Browsing by Author "Pomares, Jorge"

Now showing 1 - 11 of 11
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    Direct visual servoing and interaction control for a two-arms on-orbit servicing spacecraft
    (Elsevier, 2021-12-29) Ramón, José Luis; Pomares, Jorge; Felicetti, Leonard
    A direct visual-servoing algorithm for control of a space-based two-arm manipulator is proposed in this paper. The algorithm can be utilized in a two-arm manipulators configuration, where one of the arms performs the manipulation and the second arm is dedicated to the observation of the target zone of manipulation. The algorithm utilizes both visual features extracted from onboard cameras and force and torque measured at the manipulator's end-effector to control the movements of the manipulator during on-orbit servicing operations. The algorithm takes into account the relative dynamics of the bodies involved, it relies on images taken independently from de-localized cameras, e.g. at the end-effector of a second manipulator, and it integrates an impedance control for the compensation of eventual contact reactions when the end effector touches and operates the target body. The analytical derivations demonstrate the stability of the algorithm and incorporate an impedance compliance strategy into an optimal framework formulation. Simulations results in two different scenarios have been presented to show the adequate behavior of the presented approach in on-orbit-servicing operations.
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    Image-based visual servoing control for spacecraft formation flying
    (IEEE, 2020-08-21) Felicetti, Leonard; Pomares, Jorge
    This paper proposes an image-based visual-servoing algorithm that allows for optimal formation control. The proposed distributed controller utilizes visual features of other team members, retrieved from images captured by onboard cameras, to autonomously plan and perform formation acquisition, keeping or reconfiguration maneuvers. The problems of minimization of the control effort is analyzed and the paper proposes an optimal framework for developing controllers that address the issue. The viability of such a technique is explored through numerical simulations.
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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).
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    On-orbit free-floating manipulation using a two-arm robotic system
    (Scitepress, 2021-10-27) Ramón, José Luis; Pomares, Jorge; Felicetti, Leonard
    A direct visual-servoing algorithm is proposed for the control of a space-based two-arm manipulator. The scenario under consideration assumes that one of the arms performs the manipulation task while the second one has an in-hand camera to observe the target zone of manipulation. The algorithm uses both the camera images and the force/torque measurements as inputs to calculate the control action to move the arms to perform a manipulation task. The algorithm integrates the multibody dynamics of the robotic system in a visual servoing framework that uses de-localized cameras. Impedance control is then used to compensate for eventual contact reactions when the end effector touches and operates the target body. Numerical results demonstrate the suitability of the proposed algorithm in specific tasks used in on-orbit servicing operations.
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    Path generation and control of humanoid robots during extravehicular activities
    (International Astronautical Federation (IAF), 2022-09-22) Ramón, José Luis; Calvo, R.; Trujillo, A.; Pomares, Jorge; Felicetti, Leonard
    This paper proposes and investigates strategies that can be used to plan the motion and control of humanoid robots in some elementary tasks that characterize extravehicular activities. The humanoid robot taken into account is a torso with two arms and two grippers at their extremities. This study addresses the problem of robot motion on the complex system of handrails and handles that characterize the International Space Station. Such a complex task has been divided into two elementary sub-tasks: motion planning and tracking the planned trajectories. First, an optimization procedure is presented to plan and coordinate the robot's arms motions and graspers to achieve the desired location using handrails. Then, a low-level controller is used to guarantee that the robots' actuators can follow these previously generated trajectories. Simulation results assess the applicability of the proposed strategy in different typical operations that potentially can be performed in an extravehicular activity scenario.
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    A ROS/Gazebo-based framework for simulation and control of on-orbit robotic systems
    (International Astronautical Federation (IAF), 2022-09-22) Ramón, José Luis; Pomares, Jorge; Felicetti, Leonard
    The use of simulation tools such as ROS/Gazebo is currently common practice for testing and developing control algorithms for typical ground-based robotic systems but still is not commonly accepted within the space community. Numerous studies in this field use ad-hoc built, but not standardized, not open-source, and, sometimes, not verified tools that complicate, rather than promote, the development and realization of versatile robotic systems and algorithms for space robotics. This paper proposes an open-source solution for space robotics simulations called OnOrbitROS. This paper presents a description of the architecture, the different software modules, and the simulation possibilities of OnOrbitROS. It shows the key features of the developed tool, with a particular focus on the customization of the simulations and eventual possibilities of further expansion of the tool. In order to show these capabilities, a computed torque-based controller for the guidance of a free-floating manipulator is proposed and simulated using the ROS/Gazebo-based framework described in the paper.
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    Spacecraft formation keeping and reconfiguration using optimal visual servoing
    (Springer, 2024-03-26) Pomares, Jorge; Felicetti, Leonard; García, Gabriel J.; Ramón, José L.
    This paper proposes a direct visual servoing system for spacecraft guidance in formation flying scenarios. The proposed image-based visual servoing system uses image information for planning and executing formation acquisition, reconfiguration, and maintenance maneuvers. The system assumes that LEDs are located at specific points on the satellites, enabling the visual servoing controller to rely on continuous tracking of these features in the camera’s image plane. Analytical developments demonstrate that the proposed optimal visual control system is stable and optimal, and it acts on both the orbital and attitude dynamics of the spacecraft, considering circular and elliptical reference orbits. The distributed image-based controller defines a cost function that minimizes control efforts, and the paper proses an optimal framework for developing controllers that address the issue. A ROS-based simulation tool was used to test the proposed visual servoing controller in a realistic small-sat formation flying scenario. Results indicate that the proposed distributed control strategy is viable and robust against environmental perturbations and disturbances in sensing and actuation.
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    Task space control for on-orbit space robotics using a new ROS-based framework
    (Elsevier, 2023-06-17) Ramón, José Luis; Pomares, Jorge; Felicetti, Leonard
    This paper proposes several task space control approaches for complex on-orbit high degrees of freedom robots. These approaches include redundancy resolution and take the non-linear dynamic model of the on-orbit robotic systems into account. The suitability of the proposed task space control approaches is explored in several on-orbit servicing operations requiring visual servoing tasks of complex humanoid robots. A unified open-source framework for space-robotics simulations, called OnOrbitROS, is used to evaluate the proposed control systems and compare their behaviour with state-of-the-art existing ones. The adopted framework is based on ROS and includes and reproduces the principal environmental conditions that eventual space robots and manipulators could experience in an on-orbit servicing scenario. The architecture of the different software modules developed and their application on complex space robotic systems is presented. Efficient real-time implementations are achieved using the proposed OnOrbitROS framework. The proposed controllers are applied to perform the guidance of a humanoid robot. The robot dynamics are integrated into the definition of the controllers and an analysis of the results and practical properties are described in the results section.
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    Trajectory optimization and control of a free-floating two arms humanoid robot
    (AIAA, 2022-05-02) Ramón, José Luis; Calvo, Ramon; Trujillo, Adrian; Pomares, Jorge; Felicetti, Leonard
    An optimization algorithm for planning the motion of a humanoid robot during extravehicular activities is presented in this paper. The algorithm can schedule and plan the movements of the two robotic arms to move the humanoid robot by using the handrails present outside the international space station. The optimization algorithm considers the eventual constraints imposed by the topology of the handrails and calculates the sequence of grasping and non-grasping phases needed to push and pull the robot along the handrails. A low-level controller is also developed and used to track the planned arms and end-effectors trajectories. Numerical simulations assess the applicability of the proposed strategy in three different typical operations that potentially can be performed in an extravehicular activity scenario.
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    Trajectory optimization and control of multipod robots in on-orbit servicing operations
    (European Space Agency (ESA), 2023) Pomares, Jorge; Ramon, José Luis; Felicetti, Leonard; Olivares-Mendez, Miguel A.
    This paper presents a trajectory optimization method applied to multipod robots performing extravehicular activities. The presented approach automatically determines the leg motion required to achieve a desired location on the exterior of the target spacecraft. A 3D camera is located at the robot body, and a 3D map of the target spacecraft is generated from the point cloud. A trajectory optimization is obtained given the system's initial and desired state, the manoeuvre's total duration, and the number of steps for each leg. From this information, the trajectory optimization approach generates the legs trajectories and contact forces required to guide the multipod robot. Numerical simulations assess the applicability of the proposed strategy in typical operations that can potentially be performed in an extravehicular activity scenario.
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    Visual guidance of an on-orbit free-floating manipulator using a mobile camera
    (Springer, 2022-11-10) Ramón, José Luis; Pomares, Jorge; Felicetti, Leonard
    A direct visual-servoing algorithm for control a space-based manipulator is proposed. A two-arm manipulator is assumed as a baseline scenario for this investigation, with one of the arms performing the manipulation and the second arm dedicated to the observation of the target zone of manipulation. The algorithm relies on images taken independently from de-localized cameras, e.g. at the end-effector of a second manipulator. Through the implementation of a Kalman filter, the algorithm can estimate the movements of the features in the image plane due to the relative movements between the camera and the target and then calculate the torques to be provided to the joints of the manipulator by adopting a visual servoing control strategy. Simulations results in two different scenarios have been presented to show an adequate behaviour of the presented approach in on-orbit-servicing operations.