A new piece-wise fast alignment method for SINS stationary self-alignment

In this paper, a new piece-wise fast alignment method for SINS stationary alignment is proposed. First of all, the fine horizontal alignment is executed. After the fine horizontal alignment, using the output angle velocity of the gyros, we can calculate the azimuth misalignment angle in high speed. Theoretical analysis as well as the simulation result indicate: Compared with the method using Kalman filter in the whole process of the alignment, the piece-wise fast alignment method has the same steady-state accuracy,but in the process of the fine azimuth alignment, the mechanical arrangement of SINS is not needed and the computational complexity is reduced. The time of fine alignment can be shortened to 60 seconds or so. This method makes up the defect that the convergence of the azimuth misalignment angle is slow, accelerates the initial alignment process and has an important practical value.