Combining Global Navigation Satellite System (GNSS) with visual and inertial sensors can give smooth pose estimation without drifting in geographical coordinates. The fusion system gradually degrades to Visual-Inertial Odometry (VIO) with the number of satellites decreasing, which guarantees robust global navigation in GNSS unfriendly environments. In this letter, we propose an open-sourced invariant filter-based platform, InGVIO, to tightly fuse monocular/stereo visual-inertial measurements, along with raw data from GNSS, i.e. pseudo ranges and Doppler shifts. InGVIO gives highly competitive results in terms of accuracy and computational load compared to current graph-based and `naive' EKF-based algorithms. Thanks to our proposed key-frame marginalization strategies, the baseline for triangulation is large although only a few cloned poses are kept. Besides, landmarks are anchored to a single cloned pose to fit the nonlinear log-error form of the invariant filter while achieving decoupled propagation with IMU states. Moreover, we exploit the infinitesimal symmetries of the system, which gives equivalent results for the pattern of degenerate motions and the structure of unobservable subspaces compared to our previous work using observability analysis. We show that the properly-chosen invariant error captures such symmetries and has intrinsic consistency properties. InGVIO is tested on both open datasets and our proposed fixed-wing datasets with variable levels of difficulty. The latter, to the best of our knowledge, are the first datasets open-sourced to the community on a fixed-wing aircraft with raw GNSS.
翻译:将全球导航卫星系统(GNSS)与视觉和惯性传感器相结合,就可以在地理坐标中不漂移地进行平滑的估测。结合系统随着卫星数量减少,逐渐降解为视觉-内在测量(VIO),这保证了全球导航卫星系统不友好环境中的稳健全球导航。在这封信中,我们建议使用一个开放源源的无变化过滤平台,InGVIO,与全球导航卫星系统的原始数据,即模拟测距和多普勒转换相匹配。 InGVIO在准确性和计算负荷方面得出高度竞争的结果,与当前基于图形和“NAIF”的算法相比,这保证了在全球导航卫星系统不友好环境中进行强有力的全球导航。此外,我们建议一个开放源源源源源的单克隆的视觉-视觉-视觉-视觉-内脏测量,同时与IMU各州进行分解的传播。此外,我们利用不穷的奥性Onal-内脏-内脏-计算结果,我们用原始-Onal-Oral-na-nacial-demodal slational fal sal ravely sal laftal laft laft laft servial laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft laft latips laft laft laft laft laft laftal laft laft laftal lax lax lax lax lax lax laft laft lax 和我们使用了比好算系统,我们的不进行了比制的数值系统, 和我们的不等比制的数值分析系统,我们系统的不固定的不固定的数值分析系统,我们的不固定的固定的固定的系统, 和不固定的系统,我们对等比制的固定的固定的固定的固定的固定的固定的固定的固定的固定的固定的固定的固定的固定的轨道和不固定的轨道