Prediction of the Extreme Values and the OptimalRatios of Triple Jump Based on the Grey System Theory

We have applied the grey system theory to study triple jumps. In this Paper we introducethe grey system theory, apply it to establish a monotonic sequence nonlinear Verhulst differentialdynamic model. Using that model and the triple jump records in recent 45 years we calculate thefuture extreme values of world triple jump, predict the optimal apportionment among the three phases,and study the tendency of development of triple jumP techniques and strategy. Every event has itsown development, maturity and peak periods. Our study helps coaches and athletes to develop theirstrategy on a scientific base. Based on the grey system theory we predict that the record of worldtriple jump will finally approach 20.65m. The distance of hop, step, and jump will approach 7.56m,6.06m, and 7.03m respectively. The apportionment will approach 36.6% for hop. 29.4% for step, and34.00% for jump. According to our calculation the tendency of development is to follow the model ofthe Russian style basically, and at the same time to absorb the advantage of the Polish style to place agreater emphasis on the distance of the distance of the third phase.

Modeling and analysis of knee joint impact damage in triple jump manipulators based on finite element method

In order to study the three jump training and competition on knee joint impact damage degree,left knee joint of one healthy male athletes is used as the research object,a complete knee three-dimensional model was established based on the jumper’s knee CT scan and magnetic resonance imaging(MRI),including the femur,tibia,fibula,patella and knee major cartilage,ligaments.The multi-body dynamics analysis(MDA)and finite element analysis(FEA)method are used to calculate the three jump,jump starting,landing process of athletes knee joint impact,the state should change the status of stress,strain and displacement.The results show that in the three jump process,the load on the lateral contact area of the knee joint is the largest,the displacement is the largest,and it increases with the impact of jump and landing.This exacerbated the degree of wear and tear of the tibia,it tends to induce knee injury in athletes.The results show that the combination of finite element and MDA can better study the knee joint’s shock and vibration during the three-level jump training and competition,and these open up a new research method for the knee joint injury.It also provides a certain reference for the prevention and treatment of knee joint injury.

Intelligent self-powered sensor based on triboelectric nanogenerator for take-off status monitoring in the sport of triplejumping

In the era of big data and the Internet of Things,the digital information of athletes is particularly significant in sports competitions.Here,an intelligent self-powered take-off board sensor(TBS)based on triboelectric nanogenerator(TENG)with a solid-wooden substrate is provided for precise detection of athletes’take-off status in the sport of triple-jumping,which is sufficient for triplejumping training judgment with a high accuracy of 1 mm.Meanwhile,a foul alarm system and a distance between the athlete’s foot and take-off line(GAP)measurement system are further developed to provide take-off data for athletes and referees.The induced charges are formed by the TBS during taking-off,and then the real-time exercise data is acquired and processed via the test program.This work presents a self-powered sports sensor for intelligent sports monitoring and promotes the application of TENG-based sensors in intelligent sports.