航天器发射前动基座自对准方法比较研究

Comparative Research on Alignment Methods of Spacecraft on Moving Base before Launch

针对从发射段开始即要求具备全程自主导航能力的航天器,对其发射前惯性姿态自对准方法的应用问题进行研究.针对纯惯导姿态自对准的3种经典方法:解析式粗对准、罗经对准、惯性系对准,分析不同方法在不同应用场景中的适应性,分析惯性敏感器误差特性和噪声特性对算法精度的影响,以箭体微幅晃动为典型工况,基于罗经法中地速增量为零的假设条件,设计一种适应周期性晃动基座的改进罗经对准回路.通过惯性敏感器不同噪声组合的蒙特卡洛打靶仿真,对罗经对准和惯性对准算法的实现情况和精度进行数值验证,为工程实践中的方案选取提供参考.

The initial self-alignment for a kind of spacecraft which requires autonomous navigation from the launch phase is studied in this paper.Three classical self-alignment methods of SINS including analytical coarse alignment,compass alignment and inertial frame based alignment are presented and analyzed.Firstly,the adaptability of these different methods in different scenes is analyzed,and then the influence of the measurement error characteristic of IMU is studied.Finally,an improved gyro-compassing alignment method adapted to periodic shaking base is designed to solve the self-alignment in the environment of slightly shaking launch vehicle.Through the Monte Carlo simulation under different IMU measurement noise combinations,the results and accuracy of the gyro-compassing alignment method and inertial frame based alignment method are numerically analyzed,which provides a basis for the scheme selection in engineering practice.