골프 셀프-코칭 시스템을 위한 인체모델 기반 골프 스윙 모션 데이터 취득

고경리(Kyeong-Ri Ko),반성범(Sung Bum Pan) 한국정보기술학회 2015 한국정보기술학회논문지 Vol.13 No.8

As the golf population increase, the concern with individual swing posture analysis and diagnosis has been growing. To prevent injuries caused by incorrect swing and golf swing capability upgrade. For the golf swing posture analysis and diagnosis, it is important that analysis of the swing motion and transmit information for posture correction can be performed to correction swing. The swing motion data acquisition of expert and user is needed for swing posture analysis. In this paper, human body model based golf swing motion data acquisition and explain. The motion data is full swing motion data of the teaching professional and the publics. It has acquired each 20 times using driver and 7 iron club. Swing motion comparison result, the differences appeared in the arm bend and straighten state, weight shift of lower body, bow head degree.

대학 골프 선수의 Pitching wedge 스윙동작의 운동학적 특성 분석

백진호,윤동섭,김재필,Back, Jin-Ho,Yoon, Dong-Seob,Kim, Jae-Phil 한국운동역학회 2003 한국운동역학회지 Vol.13 No.3

The purposes of present study were to determine the major check-points of golf swing from the review of previous studies, and to suggest additional information on the teaching theory of golf. The golf swing motion of 6 male and female elite university golf players were filmed with 16mm Locam II high speed cameras at the speed of 200f/s, and variables such as time, displacement, angle, velocity were calculated and analyzed by 3D Cinematography using DLT method. The results were: 1. Differences were shown in the ratio of weight distribution on the feet, cocking angle, take-back velocity, club-head velocity at impact depending upon the physical characteristics and club used for swing. 2. Time for the down-swing and impact were $0.27{\sim}0.29s$ in men and $0.29{\sim}0.32s$ in women, which was 1/3 of the time for the back-swing. Women showed longer total swing time than men because of longer time in back-swing, follow-through and finish. 3. Men showed larger range of motion in shoulder and knee joints than women, on the other hand women showed larger range of motion in hip joint than men. 4. Cocking motion and right elbow flexion were occurred at the top of back-swing and cocking release was occurred at the moment of impact. Maximum rotations of shoulder and hip joints were found between the top of back-swing and down-swing phase. 5. Women showed lower back-swing velocity than men, and men showed higher club velocity(men: $38.2{\sim}38.6m/s$, women: $35.1{\sim}36.4m/s$) than women.

Estimation of Unmeasured Golf Swing of Arm Based on the Swing Dynamics

Lee, Changwon,Park, Sukyung Korean Society for Precision Engineering 2018 International Journal of Precision Engineering and Vol.19 No.5

The design of wearable golf swing monitoring system is challenging because it has to resolve the trade-off between the convenience of wearability and the quantity of the data collected. If the swing dynamics are describable by a multi-segment mechanical model, the motion measurement of one segment could inform that of the others by mechanical relationship. In this study, we propose a method of estimating unmeasured arm swing data based on the dynamic characteristics of swing motion. Specifically, we hypothesized that the arm swing dynamics could be represented by rigid body dynamics with the specifiable joint toque profiles, which is formulated as a linear combination of joint kinematics. To simplify the complexity of the multi-joint 3D motion, we proposed a projection analysis of 3D motion data onto the two dimensional plane of the downswing. To validate the proposed model and the estimation methods, we collected the golf swing data of driver and iron 7 club of 12 subjects with various skill levels. Results showed that the subjects made swing plane very consistently during the repeated swing trials regardless the skill levels. The joint torque data were well represented by the linear combination of joint kinematics during the downswing.

A Synchronized Playback Method of 3D Model and Video by Extracting Golf Swing Information from Golf Video

오황석 (사)한국컴퓨터게임학회 2018 한국컴퓨터게임학회논문지 Vol.31 No.4

In this paper, we propose a synchronized playback method of 3D reference model and video by extracting golf swing information from learner's golf video to precisely compare and analyze each motion in each position and time in the golf swing, and present the implementation result. In order to synchronize the 3D model with the learner's swing video, the learner's golf swing movie is first photographed and relative time information is extracted from the photographed video according to the position of the golf club from the address posture to the finishing posture. Through applying time information from learners' swing video to a 3D reference model that rigs the motion information of a pro-golfer’s captured swing motion at 120 frames per second through high-quality motion capture equipment into a 3D model and by synchronizing the 3D reference model with the learner's swing video, the learner can correct or learn his / her posture by precisely comparing his or her posture with the reference model at each position of the golf swing. Synchronized playback can be used to improve the functionality of manually adjusting system for comparing and analyzing the reference model and learner's golf swing. Except for the part where the image processing technology that detects each position of the golf posture is applied, It is expected that the method of automatically extracting the time information of each location from the video and of synchronized playback can be extended to general life sports field.

카메라를 이용한 흔들림 계측 및 제어

김영복(Y. B. Kim),H. Kawai,최용운(Y. W. Choi),이권순(K. S. Lee),채규훈(G. H. Chae) 한국동력기계공학회 2007 한국동력기계공학회 학술대회 논문집 Vol.- No.-

In general, the swing motion of the crane is controlled and suppressed by activating the trolley motion. In many papers reported by us, we suggested a new type of anti-sway control system of the crane. In the proposed control system, a small auxiliary mass(moving-mass) is installed on the spreader and the swing motion is controlled by moving the auxiliary mass. The actuator reaction against the auxiliary mass applies inertial control forces to the container in order to reduce the swing motion in the desired manner. The measuring system is based on laser sensor or others. However it is not so useful in real world. In this paper, we use the camera based measurement system to measure sway motion of the crane. And the H∞ based control technique is applied to suppress swing motion of the crane. And the experimental result shows that the proposed control system is useful and robust to disturbances.

이송중 발생하는 흔들림 방지에 의한 크레인 성능향상에 관한 연구

김도형(D. H. Kim),김영복(Y. B. Kim),이권순(K. S. Lee),서진호(J. H. Sur) 한국동력기계공학회 2005 한국동력기계공학회 학술대회 논문집 Vol.- No.-

In general, the swing motion of the crane is controlled and suppressed by activating the trolley motion. In this paper, we suggest a new type of anti-sway control system of the crane. In the proposed control system, a small auxiliary mass(moving-mass) is installed on the spreader and the swing motion is controlled by moving the auxiliary mass. The actuator reaction against the auxiliary mass applies inertial control forces to the container in order to reduce the swing motion in the desired manner. In this paper, we apply the H∞ based control technique to the anti-sway control system design problem. And the experimental result shows that the proposed control system is useful and robust to disturbances like winds and initial sway motion. Especially, we consider the case in which the actual transportation process is considered, because the all process of capturing and loading produce the undesirable swing motion.

케틀벨 스윙 시 적당한 케틀벨의 무게는 얼마일까?

( Bo Kyeong Kim ),( Dao Van Thau ),( Sukhoon Yoon ) 한국운동역학회 2021 한국운동역학회지 Vol.31 No.4

Objective: The purpose of this study was to investigate the effect of different kettlebell mass (30%, 40%, and 50% of the body mass) on kinematics and kinetic variables of kettlebell swing. Method: Total of 16 healthy male who had at least 1 year of kettlebell training experience were participated in this study (age: 31.69 ± 3.46 yrd., height: 173.38 ± 4.84 cm, body mass: 74.53 ± 6.45 kg). In this study, a 13- segments whole-body model (upper trunk, lower trunk, pelvis, both side of forearm, upperarm, thigh, and shank) was used and 26 reflective markers were attached to the body to identify the segments during the movement. A 3-dimensional motion analysis with 8 infrared cameras and 4 channeled EMG was performed to find the effect of kettlebell mass on its swing. To verify the kettlebell mass effect, a one-way ANOVA with a repeated measure was used and the statistical significance level was set at α=.05. Results: Firstly, in all lower extremity joints and thoracic vertebrae, a statistically significant change in angle was shown according to an increase in kettlebell mass during kettlebell swing (p<.05). Secondly, in both the up-swing and down-swing phases, the knee joint and ankle joint ROM showed a statistically significant increase as the kettlebell mass increased (p< .05) but no statistically significant difference was found in the hip joint and thoracic spine (p >.05). Lastly, the hamstrings muscle activity was statistically significantly increased as the kettlebell mass increased during up-swing phases (p<.05). Also, as the kettlebell mass increased in P4 of the down swing phase, the gluteus maximus showed a statistically significantly increased muscle activation, whereas the rectus femoris showed a statistically significantly decreased muscle activation (p <.05). Conclusion: As a result of this study, hip extension decreased and knee extension increased at 40% and 50% of body mass, and the spine also failed to maintain neutrality and increased flexion. Also, when kettlebell swings are performed with 50% of body mass, synergistic muscle dominance appears over 30% and 40% of body mass, which is judged to have a risk of potential injury. Therefore, it is thought that for beginners who start kettlebell exercise, swing practice should be performed with 30% of body mass. In addition, even in the case of experienced seniors, as the weight increases, the potential injury risk may increase, so it is thought that caution should be exercised when performing swings with 40% and 50% of body mass. In conclusion, it is thought that increasing the weight after sufficiently training with 30% of the weight of all subjects performing kettlebell swing is a way to maximize the exercise effect as well as prevent injury.

소프트 골프 스윙 시 스윙 패턴 분석

소하주,유미,곽기영,김성현,김남균,김동욱,So, H.J.,Yu, M.,Kwak, K.Y.,Kim, S.H.,Kim, N.G.,Kim, D.W. 대한의용생체공학회 2010 의공학회지 Vol.31 No.2

Soft Golf is a newly developed recreational sport in our research team aimed to become a safe and easy-to-learn sport for all ages. The advantage of Soft Golf stems from lighter weight of the club and much larger area of the sweet spot. The purpose of this study is to analyze ground reaction force(GRF) and joint angle during soft Golf club and regular golf club swing. The GRF of golf swing was recorded by 3-D motion analysis system and forceplate. The joint angle of golf swing was obtained from computer simulation model. The GRF and joint angle of golf swing are used to analysis of golf swing pattern. The pattern of GRF and joint angle during soft golf club swing was similar to that during regular golf club swing. This result means that soft golf club reduces the risk of injury and has an effect on similar entertainment of regular golf.

소프트볼 좌타자들의 효율적인 타격자세 개발

하철수(Ha Chul-Soo),최명수(Choi Myung-Soo),여철훈(Yeo Chul-Hoon),윤주식(Yoon Ju-Sik) 한국체육과학회 2009 한국체육과학회지 Vol.18 No.2

Through the study on the development of an effective swing motion for a left-handed softball player, we can get the conclusion as below. 1. In each step, superior players make sliding time slow while they make the stride length wider than their own shoulder width. Taking the stable pose, they do make fast movement till the impact which is followed by natural throw movement. 2. If the nose moves up and down largely, players can make more accurate hitting. Because the time that takes to reach the impact moment from pitchers' throwing that occurs 13.11m away is very short. In the 2nd and 3rd period of swing, the less nose movenment is, the better body balance occurs, which makes higher possibility for a good swing. 3.It is recommendable to make stride length wider than width of own shoulders but if that is too wider, it is hard to give the enough strength to swing because of the swing motion that is naturally formed. 4.In each step, the velocity(Y) after and before the change of maximum one of center of mass was made when the left handed player made his or her right leg stride while the center of mass or power point moved to the left leg by revolving his/her trunk such as shoulders and waist and move the center of mass to home plate direction, which is followed by simple swing pulled back in order to concentrate the force. In case of vertical velocity(Z), it is necessary to extend the right foot forward from the impact to follow swing and upright the upper body to get the maximized change of velocity.5.When it comes to the velocity of a bat, average players' group makes the maximum one which is 0.017 sec after impact while superior players' group makes it before the impact. 6. An accurate bat could arise when the angle of that levelled out with the X axis. Also, if the angle of trunk is moving too much backward or forward, the balance between trunk and legs is unstable, which makes a player not see the ball until the last moment. That makes the shoulders lose the balance faster, which means it is not possible to make accurate impact and follow swing. The angle of wrist shouldn't be un-cocked until the end of impact and the left hand should move to the right armpit with a bat. Right hand face the ground and left hand turns upward. It was proved that the player should flex the left knee to support the body, and the heel of left foot should be raised when the player swing.

Nonlinear dynamic response of cable-suspended systems under swinging and heaving motion

Guohua Cao,Naige Wang,Lei Wang,Zhencai Zhu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.7

In order to enhance the fidelity, convenient and flexibility of swinging motion, the structure of incompletely restrained cablesuspended system controlled by two drums was proposed, and the dynamic response of the system under swinging and heaving motion were investigated in this paper. The cables are spatially discretized using the assumed modes method and the system equations of motion are derived by Lagrange equations of the first kind. Based on geometric boundary conditions and linear complementary theory, the differential algebraic equations are transformed to a set of classical difference equations. Nonlinear dynamic behavior occurs under certain range of rotational velocity and frequency. The results show that asynchronous motion of suspension platform is easily caused imbalance for cable tension. Dynamic response of different swing frequencies were obtained via power frequency analysis, which could be used in the selection of the working frequency of the swing motion. The work will contribute to a better understanding of the swing frequency, cable tension and posture with dynamic characteristics of unilateral geometric and kinematic constraints in this system, and it is also useful to investigate the accuracy and reliability of instruments in future.