Learning to Control Orientation and Force in a Hammering Task

2012 ◽  
Vol 220 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Carlijn A. Vernooij ◽  
Leonora J. Mouton ◽  
Raoul M. Bongers
Keyword(s):  
Shoulder Joint ◽  
Joint Angle ◽  
Wrist Joint ◽  
Force Plate ◽  
Stone Tools ◽  
Human Cognition ◽  
Joint Angles ◽  
Force Vector ◽  
Initial Learning ◽  
Control Orientation

The ability to create stone tools is considered an important step in the emergence of human cognition. To further our understanding of these evolutionary processes we focused on the initial learning processes with which this percussive skill may be acquired. We studied a hammering task in which participants had to create a ground force vector by hitting a target on a force plate with a hammerstone. The produced ground force vector was presented as an arrow on a computer screen and had to end in a displayed target. The target could vary in its angle of azimuth and inclination. Over 5 days, three of the five participants adapted a wrist joint angle and two of these three participants adapted a shoulder joint angle that affected only angle of inclination of the ground force vector. Length and angle of azimuth of the ground force vector were not affected. In learning to control a hammering task, the first parameter to be manipulated seems to be the angle of inclination by adjusting the wrist and shoulder joint angles. This suggests that in the initial stages of learning a hammering task only one parameter is adapted.

Biomechanical Model of the Press Handstand in Gymnastics

1988 ◽  
Vol 4 (4) ◽  
pp. 326-341 ◽  
Author(s):  
Spiros G. Prassas
Keyword(s):  
Shoulder Joint ◽  
Joint Angle ◽  
Wrist Joint ◽  
Center Of Mass ◽  
Biomechanical Model ◽  
Joint Torque ◽  
Joint Torques ◽  
Skilled Performance ◽  
The Press ◽  
Line Passing

A biomechanical model of the press handstand was developed to evaluate and predict the shoulder joint torque requirements as well as the motion of a gymnast’s center of mass (CM) from an initial to a final (handstand) position. Five press handstands executed by gymnasts of differing abilities were filmed and analyzed. The results were compared to the predicted parameters of simulated presses. It was found that execution of the skill with fewer fluctuations in trunk and lower extremities angular velocity—a characteristic of skilled performance—required smoother and at times larger shoulder joint torques. Reduction of the hip joint angle by only 5 or 10° did not substantially reduce the shoulder joint torque requirements. Regarding CM motion, it was found that during performance the CM continuously elevated and remained close to a vertical line passing through the center of the wrist joint. All gymnasts, however, were found to be leaning slightly backward during the first part of the movement and slightly forward during the later phases. Modifications in wrist joint angle required to maintain each gymnast’s CM precisely above the center of the wrist joint were investigated.

scholarly journals JOINTS ACTIVITY AND ITS ROLE IN THE UPPER EXTREMITY IN BADMINTON STROKES: A BIOMECHANICAL PERSPECTIVE OF SPORTS EDUCATION

2020 ◽  
Vol 8 (4) ◽  
pp. 522-529
Author(s):  
Mottakin Ahmed ◽  
G. D. Ghai
Keyword(s):  
Upper Extremity ◽  
Muscle Activity ◽  
Shoulder Joint ◽  
Elbow Joint ◽  
High Performance ◽  
Joint Angle ◽  
Wrist Joint ◽  
Video Camera ◽  
Total N ◽  
Practice Group

Purpose of the Study: This study aims to describe the muscle activity and its role in the upper extremity in Badminton Strokes and also investigates the Kinematics differences of Badminton forehand overhead shot, i.e., precise, smash and drop in wrist joint, elbow joint, and shoulder Joint from a biomechanics perspective. Methodology: Total [n=10] numbers of male badminton players were randomly selected from the badminton match practice group of L.N.I.P.E. Gwalior, Madhya Pradesh, India. The match practice group consisted of (n=78) players who at least participated in Inter-University badminton competition, and their age ranges from 17-25 years of old. Go Pro HERO 7, 2D camera was used. A video camera was mounted on a tripod at a height of 1.05 meters from the ground. 2D data of wrist joint, elbow joint, and shoulder joint were put in Kinovea 0.8.27 software. One way ANOVA was used. Principal Findings: The results of the finding demonstrate that Brain vibrations, paradoxically, are critical to the stability of movement and high performance. There are significant muscle activity and kinematics differences among forehand clear, forehand smash and forehand drop-in shoulder joint angle, elbow joint angle, and wrist joint angle. Applications of this Study: The Study may use by the badminton Players as well as coaches for the successful execution of badminton Skill. This study will provide the mechanical area of movement of badminton Players. The same kind of study may use in other games. Novelty/Originality of this Study: The Study explores the mechanical advantages of badminton forehand overhead Skill. It will give the reader new ideas to think of a similar kind of study in different games.

A Study on Tele-Existence of the Tactile Sense

1997 ◽  
Vol 9 (3) ◽  
pp. 197-202 ◽  
Author(s):  
Tohru Ifukube ◽  
Keyword(s):  
Joint Angle ◽  
View Point ◽  
Joint Angles ◽  
Pressure Force ◽  
Tactile Sense ◽  
Force Vector ◽  
Vector Sensor ◽  
Pressure Sense ◽  
Finger Tip ◽  
Force Displacement

This report describes, first, a glove with joint angle sensors made of chip coils to detect the joint angles of human fingers in real time and also describes artificial fingers with multiple joints used for a tele-existence system on the tactile sense. Characteristics of the artificial skin to be attached to the artificial fingers are based on the experimental results of force-displacement characteristics of the human skin. Secondly, sensations produced by the pressure and the strain applied to the finger tip surface were measured as functions of pressure force level and the direction of the strain force using psychophysical techniques. A study of pressure sense and a force vector sensor is useful from the view point of the tele-existence system for the tactile sense.

scholarly journals Genome-Wide Association Studies Based on Equine Joint Angle Measurements Reveal New QTL Affecting the Conformation of Horses

Genes ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 370 ◽  
Author(s):  
Annik Imogen Gmel ◽  
Thomas Druml ◽  
Rudolf von Niederhäusern ◽  
Tosso Leeb ◽  
Markus Neuditschko
Keyword(s):  
Joint Angle ◽  
Association Studies ◽  
Genome Wide Association ◽  
Cranial Morphology ◽  
Genome Wide Association Studies ◽  
Joint Angles ◽  
Mineral Density ◽  
Mixed Effect ◽  
Stifle Joint ◽  
Genome Wide

The evaluation of conformation traits is an important part of selection for breeding stallions and mares. Some of these judged conformation traits involve joint angles that are associated with performance, health, and longevity. To improve our understanding of the genetic background of joint angles in horses, we have objectively measured the angles of the poll, elbow, carpal, fetlock (front and hind), hip, stifle, and hock joints based on one photograph of each of the 300 Franches-Montagnes (FM) and 224 Lipizzan (LIP) horses. After quality control, genome-wide association studies (GWASs) for these traits were performed on 495 horses, using 374,070 genome-wide single nucleotide polymorphisms (SNPs) in a mixed-effect model. We identified two significant quantitative trait loci (QTL) for the poll angle on ECA28 (p = 1.36 × 10−7), 50 kb downstream of the ALX1 gene, involved in cranial morphology, and for the elbow joint on ECA29 (p = 1.69 × 10−7), 49 kb downstream of the RSU1 gene, and 75 kb upstream of the PTER gene. Both genes are associated with bone mineral density in humans. Furthermore, we identified other suggestive QTL associated with the stifle joint on ECA8 (p = 3.10 × 10−7); the poll on ECA1 (p = 6.83 × 10−7); the fetlock joint of the hind limb on ECA27 (p = 5.42 × 10−7); and the carpal joint angle on ECA3 (p = 6.24 × 10−7), ECA4 (p = 6.07 × 10−7), and ECA7 (p = 8.83 × 10−7). The application of angular measurements in genetic studies may increase our understanding of the underlying genetic effects of important traits in equine breeding.

scholarly journals Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2690
Author(s):  
Bo Pan ◽  
Xuguang Wang ◽  
Zhenyang Xu ◽  
Lianjun Guo ◽  
Xuesong Wang
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Joint Angle ◽  
Simulation Software ◽  
Dissipated Energy ◽  
Energy Structure ◽  
Joint Angles ◽  
Crack Penetration ◽  
Before And After ◽  
The Impact

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of the cement mortar specimen with pre-set joints at different angles to explore the influence of joint attitudes of underground rock engineering on the failure characteristics of rock mass structure. The nuclear magnetic resonance (NMR) has also been used to measure the pore distribution and internal cracks of the specimen before and after the testing. In combination with numerical analysis, the paper systematically discusses the influence of joint angles on the failure mode of rock-like materials from three aspects of energy dissipation, microscopic damage, and stress field characteristics. The result indicates that the impact energy structure of the SHPB is greatly affected by the pre-set joint angle of the specimen. With the joint angle increasing, the proportion of reflected energy moves in fluctuation, while the ratio of transmitted energy to dissipated energy varies from one to the other. NMR analysis reveals the structural variation of the pores in those cement specimens before and after the impact. Crack propagation direction is correlated with pre-set joint angles of the specimens. With the increase of the pre-set joint angles, the crack initiation angle decreases gradually. When the joint angles are around 30°–75°, the specimens develop obvious cracks. The crushing process of the specimens is simulated by LS-DYNA software. It is concluded that the stresses at the crack initiation time are concentrated between 20 and 40 MPa. The instantaneous stress curve first increases and then decreases with crack propagation, peaking at different times under various joint angles; but most of them occur when the crack penetration ratio reaches 80–90%. With the increment of joint angles in specimens through the simulation software, the changing trend of peak stress is consistent with the test results.

Approximation of the Kinematics of Foot Joints by Using Passive Elastic Characteristics of Joint

2007 ◽  
Vol 342-343 ◽  
pp. 621-624
Author(s):  
Hyeon Ki Choi ◽  
Si Yeol Kim ◽  
Won Hak Cho
Keyword(s):  
Joint Angle ◽  
Reaction Force ◽  
Force Plate ◽  
Least Square Method ◽  
Least Square ◽  
Biomechanical Analysis ◽  
Clinical Evaluations ◽  
Foot Joints ◽  
The Relationship ◽  
Elastic Characteristics

We investigated the relationship between kinematic and kinetic characteristics of foot joints resisting ground reaction force (GRF). Passive elastic characteristics of joint were obtained from the experiment using three cameras and one force plate. The relationship between joint angle and moment was mathematically modeled by using least square method. The calculated ranges of motion were 7o for TM joint, 4o for TT joint and 20o for MP joint. With the model that relates joint angle and plantar pressure, we could get the kinematic data of the joints which are not available from conventional motion analysis. The model can be used not only for biomechanical analysis which simulates gait but also for the clinical evaluations.

scholarly journals The Effects of Repeated Sprints on the Kinematics of 3-Point Shooting in Basketball

2018 ◽  
Vol 62 (1) ◽  
pp. 5-14 ◽  
Author(s):  
Jean Slawinski ◽  
Julien Louis ◽  
Julien Poli ◽  
Eve Tiollier ◽  
Charles Khazoom ◽  
...  
Keyword(s):  
Wrist Joint ◽  
Height Velocity ◽  
Centre Of Mass ◽  
Joint Angles ◽  
Basketball Players ◽  
Repeated Sprints ◽  
Fatigue Protocol ◽  
Before And After ◽  
Measurement Units ◽  
Maximal Exercise Capacity

AbstractFatigue modifies the kinematics of various sports-related movements. Basketball induces fatigue, however, the effects of fatigue on the kinematics of shooting have never been studied. This study analysed the effects of fatigue induced by repeated sprints on the kinematics of 3-point shooting (3PS) in young, elite basketball players (U18 level). 3D joint angles were calculated at the maximum and minimum heights of the centre of mass during 3PS, using inertial measurement units (Biomech system, Xsens Technologies BV, Enschede, The Netherlands). Height, velocity and the angle of the ball at the time of release were extrapolated from the wrist joint angles. All players performed four 3PS actions in dynamic conditions before and after a fatigue protocol at 70% of their maximal exercise capacity. The fatigue protocol consisted of a shuttle test with repeated 20-m sprints interspersed with sets of 5 jumps. There was no change in the kinematics of 3PS (p > 0.05), or the ball release variables (p > 0.05) following the fatigue protocol. This suggests that elite basketball players are able to cope with physical fatigue while performing coordinated movements such as 3PS.

Gyroscope-Free Link Parameter Measurement Using Accelerometers and Magnetometer

2014 ◽  
Author(s):  
Vishesh Vikas ◽  
Carl D. Crane
Keyword(s):  
Angular Velocity ◽  
Joint Angle ◽  
Inertial Sensors ◽  
Angular Acceleration ◽  
Parameter Measurement ◽  
Joint Angles ◽  
Symmetry Constraint ◽  
Estimation Techniques ◽  
Angular Velocities ◽  
Joint Parameters

Knowledge of joint angles, angular velocities is essential for control of link mechanisms and robots. The estimation of joint angles and angular velocity is performed using combination of inertial sensors (accelerometers and gyroscopes) which are contactless and flexible at point of application. Different estimation techniques are used to fuse data from different inertial sensors. Bio-inspired sensors using symmetrically placed multiple inertial sensors are capable of instantaneously measuring joint parameters (joint angle, angular velocities and angular acceleration) without use of any estimation techniques. Calibration of inertial sensors is easier and more reliable for accelerometers as compared to gyroscopes. The research presents gyroscope-less, multiple accelerometer and magnetometer based sensors capable of measuring (not estimating) joint parameters. The contribution of the improved sensor are four-fold. Firstly, the inertial sensors are devoid of symmetry constraint unlike the previously researched bio-inspired sensors. However, the accelerometer are non-coplanarly placed. Secondly, the accelerometer-magnetometer combination sensor allows for calculation of a unique rotation matrix between two link joined by any kind of joint. Thirdly, the sensors are easier to calibrate as they consist only of accelerometers. Finally, the sensors allow for calculation of angular velocity and angular acceleration without use of gyroscopes.

Evolution of Cognitive Archaeology through Evolving Cognitive Systems

2019 ◽  
pp. 79-101 ◽  
Author(s):  
Iain Davidson
Keyword(s):  
Original Work ◽  
Stone Tools ◽  
Human Cognition ◽  
Stone Tool ◽  
Cognitive Systems ◽  
Cognitive Evolution ◽  
Subsequent Work ◽  
Productive Research ◽  
Tool Technology

Tom Wynn’s original work that looked at the evolution of stone tool technology using Piaget’s developmental sequence was the beginning of productive research into the evolution of hominin and human cognition. In this chapter, I evaluate those beginnings and discusses recent attempts to provide a more satisfactory understanding of changes in stone tool technologies, including work by Philip Barnard and William McGrew, subsequent work by Tom Wynn, and my own work with various collaborators. It suggests that some of the previous understandings of cognitive evolution were shaped by the fact that approaches to stone tools were largely determined in the nineteenth century. I propose some new ways of looking at stone tools and the sort of story that allows for more productive models of the evolution of human cognition.

scholarly journals A Workspace Visualization Method for a Multijoint Industrial Robot Based on the 3D-Printing Layering Concept

2020 ◽  
Vol 10 (15) ◽  
pp. 5241
Author(s):  
Guoqiang Fu ◽  
Chun Tao ◽  
Tengda Gu ◽  
Caijiang Lu ◽  
Hongli Gao ◽  
...  
Keyword(s):  
3D Printing ◽  
Joint Angle ◽  
Industrial Robot ◽  
Selection Method ◽  
Forward Kinematics ◽  
Visualization Method ◽  
Joint Angles ◽  
Boundary Extraction ◽  
Simulation And Experiment ◽  
Constraint Information

The workspace of a robot provides the necessary constraint information for path planning and reliable control of the robot. In this paper, a workspace visualization method for a multijoint industrial robot is proposed to obtain a detailed workspace by introducing the 3D-printing layering concept. Firstly, all possible joint-angle groups of one pose in the joints’ ranges are calculated in detail according to the POE (product of exponential) theory-based forward-kinematics expressions of the multijoint industrial robot. Secondly, a multisolution selection method based on the key degree of the joint is proposed to select the appropriate joint-angle groups. The key degrees of all joints and their key order are obtained according to the sensitivity expressions of all joint angles, calculated from the Jacobian matrix of the robot. One principle based on the smallest differences of the nominal angle is established to select the possible solutions for one joint from the possible solutions for the joint with the smaller key order. The possible solutions for the joint with the highest key order are the appropriate joint-angle group. Thirdly, a workspace visualization method based on the layering concept of 3D printing is presented to obtain a detailed workspace for a multijoint industrial robot. The boundary formula of each layer is derived by forward kinematics, which is expressed as a circle or a ring. The maximum and minimum values of the radius are obtained according to the travel range of the joint angles. The height limitations of all layers are obtained with forward kinematics. A workspace boundary-extraction method is presented to obtain the array of path points of the boundary at each layer. The proposed postprocessing method is used to generate the joint-angle code of each layer for direct 3D printing. Finally, the effectiveness of the multisolution selection method and the workspace visualization method were verified by simulation and experiment.

Sign in / Sign up

Export Citation Format

Share Document