基于强跟踪滤波的旋转捷联惯导初始对准方法

Initial alignment method for rotational strapdown inertial navigation system based on strong tracking filter

旋转捷联惯性导航系统在传统系统结构上进行了改进,陀螺和加速度计安装于转动基座上,通过捷联算法中的积分运算消除陀螺仪和加速度计中的非随机性误差。针对该导航系统的结构特点,研究了一种基于强跟踪滤波算法的快速估计平台误差角的初始对准方法,推导了系统的误差数学模型,论述了强跟踪滤波基本方法及初始对准状态方程与观测方程,进行了数字仿真验证。基于某型光纤陀螺和MEMS加速度计,通过在高精度转台上的旋转实验进一步进行了基于实际系统的算法性能验证。结果表明,对于中低精度的光纤陀螺旋转捷联惯性导航系统,所提出的对准方法具有较高的对准性能,具有工程应用价值。

The rotational strapdown inertial navigation system（RSINS） has improved its conventional system architecture,i.e.,the gyros and accelerometers are placed on a rotating base,thus their non-stochastic errors could be eliminated by the integral calculation of navigation algorithm.Considering its structure features,a novel initial alignment method based on strong tracking filtering algorithm is presented which can rapidly estimate the platform misalignment.The mathematical model of the system errors is established,and the state equations and observation equations of strong tracking filter are derived,and the verifications by digital simulation are given.An inertial measurement unit（IMU） is constructed based on a certain type of fiber-optical gyro and a certain type of MEMS accelerator.Using the IMU,semi-physical simulations are conducted on a high-precision rotary table using the real data measured by the data acquisition system to verify the performance of the proposed method.The simulation results show that,compared with SINS＇s conventional initial alignment method,the proposed method has higher initial alignment performance for medium and low precision rotating SINS,and is valuable for engineering application.