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Nowadays, one of the largest environmental challenges that European countries must face consists in dealing with the past half century of nuclear waste. In order to optimize maintenance costs, nuclear waste must be sorted, segregated and stored according to its radiation level. Towards this end, in [1] we have recently proposed a visual-based shared control architecture meant to facilitate a human...
Despite the availability in the literature of several constraint-based motion generation algorithms, modest attention has been paid to their robustness with respect to noise, and more in general, to unstructured uncertainties. Especially in the case of sensor-related constraints, the envisaged robustness properties are clearly crucial to enforce the correct and expected behaviour of these algorithms...
To predict the trajectory of a motion target floating in an outer space, a nonequidistant fractional-order accumulation (NEFA) model of a visual-based space manipulator is presented in this paper. This model is a modified extrapolate method of trajectory prediction. First, the initial discrete point set of a motion trajectory is real-time accumulated to a fractional-order differential model. Second,...
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...
In this paper, a repetitive assembling task is considered for industrial manipulator, where vision-based precise trajectory tracking is necessary. Conventional visual servoing methods suffer from their poor dynamic performance, while the proposed open-plus-closed loop framework solved this problem by iterative learning. System error is defined by the directly measurable homography matrix and feature...
This paper proposed a visual control method with a relative position measurement model of stereo vision fixed in the work space for the approach movements of 7-DOF redundant manipulator. The relative position between the end-effectors' endpoint and object will be solved in real-time by the measurement model of stereo vision, then using position-based visual servo method, the endpoint position will...
We demonstrate that millimeter-level bimanual manipulation accuracy can be achieved without the static camera registration typically required for visual servoing. We register multiple cameras online, converging in seconds, by visually tracking features on the robot hands and filtering the result. Then, we compute and track continuous-velocity relative workspace trajectories for the end-effector. We...
This paper describes a development of a tracked mobile robot that consists of two tracks and two arms. A rescue robot should be able to not only move and explore in a disaster area but also complete handling tasks by itself. A tracked mobile robot with two 4-degrees-of-freedom arms was developed in this study. The robot can remove an obstacle or handle a target object in its movement by using one...
A novel image based visual servoing (IBVS) method under the predictive control frame is proposed in order to solve the visual tracking problem of robot manipulator with multiple constraints. A vision predictive frame is presented by employing the motion model between camera's velocity and image features. And the design step of vision predictive controller is presented. Then, an effective vision predictive...
Intervention autonomous underwater vehicles (I-AUVs) are a promising platform to perform intervention task in underwater environments, replacing current methods like remotely operate underwater vehicles (ROVs) and manned sub-mersibles that are more expensive. This article proposes a complete system including all the necessary elements to perform a valve turning task using an I-AUV. The knowledge of...
AUVs have experimentally done the first steps to solve basic intervention tasks. First results have been promising in the task of retrieving an object from the seabed. In this paper we extend the complexity of the task with the help of a Learning by Demonstration (LbD) approach. An extension of a LbD algorithm to learn the pose and orientation of the trajectory is presented to achieve a valve turning...
Recently, tele-operated robots are expected to search and rescue victims in a disaster area. However, there is a problem that the operation of rescue robots is too complex. One of this reasons is that an operator has to operate the mobile platform and the manipulator of a rescue robot simultaneously when the operator finds victims. In this study, a control method to coordinate locomotion and manipulation...
We address the problem of incorporating path planning with image-based control of a wheeled mobile manipulator (WMM) performing visually-guided tasks in complex environments. TheWMMconsists of a wheeled (non-holonomic) mobile platform and an on-board robotic arm equipped with a camera mounted at its end-effector. The visually-guided task is to move the WMM from an initial to a desired location while...
In this paper, optimized combined control of a 9-DoF prototype wheelchair-mounted robotic arm (WMRA) system, consisting of a 7-DoF manipulator and a 2-DoF power wheelchair, is demonstrated using vision-based dual-trajectory control that generates separate wheelchair and end-effector trajectories. Physical results of this work are provided with a “Go to and Pick Up” task. Image-based visual servoing...
This paper presents an imitation learning method for object manipulation such as rotating an object or placing one object on another. In the proposed method, motions are learned using reference-point-dependent probabilistic models. Trajectory hidden Markov models (HMMs) are used as the probabilistic models so that smooth trajectories can be generated from the HMMs. The method was evaluated in physical...
This paper describes the system of telecontrol by multi-link manipulator. This system allows carrying out objects grasp by the manipulator in an automatic mode using known position and orientation of these objects. The algorithm of work of computing system which forms setting signals on drives of manipulator is also represented in the paper. The results of executed mathematical simulation confirm...
This paper shows global reconfiguration capability evaluation for redundant manipulator while its hand tracking target trajectory and the shape avoiding obstacle. In this research, aiming at constructing an automation system that can operate a given task to the arbitrarily shaped target object without preparatory operation, we propose a production system composed of redundant manipulator and movable...
In this paper, we shed new light on PBVS (Position-Based Visual Servoing) by introducing the concept of a 3D (Dimension) visible set for PBVS, which can serve to play exactly the role of the 2D visible set, image plane, for IBVS. Our 3D visible set is convex even in the presence of uncertainties in intrinsic and extrinsic parameters of the camera, just as the image plane is a convex set. Then, we...
A new uncalibrated visual servoing approach for motion control of 6-DOF manipulators is presented. Instead of image features, the elements of the scene-independent trifocal tensor of three views is used as features for visual servoing. These trifocal features depend only on the camera projection matrices and can be retrieved from point correspondences across the three views: initial, current, and...
Landmines continue killing and injuring people even many years after the end of conflicts. Mechanical systems and robots have been used for assisting in landmines location and improving the quality of humanitarian demining tasks. These new systems are expected to enhance safety, efficiency, time duration, etc, but many improvements are still needed in order to realize a practical system. In this paper,...
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