scholarly journals Study of soccer ball flight trajectory

2018 ◽  
Vol 145 ◽  
pp. 01002 ◽  
Author(s):  
Juliana Javorova ◽  
Anastas Ivanov
Keyword(s):  
Differential Equations ◽  
Degrees Of Freedom ◽  
Spherical Body ◽  
Flight Trajectory ◽  
Aerodynamic Forces ◽  
Soccer Ball ◽  
Six Degrees Of Freedom ◽  
Football Game ◽  
Ball Flight ◽  
General Motion

In this paper the trajectories of a soccer ball for the most important kicks in the football game - a corner kick and a direct free kick are studied. The soccer ball is modelled as an ideal rigid hollow spherical body with six degrees of freedom, which performs a general motion in an immovable air environment with constant parameters. The ball 3D orientation is determined by the three Cardan angles. The aerodynamic forces and moments with which the air environment acts to the ball are taken into account. Two of the most dangerous areas of the football goal are defined. Differential equations which describe the motion of the soccer ball are solved numerically by MatLab-Simulink.

Coupling in-flight trajectory planning and flocking for multiple autonomous parafoils

2012 ◽  
Vol 226 (6) ◽  
pp. 691-720 ◽  
Author(s):  
A Rosich ◽  
P Gurfil
Keyword(s):  
Global Positioning System ◽  
Autonomous Navigation ◽  
Degrees Of Freedom ◽  
Reference Trajectory ◽  
Flight Trajectory ◽  
Multiagent Simulation ◽  
Six Degrees Of Freedom ◽  
Wide Range ◽  
Global Positioning ◽  
Simple Rules

Much effort has been invested during the past decades in design of parafoils for a wide range of payloads and in development of means for their guidance. Existing parafoils are capable of autonomous navigation using the global positioning system and other onboard sensors. The purpose of this study is to explore the advantages of coordination among multiple autonomous parafoils. Each parafoil is able to navigate to the target on its own by following a real-time-generated reference trajectory. A new method for trajectory generation is presented and behaviour-based rules are developed that control the relative motion of the descending parafoils. The set of simple rules results in an emergent behaviour known as flocking. The coupling between trajectory following and flocking is studied in a multiagent simulation. The simulation uses a realistic six-degrees-of-freedom model of a heavy cargo parafoil. The obtained results demonstrate the possibility of flocking behaviour for guided parafoils. The flocking rules ensure safe separation between the vehicles headed for the same target and allow the parafoils to follow a reference trajectory as a group.

Effect of a soccer ball’s surface texture on its aerodynamics and trajectory

2018 ◽  
Vol 233 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Sungchan Hong ◽  
John Eric Goff ◽  
Takeshi Asai
Keyword(s):  
Wind Tunnel ◽  
Surface Texture ◽  
Flight Trajectory ◽  
Wind Tunnel Experiments ◽  
Aerodynamic Forces ◽  
Design And Development ◽  
Surface Textures ◽  
Soccer Ball ◽  
Future Design ◽  
The Future

The effect of a soccer ball’s surface texture on its aerodynamics and flight trajectory is not definitively known. For this study, five soccer balls were used, each having 32 panels with different surface textures. Their aerodynamics were examined via wind-tunnel experiments and then several non-spin trajectories were calculated for each ball. The results showed that the aerodynamic forces acting on a soccer ball change significantly depending on the surface texture of the ball, which in turn influences flight trajectories. The study contributes to an understanding of how a soccer ball’s surface influences the aerodynamics, which may impact the future design and development of soccer balls.

scholarly journals Analysis of the Impact of the Target Illumination Time on the Effectiveness of the Flight Trajectory Correction System

2019 ◽  
Vol 49 (1) ◽  
pp. 229-253
Author(s):  
Grzegorz Kowaleczko ◽  
Mariusz Pietraszek ◽  
Łukasz Słonkiewicz
Keyword(s):  
Degrees Of Freedom ◽  
Flight Trajectory ◽  
Control Laws ◽  
Illumination Time ◽  
Six Degrees Of Freedom ◽  
Laser Sensors ◽  
Main Factors ◽  
The Impact ◽  
Flight Simulations ◽  
Correction System

Abstract This paper presents method of flight simulations for released laser guided bomb. Calculations were performed using six-degrees-of-freedom mathematical model of a bomb motion. Aerodynamics of the bomb was calculated using commercial software. Control laws were determined on the basis of signals detected by two pairs of laser sensors. Exemplary results of numerical calculations are submitted and conclusions focused on the main factors influencing on bombing accuracy are shown.

Unsteady Aerodynamics Simulation of a Heavy-Duty Truck in Wind Gusts Coupled With Vehicle Motion Analysis in Six Degrees of Freedom

2011 ◽  
Author(s):  
Takuji Nakashima ◽  
Makoto Tsubokura ◽  
Syumei Matsuda ◽  
Yasuaki Doi
Keyword(s):  
Vehicle Dynamics ◽  
Degrees Of Freedom ◽  
Vertical Direction ◽  
Dynamics Simulation ◽  
Strong Wind ◽  
Heavy Duty ◽  
Aerodynamic Forces ◽  
Six Degrees Of Freedom ◽  
Heavy Duty Truck ◽  
Wind Gusts

A one-way coupled analysis was used to investigate both the unsteady aerodynamic forces on a simplified heavy-duty truck in strong wind gusts and their effects on its motion. The vehicle model for the dynamics simulation was extended to six degrees of freedom (6DoF). First, a transitional aerodynamics simulation was conducted for the simplified truck with a fixed vehicle attitude but subject to a sudden crosswind. Based on the visualized results of this aerodynamics simulation, flow phenomena generating transitional aerodynamic forces and moments are discussed, especially those acting in the vertical direction. While the truck was running into the crosswind region, the growth and breakdown of a large-scale vortex above the container generated a transitional behavior of aerodynamic lift and pitching moment. Next, time series of the six components of the aerodynamic forces and moments were input into the vehicle dynamics simulation. By comparing the results with those of a quasi-steady aerodynamics simulation, the effect of transitional aerodynamics on vertical motions was clarified, with the largest difference found in a rolling motion. Moreover, the effect of considering 6DoF was investigated by also conducting the vehicle dynamics simulation with 3DoF. The consideration of dynamics in the vertical direction changed the estimation of tire forces, which were related to a vertical load on the tire. Finally, the effects of considering 6DoF were also identified for horizontal motions.

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]

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