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Unmanned manipulator-equipped satellite could perform on-orbit servicing mission or could be used to remove large space debris from orbit. Planning a manipulator trajectory that will lead to a safe capture of a selected grasping point on the target object is a challenging task, as the satellite-manipulator system is in a free-floating state. Moreover, complicated structure of the target satellite...
In this paper, we propose a dual shooting manipulation system for a cooperative string looping. The string looping is cooperative manipulation by two flexible arms. One shooting manipulation system named “loop arm” passes behind a target from one side, and it is captured by the other named “hook arm” at the opposite side of the target. By the string looping, the dual shooting manipulation system achieves...
Inverse kinematics is an active research domain in robotics since several years due to its importance in multiple robotics application. Among the various approaches, differential inverse kinematics is widely used due to the possibility to real-time implementation. Redundant robotic systems exhibit more degrees of freedom than those strictly required to execute a given end-effector task, in such a...
This paper deals with the problem of interpolation of generated end-effector trajectories for application in robotics. For complex shaped trajectories there are often many high resolution coincident points generated from CAD/CAM systems or trajectory generators. The preprocessing (refining) is necessary for proceeding these points to the manipulator control system. Two interpolation methods are discussed:...
The problem of improving the stability of a mobile manipulator over a sloped terrain is addressed in the present work. Such an improvement is achieved by finding the location of the manipulator's center of mass that maximizes the overall quasi-static stability, defined here as the force-angle stability, using a stochastic optimization approach known as the Covariance Matrix Adaptation. The tracking...
We present a randomized kinodynamic planner that solves rearrangement planning problems. We embed a physics model into the planner to allow reasoning about interaction with objects in the environment. By carefully selecting this model, we are able to reduce our state and action space, gaining tractability in the search. The result is a planner capable of generating trajectories for full arm manipulation...
We present an incremental method for motion generation in environments with unpredictably moving and initially unknown obstacles. The key to the method is its incremental nature: it locally augments and adapts global motion plans in response to changes in the environment, even if they significantly change the connectivity of the world. The restriction to local changes to a global plan results from...
A novel algorithm is proposed for offline motion planning of a robotic arm to perform a throw task of an object to reach a goal target. The planning algorithm searches for a throw trajectory that could be performed under kinematic and dynamic (i.e., kinodynamic) constraints. We parameterize the throw trajectory by a time-invariant high-dimensional vector. Then, the kinodynamic and target constraints...
This paper considers pick-and-place tasks using aerial vehicles equipped with manipulators. The main focus is on the development and experimental validation of a nonlinear model-predictive control methodology to exploit the multi-body system dynamics and achieve optimized performance. At the core of the approach lies a sequential Newton method for unconstrained optimal control and a high-frequency...
Robot manipulator teaching is a time consuming procedure where qualified operator programs the execution path. In this paper we introduce and discuss the improvement of traditional teaching method with application of hand gesture recognition system. The paper presents the most common robot programming and hand gesture recognition issues and presents the possibility of joining this two research fields.
The aim of this work is to design, analyze and test the behaviour of first-order CLIK (Closed-Loop Inverse Kinematics) manipulator algorithms under the influence of Cartesian integral error feedback. Although CLIK algorithms has been widely and successfully applied in robot manipulators with structured workspaces, in aerial manipulators the lack of structured workspaces is highly demanding for the...
We are proposing a general framework that incorporates multiple task definitions in the prioritized inverse kinematics problem. First, a mathematical description of multiple task definitions is constructed that provides an efficient way to show unprioritized or prioritized accumulations of tasks. Then, smooth transitions between all task definitions are studied, so a method, called task transition...
Throwing an object by a powered robot system is of great importance in unmanned environments. In this paper, we consider the problem of throwing a point-mass object to minimize uncertainty in the object's landing position, given uncertainty in (1) the robot's initial configuration and (2) friction at the joints. Our analysis assumes that the robot's throw is executed using open-loop torque commands,...
For a mobile manipulator to interact with large everyday objects, such as office tables, it is often important to have dynamic models of these objects. However, as it is infeasible to provide the robot with models for every possible object it may encounter, it is desirable that the robot can identify common object models autonomously. Existing methods for addressing this challenge are limited by being...
The performance of feedforward controllers is known to be subject to the accuracy of the mathematical models used for controlled objects. To obtain an accurate mathematical model for a single-link flexible manipulator, we perform nonlinear modeling based on large-deflection theory. A feedforward vibration control technique is applied to the resulting mathematical model in which we consider point-to-point...
In the present work, a method based on belief space planning, assuming maximum likelihood of the observations, is applied to the planning of manipulation for an underwater robotic arm. The manipulator is rigidly connected to a floating platform, such as a ROV (Remotely Operated Vehicle) or an AUV (Autonomous Underwater Vehicle). The arm and platform motions are statistically independent from the motion...
Mobile manipulators are robots able to accomplish complicated missions, requiring the conjunction of the mobility and the manipulation. This paper is centred on the study of the movement of a single-armed wheeled vehicle. The mobile robot provides mobility to the robotic arm, and adds more degrees of freedom. Manipulation tasks might be, thus, performed in a large workspace. Human can often be replaced...
Recent efforts in the field of intervention-autonomous underwater vehicles (I-AUVs) have started to show promising results in simple manipulation tasks. However, there is still a long way to go to reach the complexity of the tasks carried out by ROV pilots. This paper proposes an intervention framework based on parametric Learning by Demonstration (p-LbD) techniques in order to acquire multiple strategies...
This paper presents algorithms for optimal selection of needle grasp, for autonomous robotic execution of the minimally invasive surgical suturing task. In order to minimize the tissue trauma during the suturing motion, the best practices of needle path planning that are used by surgeons are applied for autonomous robotic surgical suturing tasks. Once an optimal needle trajectory in a well-defined...
In this work, we propose a constraint-based algorithm for combined trajectory generation and kinematic control for robotic manipulators. The main feature of the algorithm is to ease robot programming, shifting from an imperative paradigm, in which task constraints are semantically and uniquely mapped into a suitable end-effector velocity profile, towards a declarative motion programming, where such...
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