Ultrasonic- and IMU-Based High-Precision UAV Localization for the Low-Cost Autonomous Inspection in Oil and Gas Pressure Vessels
Beiya Yang, Erfu Yang, Leijian Yu, Cong Niu
Abstract
With the increasing demands for unmanned aerial vehicle (UAV)-based autonomous inspections in the oil and gas industry, one of the challenging issues for 3-D UAV positioning has emerged due to the satellite signal blocking. Considering the existing characteristics of the ultrasonic-based technique, such as the low cost, extremely lightweight, and high positioning accuracy, it can be promising as the potential solution. Nevertheless, the low position update rate and vulnerable positioning performance to the changing environment still limit its applications on UAV. Therefore, in this article, an ultrasonic- and inertial measurement unit (IMU)-based localization algorithm and low-cost UAV autonomous inspection system are presented. With the incorporation of the IMU, the position update rate, accuracy, and stability of the algorithm can all be significantly improved. This is done by the adaptively estimated noise covariance matrices through the proposed adaptive extended Kalman filter algorithm and the added weighting factors. Followed by, an additional virtual observation process is presented to overcome the unavailability of the observation information for further performance improvement. Finally, extensive numerical results and field tests demonstrate that the proposed algorithm and system can achieve the high update rate, reliable, accurate, and precision UAV positioning in oil and gas pressure vessels and are feasible for the UAV autonomous inspection in these environments.