捷联惯导快速传递对准可观测性分析与机动方案设计

Observability analysis and maneuver scheme design for rapid transfer alignment of SINS

基于“速度+姿态”的快速传递对准对实际失准角的估计精度和速度与载体机动密不可分,尤其在大失准角条件下非线性系统观测性分析和可观测度定义仍没有统一方法。首先,在基于量测失准角快速传递对准线性模型的基础上,通过构造可观测性矩阵,分析得出状态量可观测的充分条件;然后,通过构建大失准角条件下快速传递对准非线性数学模型,从全局可观测性的角度出发,系统地推衍非线性系统可观测性与载体机动之间的关系,为载体机动方案的选取提供理论基础;最后,通过仿真实验验证理论分析的正确性。仿真结果表明:在摇摆机动条件下,无论是小失准角还是大失准角,主、子惯导载体的实际失准角在10 s内均可达到约3’的精度。

The estimation accuracy and speed of the actual misalignment angles of the fast transfer alignment based on"velocity+attitude"are closely related to the carrier maneuver.There is still no unified method for the observability analysis and the definition of observable degree in the nonlinear system,especially under the condition of large misalignment angles.Firstly,based on the fast transfer alignment model of measuring misalignment angles,the sufficient condition of state observability is obtained by constructing observability matrix.Then,the nonlinear mathematical model of fast transfer alignment under the condition of large misalignment angles is constructed,and the relationship between the observability of nonlinear system and the carrier maneuver is deduced systematically from the perspective of global observability,which provides a theoretical basis for the selection of the carrier maneuver scheme.Finally,the theoretical analysis is verified by simulation experiment.The simulation results show that under the swaying conditions,the actual misalignment angles of the master inertial navigation system(INS)and the slave INS can reach about 3¢within 10 s regardless of small or large misalignment angles.