Research and Implementation of the Sports Analysis System Based on 3D Image Technology

On the basis of existing research, this paper analyzes the algorithms and technologies of 3D image-based sports models in depth and proposes a fusion depth map in view of some of the shortcomings of the current hot spot sports model methods based on 3D images. We use the 3D space to collect the depth image, remove the background from the depth map, recover the 3D motion model from it, and then build the 3D model database. In this paper, based on the characteristics of continuity in space and smoothness in time of a rigid body moving target, a reasonable rigid body target motion hypothesis is proposed, and a three-dimensional motion model of a rigid body target based on the center of rotation of the moving target and corresponding motion is designed to solve the equation with parameters. In the case of unknown motion law, shape, structure, and size of the moving target, this algorithm can achieve accurate measurement of the three-dimensional rigid body motion target’s self-rotation center and related motion parameters. In the process of motion parameter calculation, the least square algorithm is used to process the feature point data, thereby reducing the influence of noise interference on the motion detection result and correctly completing the motion detection task. The paper gives the measurement uncertainty of the stereo vision motion measurement system through simulated and real experiments. We extract the human body motion trajectory according to the depth map and establish a motion trajectory database. For using the recognition algorithm of the sports model based on the 3D image, we input a set of depth map action sequences. After the above process, the 3D motion model is obtained and matched with the model in the 3D motion model database, and the sequence with the smallest distance is calculated. The corresponding motion trajectory is taken as the result of motion capture, and the efficiency of this system is verified through experiments.

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Measurement of three-dimensional rigid body motion by multiple exposure speckle photography: use of uncollimated beam illumination in free space geometry

Optics & Laser Technology ◽

10.1016/0030-3992(92)90006-n ◽

1992 ◽

Vol 24 (1) ◽

pp. 27-32 ◽

Cited By ~ 7

Author(s):

A. Kumar ◽

K. Singh

Keyword(s):

Rigid Body ◽

Free Space ◽

Three Dimensional ◽

Rigid Body Motion ◽

Body Motion ◽

Speckle Photography ◽

Multiple Exposure ◽

Space Geometry

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Acceleration Signal Processing Method of Impact Response of Floating Shock Platform Based on Rigid Body Motion Model

Shock and Vibration ◽

10.1155/2020/8826675 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Wenqi Zhang ◽

Xiongliang Yao ◽

Zhikai Wang ◽

Jin Chen ◽

Heng Yang

Keyword(s):

Signal Processing ◽

Rigid Body ◽

High Frequency ◽

Response Spectrum ◽

Low Frequency ◽

Rigid Body Motion ◽

Body Motion ◽

Shock Acceleration ◽

Motion Model ◽

Acceleration Signal

Floating shock platform is generally used to test the antishock performance of large shipboard equipment. Shock acceleration signal will produce zero-shift phenomenon in the test measurement process, which will affect the subsequent shock response spectrum analysis. In this paper, a method of shock acceleration signal processing based on rigid body motion revision model is established. The rigid body motion revision model adopts the theory of ship’s seakeeping based on the hypothesis of KrylovFroude, in which the shock wave load of underwater explosion adopts the empirical formula. The bubble pulsation load adopts the GeersHunter spherical bubble model. The empirical mode decomposition method is used to eliminate the trend term of the low-frequency part of the acceleration signal, and the frequency filtering technology is used to eliminate the noise of the high frequency part. The response estimated by the rigid body motion model is used to modify the measured signal. The modified signal is analyzed by shock response spectrum to get the round design spectrum. The validity of the signal is determined by the Pauta criterion. Finally, the shock environment statistics of the whole platform is given. This method can eliminate the low-frequency trend term and high frequency noise and has good robustness. It can be applied to many kinds of signals. This method can provide technical support for antishock performance of shipboard equipment and also applied to other shock signal processing fields.

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Estimating rigid-body motion from three-dimensional data without matching point correspondences

International Journal of Imaging Systems and Technology ◽

10.1002/ima.1850020108 ◽

1990 ◽

Vol 2 (1) ◽

pp. 55-62 ◽

Cited By ~ 3

Author(s):

Zse-Cherng Lin ◽

Hua Lee ◽

Thomas S. Huang

Keyword(s):

Rigid Body ◽

Three Dimensional ◽

Rigid Body Motion ◽

Body Motion

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DSRF: A flexible descriptor for effective rigid body motion trajectory recognition

2016 IEEE International Conference on Mechatronics and Automation ◽

10.1109/icma.2016.7558815 ◽

2016 ◽

Cited By ~ 1

Author(s):

Yao Guo ◽

Youfu Li ◽

Zhanpeng Shao

Keyword(s):

Rigid Body ◽

Rigid Body Motion ◽

Body Motion ◽

Motion Trajectory

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Calculation of Rigid-Body Motion of Integrated Raft Isolation System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.80 ◽

2012 ◽

Vol 184-185 ◽

pp. 80-85

Author(s):

Zhi Qiang Lv ◽

Wei Xu ◽

Chang Geng Shuai

Keyword(s):

Rigid Body ◽

Rigid Body Motion ◽

Body Motion ◽

Design Stage ◽

Motion Model ◽

Isolation System ◽

Rigid Body Mode ◽

Mode Behavior ◽

Elastic Couplings ◽

Six Degree Of Freedom

Integrated raft isolation system (IRIS) has some advantages over raft system of much smaller scale, such as higher isolation efficiency, less use of elastic couplings, etc. But the calculation of IRIS’s dynamic characteristics is complex. Finite element method usually adopted by raft designers is inefficient due to the iterative nature of design process. In this paper a six-degree-of-freedom rigid-body motion model is presented to calculate the static，quasi-static and rigid-body mode behavior of IRIS. The model is especially suitable to compare different design schemes and select out feasible ones efficiently at the initial design stage of IRIS.

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Segmental motion and deformation of transmurally infarcted myocardium in acute postinfarct period

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1995.268.3.h1304 ◽

1995 ◽

Vol 268 (3) ◽

pp. H1304-H1312 ◽

Cited By ~ 8

Author(s):

J. A. Lima ◽

V. A. Ferrari ◽

N. Reichek ◽

C. M. Kramer ◽

L. Palmon ◽

...

Keyword(s):

Rigid Body ◽

Coronary Occlusion ◽

Three Dimensional ◽

Magnetic Resonance Images ◽

Body Motion ◽

Segmental Motion ◽

Infarcted Myocardium ◽

Tissue Tagging ◽

Coronary Ligation ◽

Principal Strains

Mechanical behavior of infarcted myocardium in the first week following coronary occlusion has not been well characterized. Prior unidimensional studies failed to account for perpendicular deformation or shearing. This study characterizes three-dimensional motion and deformation of transmural infarcts 1 wk after coronary ligation in seven sheep. Principal strains and systolic in-plane translation and rotation were calculated for triangular elements defined by tissue tagging in short- and long-axis magnetic resonance images. The magnitudes of the first and second principal strains were reduced in both the short- and long-axis planes 1 wk after infarction. In addition, the absolute angular difference between the direction of the first principal strain and the radial direction increased from 14.7 +/- 1.9 to 43.5 +/- 2.7 degrees in the short-axis plane and from 19.6 +/- 7.3 to 43.9 +/- 10.0 degrees (P < 0.05) in the long-axis plane. In-plane rigid-body translation and rotation were also reduced in both planes. In conclusion, marked reduction and reorientation of principal strains and reduction in segmental rigid-body motion characterize nonreperfused transmural myocardial infarctions 1 wk after coronary occlusion.

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Active Control of Elastic and Rigid Body Response of a Three Dimensional Underwater Structure

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2826988 ◽

1995 ◽

Vol 117 (1) ◽

pp. 30-37 ◽

Cited By ~ 3

Author(s):

H. Suzuki ◽

K. Yoshida ◽

K. Watanabe

Keyword(s):

Numerical Model ◽

Rigid Body ◽

Active Control ◽

Structural Model ◽

Scale Up ◽

Three Dimensional ◽

Basic Research ◽

Weather Conditions ◽

Body Motion ◽

Elastic Response

One key technology for the offshore development of the increasing water depth will be remotely operated installation and construction of flexible structure in the deep water or on the seabed. The flexibility comes from scale-up or weight reduction of the structure. Conventional operation from the sea surface is affected by the weather conditions, and, therefore, not so efficient. This paper presents basic research on active control of elastic response and rigid body motion of an underwater elastic structure toward the remotely operated installation technique. The numerical model of the dynamics of the structural model is formulated, and based on the numerical model the control is formulated. The formulated control is tested by computer simulations and model experiments. The structural model is propelled by thrusters and taken from initial position to another position, while the elastic responses are controlled by variable buoyancy-type actuators.

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