【摘要】 针对低成本惯性/卫星组合导航系统在复杂环境中易受环境干扰、航向精度较差等问题,对双天线GPS/MEMS-INS深组合导航方法开展研究。考虑不同信号强度下的跟踪特性,基于矢量延迟锁定环(VDLL)、二阶锁相环(PLL)、速度辅助的一阶锁相环,设计了分别适应强信号、弱信号、失锁状态的跟踪环路结构。同时提出一种实用的信号强度判别方法,防止失准通道参与导航滤波器计算,提高导航精度。为保证航向精度,使用双天线接收卫星信号,将双天线载波相位差加入到导航滤波器的量测量中。采用视线矢量水平投影变换,构造了隔离俯仰信息的相位差量测方程,在不对俯仰角造成干扰的条件下修正航向角误差。车载导航试验表明,所设计的导航系统可以在城市环境中提供连续、高精度的导航输出。更多还原

【Abstract】 The low-cost INS/GNSS integrated navigation system is susceptible and has a larger heading error in complex environment. For solving these problems, a dual-antenna GPS/MEMS-INS deeply-integrated navigation approach is studied. Considering the tracking characteristics of signals with different intensities, three tracking structures are designed for strong signal, weak signal and loss-of-lock status based on vector delay-locked loop(VDLL), second-order phase-locked loop(PLL) and velocity-aided first-order PLL respectively. A practical method of estimating signal intensity is presented to prevent channels with large error from participating in the calculation of navigation filter, and the navigation accuracy is improved. In order to ensure the heading accuracy, two antennas are used. The carrier phase difference of the two antennas is added into the measurement of the navigation filter. A phase difference measurement equation in which the pitch information is isolated is constructed by using the line-of-sight vector horizontal projection transformation. Vehicular navigation test shows that the designed navigation system can provide continuous and high-precision navigation output in urban environment.更多还原