• 제목/요약/키워드: Ball-based

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Analysis of Golf Ball Mobility and Balancing based on IoT Sports Environments

  • Lee, Tae-Gyu
    • International journal of advanced smart convergence
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    • 제8권3호
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    • pp.78-86
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    • 2019
  • Recently, IoT researches using sensor data based on embedded networks in various fields including healthcare and sports have been continuously attempted. This study analyzes golf ball mobility to support IoT application in golf sports field. Generally, since the difference in density occurs due to the condition of the inner material and the abnormal state at the time of the outer skin joining during the manufacturing of the golf ball, the weight of each subset is equal for any two points with the same radius in the sphere cannot be guaranteed. For this reason, the deflected weight of the sphere has the undesirable effect of hitting the ball in a direction in which the weight of the ball is heavy. In this study, it is assumed that there is a unique center of gravity of the ball, and even if the golf ball cannot be manufactured perfectly, it wants to establish the basic principle to accurately recognize or mark the putting line based on the center of gravity. In addition, it is evaluated how the mobility of the golf ball with a deviation from the center of gravity of the golf ball affects the progress path (or movement direction) and the moving distance (or carry distance) after the golfer hits. The basic model of the mobility of the golf ball can help the golfer exercise model and the correlation analysis. The basic model of the mobility of the golf ball can help the golfer exercise model and the correlation analysis.

볼빔 시스템에 대한 입자 군집 최적화를 이용한 최적 퍼지 직렬형 제어기 설계 (Design of Optimized Fuzzy Cascade controller Based on Partical Swarm Optimization for Ball & Beam System)

  • 장한종;오성권
    • 전기학회논문지
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    • 제57권12호
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    • pp.2322-2329
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    • 2008
  • In this study, we introduce the design methodology of an optimized fuzzy cascade controller with the aid of particle swarm optimization(PSO) for ball & beam system. The ball & beam system consists of servo motor, beam and ball, and remains mutually connected in line in itself. The ball & beam system determines the position of ball through the control of a servo motor. We introduce the fuzzy cascade controller scheme which consists of the outer(1st) controller and the inner(2nd) controller as two cascaded fuzzy controllers, and auto-tune the control parameters(scaling facrors) of each fuzzy controller using PSO. For a detailed comparative analysis from the viewpoint of the performance results and the design methodology, the proposed method for the ball & beam system which is realized by the fuzzy cascade controller based on PSO, is presented in comparison with the conventional PD cascade controller based on serial genetic alogritms.

영상 기반 회전 골프공 무게중심 검출 시스템 (A Visual Detecting System for The Rotation Axis of Golf Ball)

  • 현웅근
    • 한국전자통신학회논문지
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    • 제14권2호
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    • pp.411-416
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    • 2019
  • 본 연구에서는 딤플공의 회전축을 찾아가는 상태를 측정하는 영상 기반 시스템을 개발였다. 일부 골프공은 제조과정에서의 불량 및 공을 치면서 발생하는 볼표면의 스크래치에 의해서 회전축이 틀어진다. 이렇게 흠이있는 골프공은 드라이브샷등에 의해 비행하는 과정중에 슬라이스 등의 원인이 된다. 딤플 골프공은 아이언이나 드라이버로 타격시 회전 및 직선운동을 이루며 진행을 하며 회전은 일정한 시간이 지나면 일정한 축을 중심으로 진행되는 바, 회전중심을 찾아가는 과정에서 슬라이스등이 진행된다. 만일 볼을 타격하는 시점부터 고유 회전축에 일치시켜 타격한다면 골프샷의 오차가 줄어든다. 본 논문에서는 골프공의 수렴회전축을 찾는 시스템을 영상 시스템으로 개발하였으며, 실험을 통해 시스템 개발의 타당성을 입증하였다.

볼 베어링의 전동체 기반 및 응력 기반 접촉 피로수명의 비교 (Comparison of Rolling Element Loads and Stress-based Fatigue Life Predictions for Ball Bearings)

  • 곽재섭;박영환;김찬중;김태완
    • Tribology and Lubricants
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    • 제36권6호
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    • pp.371-377
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    • 2020
  • In In this study, we compared the results of a ball bearing life prediction model based on rolling element loads with the results of fatigue life prediction of ball bearings when a stress-based contact fatigue life prediction technique is applied to the ball bearing. We calculate the load acting on each rolling element by the external load of the bearing and apply the result to the Lundberg-Palmgren (LP) theory to calculate ball bearing life based on the rolling element. We also calculate stress-based ball bearing life through contact and fatigue analyses based on contact modeling of the ball and raceway while considering the fatigue test results of AISI 52100 steel. In stress-based life prediction, we use three high-cycle fatigue-determination equations that can predict the fatigue life when multi-axis proportional loads such as rolling-slide contact conditions are applied. These equations are derived from the stress invariant and critical plane methods and the mesoscopic approach. Life expectancy results are compared with those of the LP model. Results of the analysis indicated that the fatigue life was predicted to be lower in the order of the Crossland, Dang Van, and Matake models. Of the three, the Dang Van fatigue model was found to be the closest to the LP life.

볼빔 시스템에 대한 계층적 공정 경쟁 유전자 알고리즘을 이용한 최적 퍼지 Cascade 제어기 설계 (Design of Optimized Fuzzy Cascade Controller Based on HFCGA for Ball & Beam System)

  • 장한종;오성권;김현기
    • 전기학회논문지
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    • 제58권2호
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    • pp.391-398
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    • 2009
  • In this study, we introduce the design methodology of an optimized fuzzy cascade controller with the aid of hierarchical fair competition-based genetic algorithm(HFCGA) for ball & beam system. The ball & beam system consists of servo motor, beam and ball, and remains mutually connected in line in itself. The ball & beam system determines the position of ball through the control of a servo motor. The displacement change the position of ball leads to the change of the angle of the beam which determines the position angle of a servo motor. Consequently the displacement change of the position of the moving ball and its ensuing change of the angle of the beam results in the change of the position angle of a servo motor. We introduce the fuzzy cascade controller scheme which consists of the outer(1st) controller and the inner(2nd) controller as two cascaded fuzzy controllers, and auto-tune the control parameters(scaling factors) of each fuzzy controller using HFCGA. The inner controller controls the position of lever arm which corresponds to the position angle of a servo motor and the outer controller decides the set-point value of the inner controller. HFCGA is a kind of parallel genetic algorithms(PGAs), and helps alleviate the premature convergence being generated in conventional genetic algorithms (GAs). For a detailed comparative analysis from the viewpoint of the performance results and the design methodology, the proposed method for the ball & beam system which is realized by the fuzzy cascade controller based on HFCGA, is presented in comparison with the conventional PD cascade controller based on serial genetic algorithms.

Generating a Ball Sport Scene in a Virtual Environment

  • Choi, Jongin;Kim, Sookyun;Kim, Sunjeong;Kang, Shinjin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권11호
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    • pp.5512-5526
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    • 2019
  • In sports video games, especially ball games, motion capture techniques are used to reproduce the ball-driven performances. The amount of motion data needed to create different situations in which athletes exchange balls is bound to increase exponentially with resolution. This paper proposes how avatars in virtual worlds can not only imitate professional athletes in ball games, but also create and edit their actions effectively. First, various ball-handling movements are recorded using motion sensors. We do not really have to control an actual ball; imitating the motions is enough. Next, motion is created by specifying what to pass the ball through, and then making motion to handle the ball in front of the motion sensor. The ball's occupant then passes the ball to the user-specified target through a motion that imitates the user's, and the process is repeated. The method proposed can be used as a convenient user interface for motion based games for players who handle balls.

자동차 서스펜션용 볼 시트 사출성형품 개발 (Development of the Injection Molded Ball Seat for Automobile Suspension)

  • 예상돈;민병현
    • 한국기계가공학회지
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    • 제10권4호
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    • pp.50-56
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    • 2011
  • Injection molding process is one of the popular manufacturing methods to produce plastic parts with high efficiency and low cost. Ball seat for automobile suspension is made by an injection molding process as a part to support pivot function of ball joint consisted of ball stud and housing. It is necessary for a ball seat to have a dimensional stability in the three dimensional inner area to be contacted with ball stud. In this paper, the dimensional stability of inner surface is indirectly analyzed by checking the difference of inner diameter around the circumferential direction and the thickness variation at the top part of ball seat. Measurement was performed by using the coordinate measuring machine and the fixture to hold ball seat. Optimization of injection molding processes such as injection time, cooling time and temperatures of cylinder barrel was derived to reduce the difference of inner diameter and the thickness variation at the top part of ball seat based on the Taguchi method.

최적 퍼지 직렬형 제어기 설계: Type-2 퍼지 제어기 및 공정경쟁기반 유전자알고리즘을 중심으로 (The Design of Optimized Fuzzy Cascade Controller: Focused on Type-2 Fuzzy Controller and HFC-based Genetic Algorithms)

  • 김욱동;장한종;오성권
    • 전기학회논문지
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    • 제59권5호
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    • pp.972-980
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    • 2010
  • In this study, we introduce the design methodology of an optimized type-2 fuzzy cascade controller with the aid of hierarchical fair competition-based genetic algorithm(HFCGA) for ball & beam system. The ball & beam system consists of servo motor, beam and ball, and remains mutually connected in line in itself. The ball & beam system determines the position of ball through the control of a servo motor. Consequently the displacement change of the position of the moving ball and its ensuing change of the angle of the beam results in the change of the position angle of a servo motor. The type-2 fuzzy cascade controller scheme consists of the outer controller and the inner controller as two cascaded fuzzy controllers. In type-2 fuzzy logic controller(FLC) as the expanded type of type-1 fuzzy logic controller(FLC), we can effectively improve the control characteristic by using the footprint of uncertainty(FOU) of membership function. The control parameters(scaling factors) of each fuzzy controller using HFCGA which is a kind of parallel genetic algorithms(PGAs). HFCGA helps alleviate the premature convergence being generated in conventional genetic algorithms(GAs). We estimated controller characteristic parameters of optimized type-2 fuzzy cascade controller applied ball & beam system such as maximum overshoot, delay time, rise time, settling time and steady-state error. For a detailed comparative analysis from the viewpoint of the performance results and the design methodology, the proposed method for the ball & beam system which is realized by the fuzzy cascade controller based on HFCGA, is presented in comparison with the conventional PD cascade controller based on serial genetic algorithms.

이산요소해석에 기초한 블레이드 형상에 따른 숏볼의 투사속도 예측 (Prediction of Velocity of Shot Ball with Blade Shapes based on Discrete Element Analysis)

  • 김태형;이승호;정찬기
    • 한국기계기술학회지
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    • 제20권6호
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    • pp.844-851
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    • 2018
  • In this study, the regression equation was suggested to predict of the shot ball velocity according to blade shapes based on discrete element (DE) analysis. First, the flat type blade DE model was used in the analysis, the validity of the DE model was verified by giving that the velocity of the shot ball almost equal to the theoretical one. Next, the DE analyses for curved and combined blade models was accomplished, and their analytical velocities of shot ball were compared with the theoretical one. The velocity of combined blade model was greatest. From this, the regression equation for velocity of shot ball according to the blade shape based on the DE analysis was derived. Additionally, the wind speed measurement experiment was carried out, and the experimental result and analytical one were the same. Ultimately, it was confirmed that the prediction method of the velocity of shot ball based on DE analysis was effective.

RVEGA SMC를 이용한 Ball-Beam 시스템의 안정화 (Stabilization of Ball-Beam System using RVEGA SMC)

  • 김태우;이준탁
    • 대한전기학회논문지:전력기술부문A
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    • 제48권10호
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    • pp.1327-1334
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    • 1999
  • The stabilization control of ball-beam system is difficult because of its nonlinearity and structural unstability. Futhermore, a series of classical methods such as the PID and the full state feedback controller(FSFC) based on the local linearizations have narrow stabilizable regions. At the same time, the fine tunings of their gain parameters are also troublesome. Therefore, in this paper, three improved design techniques of stabilization controller for a ball-beam system were proposed. These parameter tuning methods in the double PID controller(DPIDC), the FSFC and the a sliding mode controller(SMC) were dependent upon the Real Value Elitist Genetic Algorithm (RVEGA). Finally, by applying the DPIDC, the FSFC and the Real Variable Elitist Genetic Algorithm based Sliding Mode Control(RVEGA SMC) to the stabilizations of a ball-beam system, the performances of the RVEGA SMC technique were showed to be superior to those of two other type controllers.

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