Low-cost mini-drones with advanced sensing and maneuverability enable a new class of intelligent sensing systems. This trend motivated several research efforts to employ drones as standalone systems or to assist legacy deployments. However, several fundamental challenges remain unsolved including: 1) Adequate coverage of sizable targets; 2) Target orientation that render coverage effective only from certain view points; 3) Occlusion by elements in the environment, including other targets. In this paper, we present Argus, a system that provides coverage of wide and oriented targets, using camera-mounted drones, taking into account the challenges stated above. Argus relies on a geometric model that captures both target shapes and coverage constraints. With drones being the scarcest resource in Argus, we study the problem of minimizing the number of drones required to cover a set of such targets and derive a best-possible approximation algorithm. Furthermore, we present a sampling heuristic that yields a comparable performance, yet is up to 100x faster than the approximation algorithm. We build a prototype of Argus to demonstrate and evaluate the proposed coverage algorithms as part of a complete autonomous surveillance system. We evaluate the proposed algorithms using simulations to compare their performance at scale under various conditions. Finally, we present extensions and discuss open problems related to the studied problem.
There is significant interest in using drones and drone swarms for surveillance and video capture @cite_41 . Challenges of executing capturing video using using drones has been studied in @cite_8 including low quality footage due to distance and the need to adapt to target mobility. Several proposals have been made for mobile target tracking using a single drone @cite_25 and persistent tracking by handing over targets between multiple drones @cite_39 . Such applications focus on having target in view while not focusing on the angle the target is viewed from. Another direction of using drones for video capture is autonomous cinematography where not only having and maintaining targets in view is important, but also the aesthetic quality plays a role in the selection of footage @cite_46 . In earlier work, we developed several target coverage algorithms for targets represented as points and deployed them on our testbed @cite_1 @cite_38 @cite_18 .
@cite_38 @cite_18 @cite_8 @cite_41 @cite_1 @cite_39 @cite_46 @cite_25
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Mobile wireless sensor networks have been extensively deployed for enhancing environmental monitoring and surveillance. The availability of low-cost mobile robots equipped with a variety of sensors makes them promising in target coverage tasks. They are particularly suitable where quick, inexpensive, or nonlasting visual sensing solutions are required. In this paper, we consider the problem of low complexity target tracking to cover and follow moving targets using flying robots. We tackle this problem by clustering targets while estimating the camera location and orientation for each cluster separately through a cover-set coverage method. We also leverage partial knowledge of target mobility to enhance the efficiency of our proposed algorithms. Three computationally efficient approaches are developed: predictive fuzzy , predictive incremental fuzzy , and local incremental fuzzy . The objective is to find a compromise among coverage efficiency, traveled distance, number of drones required, and complexity. The targets move according to one of the following three possible mobility patterns: random waypoint, Manhattan grid, and reference point group mobility patterns. The feasibility of our algorithms and their performance are also tested on a real-world indoor testbed called drone-be-gone , using Parrot AR.Drone quadcopters. The deployment confirms the results obtained with simulations and highlights the suitability of the proposed solutions for real-time applications. Swarms of Unmanned Aerial Vehicles (drones) could provide great benefit when used for disaster response and indoor search and rescue scenarios. In these harsh environments where GPS availability cannot be ensured, prior work often relies on cameras for control and localization. This creates the challenge of identifying each drone, i.e., finding the association between each physical ID (such as their radio address) and their visual ID (such as an object tracker output). To address this problem, prior work relies on visual cues such as LEDs or colored markers to provide unique information for identification. However, these methods often increase deployment difficulty, are sensitive to environmental changes, not robust to distance and might require hardware changes. In this paper, we present IDrone, a robust physical drone identification system through motion matching and actuation feedback. The intuition is to (1) identify each drone by matching the motion detected through their inertial sensors and from an external camera, and (2) control the drones so they move in unique patterns that allow for fast identification, while minimizing the risk of collision involved in controlling drones with uncertain identification. To validate our approach, we conduct both simulation and real experimentation with autonomous drones for the simplified case of a stationary Spotter (powerful drone equipped with the camera). Overall, our initial results show that our approach offers a great tradeoff between fast identification and small collision probability. In particular, IDrone achieves faster identification time than safety-based baseline actuation (one-at-a-time), and significantly higher survival rate compared to fast, non-safety-based baseline actuation (random motion). Persistent surveillance of large geographic areas from unmanned aerial vehicles allows us to learn much about the daily activities in the region of interest. Nearly all of the approaches addressing tracking in this imagery are detection-based and rely on background subtraction or frame differencing to provide detections. This, however, makes it difficult to track targets once they slow down or stop, which is not acceptable for persistent tracking, our goal. We present a multiple target tracking approach that does not exclusively rely on background subtraction and is better able to track targets through stops. It accomplishes this by effectively running two trackers in parallel: one based on detections from background subtraction providing target initialization and reacquisition, and one based on a target state regressor providing frame to frame tracking. We evaluated the proposed approach on a long sequence from a wide area aerial imagery dataset, and the results show improved object detection rates and ID-switch rates with limited increases in false alarms compared to the competition. Recent advancements in manufacturing low-cost wireless battery operated cameras has made their application in Wireless Video Sensor Networks (WVSN) increasingly more feasible and affordable. The application of robotic sensing agents equipped with cameras in WVSNs, seems particularly promising in performing coverage tasks for ad hoc surveillance. Their application in this context can be specifically useful for surveying areas with little to no available or affordable infrastructure, or where quick deployment is necessary. In this paper, we address the target coverage problem for finding the minimum number of cameras, their placement, and orientation to cover arbitrarily located targets in an area of interest. We propose a computationally light-weight heuristic, where the number of used mobile cameras is close to those found by near-optimal algorithms. Specifically, we address this problem for non-uniform target distributions that naturally form clusters. Having light-weight heuristics will be particularly useful when the application is required to adapt to target mobility and or is implemented in embedded systems. Our simulation study shows that when clusters are sufficiently separated, the required number of cameras found by our proposed method is very close to those acquired by the near-optimal algorithm, whereas the computational complexity of our algorithm is about ten times less. We also deploy our algorithm on a drone testbed using off-the-shelf components to verify its feasibility.