基于UKF的大失准角条件下单轴旋转SINS初始对准方法

Single-axial Rotary Initial Alignment for Large Misalignment Based on UKF

论文阐述了单轴旋转调制技术对捷联惯导系统误差抑制的原理,针对单轴旋转捷联惯导系统的初始对准,推导了大失准角误差条件下非线性初始对准误差模型,同时为充分利用惯导系统输出信息,提出了一种"加速度+速度"的非线性观测模型;根据系统误差方程和观测方程同时非线性,设计了一种Unscented卡尔曼滤波算法,并对静基座单轴旋转SINS初始对准进行了仿真试验。结果表明,采用该算法水平和方位对准在较短时间内都能达到较高精度,同时对加速度计零偏和三个陀螺漂移实现有效标定。

The error modulation principle of the single-axial rotation strap-down inertial navigation system （SINS） was introduced. To finish the alignment of single-axial rotation SINS, the nonlinear alignment error model is derived with large initial misalignment angles. Meanwhile, in order to make full use of the output information of the SINS, a kind of ＂acceleration＋speed＂ based nonlinear measurement model is put forward. According to the nonlinear characteristic of the system equation and observation equation, a kind of Unscented Kalman filtering algorithm is designed. And, single-axial rotation SINS alignment simulation tests are executed, and the results show that with the scheme designed in this paper, the level and heading initial alignment can achieve higher accuracy in shorter time, meanwhile the gyro＇s and accelerometer＇s bias can be calibrated effectively.