A Guidance System For Swimmers' Turning Movements

With the rapid development of China's swimming,China's position in the world's swimming field is increasing.In the vigorous development of the present,the physical quality and technical deficiencies of Chinese swimmers gradually appear.To improve the competitive level of swimmers rapidly,this paper proposes a scientific guidance system in the field of professional swimming,which make training more scientific,so that most swimmers can accelerate their growth.Because the quality of turning has a key influence on the result of the competition,the movement guidance system designed in this paper is mainly aimed at the turning movement.Turning movement is the general term for a series of movements,such as touching the wall,accumulating force,and pedaling the wall of the pool after the athletes swim to the edge of the pool.In the research of the turning movement,we found that an excellent turning movement requires the athlete to reach the edge without slowing down,to turn the body direction quickly,and to pedal the pool wall with high efficiency.Starting from these three requirements,through the communication with professional coaches,the system tests the two stages before and when the athletes turn around,including the specific test indicators:the angle between the knee joint,hip joint and the angle between the trunk and the horizontal plane.Through the determination of these three included angle information,we can judge whether the athlete's movement rhythm and amplitude are standard or not.Swimming scene has higher requirements for motion capture system,for example,wearing motion recording equipment will bring great resistance to athletes,and then make the technical movements of athletes change.Therefore,after analyzing the advantages and disadvantages of the existing motion capture technology in the field of swimming,due to the non-contact measurement and low threshold of use,this system chooses the optical non-standard motion capture system,that is,using the image processing method for motion capture.To be able to accurately detect the key position information of athletes,the grayscale,denoising and edge detection links of the image are studied.From the above links,a variety of implementation methods are selected and applied to the image processing in the swimming field,and the image processing methods suitable for use in the swimming field are determined by comparison.For the processed image,Hough line is used to detect and locate the key position of athletes,and then the above three included angles are calculated.To accurately locate the problem of swimmer's swimming movement,we observed the turning movement of 8 high-level athletes in Shaanxi Province,established the standard data,through the comparison of the data of the observed and the standard data,we can locate the problem of the observed turning movement,and then give the targeted optimization suggestions.To make users have a clearer understanding of their actions and a more quantitative perception of the improvement of action standards,the evaluation algorithm of this system gives users a quantitative action score after giving users optimization suggestions.To let more athletes use the system to improve the turning movement and reduce the threshold of using the system,the author built an action guidance system based on Open CL technology.Because FPGA can carry out real-time pipeline operation and has strong real-time performance,the author chose to implement the system on the FPGA development board(DE10-Nano).After a brief description of the building process from the two levels of hardware and software,the operation results of the system are displayed on the development board.