基于CKF的SINS大方位失准角初始对准

Initial alignment of large azimuth misalignment angle in SINS based on CKF

大方位失准角捷联惯导系统(strapdown inertial narigation system,SINS)误差方程是非线性的,为改善非线性模型下初始对准的精度,提出将一种新的非线性滤波方法(cubature Kalman filter,CKF)应用于捷联惯导系统初始对准中。为此建立了大方位失准角下初始对准非线性模型,分析了基于spherical-radial cubature准则的CKF滤波原理,对非线性模型进行了CKF滤波仿真。仿真结果表明CKF能够很好地处理初始对准中的非线性问题,提高初始对准精度,方位失准角误差能够收敛到-33.13',接近理论估计精度-32.40',优于EKF的-84.14'。

The error equation of large azimuth misalignment angle in SINS is nonlinear. To improve the accuracy of the initial alignment in nonlinear model, a new nonlinear filtering method named cubature Kalman filter （CKF） is applied in the initial alignment of SINS. Therefore, an initial alignment nonlinear model under large azimuth mis- alignment angle is established, and the CKF filter theory based on the spherical-radial cubature criteria is analyzed; then the nonlinear model is simulated with CKF. Simulation results show that the CKF can nicely deal with the non- linear problems in initial alignment and improve the precision of initial alignment; and the azimuth misalignment an- gle error can converge to- 33.13′, which is close to the theoretical estimation precision- 32.40′ and is better than the - 84.14′ of EKF.