23 accepted papers
In this work, we propose a novel control strategy for the displacement of an orbital manipulator equipped with a thruster module at its end-effector. In contrast to the use of base-mounted thrusters, which often leads to allocation problems and fuel inefficiencies, the proposed approach achieves cen
In on-orbit servicing missions using robotic manipulators, certain challenging scenarios require the use of combined control i.e. actuation of spacecraft and the manipulator, to meet mission requirements. The low frequency of the controller of the spacecraft compared to the manipulator can compromis
In on-orbit servicing missions using robotic manipulators, certain challenging scenarios require the use of combined control i.e. actuation of spacecraft and the manipulator, to meet mission requirements. The low frequency of the controller of the spacecraft compared to the manipulator can compromis…
This paper exploits the robotic capabilities of an orbital manipulator equipped with an actuation module at its end-effector to perform close-proximity robotic operations. The proposed control strategy enables repositioning the system's center-of-mass by reconfiguring the manipulator configuration a
In the context of in-orbit assembly, modular building blocks offer the advantage of distributed launches. After the orbit-injection, the overall motion control requires the individual modules to approach each other while regulating their relative shape and the total formation. This kind of formation
The on-ground validation of orbital manipulators is a challenging task because the robot is designed for a gravity-free operational environment, but it is validated under the effect of gravity. As a consequence, joint torque limits can be easily reached in certain configurations when gravity is acti…
In this paper, we propose a detumbling strategy that stabilizes the motion of a tumbling client satellite using an orbital servicing manipulator, which is the goal of the post-grasp phase. One of the critical aspects in this phase is ensuring that excessive contact forces are not generated at the gr…
In this letter, a novel partitioned shared controller is proposed, which exploits a fully-actuated orbital robot to perform a primary end-effector task involving environmental interactions. This task is remotely performed using a bilateral teleoperation controller, while a secondary task is automati
In this letter, we propose a novel method for the on-ground simulation of a space robotic mission, while exploiting a robotic hardware-in-the-loop facility. The simulated dynamics replicated by the robots are defined with respect to a nominal motion. This approach enables simulating the motion of la
This letter presents a compliant feedback controller of an arm-equipped spacecraft, which does not enforce requirements on the spacecraft position and attitude. The controller is applicable to the pre-contact, contact, and post-contact phases of a robotic operation. In contrast to conventional float
Ensuring stability in time-delayed teleoperation can be difficult in some cases where the feedback forces need to be modified as defined by the user, to increase transparency. In the present letter, we propose an approach to ensure stability of any feedback controller selected by the user by conside
In this paper, we propose three novel Hardware-in-the-loop simulation (HLS) methods for a fully-actuated orbital robot in the presence of external interactions using On-Ground Facility Manipulators (OGFM). In particular, a fixed-base and a vehicle-driven manipulator are considered in the analyses. T…
This paper presents a novel telepresence system for enhancing aerial manipulation capabilities. It involves not only a haptic device, but also a virtual reality that provides a 3D visual feedback to a remotely-located teleoperator in real-time. We achieve this by utilizing onboard visual and inertia…
In this letter we design a novel control strategy for a space manipulator operating on a controlled base. The proposed controllers resolve the tracking of the end-effector and the regulation of the base. In particular, we focus on the effects due to the different sampling rates of the manipulator an
In this work we present a novel approach which compensates the destabilising effects of the time delay intrinsic in the control loop of an admittance-controlled robot employed for satellite dynamics simulation. The method is based on an energy storing element, the tank, which is exploited by the con…
In this paper we address the problem of controlling a robotic system mounted on an actuated floating base for space applications. In particular, we investigate the stability issues due to the low rate of the base control unit. We propose a passivity-based stabilizing controller based on the time dom…
This paper presents a passive compliance control for aerial manipulators to achieve stable environmental interactions. The main challenge is the absence of actuation along body-planar directions of the aerial vehicle which might be required during the interaction to preserve passivity. The controlle…
In this letter, a novel method is presented for grasping a partially cooperative tumbling satellite with a free-floating robot. A reference trajectory, provided by an offline motion planner and adapted online to account for modeling uncertainties, is tracked with a visual servo for the approach phas
This paper proposes a passive and explicit integrator for simulating a rotational rigid-body dynamics rendered by a robot. Considering the Euler integration method, active energy terms are identified. These sources of energy are due to the external torque and the coupled dynamics which can lead to a…
In this paper we present a passive and reliable explicit discrete integrator, which allows to preserve the energy and dynamic properties of a physical body rendered on a hardware-in-the-loop simulator. Starting from the standard Euler integrator, we identify the energy generation that results from t…
This paper introduces a performance oriented method for simulating stable free-floating satellite dynamics on a position controlled robot. Intrinsic latencies found in robot controllers, i.e. between input and output data, are known to produce stability issues and performance degradation. These issu…
This paper describes a control strategy to achieve high fidelity dynamics simulation rendered on admittance controlled robotic facilities. It explores the reasons for an increasing energy found in the virtual dynamics of a free-floating satellite rendered on a six degree of freedom robot, which can…
On-orbit servicing involves a new class of space missions in which a servicer spacecraft is launched into the orbit of a target spacecraft, the client. The servicer navigates to the client with the intention of manipulating it, using a robotic arm. Within this framework, this work presents a new rob…