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One of the challenging issues in the robotic technology is to use robotics arm for surgeries, especially in eye operations. Among the recently developed mechanisms for this purpose, there exists a robot, called Eye-RHAS, that presents sustainable precision in vitreo-retinal eye surgeries. In this work the closed-form dynamical model of this robot has been derived by Gibbs-Appell method. Furthermore,...
In the power packet dispatching system, electric power is transferred with information tags attached physically. An application of the system to robots can enable flexible and efficient power management with a dynamically varying powerline connection between power sources and loads. In this paper, a numerical simulation verifies the achievement of a trajectory control of a manipulator by power packets...
The representation space (R-Space) is proposed and constructed for a robot system to evaluate its feasibility to a prescribed task. The process of a task realization is transformed to be a process that the system representations transit in its Rspace. All factors affecting the task realization, including system configurations and physical and environmental constraints, are denoted as unreachable areas...
Robotic manipulation under unstructured environments still is an open challenge to the research community. Lots of effort have been addressed to visual perception and remarkable progress has been achieved in the area. However, the information obtained from vision systems is frequently incomplete and noisy, incapacitating robotic systems to complete their target tasks in some cases. Moreover, little...
The most common approach used in modeling humanoid robots is to restrict the motion in two different planes, namely the frontal and sagittal plane, thereby using trigonometric expressions and Euler-angles for its description. In this paper some problems of trajectory interpolation and singularity of motion representation are discussed and the dual quaternion representation is used as an alternative...
This paper aims to smooth jerky trajectories for high-DOF manipulators with Soft Motion [1] shortcuts which are bounded in velocity, acceleration and jerk. The algorithm presented here iteratively picks two points on the trajectory and attempts to replace the intermediate trajectory with a shorter and collision-free segment. The objective of this algorithm is to shorten the execution time of an input...
The interaction of a single human with a team of cooperative robots, which collaboratively manipulate an object, poses a great challenge by means of the numerous possibilities of issuing commands to the team or providing appropriate feedback to the human. In this paper we propose a formation-based approach in order to avoid deformations of the object and to virtually couple the human to the formation...
In this paper, a human robot shared control strategy is developed and tested on a Baxter robot. Using the proposed method, the human operator only needs to consider the motion of the end-effector of the manipulator, while the manipulator will avoid obstacle by itself without sacrificing the end effector motion performance. An improved obstacle avoidance strategy based on the joint space redundancy...
Tubular continuum robots are particularly useful for minimally invasive surgery due to their small size and ability to dexterously manipulate in constrained environments. The robot can be used teleoperated or operated (semi-)autonomously. In both cases, safe manipulation has to be ensured considering constraints from the patient's unique anatomy and pathology to prevent injury of nerves, vessels,...
This paper addresses the problem of cooperative object manipulation with the coordination relying solely on implicit communication. We consider a decentralized leader-follower architecture where the leading robot, that has exclusive knowledge of the object's desired trajectory, tries to achieve the desired tracking behavior via an impedance control law. On the other hand, the follower estimates the...
Although in recent years several studies aimed at the navigation of robots in cluttered environments, just a few have addressed the problem of robots navigating while moving a large or heavy object. This is especially useful when transporting loads with variable weights and shapes without having to change the robot hardware. On one hand, a major advantage of using a humanoid robot to move an object...
Assistive robotic manipulators have the potential to improve the lives of people with motor impairments. They can enable individuals to perform activities such as pick-and-place tasks, opening doors, pushing buttons, and can even provide assistance in personal hygiene and feeding. However, robotic arms often have more degrees of freedom (DoF) than the dimensionality of their control interface, making...
To address the problem that joints would exceed limitation in motion control of Tele-operation, a novel efficient inverse kinematics method for the 7 DOF manipulator of the thermonuclear fusion reactor to trajectory planning is presented in this paper. Based on Weighted Least-Norm (WLN) solution, the fixed joint angle inversion method is applied to decrease the accumulated error and avoid joint limits...
Using manipulators to draw artistic figures is a benchmark problem in robotics. In this paper we describe a 3-link planar manipulator which draws artistic shapes or geometric shapes on a canvas. We first take a snapshot of the shape to draw from the camera and process it for finding the outer boundary or edges. The edges are mapped onto the drawing canvas. The edges are converted from Cartesian coordinate...
This paper address the output feedback learning tracking control problem for robot manipulators with repetitive desired joint level trajectories. Specifically, an observer-based output feedback learning controller for periodic trajectories with known period have been proposed. The proposed learning controller guarantees semi-global asymptotic tracking despite the existence of parametric uncertainties...
The paper presents an outline of the specification of a robot controller used in manipulation tasks requiring object grasping by a multi-fingered gripper and interaction with the environment. The specification assumes that the robot is represented as an embodied agent composed of real and virtual effectors and receptors and the control subsystem. The actions of those subsystems are defined by finite...
In motion planning of a symmetric affine system under kinematic non-holonomic constraints, a control method using holonomy is known. The holonomy is a state displacement caused by periodic control inputs. A class of kinematic non-holonomic systems can be expressed by the first-order chained form; a class of dynamic non-holonomic systems can be represented by the second-order chained form. To my best...
A method of planning sub-optimal trajectory for a mobile manipulator working in the environment including obstacles is presented. The robot's task is to move the end-effector from a given initial to a final position in the workspace. The motions are planned in order to maximize a manipulability measure to avoid manipulator singularities. Control and mechanical constraints are taken into consideration...
In this study, we describe a manipulator that induces a horizontal surface rotation motion of the shoulder so as to change the phase difference between the shoulder and the upper arm. We constructed an algorithm that estimates the time of heel contact while participants walk on a treadmill, and controls the axial rotation angle of the shoulder at that time. We verified the accuracy of the proposed...
This paper addresses the kinematic control problem of the non-redundant and/or redundant manipulators. A computationally simple class of the Jacobian transpose control algorithms is proposed for the end-effector trajectory tracking. These controllers use a new non-singular Terminal Sliding Mode (TSM) manifold, as being a non-linear integral mapping of the second order with respect to the task space...
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