Browsing by Author "Varagnolo, Damiano"

Now showing 1 - 3 of 3
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    Collision-avoiding model predictive rendezvous strategy to tumbling launcher stages
    (AIAA, 2023-06-07) Ramírez, Jesús; Felicetti, Leonard; Varagnolo, Damiano
    This paper considers the situation where a small satellite shall autonomously rendezvous with a tumbling object in a circular low Earth orbit (LEO) and derives a path-based model predictive controller that uses the docking point state and position of the chaser to guide it to a safe docking autonomously. The strategy embeds collision avoidance elements and reduces the computational effort for calculating the pulses to be provided by the thrusters through opportune algebraic manipulations, a Runge–Kutta 4 propagation method using linearized state transition matrices, and implicit embedding of dynamically equivalent thrust models, leading to constant state propagation matrices. Furthermore, the inputs design optimization problem and the embedded collision avoidance scheme are modeled and explicitly crafted as convex problems, contributing positively to low computational requirements. The docking and collision avoidance capabilities of the proposed scheme are extensively tested in an environment that accounts for all the perturbations relevant to LEO frameworks, for realistic thrust schemes, and for uncertainties in the measurement. Numerical results assess which tumbling objects can be docked or not by means of the proposed schemes as a function of the tumbling rates versus the thrust capabilities and hardware uncertainty of the docker.
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    A computationally efficient model predictive control scheme for space debris rendezvous
    (Elsevier, 2019-11-25) Larsén, Alexander Korsfeldt; Chen, Yutao; Bruschetta, Mattia; Carli, Ruggero; Cenedese, Angelo; Varagnolo, Damiano; Felicetti, Leonard
    We propose a non-linear model predictive scheme for planning fuel efficient maneuvers of small spacecrafts that shall rendezvous space debris. The paper addresses the specific issues of potential limited on-board computational capabilities and low-thrust actuators in the chasing spacecraft, and solves them by using a novel MatLab-based toolbox for real-time non-linear model predictive control (MPC) called MATMPC. This tool computes the MPC rendezvous maneuvering solution in a numerically efficient way, and this allows to greatly extend the prediction horizon length. This implies that the overall MPC scheme can compute solutions that account for the long time-scales that usually characterize the low-thrust rendezvous maneuvers. The so-developed controller is then tested in a realistic scenario that includes all the near- Earth environmental disturbances. We thus show, through numerical simulations, that this MPC method can successfully be used to perform a fuel-efficient rendezvous maneuver with an uncontrolled object, plus evaluate performance indexes such as mission duration, fuel consumption, and robustness against sensor and process noises.
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    Multi-robot systems for space applications [Editorial]
    (Frontiers, 2023-07-25) Pomares, Jorge; Felicetti, Leonard; Varagnolo, Damiano
    The utilization of robotic systems in space is currently enabling new mission concepts and applications for both in-orbit operations Papadopoulos et al. (2021) and off-world exploration and exploitation Zarei and Chhabra (2022). Space robots are foreseen as essential for numerous on-orbit operations (e.g., servicing, assembly, and manufacturing), and their utilization in ongoing and under-development missions seems already consolidated or, in any case, achievable in a relatively short time Flores-Abad et al. (2014).