一种双天线辅助的两段连续式对准以及误差分析

针对低精度微惯性测量单元/全球导航卫星系统 (IMU/GNSS)松组合导航系统中初始方位难以精确得到和行进间航向容易发散的问题，该文设计了一种双天线辅助的两段连续式对准方法。首先分析了初始方位误差对航向精度的影响；其次，由于GNSS测向系统精度高、无姿态漂移误差的特点，基于双天线基线矢量推导了一种最小二乘算法的测姿模型，进行初始对准；最后针对行进间对准，研究扩展了基于航向差值的1维量测以抑制航向发散。设计试验探讨了双天线基线矢量对初始对准与行进间航向精度的影响，改进方法可以使得初始方位误差优于0.7°，行进间航向能够更准确地被跟踪。针对目标的初始对准与行进间对准，双天线可提供辅助信息，其效果优于单天线IMU/GNSS的组合，且方法计算量适中。

Two-segment Continuous Alignment and Error Analysis Method Based on Dual Antenna Assistance

Considering the problem that it is difficult to obtain the initial position accurately in the low-precision Inertial Measurement Unit/Global Navigation Satellite System (IMU/GNSS) loose integrated navigation system and the course divergence is easy to travel. A two-segment continuous alignment method assisted by dual antennas is designed. Firstly, the influence of initial bearing error on heading accuracy is analyzed. Secondly, due to the characteristics of high accuracy and poor dynamic response of the GNSS direction-finding system, a least-squares attitude estimation model is derived based on the dual-antenna baseline vector for initial alignment. Finally, for the alignment between travels, the research extendes the one-dimensional measurement based on the heading difference to suppress the heading error. The design experiment explores the influence of the dual antenna baseline vector on the initial alignment and the heading accuracy between travels. The improved method can make the initial azimuth error better than 0.7°. At the same time, the heading angle between travels can be tracked more accurately. For the initial alignment of the target and the alignment between the traveling, the dual antenna can provide auxiliary information, its effect is better than the single antenna IMU/GNSS combination, and the method calculation is moderate.