract:

In the traditional attitude matching transfer alignment, observation is constructed with two attitude vectors or attitude matrixes respectively calculated by master and slave inertial navigation systems. A new transfer alignment scheme of relative attitude matching is proposed in detail. The relative attitude is calculated directly using output of master and slave strapdown inertial measurement units (IMUs). Firstly, the differential equation of rotation matrix from the master IMU frame to the slave is derived, and a solution for the equation is given. The resulting relative attitude multiplying the initial relative attitude forms the observation. Then the relative attitude error propagation function is derived. Based on this, a statespace model of the transfer alignment is represented. Finally, the evaluation environment for simulation is discussed and built. Results indicate that when the gyroscope precision of the slave IMU is 1（°）/h, the alignment accuracy reaches to 3′ and converges quickly in 10 s. The method is suitable for the accurate determination of both small and large relative attitudes of the slave IMU, and thus provides a technical reference for the real-time attitude acquisition of critical position with high accuracy.