The Experts below are selected from a list of 5610 Experts worldwide ranked by ideXlab platform
Timothy Bretl - One of the best experts on this subject based on the ideXlab platform.
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a compliant four bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant
International Conference on Robotics and Automation, 2017Co-Authors: Kyung Yun Choi, Aadeel Akhtar, Timothy BretlAbstract:Repeated mechanical failure due to accidental impact is one of the main reasons why people with upper-limb amputations abandon commercially-available prosthetic hands. To address this problem, we present the design and evaluation of a compliant four-bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant. Our design replaces both the rigid input and coupler links with a monolithic compliant bone, and replaces the follower link with three layers of pre-stressed spring steel. This design behaves like a conventional four-bar linkage but adds lateral compliance and eliminates a Pin Joint, which is a main site of failure on impact. Results from free-end and fixed-end impact tests show that, compared to those made with a conventional four-bar linkage, fingers made with our design absorb up to 11% more energy on impact with no mechanical failure. We also show the integration of these fingers in a prosthetic hand that is low-cost, light-weight, and easy to assemble, and that has grasPing performance comparable to commercially-available hands.
R S Dwyerjoyce - One of the best experts on this subject based on the ideXlab platform.
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friction and wear behaviours of self lubricating peek composites for articulating Pin Joints
Tribology International, 2019Co-Authors: R S DwyerjoyceAbstract:Abstract With the rapid development of engineering materials, self-lubricating and high strength composites have become a high demand candidate material for Pin Joints due to their significant potential in downsizing and weight saving. In this study, bearing bushes made from unfilled polyetheretherketone (PEEK) and PEEK composites were investigated for their tribological performance through two sets of experiments, (i) ball-on-disc dry sliding on CETR UMT, and (ii) Pin/bush contact on a purpose built Pin Joint test rig. Continuous rotation and oscillation of shaft were performed with the Pin/bush contact configuration. The contact pressure between the bush and shaft ranged from 20 MPa to 140 MPa and articulation speed from 10 deg/s to 60 deg/s. Wear mechanism was investigated through microscopic observation.
Yoon Keun Kwak - One of the best experts on this subject based on the ideXlab platform.
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Optimal Design of a New Wheeled Mobile Robot by Kinetic Analysis for the Stair-Climbing States
'IntechOpen', 2021Co-Authors: Chun-kyu Woo, Hyun Do Choi, Mun Sang Kim, Soo Hyun Kim, Yoon Keun KwakAbstract:In order to be utilized in building inspection, building security, and military reconnaissance, a new type of WMR was designed with a passive linkage-type locomotive mechanism for improved adaptability to rough terrain and stair-climbing without the active control techniques. Two designed concepts, `adaptability\u27 and `passivity\u27, were considered for the design of the linkage-type locomotive mechanism of the WMR. The proposed mechanism, composed of a simple 4-bar linkage mechanism and a limited Pin Joint, allows the WMR to adapt passively to rough terrain and to climb stairs. A state analysis was carried out to determine the states that primarily influence the WMR\u27s ability to climb the stair. For the several dominant states suggested from the state analysis, a kinetic analysis was accomplished in order to improve the WMR\u27s ability to climb the stair. The validation of the kinetic analysis was done for the states using ADAMSTM. The object functions were formulated from the kinetics of the WMR and we optimized passive link mechanism using the multi-objective optimization method. The proposed WMR with the optimal design values could climb a stair with a height about three times the wheel radius
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Optimal Design of a New Wheeled Mobile Robot Based on a Kinetic Analysis of the Stair Climbing States
Journal of Intelligent and Robotic Systems, 2007Co-Authors: Hyun Do Choi, Sukjune Yoon, Yoon Keun KwakAbstract:In this paper, we propose a new wheeled mobile robot (WMR) with a passive linkage-type locomotive mechanism that allows the WMR to adapt passively to rough terrain and climb up stairs, making it ideal for applications such as building inspection, building security, and military reconnaissance. A simple four-bar linkage mechanism and a limited Pin Joint are proposed after considering two design needs: adaptability and passivity. To improve the WMR’s ability to climb stairs, we divided the stair-climbing motion into several stages, taking into consideration the status of the points of contact between the driving wheels and the step. For each of the suggested stages, a kinetic analysis was accomplished and validated using the multi-body dynamic analysis software package ADAMS. The object functions are presented for the stages that influence the WMR’s ability to climb stairs. The optimization of the object functions is carried out using the multi-objective optimization method.
Kyung Yun Choi - One of the best experts on this subject based on the ideXlab platform.
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a compliant four bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant
International Conference on Robotics and Automation, 2017Co-Authors: Kyung Yun Choi, Aadeel Akhtar, Timothy BretlAbstract:Repeated mechanical failure due to accidental impact is one of the main reasons why people with upper-limb amputations abandon commercially-available prosthetic hands. To address this problem, we present the design and evaluation of a compliant four-bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant. Our design replaces both the rigid input and coupler links with a monolithic compliant bone, and replaces the follower link with three layers of pre-stressed spring steel. This design behaves like a conventional four-bar linkage but adds lateral compliance and eliminates a Pin Joint, which is a main site of failure on impact. Results from free-end and fixed-end impact tests show that, compared to those made with a conventional four-bar linkage, fingers made with our design absorb up to 11% more energy on impact with no mechanical failure. We also show the integration of these fingers in a prosthetic hand that is low-cost, light-weight, and easy to assemble, and that has grasPing performance comparable to commercially-available hands.
Aadeel Akhtar - One of the best experts on this subject based on the ideXlab platform.
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a compliant four bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant
International Conference on Robotics and Automation, 2017Co-Authors: Kyung Yun Choi, Aadeel Akhtar, Timothy BretlAbstract:Repeated mechanical failure due to accidental impact is one of the main reasons why people with upper-limb amputations abandon commercially-available prosthetic hands. To address this problem, we present the design and evaluation of a compliant four-bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant. Our design replaces both the rigid input and coupler links with a monolithic compliant bone, and replaces the follower link with three layers of pre-stressed spring steel. This design behaves like a conventional four-bar linkage but adds lateral compliance and eliminates a Pin Joint, which is a main site of failure on impact. Results from free-end and fixed-end impact tests show that, compared to those made with a conventional four-bar linkage, fingers made with our design absorb up to 11% more energy on impact with no mechanical failure. We also show the integration of these fingers in a prosthetic hand that is low-cost, light-weight, and easy to assemble, and that has grasPing performance comparable to commercially-available hands.