The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform
Cameron N Riviere - One of the best experts on this subject based on the ideXlab platform.
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Hybrid position force Control of an active handheld micromanipulator for membrane peeling
International Journal of Medical Robotics and Computer Assisted Surgery, 2016Co-Authors: Trent S Wells, Sungwook Yang, Robert A Maclachlan, Louis A Lobes, Joseph N Martel, Cameron N RiviereAbstract:Background Peeling procedures in retinal surgery require micron-scale manipulation and Control of sub-tactile forces. Methods Hybrid position/force Control of an actuated handheld microsurgical instrument is presented as a means for simultaneously improving positioning accuracy and reducing forces to prevent avoidable trauma to tissue. The system response was evaluated, and membrane-peeling trials were performed by four test subjects in both artificial and animal models. Results Maximum force was reduced by 56% in both models compared with position Control. No statistically significant effect on procedure duration was observed. Conclusions A Hybrid position/force Control system has been implemented that successfully attenuates forces and minimizes unwanted excursions during microsurgical procedures such as membrane peeling. Results also suggest that improvements in safety using this technique may be attained without increasing the duration of the procedure. Copyright © 2015 John Wiley & Sons, Ltd.
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toward Hybrid position force Control for an active handheld micromanipulator
International Conference on Robotics and Automation, 2014Co-Authors: Trent S Wells, Robert A Maclachlan, Cameron N RiviereAbstract:Vitreoretinal microsurgery requires precise hand-eye coordination to manipulate delicate structures within the eye on the order of tens of microns. To achieve these tasks, surgeons use tools of diameter 0.9 mm or less to access the eye's interior structures. The level of force required during these manipulations is often below the human tactile threshold, requiring the surgeon to rely on subtle visual cues or to apply larger forces above the tactile threshold for feedback. However, both of these methods can lead to tissue damage. Excursions can be made into tissues which are not felt by the surgeon, while larger forces have a higher chance of damaging tissue within the eye. To prevent damage to the retina and other anatomy, we present the implementation of Hybrid position/force Control operating in the sub-tactile force range for a handheld robotic system. This approach resulted in a 42% reduction in the mean force and 52% reduction in maximum force during peeling tasks.
A Sudou - One of the best experts on this subject based on the ideXlab platform.
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dynamic Hybrid position force Control of robot manipulators on line estimation of unknown constraint
International Conference on Robotics and Automation, 1993Co-Authors: Tsuneo Yoshikawa, A SudouAbstract:A dynamic Hybrid position/force Control method, which takes into consideration the manipulator dynamics and the constraints on the end-effector specified by the given task, is obtained by extending the method of M.H. Raibert and J.J. Craig (1981). One difficulty in implementing the method is that precise information on the size and position of the object with which the end-effector contacts is not usually available. To cope with this difficulty, a problem of dynamic Hybrid Control with unknown constraint is studied. An online algorithm is developed that estimates the local shape of the constraint surface by using measured data on the position and force of the end-effector. It is shown by experiments, using a SCARA-type robot, that the combination of this algorithm with the dynamic Hybrid Control method works fairly well, making the dynamic Hybrid Control approach more practical. >
Trent S Wells - One of the best experts on this subject based on the ideXlab platform.
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Hybrid position force Control of an active handheld micromanipulator for membrane peeling
International Journal of Medical Robotics and Computer Assisted Surgery, 2016Co-Authors: Trent S Wells, Sungwook Yang, Robert A Maclachlan, Louis A Lobes, Joseph N Martel, Cameron N RiviereAbstract:Background Peeling procedures in retinal surgery require micron-scale manipulation and Control of sub-tactile forces. Methods Hybrid position/force Control of an actuated handheld microsurgical instrument is presented as a means for simultaneously improving positioning accuracy and reducing forces to prevent avoidable trauma to tissue. The system response was evaluated, and membrane-peeling trials were performed by four test subjects in both artificial and animal models. Results Maximum force was reduced by 56% in both models compared with position Control. No statistically significant effect on procedure duration was observed. Conclusions A Hybrid position/force Control system has been implemented that successfully attenuates forces and minimizes unwanted excursions during microsurgical procedures such as membrane peeling. Results also suggest that improvements in safety using this technique may be attained without increasing the duration of the procedure. Copyright © 2015 John Wiley & Sons, Ltd.
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toward Hybrid position force Control for an active handheld micromanipulator
International Conference on Robotics and Automation, 2014Co-Authors: Trent S Wells, Robert A Maclachlan, Cameron N RiviereAbstract:Vitreoretinal microsurgery requires precise hand-eye coordination to manipulate delicate structures within the eye on the order of tens of microns. To achieve these tasks, surgeons use tools of diameter 0.9 mm or less to access the eye's interior structures. The level of force required during these manipulations is often below the human tactile threshold, requiring the surgeon to rely on subtle visual cues or to apply larger forces above the tactile threshold for feedback. However, both of these methods can lead to tissue damage. Excursions can be made into tissues which are not felt by the surgeon, while larger forces have a higher chance of damaging tissue within the eye. To prevent damage to the retina and other anatomy, we present the implementation of Hybrid position/force Control operating in the sub-tactile force range for a handheld robotic system. This approach resulted in a 42% reduction in the mean force and 52% reduction in maximum force during peeling tasks.
Tsuneo Yoshikawa - One of the best experts on this subject based on the ideXlab platform.
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dynamic Hybrid position force Control of robot manipulators on line estimation of unknown constraint
International Conference on Robotics and Automation, 1993Co-Authors: Tsuneo Yoshikawa, A SudouAbstract:A dynamic Hybrid position/force Control method, which takes into consideration the manipulator dynamics and the constraints on the end-effector specified by the given task, is obtained by extending the method of M.H. Raibert and J.J. Craig (1981). One difficulty in implementing the method is that precise information on the size and position of the object with which the end-effector contacts is not usually available. To cope with this difficulty, a problem of dynamic Hybrid Control with unknown constraint is studied. An online algorithm is developed that estimates the local shape of the constraint surface by using measured data on the position and force of the end-effector. It is shown by experiments, using a SCARA-type robot, that the combination of this algorithm with the dynamic Hybrid Control method works fairly well, making the dynamic Hybrid Control approach more practical. >
Tzyhjong Tarn - One of the best experts on this subject based on the ideXlab platform.
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real time integration of sensing planning and Control in robotic work cells
Control Engineering Practice, 2004Co-Authors: Di Xiao, Bijoy K Ghosh, Mumin Song, Tzyhjong TarnAbstract:This paper addresses real-time planning and Control for robot manipulators in a re-configurable work-cell or an unknown workspace. The considered tasks in robotic work-cell are (1) to catch a moving object by using vision-guidance system, and (2) to follow a path on an unknown surface. These two tasks are commonly performed in the applications of material handling and processing. In order to efficiently and successfully accomplish the tasks, novel strategies for integrating real-time planning and Control are proposed to improve agility and reconfigurability of robotic systems and to deal with the uncertainties in the environment by means of multi-sensor fusion. In the proposed schemes, a novel calibration-free stereo vision algorithm and a new Hybrid position/force Control strategy are utilized. In order to achieve intelligent robot manipulation in an unstructured workspace and reconfigurable work-cell, complementary sensory data from different types of sensors, such as force/torque, encoders and visual sensors, are integrated simultaneously during robot constrained motion.
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sensor based Hybrid position force Control of a robot manipulator in an uncalibrated environment
IEEE Transactions on Control Systems and Technology, 2000Co-Authors: Di Xiao, Bijoy K Ghosh, Tzyhjong TarnAbstract:The paper is devoted to the problem of Controlling a robot manipulator for a class of constrained motions. The task under consideration is to Control the manipulator, such that the end-effector follows a path on an unknown surface, with the aid of a single camera assumed to be uncalibrated with respect to the robot coordinates. To accomplish a task of this kind, we propose a new Control strategy based on multisensor fusion. We assume that three different sensors-that is, encoders mounted at each joint of the robot with six degrees of freedom, a force-torque sensor mounted at the wrist of the manipulator, and a visual sensor with a single camera fixed to the ceiling of the workcell-are available. Also, we assume that the contact point between the tool grasped by the end-effector and the surface is frictionless. To describe the proposed algorithm that we have implemented, first we decouple the vector space of Control variables into two subspaces. We use one for Controlling the magnitude of the contact force on the surface and the other for Controlling the constrained motion on the surface. This way, the Control synthesis problem is decoupled and we are able to develop a new scheme that utilizes sensor fusion to handle uncalibrated parameters in the workcell, wherein the surface on which the task is to be performed is assumed to be visible, but has an a priori unknown position.
