Drogue tracking using 3D flash lidar for autonomous aerial refueling

Abstract

Autonomous aerial refueling (AAR) is an important capability for an unmanned aerial vehicle (UAV) to increase its flying range and endurance without increasing its size. This paper presents a novel tracking method that utilizes both 2D intensity and 3D point-cloud data acquired with a 3D Flash LIDAR sensor to establish relative position and orientation between the receiver vehicle and drogue during an aerial refueling process. Unlike classic, vision-based sensors, a 3D Flash LIDAR sensor can provide 3D point-cloud data in real time without motion blur, in the day or night, and is capable of imaging through fog and clouds. The proposed method segments out the drogue through 2D analysis and estimates the center of the drogue from 3D point-cloud data for flight trajectory determination. A level-set front propagation routine is first employed to identify the target of interest and establish its silhouette information. Sufficient domain knowledge, such as the size of the drogue and the expected operable distance, is integrated into our approach to quickly eliminate unlikely target candidates. A statistical analysis along with a random sample consensus (RANSAC) is performed on the target to reduce noise and estimate the center of the drogue after all 3D points on the drogue are identified. The estimated center and drogue silhouette serve as the seed points to efficiently locate the target in the next frame.

Docking navigation method for UAV autonomous aerial refueling

“…The robust pose estimation algorithm proposed in [11] effectively avoids the problem of "position and pose blur" and improves the accuracy of position and pose estimation. A novel method with an inverse projection ray approach and a new tracking method with a 3D flash light detection and ranging sensor were established to determine the relative position and pose between the UAV and RCS in [12,13]. A new visual pose estimation method based on a circle feature was proposed in [14].…”

A binocular vision-based UAVs autonomous aerial refueling platform

“…Under this circumstance, autonomous aerial refueling (AAR) becomes an important capability for the future employment of UAVs. Vision based sensor and navigation system are widely used in AAR, while experiments are done for both probe-and-drogue refueling system [7][8][9][10] and boom approach [11,12]. To detect the drogue, a set of beacons mounted on the drogue can be supervised by a VisNav sensor [7], and 3D flash lidar is also used for drogue tracking [8].…”

Autonomous Aerial Refueling Ground Test Demonstration—A Sensor-in-the-Loop, Non-Tracking Method

“…It is still a difficult problem to reconstruct 3D information reliably from 2D images due to the inherent ambiguity caused by projective geometry [ 41 , 42 , 43 ] and the benefits of using 2.5D information in robotic systems for various tasks have been documented [ 44 , 45 ]. For probe-and-drogue autonomous aerial refueling application specifically, using a time-of-flight (ToF) based 3D Flash LIDAR system [ 46 , 47 ] to acquire information of the drogue in 3D space has been proposed in Chen and Stettner’s work [ 48 ]. They utilized the characteristics of the 2.5D data sensor provided and adopted a level set method (LSM) [ 49 , 50 ] to segment out the drogue for target tracking purposes.…”

“…We encourage readers who are interested in navigation and control aspects of the unmanned systems to consult more domain specific references, such as [ 51 , 52 , 53 ]. This paper employs a 3D Flash LIDAR camera as the source of the input data, but differs from [ 48 ] in that this paper suggests a sensor-in-the-loop method incorporating both hardware and software elements. In addition, a ground feasibility test was performed to demonstrate the potential for in air autonomous aerial refueling tasks.…”