提高SINS/GNSS组合导航系统定位精度的方法研究

单纯依赖单一的导航手段难满足高精度的导航需求,因此,将捷联惯性导航系统(SINS)、全球卫星导航系统(GNSS)有效组合,实现优势互补。SINS/GNSS组合导航系统的数据处理一般采用卡尔曼滤波实现,当组合导航系统模型足够准确时,滤波性能较好,当导航系统模型存在误差或发生变化时,新的量测值对滤波估计值的修正作用下降,而旧的量测值的修正作用相对上升,从而导致滤波精度下降。针对上述问题,基于集中式卡尔曼滤波结构的SINS/GNSS组合导航系统,本文提出一种新方法,新方法在梯度方向上进行估计迭代,从而修正模型误差对滤波精度的影响,提高导航定位精度。实验结果表明,当导航系统模型和量测方程存在误差或发生变化时,新方法仍可以为导航系统提供有效的定位精度,满足高空长航时系统需求。

Research on Improving Positioning Precision of SINS/GNSS Integrated Navigation System

Relying on a single method of navigation is difficult to meet the high precision requirement. Thus, the strap-down inertial navigation system (SINS) and global navigation satellite system (GNSS) integrated with complementary advantages can better meet the performance requirement. The SINS/GNSS integrated navigation system usually uses the Kalman filter to realize the data processing. When the integrated navigation system model is accurate enough, the filtering performance is good; when the navigation system model has error or change, the correction function of new measurement decrease, but the old measurement increase relatively. In order to solve the above problem, based on the SINS/GNSS integrated navigation system with the centralized Kalman filtering structure, this paper presents a new method which can process the data by estimation iterating on the gradient direction, correct the model error and improve the navigation positioning precision. The experimental results show that the new method can provide effective positioning precision for navigation systems when the navigation system model and the measurement equation have error or change, and can meet the HALE system requirements.