Abstract The differences among SINS mechanization methods of rotation vector, quaternion and Taylor expansion were analyzed, the results indicate that the posture expression and the appropriation degree of algorithm are main reasons caused different calculation precision in those methods. A velocity constraints method and corresponding Kalman filter model were proposed. Test results show that higher accuracy can be obtained by Taylor expansion method for high accuracy analog data, and greatly delay navigation time cab be delayed by velocity constraint method for low accuracy analog data.
