Chmielewski Piotr, Sibilski Krzysztof
Institute of Aeronautics and Applied Mechanics, Faculty of Power and Aeronautical Engineering, Doctoral School No. 4, Warsaw University of Technology, 00-665 Warsaw, Poland.
Institute of Aeronautics and Applied Mechanics, Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, 00-665 Warsaw, Poland.
Sensors (Basel). 2021 Apr 13;21(8):2754. doi: 10.3390/s21082754.
In a conventional Unmanned aerial vehicles (UAV) navigational system Global Navigation Satellite System (GNSS) sensor is often a main source of data for trajectory generation. Even video tracking based systems need some GNSS data for proper work. The goal of this study is to develop an optics-based system to estimate the ground speed of the UAV in the case of the GNSS failure, jamming, or unavailability. The proposed approach uses a camera mounted on the fuselage belly of the UAV. We can obtain the ground speed of the airplane by using the digital cropping, the stabilization of the real time image, and template matching algorithms. By combining the ground speed vector components with measurements of airspeed and altitude, the wind velocity and drift are computed. The obtained data were used to improve efficiency of the video-tracking based on a navigational system. An algorithm allows this computation to be performed in real time on board of a UAV. The algorithm was tested in Software-in-the-loop and implemented on the UAV hardware. Its effectiveness has been demonstrated through the experimental test results. The presented work could be useful for upgrading the existing MUAV products (with embedded cameras) already delivered to the customers only by updating their software. It is especially significant in the case when any necessary hardware upgrades would be economically unjustified or even impossible to be carried out.
在传统的无人机导航系统中，全球导航卫星系统（GNSS）传感器通常是生成轨迹数据的主要来源。即使是基于视频跟踪的系统，也需要一些GNSS数据才能正常工作。本研究的目的是开发一种基于光学的系统，以在GNSS出现故障、受到干扰或无法使用的情况下估计无人机的地速。所提出的方法使用安装在无人机机身腹部的摄像头。我们可以通过数字裁剪、实时图像稳定和模板匹配算法来获取飞机的地速。通过将地速矢量分量与空速和高度测量值相结合，计算出风速和偏流。所获得的数据用于提高基于导航系统的视频跟踪效率。一种算法允许在无人机上实时执行此计算。该算法在软件在环测试中进行了测试，并在无人机硬件上实现。通过实验测试结果证明了其有效性。所展示的工作对于仅通过更新软件来升级已交付给客户的现有多用途无人机产品（带有嵌入式摄像头）可能是有用的。在任何必要的硬件升级在经济上不合理甚至无法进行的情况下，这一点尤其重要。
