Browsing by Author "Platanitis, Konstantinos"

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    A causal learning approach to in-orbit inertial parameter estimation for multi-payload deployers
    (International Astronautical Federation (IAF), 2024-10-18) Platanitis, Konstantinos; Arana-Catania, Miguel; Upadhyay, Saurabh; Felicetti, Leonard
    This paper discusses an approach to inertial parameter estimation for the case of cargo carrying spacecraft that is based on causal learning, i.e. learning from the responses of the spacecraft, under actuation. Different spacecraft configurations (inertial parameter sets) are simulated under different actuation profiles, in order to produce an optimised time-series clustering classifier that can be used to distinguish between them. The actuation is comprised of finite sequences of constant inputs that are applied in order, based on typical actuators available. By learning from the system’s responses across multiple input sequences, and then applying measures of time-series similarity and F1-score, an optimal actuation sequence can be chosen either for one specific system configuration or for the overall set of possible configurations. This allows for both estimation of the inertial parameter set without any prior knowledge of state, as well as validation of transitions between different configurations after a deployment event. The optimisation of the actuation sequence is handled by a reinforcement learning model that uses the proximal policy optimisation (PPO) algorithm, by repeatedly trying different sequences and evaluating the impact on classifier performance according to a multi-objective metric.
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    Implementation of a federated laboratories network for testing formation flying technologies
    (International Astronautical Federation (IAF), 2024-10-18) Sabatini, Marco; Felicetti, Leonard; Shufflebotham, Alex; Leslie, Cameron; Upadhyay, Saurabh; Platanitis, Konstantinos; Laufer, Rene; Persson, Olle; Rao Ramavaram, Harish
    Formations of microsatellites are a highly attractive solution for achieving responsive space missions focused on Earth observation and communication support, due to their low cost and mass. However, operating these formations is challenging and requires extensive testing, which can be difficult to carry out due to the need for multiple platforms and large testing spaces. This paper presents the first concept and the first steps of a research program funded by NATO in the framework of the Science for Peace and Security program, with the specific purpose to develop and evaluate the necessary infrastructure for establishing a virtual, multi-platform distributed laboratory network comprised of laboratories from Sapienza, Lulea and Cranfield Universties. The value of this network will be increased by sharing resources, equipment, and expertise among the participating laboratories.
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    Robust sliding mode controller design for orbital payload deploying spacecraft
    (Council of European Aerospace Societies (CEAS) , 2024-06-11) Platanitis, Konstantinos; Felicetti, Leonard; Upadhyay, Saurabh; Capicchiano, Leonardo
    This work demonstrates the feasibility of usage of a sliding mode controller in the case of orbital payload deployers. The proposed control law suggested herein allows for disturbance rejection during the payload deployment phase, as well as provide a basis for angular rate tracking purposes. The stability of the control law is determined by Lyapunov theory, and realistic spacecraft simulations have been created to verify the robustness in the presence of disturbances as well as the general tracking capabilities.