scholarly journals Prehension Synergies in Three Dimensions

2005 ◽  
Vol 93 (2) ◽  
pp. 766-776 ◽  
Author(s):  
Jae Kun Shim ◽  
Mark L. Latash ◽  
Vladimir M. Zatsiorsky
Keyword(s):  
Center Of Mass ◽  
Mechanical Action ◽  
Three Dimensions ◽  
Experimental Paradigm ◽  
3 Dimensional ◽  
Moment Arms ◽  
Normal Forces ◽  
Relative Contribution ◽  
Virtual Finger ◽  
Finger Forces

The goal of this study was to investigate the conjoint changes of digit forces/moments in 3 dimensions during static prehension under external torques acting on the object in one plane. The experimental paradigm was similar to holding a book vertically in the air where the center of mass of the book is located farther from the hand than the points of digit contacts. Three force and 3 moment components from each digit were recorded during static prehension of a customized handle. Subjects produced forces and moments in all 3 directions, although the external torques were exerted on the handheld object about only the Z-axis. The 3-dimensional response to a 2-dimensional task was explained by the cause–effect chain effects prompted by the noncollinearity of the normal forces of the thumb and the 4 fingers (represented by the “virtual finger”). Because the forces are not collinear (not along the same line), they generate moments of force about X- and Y-axes that are negated by the finger forces along the Y- and X-directions. The magnitudes of forces produced by lateral fingers (index and little) with longer moment arms were larger compared with the central fingers (middle and ring). At the virtual finger (an imaginary digit whose mechanical action is equivalent to the summed action of the 4 fingers) level, the relative contribution of different fractions of the resistive moment produced by subjects did not depend on the torque magnitude. We conclude that the CNS 1) solves a planar prehension task by producing forces and moments in all 3 directions, 2) uses mechanical advantage of fingers, and 3) shares the total torque among finger forces and moments in a particular way disregarding the torque magnitude.

scholarly journals Prehension Synergies: Trial-to-Trial Variability and Principle of Superposition During Static Prehension in Three Dimensions

2005 ◽  
Vol 93 (6) ◽  
pp. 3649-3658 ◽  
Author(s):  
Jae Kun Shim ◽  
Mark L. Latash ◽  
Vladimir M. Zatsiorsky
Keyword(s):  
Three Dimensional ◽  
Horizontal Axis ◽  
Torque Control ◽  
Three Dimensions ◽  
Principle Of Superposition ◽  
External Torque ◽  
Virtual Finger ◽  
Grasping Forces ◽  
Finger Forces ◽  
The Moment

We performed three-dimensional analysis of the conjoint changes of digit forces during prehension (prehension synergies) and tested applicability of the principle of superposition to three-dimensional tasks. Subjects performed 25 trials at statically holding a handle instrumented with six-component force/moment sensors under seven external torque conditions; –0.70, –0.47, –0.23, 0.00, 0.23, 0.47, and 0.70 Nm about a horizontal axis in the plane passing through the centers of all five digit force sensors (the grasp plane). The total weight of the system was always 10.24 N. The trial-to-trial variability of the forces produced by the thumb and the virtual finger (an imagined finger producing the same mechanical effects as all 4 finger forces and moments combined) increased in all three dimensions with the external torque magnitude. The sets of force and moment variables associated with the moment production about the vertical axis in the grasp plane and the axis orthogonal to the grasp plane consisted of two noncorrelated subsets each; one subset of variables was related to the control of grasping forces ( grasp control) and the other sassociated with the control of the orientation of the hand-held object ( torque control). The variables associated with the moment production about the horizontal axis in the grasp plane did not include the grip force (the normal thumb and virtual finger forces) and showed more complex noncorrelated subsets. We conclude that the principle of superposition is valid for the prehension in three dimensions. The observed high correlations among forces and moments associated with the control of object orientation could be explained by chain effects, the sequences of cause-effect relations necessitated by mechanical constraints.

Does the Body Image Exist in Three Dimensions? The Study of Visual Mental Representation of a Body and a Nonbody Object

2001 ◽  
Vol 92 (1) ◽  
pp. 223-233
Author(s):  
D. P. McCabe ◽  
D. I. Ben-Tovim ◽  
M. K. Walker ◽  
D. Pomeroy
Keyword(s):  
Spatial Information ◽  
Mental Image ◽  
The Body ◽  
Three Dimensions ◽  
Long Term Memory ◽  
Depth Information ◽  
Mental Images ◽  
Term Memory ◽  
3 Dimensional

Do the mental Images of 3-dimensional objects recreate the depth characteristics of the original objects' This investigation of the characteristics of mental images utilized a novel boundary-detection task that required participants to relate a pair of crosses to the boundary of an image mentally projected onto a computer screen. 48 female participants with body attitudes within expected normal range were asked to image their own body and a familiar object from the front and the side. When the visual mental image was derived purely from long-term memory, accuracy was better than chance for the front (64%) and side (63%) of the body and also for the front (55%) and side (68%) of the familiar nonbody object. This suggests that mental images containing depth and spatial information may be generated from information held in long-term memory. Pictorial exposure to views of the front or side of the objects was used to investigate the representations from which this 3-dimensional shape and size information is derived. The results are discussed in terms of three possible representational formats and argue that a front-view 2½-dimensional representation mediates the transfer of information from long-term memory when depth information about the body is required.

scholarly journals A framework for quantifying properties of 3-dimensional movement-based signals

2010 ◽  
Vol 56 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Shaun Td New ◽  
Richard A Peters
Keyword(s):  
Three Dimensions ◽  
Tail Flick ◽  
Signal Design ◽  
3D Animation ◽  
3D Display ◽  
Single Plane ◽  
3 Dimensional ◽  
Tail Tip ◽  
Detector Model ◽  
New Framework

Abstract Understanding how signal properties are optimized for the reliable transmission of information requires accurate description of the signal in time and space. For movement-based signals where movement is restricted to a single plane, measurements from a single viewpoint can be used to consider a range of viewing positions based on simple geometric calculations. However, considerations of signal properties from a range of viewing positions for movements extending into three-dimensions (3D) are more problematic. We present here a new framework that overcomes this limitation, and enables us to quantify the extent to which movement-based signals are view-specific. To illustrate its application, a Jacky lizard tail flick signal was filmed with synchronized cameras and the position of the tail tip digitized for both recordings. Camera alignment enabled the construction of a 3D display action pattern profile. We analyzed the profile directly and used it to create a detailed 3D animation. In the virtual environment, we were able to film the same signal from multiple viewing positions and using a computational motion analysis algorithm (gradient detector model) to measure local image velocity in order to predict view dependent differences in signal properties. This approach will enable consideration of a range of questions concerning movement-based signal design and evolution that were previously out of reach.

Three-Dimensional Anatomic Characterization of the Canine Laryngeal Abductor and Adductor Musculature

2000 ◽  
Vol 109 (5) ◽  
pp. 505-513 ◽  
Author(s):  
Corey W. Mineck ◽  
Roger Chan ◽  
Niro Tayama ◽  
Ingo R. Titze
Keyword(s):  
Vocal Fold ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Cross Sectional ◽  
3 Dimensional ◽  
Moment Arms ◽  
Intrinsic Laryngeal Muscle ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles

The biomechanics of vocal fold abduction and adduction during phonation, respiration, and airway protection are not completely understood. Specifically, the rotational and translational forces on the arytenoid cartilages that result from intrinsic laryngeal muscle contraction have not been fully described. Anatomic data on the lines of action and moment arms for the intrinsic laryngeal muscles are also lacking. This study was conducted to quantify the 3-dimensional orientations and the relative cross-sectional areas of the intrinsic abductor and adductor musculature of the canine larynx. Eight canine larynges were used to evaluate the 3 muscles primarily responsible for vocal fold abduction and adduction: the posterior cricoarytenoid, the lateral cricoarytenoid, and the interarytenoid muscles. Each muscle was exposed and divided into discrete fiber bundles whose coordinate positions were digitized in 3-dimensional space. The mass, length, relative cross-sectional area, and angle of orientation for each muscle bundle were obtained to allow for the calculations of average lines of action and moment arms for each muscle. This mapping of the canine laryngeal abductor and adductor musculature provides important anatomic data for use in laryngeal biomechanical modeling. These data may also be useful in surgical procedures such as arytenoid adduction.

Stability and Robustness of a 3D Slip Model for Walking Using Lateral Leg Placement Control

2012 ◽  
Author(s):  
Dominik Budday ◽  
Fabian Bauer ◽  
Justin Seipel
Keyword(s):  
Humanoid Robot ◽  
Performance Test ◽  
Control Mechanism ◽  
Sagittal Plane ◽  
Control Strategies ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Slip Model ◽  
The Stability

The SLIP model has shown a way to easily represent the center of mass dynamics of human walking and running. For 2D motions in the sagittal plane, the model shows self-stabilizing effects that can be very useful when designing a humanoid robot. However, this self-stability could not be found in three-dimensional running, but simple control strategies achieved stabilization of running in three dimensions. Yet, 3D walking with SLIP has not been analyzed to the same extent. In this paper we show that three-dimensional humanoid SLIP walking is also unstable, but can be stabilized using the same strategy that has been successful for running. It is shown that this approach leads to the desired periodic solutions. Furthermore, the influence of different parameters on stability and robustness is examined. Using a performance test to simulate the transition from an upright position to periodic walking we show that the stability is robust. With a comparison of common models for humanoid walking and running it is shown that the simple control mechanism is able to achieve stable solutions for all models, providing a very general approach to this problem. The derived results point out preferable parameters to increase robustness promising the possibility of successfully realizing a humanoid walking robot based on 3D SLIP.

Constituent Particles and Dispersoids in an Al-Mn-Fe-Si Alloy Studied in Three-Dimensions by Serial Sectioning

2013 ◽  
Vol 765 ◽  
pp. 451-455 ◽  
Author(s):  
Liam Dwyer ◽  
Joseph Robson ◽  
Joao Quinta da Fonseca ◽  
Nicolas Kamp ◽  
Teruo Hashimoto ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Three Dimensions ◽  
Process Conditions ◽  
Second Phase ◽  
Serial Sectioning ◽  
3 Dimensional ◽  
Intermetallic Particles ◽  
Second Phase Particles ◽  
Proper Consideration

Second phase particles in wrought aluminium alloys are crucial in controlling recrystallization and texture. In Al-Mn-Fe-Si (3xxx) alloys, the size, spacing, and distribution of both large constituent particles and small dispersoids are manipulated by heat treatment to obtain the required final microstructure and texture for operations such as can-making. Understanding how these particles evolve as a function of process conditions is thus critical to optimize alloy performance. In this study, a novel 3-dimensional technique involving serial sectioning in the scanning electron microscope (SEM) has been used to analyse the intermetallic particles found in an as-cast and homogenized Al-Mn-Fe-Si alloy. This has allowed an accurate determination of the size and shape of the constituent particles and dispersoids derived from a 3-dimensional dataset. It is demonstrated that a proper consideration of the 3-dimensional microstructure reveals important features that are not obvious from 2-dimensional sections alone.

A computational analysis of locomotor anatomy and body mass evolution in Allosauroidea (Dinosauria: Theropoda)

Paleobiology ◽  
2012 ◽  
Vol 38 (3) ◽  
pp. 486-507 ◽  
Author(s):  
Karl T. Bates ◽  
Roger B. J. Benson ◽  
Peter L. Falkingham
Keyword(s):  
Body Size ◽  
Soft Tissue ◽  
Center Of Mass ◽  
Soft Tissue Reconstruction ◽  
Locomotor Performance ◽  
Body Proportions ◽  
Data Set ◽  
Positive Allometry ◽  
Moment Arms ◽  
Musculoskeletal Anatomy

We investigate whether musculoskeletal anatomy and three-dimensional (3-D) body proportions were modified during the evolution of large (>6000 kg) body size in Allosauroidea (Dinosauria: Theropoda). Three adaptations for maintaining locomotor performance at large body size, related to muscle leverage, mass, and body proportions, are tested and all are unsupported in this analysis. Predictions from 3-D musculoskeletal models of medium-sized (Allosaurus) and large-bodied (Acrocanthosaurus) allosauroids suggest that muscle leverage scaled close to isometry, well below the positive allometry required to compensate for declining muscle cross-sectional area with increasing body size. Regression analyses on a larger allosauroid data set finds slight positive allometry in the moment arms of major hip extensors, but isometry is included within confidence limits. Contrary to other recent studies of large-bodied theropod clades, we found no compelling evidence for significant positive allometry in muscle mass between exemplar medium- and large-bodied allosauroids. Indeed, despite the uncertainty in quantitative soft tissue reconstruction, we find strong evidence for negative allometry in the caudofemoralis longus muscle, the single largest hip extensor in non-avian theropods. Finally, we found significant inter-study variability in center-of-mass predictions for allosauroids, but overall observe that consistently proportioned soft tissue reconstructions produced similar predictions across the group, providing no support for a caudal shift in the center of mass in larger taxa that might otherwise reduce demands on hip extensor muscles during stance. Our data set provides further quantitative support to studies that argue for a significant decline in locomotor performance with increasing body size in non-avian theropods. However, although key pelvic limb synapomorphies of derived allosauroids (e.g., dorsomedially inclined femoral head) evolved at intermediate body sizes, they may nonetheless have improved mass support.

scholarly journals 3D Water Vapor Field in the Atmospheric Boundary Layer Observed with Scanning Differential Absorption Lidar

2016 ◽  
Author(s):  
F. Späth ◽  
A. Behrendt ◽  
S. K. Muppa ◽  
S. Metzendorf ◽  
A. Riede ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
Atmospheric Boundary Layer ◽  
Elevation Angle ◽  
Three Dimensions ◽  
Dimensional Structure ◽  
Differential Absorption ◽  
Differential Absorption Lidar ◽  
3 Dimensional ◽  
Western Germany

Abstract. The scanning differential absorption lidar (DIAL) of the University of Hohenheim (UHOH) determines fields of the atmospheric water vapor number density with a temporal resolution of a few seconds and spatial resolution of up to a few tens of meters. We present three case studies which show that this high resolution combined with 2- and 3-dimensional scans allows for new insights in the 3-dimensional structure of the water vapor field in the atmospheric boundary layer (ABL). In spring 2013, the UHOH DIAL was operated within the scope of the HD(CP)2 Observational Prototype Experiment (HOPE) in western Germany. HOPE was part of the project High Definition of Clouds and Precipitation for advancing Climate Prediction (HD(CP)2). Range-height indicator (RHI) scans of the UHOH DIAL show the water vapor heterogeneity within a range of a few kilometers and its impact on the formation of clouds at the ABL top. The uncertainty of the measured data was assessed by extending a technique, which was formerly applied to vertical time series, to scanning data. Typically, even during daytime, the accuracy of the DIAL measurements is between 0.5 and 0.8 g m−3 (or < 6 %) within the ABL, so that now the performance of an RHI scan from the surface to an elevation angle of 90 degrees becomes possible within 10 min. In summer 2014, the UHOH DIAL participated in the Surface-Atmosphere-Boundary-Layer-Exchange (SABLE) campaign in south-western Germany. Volume scans show the water vapor field in three dimensions. In this case, multiple humidity layers were present. Differences in their heights in different directions can be attributed to different surface elevation. With low elevation scans in the surface layer, the humidity profiles and gradients related to different land use and surface stabilities were also revealed.

scholarly journals Validity of Mechanical advantage hypothesis of human grasping depends on the nature of task difficulty

2021 ◽  
Author(s):  
Banuvathy Rajakumar ◽  
Swarnab Dutta ◽  
Varadhan SKM
Keyword(s):  
Center Of Mass ◽  
Tangential Force ◽  
Contact Forces ◽  
Human Hand ◽  
Mechanical Advantage ◽  
Moment Arms ◽  
The Central Nervous System ◽  
Constant Magnitude ◽  
The Individual ◽  
External Loads

Abstract Successful object interaction during daily living involves maintaining the grasped object in a static equilibrium by properly arranging the fingertip contact forces. According to the mechanical advantage hypothesis, during supination or pronation torque production, fingers with longer moment arms would produce greater normal force than those with shorter moment arms. Previous studies have probed this hypothesis by investigating the force contributions of the individual fingers through systematic variations (or perturbations) of properties of the grasped handle. In the current study, we examined the applicability of this hypothesis in a paradigm wherein the thumb tangential force was constrained to a minimal constant magnitude. This was achieved by placing the thumb on a freely movable slider platform. The total mass of the handle was systematically varied by adding external loads directly below the center of mass of the handle. Our findings suggest that in the human hand, the central nervous system (CNS) adopts the principle of mechanical advantage depending on an abstract sense of challenge attached to the task situation.

scholarly journals TRAINING AUTODESK FUSION 360 FOR TEENAGE OF SENIOR HIGH SCHOOL GRADUATES IN IMPROVING ABILITY IN DISASTERS

ICCD ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 285-289 ◽  
Author(s):  
Resa Trauna Suhada ◽  
Silvi Ariyanti ◽  
Anggun Vionieta Fajar ◽  
Aam Komalasari
Keyword(s):  
High School ◽  
Junior High School ◽  
High School Graduates ◽  
Three Dimensions ◽  
3 Dimensional ◽  
App Store ◽  
Design Collaboration ◽  
Training Materials ◽  
Service Activity ◽  
Design Activities

Autodesk launches Autodesk Fusion 360 - a cloud-based device that combines industrial design and 3D mechanics, collaboration, machinery in one package - the first solution available for purchase on Mac App Store worldwide including Indonesia. The Fusion 360 combines design, collaboration and machine tools into one package and is now available with the security and simplicity of the Mac App Store. With Fusion 360, designers and engineers can create products that have shapes and functions and prepare them for the fabrication process by using a single device. This community service activity is in the form of Autodesk Fusion 360 application training, with a total of 26 participants. Training activities include: introduction, visual demonstration and practice. The training materials are as follows: introduction of Autodesk Fusion 360, drawing 3-dimensional shapes, 3-dimensional drawing modifications, Solid modeling, Plotting. The purpose of this devotional activity is: Introduce and explain the basic theory of drawing using the computer, especially the use of Autodesk Fusion 360 program in the form of three dimensions. The benefits of this devotional activity are the junior high school graduates can recognize and apply computer-based drawing techniques. Improving the skills of high school graduates especially skills in the field of Fusion 360 applications. The results of this activity are the participants can carry out all product design activities and declared to pass and are entitled to receive a certificate issued directly by the company that produces Autodesk Fusion 360 Software.

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