Attitude solution for strapdown inertial navigation system based on quaternion algorithm

The attitude solution for carrier is one of the key technologies for precision navigation of Strapdown Inertial Navigation System(SINS).In this paper,the strongpoints and defects of Euler algorithm, direction cosine algorithm and quaternion algorithm were analyzed.Then,the carrier attitude was computed separately according to quaternion algorithm and direct cosine algorithm,and the comparative deviation was obtained by contrasting these two solution deviation with theory results.These comparsons prove the validity of quaternion algorithm and conclude that increasing sampling frequency and adopting high-level compute algorithm can lower compute deviation.Digital simulation and experiment results show that the carrier attitude solution relative deviation is 10-10% with numerical theory and 10-3% with test experiment results,the compute time is 36 μs.The proposed attitude solution method can satisfy the real-time demand,and can offer a useful reference for strapdown inertial navigation technology applied in engineering.