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Creators/Authors contains: "Papachristos, C."

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  1. null (Ed.)
    This paper presents a novel strategy for the autonomous deployment of Micro Aerial Vehicle scouts through constricted aperture-like ingress points, by narrowly fitting and launching them with a high-precision Mobile Manipulation robot. A significant problem during exploration and reconnaissance into highly unstructured environments, such as indoor collapsed ones, is the encountering of impassable areas due to their constricted and rigid nature. We propose that a heterogeneous robotic system-of-systems armed with manipulation capabilities while also ferrying a fleet of micro-sized aerial agents, can deploy the latter through constricted apertures that marginally fit them in size, thus allowing them to act as scouts and resume the reconnaissance mission. This work's contribution is twofold: first, it proposes active-vision based aperture detection to locate candidate ingress points and a hierarchical search-based aperture profile analysis to position a MAV's body through them, and secondly it presents and experimentally demonstrates the novelty of a system-of-systems approach which leverages mobile manipulation to deploy other robots which are otherwise incapable of entering through extremely narrow openings. 
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  2. null (Ed.)
    This work addresses the rapidly-prototyped design of a small Tricopter/Fixed-Wing Vertical Take-Off and Landing UAS with solar-recharge-capability, capable of repeatedly landing, recharging, and taking off, without need for physical intervention or externally placed maintenance devices or platforms. The design uses Fused Deposition Modeling 3D printing to rapidly prototype and fabricate the majority of the aircraft structures and parts. Provisions are made for carrying high-level single board computing solutions, or other similar payloads. Details are provided for mechanisms, aerodynamic geometry, solar cell integration and manufacturability. The design is analyzed to estimate inertial moments, aerodynamic performance, and static and dynamic stability. Simulation models for the Gazebo and RealFlight environments are provided, targeting Software-In-The-Loop architectures that run the ArduPilot and PX4 flight stacks. A flight testing methodology is developed, and results are presented with multiple prototype vehicles constructed. We finally contribute all production definitions, files, and models as open-access resources, with the goal of supporting and promoting migratory/swarming behavior and autonomy research. 
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  3. null (Ed.)
    This paper addresses the problem of autonomously deploying an unmanned aerial vehicle in non-trivial settings, by leveraging a manipulator arm mounted on a ground robot, acting as a versatile mobile launch platform. As real-world deployment scenarios for micro aerial vehicles such as searchand- rescue operations often entail exploration and navigation of challenging environments including uneven terrain, cluttered spaces, or even constrained openings and passageways, an often arising problem is that of ensuring a safe take-off location, or safely fitting through narrow openings while in flight. By facilitating launching from the manipulator end-effector, a 6- DoF controllable take-off pose within the arm workspace can be achieved, which allows to properly position and orient the aerial vehicle to initialize the autonomous flight portion of a mission. To accomplish this, we propose a sampling-based planner that respects a) the kinematic constraints of the ground robot / manipulator / aerial robot combination, b) the geometry of the environment as autonomously mapped by the ground robots perception systems, and c) accounts for the aerial robot expected dynamic motion during takeoff. The goal of the proposed planner is to ensure autonomous collision-free initialization of an aerial robotic exploration mission, even within a cluttered constrained environment. At the same time, the ground robot with the mounted manipulator can be used to appropriately position the take-off workspace into areas of interest, effectively acting as a carrier launch platform. We experimentally demonstrate this novel robotic capability through a sequence of experiments that encompass a micro aerial vehicle platform carried and launched from a 6-DoF manipulator arm mounted on a four-wheel robot base. 
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