Li Zengke, Wang Jian, Gao Jingxiang, Li Binghao, Zhou Feng
School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 22116, China.
School of Surveying and Spatial Information Systems, The University of New South Wales, Sydney 2052, Australia.
Sensors (Basel). 2014 Dec 10;14(12):23803-21. doi: 10.3390/s141223803.
The initial alignment of the Inertial Measurement Unit (IMU) is an important process of INS to determine the coordinate transformation matrix which is used in the integration of Global Positioning Systems (GPS) with Inertial Navigation Systems (INS). In this paper a novel alignment method for a disturbed base, such as a vehicle disturbed by wind outdoors, implemented with the aid of a Vondrak low pass filter, is proposed. The basic principle of initial alignment including coarse alignment and fine alignment is introduced first. The spectral analysis is processed to compare the differences between the characteristic error of INS force observation on a stationary base and on disturbed bases. In order to reduce the high frequency noise in the force observation more accurately and more easily, a Vondrak low pass filter is constructed based on the spectral analysis result. The genetic algorithms method is introduced to choose the smoothing factor in the Vondrak filter and the corresponding objective condition is built. The architecture of the proposed alignment method with the Vondrak low pass filter is shown. Furthermore, simulated experiments and actual experiments were performed to validate the new algorithm. The results indicate that, compared with the conventional alignment method, the Vondrak filter could eliminate the high frequency noise in the force observation and the proposed alignment method could improve the attitude accuracy. At the same time, only one parameter needs to be set, which makes the proposed method easier to implement than other low-pass filter methods.
惯性测量单元（IMU）的初始对准是惯性导航系统（INS）的一个重要过程，用于确定在全球定位系统（GPS）与惯性导航系统（INS）集成中使用的坐标变换矩阵。本文提出了一种在受干扰基座（如户外受风力干扰的车辆）上借助冯德拉科低通滤波器实现的新型对准方法。首先介绍了包括粗对准和精对准在内的初始对准的基本原理。进行频谱分析以比较INS力观测在静止基座和受干扰基座上的特征误差之间的差异。为了更准确、更轻松地降低力观测中的高频噪声，基于频谱分析结果构建了冯德拉科低通滤波器。引入遗传算法方法来选择冯德拉科滤波器中的平滑因子并建立相应的目标条件。展示了所提出的带有冯德拉科低通滤波器的对准方法的架构。此外，进行了模拟实验和实际实验以验证新算法。结果表明，与传统对准方法相比，冯德拉科滤波器可以消除力观测中的高频噪声，所提出的对准方法可以提高姿态精度。同时，只需要设置一个参数，这使得所提出的方法比其他低通滤波器方法更易于实现。
