SINS Alignment Using Velocity Matching and Simplified Cubature Kalman Filter

This paper proposes a novel nonlinear alignment method for the strapdown inertial navigation system (SINS). The method uses the simplified cubature Kalman filter (CKF) and velocity matching. The system equations are the navigation equation, the Euler angle differential equations and the inertial sensor measurement error models. The system equations are nonlinear, whereas the measurement equations are linear. The CKF is simplified under the condition of the linear measurement equations. The time updating cycle and measurement updating cycle are different. Finally inertial measurement unit experimental data are used to do alignment. The results show that the proposed method can effectively obtain an accurate initial attitude within a short time, thus also be considered a new and simple addition to the kit of solutions for SINS alignment.