Improved Active Handrest Performance Through Use of Virtual Fixtures

Fehlberg, Mark A.; Nisky, Ilana; Doxon, Andrew J.; Provancher, William R.

doi:10.1109/thms.2014.2321531

Cited by 8 publications

(9 citation statements)

References 61 publications

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“…While laying the forearm on the armrest, surgeons might limit their capabilities in finding the arm configuration that would allow for the maximization of the ratio between task unrelated and task related variability. Future studies are needed to consider the possible tradeoffs in using armrests, including fixed and dynamic support [59] C. Limitations and future work An important limitation of the UCM approach is the coordinate sensitivity of the computational procedures that define the task relevant and irrelevant manifolds [29]. The structure of the observed variability is defined in a coordinate space which is arbitrarily selected by the researcher among multiple others.…”

Section: B Error Metricsmentioning

confidence: 99%

An Uncontrolled Manifold Analysis of Arm Joint Variability in Virtual Planar Position and Orientation Telemanipulation

Buzzi

Momi

Nisky³

2019

IEEE Trans. Biomed. Eng.

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Abstract-Objective: In teleoperated robot-assisted tasks, the user interacts with manipulators to finely control remote tools. Manipulation of robotic devices, characterized by specific kinematic and dynamic proprieties, is a complex task for the human sensorimotor system due to the inherent biomechanical and neuronal redundancies that characterize the human arm and its control. We investigate how master devices with different kinematics structures and how different task constraints influence users capabilities in exploiting arm redundancy. Methods: A virtual teleoperation workbench was designed and the arm kinematics of seven users was acquired during the execution of two planar virtual tasks, involving either the control of position only or position-orientation of a tool. Using the UnControlled Manifold Analysis of arm joint variability we estimated the logarithmic ratio between task irrelevant and the task relevant manifolds (Rv). Results: The Rv values obtained in the position-orientation task were higher than in the position only task while no differences were found between the master devices. A modulation of Rv was found through the execution of the position task and a positive correlation was found between task performance and redundancy exploitation. Conclusion: Users exploited additional portions of arm redundancy when dealing with the tool orientation. The Rv modulation seems influenced by the task constraints and by the users possibility of reconfiguring the arm position. Significance: This work advances the general understanding of the exploitation of arm redundancy in complex tasks, and can improve the development of future robotic devices.

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Section: B Error Metricsmentioning

confidence: 99%

An Uncontrolled Manifold Analysis of Arm Joint Variability in Virtual Planar Position and Orientation Telemanipulation

Buzzi

Momi

Nisky³

2019

IEEE Trans. Biomed. Eng.

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“…To evaluate the performance of these strategies, we used similar tracing tasks as used to evaluate the PAHR in Fehlberg et al (2014). We had participants explore shapes with various spatial features (e.g., open vs. closed/cyclic paths and paths with continuously changing curvature vs. paths with discontinuous changes in curvature).…”

Section: General Methodsmentioning

confidence: 99%

“…where -velocity -accommodation/admittance gain (~inverse of damping) -force input For all controller strategies, was generally set at 0.010 (m/s)/N based on previous device performance as measured in Fehlberg, Gleeson, &Provancher, 2012 andFehlberg et al, 2014). We then implemented a closed-loop PID controller to achieve this desired translational velocity.…”

Section: E-pahr Controller Strategiesmentioning

confidence: 99%

“…Previous studies with this device demonstrated that use of the PAHR provides increased task accuracy and user skill level compared to freehand, fixed, and passive repositionable supports (Fehlberg, Gleeson, & Provancher, 2012). Additional studies showed that user skill level could be further improved by adding virtual fixtures to the device's controller (Fehlberg, Nisky, Doxon, & Provancher, 2014). In the research presented herein, we endeavor to improve the PAHR device to better match human arm kinematics by adding a rotational DOF and to investigate its effect when interacting with this device.…”

Section: Introductionmentioning

confidence: 97%

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Enhancements to the Planar Active Handrest

Fehlberg

Sani

Provancher

2015

Journal of Human-Robot Interaction

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The Planar Active Handrest (PAHR) is a large workspace assistive device that improves user precision manipulation. The PAHR is restricted in its use, because it does not rotate in the horizontal plane, which limits the workspace size and reduces user comfort. This paper evaluates an improved device, the Enhanced Planar Active Handrest (E-PAHR), which allows lateral/medial rotation of the upper arm. Under the E-PAHR design, the desired hand position can be obtained with redundant arm and device configurations. As such, we gave consideration to controller input choices and resultant device motions that are available. Three experiments evaluated the controller designs to select the most effective method to control our device. We conclude that a rotational DOF (degrees of freedom) allows the E-PAHR to better follow the kinematics of a user's planar arm movements while allowing skill level equal to the PAHR, with reduced user force input and lower perceived exertion.

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“…Virtual fixture was first proposed to extract relevant information between the human operator and the remote environment for HRI (Rosenberg, L. B , 1993). In (Fehlberg et al, 2014), a virtual fixture control strategy was presented to improve the manipulation performance of the active handrest. Brian et al developed a derivation of virtual fixtures based on the motion of the instrument in real time for system control (Becker et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Enhanced teleoperation performance using hybrid control and virtual fixture

Luo

Yang

Wang

et al. 2019

International Journal of Systems Science

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To develop secure, natural, and effective teleoperation, the perception of the slave plays a key role for the interaction of a human operator with the environment. By sensing slave information, the human operator can choose the correct operation in a process of human-robot interaction. This paper develops an integrated scheme based on a hybrid control and virtual fixture approach for the telerobot. The human operator can sense the slave interaction condition and adjust the master device via the surface electromyographic signal. This hybrid control method integrates proportional-derivative control and variable stiffness control, and involves muscle activation at the same time. It is proposed to quantitatively analyse the human operator's control demand to enhance the control performance of the teleoperation system. In addition, due to unskilful operation and muscle physiological tremor of the human operator, a virtual fixture method is developed to ensure accuracy of operation and to reduce the operation pressure on the human operator. Experimental results demonstrated the effectiveness of the proposed method for the teleoperated robot.

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Improved Active Handrest Performance Through Use of Virtual Fixtures

Cited by 8 publications

References 61 publications

An Uncontrolled Manifold Analysis of Arm Joint Variability in Virtual Planar Position and Orientation Telemanipulation

An Uncontrolled Manifold Analysis of Arm Joint Variability in Virtual Planar Position and Orientation Telemanipulation

Enhancements to the Planar Active Handrest

Enhanced teleoperation performance using hybrid control and virtual fixture

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