scholarly journals Modelamiento Cinemático Aproximado de un Prototipo de Robot Equino de 6 Grados de Libertad Para un Simulador de Tiro

2018 ◽  
Vol 3 (1) ◽  
pp. 532
Author(s):  
Jaime Eduardo Andrade Ramírez ◽  
Yeison Andrey Gómez Rubio ◽  
Diego Andrés Carranza Rivera
Keyword(s):  
Degrees Of Freedom ◽  
Robot Kinematics ◽  
Programming Environment ◽  
Control Software ◽  
Six Degrees Of Freedom ◽  
Psychological Injuries ◽  
Kinematic Study ◽  
Real Practice ◽  
Approximate Simulation ◽  
Direct Kinematics

This article shows the design, analysis and manufacturing of one equine robot prototype with six degrees of freedom along with the development and implementation of control software. This software has the purpose to drive and to calculate the robot kinematics. All of this allows studding the elements necessaries to make a simulator of shots for riders that can be used in education areas as a tool of didactic support in the courses in the police national of Colombia, ensuring that the riders do not suffer physical and psychological injuries during their formation and avoiding hurting the horses in the training of that courses. In addition, the riders can interact and experiment of safety way every situation that they could find in real practice. The system is based on the kinematic study according to the Denavit-Hartenberg algorithm, approximate simulation using Kinematic-ARM® and the mathematic medeling in the Matlab® programming environment. All tecniques give aproximate results of location of the manipulator tool.    Finally, it is possible to validate and analising the results comparing the practical and theoric values to determine the TCP error estimated in each movement.Keywords: Direct kinematics, equine robot, Denavit-Hartenberg (D-H), Degrees of Freedom (DOF), Tool Center Point (TCP).

The Kinematics of Spatial Double-Triangular Parallel Manipulators

1995 ◽  
Vol 117 (4) ◽  
pp. 658-661 ◽  
Author(s):  
H. R. Mohammadi Daniali ◽  
P. J. Zsombor-Murray ◽  
J. Angeles
Keyword(s):  
Degrees Of Freedom ◽  
Quaternion Algebra ◽  
Parallel Manipulators ◽  
Numerical Examples ◽  
Six Degrees Of Freedom ◽  
Dual Number ◽  
Direct Kinematics

Two versions of spatial double-triangular mechanisms are introduced, one with three and one with six degrees of freedom. Using dual-number quaternion algebra, a formula for the direct kinematics of these manipulators is derived. Numerical examples are included.

The Effects of Knee Motion and External Loading on the Length of the Anterior Cruciate Ligament (ACL): A Kinematic Study

1991 ◽  
Vol 113 (2) ◽  
pp. 208-214 ◽  
Author(s):  
J. M. Hollis ◽  
S. Takai ◽  
D. J. Adams ◽  
S. Horibe ◽  
S. L.-Y. Woo
Keyword(s):  
Knee Flexion ◽  
Degrees Of Freedom ◽  
Cruciate Ligament ◽  
External Loading ◽  
Tibial Rotation ◽  
Knee Motion ◽  
Six Degrees Of Freedom ◽  
Kinematic Study ◽  
Insertion Sites ◽  
Anterior Cruciate

A six-degrees-of-freedom mechanical linkage device was designed and used to study the unconstrained motion of ten intact human cadaver knees. The knees were subjected to externally applied varus and valgus (V-V) moments up to 14 N-m as well as anterior and posterior (A-P) loads up to 100 N. Tests were done at four knee flexion angles; 0, 30, 45, and 90 deg. Significant coupled axial tibial rotation was found, up to 21.0 deg for V-V loading (at 90 deg of flexion) and 14.2 deg for A-P loading (at 45 deg of flexion). Subsequently, the knees were dissected and the locations of the insertion sites to the femur and tibia for the anteromedial (AM), posterolateral (PL), and intermediate (IM) portions of the ACL were identified. The distances between the insertion sites for all external loading conditions were calculated. In the case when the external load was zero, the AM portion of the ACL lengthened with knee flexion, while the PL portion shortened and the intermediate (IM) portion did not change in length. With the application of 14 N-m valgus moment, the PL and IM portions of the ACL lengthened significantly more than the AM portion (p<0.001). With the application of 100 N anterior load, the AM portion lengthened slightly less than the PL portion, which lengthened slightly less than the IM portion (p<0.005). In general, the amount of lengthening of the three portions of the ACL during valgus and anterior loading was observed to increase with knee flexion angle (p< 0.001).

Control of processing at multi-tool two-support setup

2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Factor Model ◽  
Angular Displacement ◽  
Factor Models ◽  
Technological System ◽  
Displacement Control ◽  
Model Accuracy ◽  
Six Degrees Of Freedom ◽  
Angular Displacements ◽  
And Control

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]

scholarly journals Design and Calibration of a Hall Effect System for Measurement of Six-Degree-of-Freedom Motion within a Stacked Column

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3740
Author(s):  
Olafur Oddbjornsson ◽  
Panos Kloukinas ◽  
Tansu Gokce ◽  
Kate Bourne ◽  
Tony Horseman ◽  
...  
Keyword(s):  
Hall Effect ◽  
Degrees Of Freedom ◽  
Reactor Core ◽  
Degree Of Freedom ◽  
Life Extension ◽  
Scale Model ◽  
Design Development ◽  
Seismic Safety ◽  
Six Degrees Of Freedom ◽  
Six Degree Of Freedom

This paper presents the design, development and evaluation of a unique non-contact instrumentation system that can accurately measure the interface displacement between two rigid components in six degrees of freedom. The system was developed to allow measurement of the relative displacements between interfaces within a stacked column of brick-like components, with an accuracy of 0.05 mm and 0.1 degrees. The columns comprised up to 14 components, with each component being a scale model of a graphite brick within an Advanced Gas-cooled Reactor core. A set of 585 of these columns makes up the Multi Layer Array, which was designed to investigate the response of the reactor core to seismic inputs, with excitation levels up to 1 g from 0 to 100 Hz. The nature of the application required a compact and robust design capable of accurately recording fully coupled motion in all six degrees of freedom during dynamic testing. The novel design implemented 12 Hall effect sensors with a calibration procedure based on system identification techniques. The measurement uncertainty was ±0.050 mm for displacement and ±0.052 degrees for rotation, and the system can tolerate loss of data from two sensors with the uncertainly increasing to only 0.061 mm in translation and 0.088 degrees in rotation. The system has been deployed in a research programme that has enabled EDF to present seismic safety cases to the Office for Nuclear Regulation, resulting in life extension approvals for several reactors. The measurement system developed could be readily applied to other situations where the imposed level of stress at the interface causes negligible material strain, and accurate non-contact six-degree-of-freedom interface measurement is required.

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