Kinematic Optimization of a 2-DOF U, 2PSS Parallel Wrist Device

2019 ◽  
Author(s):  
Neil M. Bajaj ◽  
Aaron M. Dollar
Keyword(s):  
Translational Motion ◽  
Optimized Design ◽  
Healthy Human ◽  
End Effector ◽  
Flexion Extension ◽  
Critical Requirement ◽  
Two Degree Of Freedom ◽  
Kinematic Optimization

Abstract The wrist plays the crucial role of orienting a hand or end effector without significant translational motion, a critical requirement of successful manipulation. In this paper, we present the kinematic design optimization a two degree of freedom universal, two-prismatic-spherical-spherical (U, 2-PSS) parallel wrist mechanism. By varying the geometric parameters of the mechanism, we examine configurations that maximize the Global Conditioning Index, a metric describing the quality of the motion and torque, over the desired workspace, which mimics a healthy human wrist range of motion in circumduction (flexion/extension and abduction/adduction). We further investigate the effects of sizing constraints on the resulting optimized design which satisfies the imposed sizing constraints.

Analytical Computation of the Actuator and Cartesian Workspace Boundaries for a Planar 2-Degree-of-Freedom Translational Tensegrity Mechanism

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Samuel Chen ◽  
Marc Arsenault
Keyword(s):  
Translational Motion ◽  
Inverse Kinematic ◽  
Degree Of Freedom ◽  
End Effector ◽  
Optimal Mechanism ◽  
High Acceleration ◽  
Pick And Place ◽  
Actuation Scheme ◽  
Two Degree Of Freedom ◽  
Robotic Applications

Tensegrity mechanisms are interesting candidates for high-acceleration robotic applications since their use of cables allows for a reduction in the weight and inertia of their mobile parts. In this work, a planar two-degree-of-freedom translational tensegrity mechanism that could be used for pick and place applications is introduced. The mechanism uses a strategic actuation scheme to generate the translational motion as well as to ensure that the cables remain taut at all times. Analytical solutions to the direct and inverse kinematic problems are developed, and the mechanism’s workspace boundaries are computed in both the actuator and Cartesian spaces. The influence of the mechanism’s geometry on the size and shape of the Cartesian workspace are then studied. Based on workspace size only, it is found that the optimal mechanism geometry corresponds to a relatively large ratio between the length of the struts and the width of the base and end-effector.

Workspace Computation and Analysis of a Planar 2-DoF Translational Tensegrity Mechanism

2010 ◽  
Author(s):  
Samuel Chen ◽  
Marc Arsenault
Keyword(s):  
Analytical Solutions ◽  
Translational Motion ◽  
Inverse Kinematic ◽  
End Effector ◽  
Optimal Mechanism ◽  
High Acceleration ◽  
Pick And Place ◽  
Actuation Scheme ◽  
Two Degree Of Freedom ◽  
Robotic Applications

Tensegrity mechanisms are interesting candidates for high-acceleration robotic applications since their use of cables allows for a reduction in the weight and inertia of their mobile parts. In this work, a planar two-degree-of-freedom translational tensegrity mechanism that could be used for pick and place applications is introduced. The mechanism uses a strategic actuation scheme to generate the translational motion as well as to ensure that the cables remain taut at all times. Analytical solutions to the direct and inverse kinematic problems are developed and the mechanism’s workspace boundaries are computed in both the actuator and Cartesian spaces. The influence of the mechanism’s geometry on the size and shape of the Cartesian workspace are then studied. Based on workspace size only, it is found that the optimal mechanism geometry corresponds to a relatively large ratio between the length of the struts and the width of the base and end-effector.

Cognitive Health Counseling 40+

2013 ◽  
Vol 21 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Anne Eschen ◽  
Franzisca Zehnder ◽  
Mike Martin
Keyword(s):  
Outcome Variable ◽  
Pilot Phase ◽  
Subjective Memory ◽  
Cognitive Health ◽  
Health Counseling ◽  
Agents Of Change ◽  
Main Outcome Variable ◽  
Further Development

This article introduces Cognitive Health Counseling 40+ (CH.CO40+), an individualized intervention that is conceptually based on the orchestration model of quality-of-life management ( Martin & Kliegel, 2010 ) and aims at improving satisfaction with cognitive health in adults aged 40 years and older. We describe the theoretically deduced characteristics of CH.CO40+, its target group, its multifactorial nature, its individualization, the application of subjective and objective measures, the role of participants as agents of change, and the rationale for choosing participants’ satisfaction with their cognitive health as main outcome variable. A pilot phase with 15 middle-aged and six older adults suggests that CH.CO40+ attracts, and may be particularly suitable for, subjective memory complainers. Implications of the pilot data for the further development of the intervention are discussed.

Role of Ethnicity on Pain Perception, Fatigue, and Quality of Life in a Pediatric Chronic Pain Population

2007 ◽  
Author(s):  
Jeffrey I. Gold ◽  
Trina Haselrig ◽  
D. Colette Nicolaou ◽  
Katharine A. Belmont
Keyword(s):  
Quality Of Life ◽  
Chronic Pain ◽  
Pain Perception ◽  
Pediatric Chronic Pain
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