相对姿态匹配传递对准方法

传统的姿态匹配传递对准需要主、子惯性测量单元 (inertial measurement unit, IMU)分别惯导解算，得到两个姿态向量或姿态阵构造观测量。提出利用主、子IMU输出直接解算主、子IMU之间的相对姿态来构造匹配量的一种新的传递对准方法。首先推导了主、子相对姿态矩阵微分方程，并给出求解方法，得到的相对姿态矩阵计算值与初始相对姿态矩阵相乘作为观测信息；然后推导建立了相对姿态的误差方程，由此给出了传递对准状态空间模型；最后讨论建立了仿真验证环境，仿真结果表明，子陀螺精度为1（°）/h时，子IMU对准精度可以达到3′以内，并在10 s内迅速收敛。该方法同时适用于精确确定大角度或小角度的子IMU相对姿态，为关键位置实时高精度姿态基准的建立提供了技术参考。

Relative attitude matching method for transfer alignment

In the traditional attitude matching transfer alignment, observation is constructed with two attitude vectors or attitude matrixes respectively calculated by master and slave inertial navigation systems. A new transfer alignment scheme of relative attitude matching is proposed in detail. The relative attitude is calculated directly using output of master and slave strapdown inertial measurement units (IMUs). Firstly, the differential equation of rotation matrix from the master IMU frame to the slave is derived, and a solution for the equation is given. The resulting relative attitude multiplying the initial relative attitude forms the observation. Then the relative attitude error propagation function is derived. Based on this, a statespace model of the transfer alignment is represented. Finally, the evaluation environment for simulation is discussed and built. Results indicate that when the gyroscope precision of the slave IMU is 1（°）/h, the alignment accuracy reaches to 3′ and converges quickly in 10 s. The method is suitable for the accurate determination of both small and large relative attitudes of the slave IMU, and thus provides a technical reference for the real-time attitude acquisition of critical position with high accuracy.