Drones
An Aerial Transport System in Marine GNSS-Denied Environment
Sun, Jianjun, Niu, Zhenwei, Dong, Yihao, Zhang, Fenglin, Din, Muhayy Ud, Seneviratne, Lakmal, Lin, Defu, Hussain, Irfan, He, Shaoming
This paper presents an autonomous aerial system specifically engineered for operation in challenging marine GNSS-denied environments, aimed at transporting small cargo from a target vessel. In these environments, characterized by weakly textured sea surfaces with few feature points, chaotic deck oscillations due to waves, and significant wind gusts, conventional navigation methods often prove inadequate. Leveraging the DJI M300 platform, our system is designed to autonomously navigate and transport cargo while overcoming these environmental challenges. In particular, this paper proposes an anchor-based localization method using ultrawideband (UWB) and QR codes facilities, which decouples the UAV's attitude from that of the moving landing platform, thus reducing control oscillations caused by platform movement. Additionally, a motor-driven attachment mechanism for cargo is designed, which enhances the UAV's field of view during descent and ensures a reliable attachment to the cargo upon landing. The system's reliability and effectiveness were progressively enhanced through multiple outdoor experimental iterations and were validated by the successful cargo transport during the 2024 Mohamed BinZayed International Robotics Challenge (MBZIRC2024) competition. Crucially, the system addresses uncertainties and interferences inherent in maritime transportation missions without prior knowledge of cargo locations on the deck and with strict limitations on intervention throughout the transportation.
Ukraine's Zelenskyy urges allies to act before N Korean troops reach front
Ukraine's President Volodymyr Zelenskyy has urged its allies to stop "watching" and take steps before North Korean troops deployed in Russia reach the battlefield, and the country's army chief warned that his troops are facing "one of the most powerful offensives" by Moscow since the all-out war started more than two years ago. Zelenskyy raised the prospect of a preemptive Ukrainian strike on camps where the North Korean troops are being trained and said Kyiv knows their location. But he said Ukraine cannot do it without permission from allies to use Western-made long-range weapons to hit targets deep inside Russia. "But instead โฆ America is watching, Britain is watching, Germany is watching. Everyone is just waiting for the North Korean military to start attacking Ukrainians as well," Zelenskyy said in a post late Friday on the Telegram messaging app. The Biden administration said on Thursday that some 8,000 North Korean soldiers are now in Russia's Kursk region near Ukraine's border and are preparing to help the Kremlin fight against Ukrainian troops in the coming days.
Wireless Federated Learning over UAV-enabled Integrated Sensing and Communication
Shaon, Shaba, Nguyen, Tien, Mohjazi, Lina, Kaushik, Aryan, Nguyen, Dinh C.
This paper studies a new latency optimization problem in unmanned aerial vehicles (UAVs)-enabled federated learning (FL) with integrated sensing and communication. In this setup, distributed UAVs participate in model training using sensed data and collaborate with a base station (BS) serving as FL aggregator to build a global model. The objective is to minimize the FL system latency over UAV networks by jointly optimizing UAVs' trajectory and resource allocation of both UAVs and the BS. The formulated optimization problem is troublesome to solve due to its non-convexity. Hence, we develop a simple yet efficient iterative algorithm to find a high-quality approximate solution, by leveraging block coordinate descent and successive convex approximation techniques. Simulation results demonstrate the effectiveness of our proposed joint optimization strategy under practical parameter settings, saving the system latency up to 68.54\% compared to benchmark schemes.
Explainable few-shot learning workflow for detecting invasive and exotic tree species
Gevaert, Caroline M., Pedro, Alexandra Aguiar, Ku, Ou, Cheng, Hao, Chandramouli, Pranav, Javan, Farzaneh Dadrass, Nattino, Francesco, Georgievska, Sonja
Deep Learning methods are notorious for relying on extensive labeled datasets to train and assess their performance. This can cause difficulties in practical situations where models should be trained for new applications for which very little data is available. While few-shot learning algorithms can address the first problem, they still lack sufficient explanations for the results. This research presents a workflow that tackles both challenges by proposing an explainable few-shot learning workflow for detecting invasive and exotic tree species in the Atlantic Forest of Brazil using Unmanned Aerial Vehicle (UAV) images. By integrating a Siamese network with explainable AI (XAI), the workflow enables the classification of tree species with minimal labeled data while providing visual, case-based explanations for the predictions. Results demonstrate the effectiveness of the proposed workflow in identifying new tree species, even in data-scarce conditions. With a lightweight backbone, e.g., MobileNet, it achieves a F1-score of 0.86 in 3-shot learning, outperforming a shallow CNN. A set of explanation metrics, i.e., correctness, continuity, and contrastivity, accompanied by visual cases, provide further insights about the prediction results. This approach opens new avenues for using AI and UAVs in forest management and biodiversity conservation, particularly concerning rare or under-studied species.
Towards Building Secure UAV Navigation with FHE-aware Knowledge Distillation
Kaushik, Arjun Ramesh, Jutla, Charanjit, Ratha, Nalini
In safeguarding mission-critical systems, such as Unmanned Aerial Vehicles (UAVs), preserving the privacy of path trajectories during navigation is paramount. While the combination of Reinforcement Learning (RL) and Fully Homomorphic Encryption (FHE) holds promise, the computational overhead of FHE presents a significant challenge. This paper proposes an innovative approach that leverages Knowledge Distillation to enhance the practicality of secure UAV navigation. By integrating RL and FHE, our framework addresses vulnerabilities to adversarial attacks while enabling real-time processing of encrypted UAV camera feeds, ensuring data security. To mitigate FHE's latency, Knowledge Distillation is employed to compress the network, resulting in an impressive 18x speedup without compromising performance, as evidenced by an R-squared score of 0.9499 compared to the original model's score of 0.9631. Our methodology underscores the feasibility of processing encrypted data for UAV navigation tasks, emphasizing security alongside performance efficiency and timely processing. These findings pave the way for deploying autonomous UAVs in sensitive environments, bolstering their resilience against potential security threats.
China sanctions US drone maker Skydio in ongoing trade war
China has sanctioned Skydio, America's largest drone maker, for providing unmanned aerial vehicles to Taiwan's national fire service. Skydio CEO Adam Bry publicly acknowledged the sanctions on Wednesday. "A few weeks ago, China announced sanctions on Skydio for selling drones to Taiwan, where our only customer today is the National Fire Agency," Bry wrote in a blog post. As first reported by the Financial Times, the ban has sent Skydio racing to find alternative battery suppliers. Although the company manufactures its drones in the US and sources many of the components that go inside of them from outside of China, Skydio had been wholly dependent on a single Chinese provider for batteries before October 11, when the country's government imposed the embargo.
Ukraine prepares to fight North Korean troops in Kursk as war escalates
Ukraine prepared to fight North Korean troops in the Russian region of Kursk on Wednesday, as the entry of a second nuclear power in Russia's war against Ukraine threatened to escalate and broaden the conflict. The United States Pentagon confirmed on Tuesday that North Korean troops were in Kursk, where Ukraine launched a counter-invasion almost three months ago. Pentagon spokesman Pat Ryder said there was "a small number [of North Korean troops] in the Kursk oblast, with a couple of thousand more that are almost there or due to arrive imminently". A senior South Korean official told reporters on Wednesday that about 3,000 North Korean troops were being moved close to the front lines. NATO Secretary-General Mark Rutte confirmed the deployment on Monday.
Drone strikes on civilians suggest new Russian tactics of fear in Ukraine
Just before noon one day Serhiy Dobrovolsky, a hardware trader, returned to his home in Kherson in southern Ukraine. He stepped into his yard, lit a cigarette and chatted with his next-door neighbour. Suddenly, they heard the sound of a drone buzzing overhead. Angela, Serhiy's wife of 32 years, says she saw her husband run and take cover as the drone dropped a grenade. "He died before the ambulance arrived. I was told he was very unlucky, because a piece of shrapnel pierced his heart," she says, breaking down.
Whole-Herd Elephant Pose Estimation from Drone Data for Collective Behavior Analysis
McNutt, Brody, Zhang, Libby, Carey-Douglas, Angus, Vollrath, Fritz, Pope, Frank, Brickson, Leandra
This research represents a pioneering application of automated pose estimation from drone data to study elephant behavior in the wild, utilizing video footage captured from Samburu National Reserve, Kenya. The study evaluates two pose estimation workflows: DeepLabCut, known for its application in laboratory settings and emerging wildlife fieldwork, and YOLO-NAS-Pose, a newly released pose estimation model not previously applied to wildlife behavioral studies. These models are trained to analyze elephant herd behavior, focusing on low-resolution ($\sim$50 pixels) subjects to detect key points such as the head, spine, and ears of multiple elephants within a frame. Both workflows demonstrated acceptable quality of pose estimation on the test set, facilitating the automated detection of basic behaviors crucial for studying elephant herd dynamics. For the metrics selected for pose estimation evaluation on the test set -- root mean square error (RMSE), percentage of correct keypoints (PCK), and object keypoint similarity (OKS) -- the YOLO-NAS-Pose workflow outperformed DeepLabCut. Additionally, YOLO-NAS-Pose exceeded DeepLabCut in object detection evaluation. This approach introduces a novel method for wildlife behavioral research, including the burgeoning field of wildlife drone monitoring, with significant implications for wildlife conservation.
Redundant Observer-Based Tracking Control for Object Extraction Using a Cable Connected UAV
Marshall, Benjamin J., Yan, Yunda, Knowles, James, Yang, Chenguang, Liu, Cunjia
A new disturbance observer based control scheme is developed for a quadrotor under the concurrent disturbances from a lightweight elastic tether cable and a lumped vertical disturbance. This elastic tether is unusual as it creates a disturbance proportional to the multicopter's translational movement. This paper takes an observer-based approach to estimate the stiffness coefficient of the cable and uses the system model to update the estimates of the external forces, which are then compensated in the control action. Given that the tethered cable force affects both horizontal channels of the quadrotor and is also coupled with the vertical channel, the proposed disturbance observer is constructed to exploit the redundant measurements across all three channels to jointly estimate the cable stiffness and the vertical disturbance. A pseudo-inverse method is used to determine the observer gain functions, such that the estimation of the two quantities is decoupled and stable. Compared to standard disturbance observers which assume nearly constant disturbances, the proposed approach can quickly adjust its total force estimate as the tethered quadrotor changes its position or tautness of the tether. This is applied to two experiments - a tracking performance test where the multicopter moves under a constant tether strain, and an object extraction test. In the second test, the multicopter manipulates a nonlinear mechanism mimicking the extraction of a wedged object. In both cases, the proposed approach shows significant improvement over standard Disturbance Observer and Extended State Observer approaches. A video summary of the experiments can be found at https://youtu.be/9gKr13WTj-k.