The Development And Test Of The Three-dimensional Digital Discus Information Collection System

It is hold discus singlehandedly and stand in the behind of the circle, give full play to the strength of whole body after rotating to discus throw, gain the most suitable speed and angle, throw the discus from rear of the body side and before the body side direction out, and got the event of degree far as much as possible. Discus throw at Golden Era when the level was developed rapidly in our country in the mid to late 1980s of the 20th century, famous discus athlete Xiao YanLing threw out 71.06 meters of good results in 1992, the men's discus throw broke the Asian record too, but because of lack of training method and discus athletes in recent years, the achievement comes down wholly, in order to obtain the break-through on the discus throw, we must proceed with scientific training, develop special sports apparatus which suit the athlete of our country and train, this becomes the key problem which we must solve at present.In order to adapt this kind of demand at present, improve traditional training and evaluation, solve the problem from the difficult point and key in practice, use modern scientific and technological idea and methods, we have developed the three-dimensional digital discus information collection system which includes a digital discus, USB connecting line, position machine software and a personal computer. The digital discus is made up of the higher and lower shell, eyelets, circuit boards, accelerometer and angular rate sensor, A/D, processor, FLASH memory, USB interface, etc. The largest measurement range is±14000N. One-dimensional error≤1.5% F.S. The greatest overload capacity is 200%. Gathering frequency is 100Hz. Resolution ratio is 0.1%F.S. The time of every data-gathering is 15 seconds. The largest number of throwing which can be saved is 13. It can gather the groups from 1 to 13 times. A 9V nickel hydrogen charge battery is installed within. Working temperature is–40℃—80℃.We have carried on the on-the-spot test two times, base on the collection of the data in the first test, we have analysed and summarized, has proposed improving methods, has improved the inside structure of the digital discus. After improving digital discus, In the track and field team of Hebei ,carry on test of the second time to 3 discus athletes, use two JVC9800 camera and use DLT three-dimensional radiation frame, in kinematics , use APAS three-dimensional sports analyze system to analyze the test result. Based on the collected data from the three-dimensional digital discus information collection system and the APAS three-dimensional sports analyze system, having carried on deep analysis to technological movements which tested the athlete, the analysis results indicate that it is more similar between Gong Jian and Li Bing in technology, the acceleration curve fluctuation of Li Bing is more than Gong Jian, from left foot lands to release discus, Guo WenXin after the left foot lands , stop one while, indicate that Guo WenXin exerts oneself too early and needs to improve the technical. From the athlete's largest acceleration, the explosive force of the Gong Jian is the largest, the others are similar. According to results tested, it is not highly dependence between the absolute value size of athlete's explosive force and achievement, the level of the achievement still relates to time lasting in effort. According to rotation stability of the discus after throwing, the rocking biggest of Li Bing's discus, Gong Jian in taking second place, after Guo WenXin throwing the discus, it is minimum to swing, the most steady.It has fully tested the effect of the digital discus through two times on-the-spot tests and has carried on the analysis deeply to the test result. It indicates that this system can collect the information of acceleration and angle velocity. This system can get the force signal of the athletes in real time during the complete process of athlete's throwing of the discus. It can measure the strength and the curves of human body through the directions of X, Y and Z; in addition it measures the amount of combined force of every direction and the impulse in any period. It can get the angular speed and changing curves in directions of X, Y and Z axes; it also can save, read and print the associated documents with the help of USB interface. This system is high in precision and quick in reaction and is capable of realizing unimpeded and non-harmful experiment. It is safe and reliable and it can measure, record and display continuously. Computer can be used to calculate, save, process information and output and print, it can not only carry on measurement independently but also can take synchronous measurement with other instrument.Though the collection of the data, it is can fast reflect the difference of technology, it offers the scientific evidence in order to improve technology and result, This system offers a scientific research instrument and monitoring system for coach and athletes in their scientific trainings. The sports scientific research worker can use this instrument and this measurement method to explore the new theory of technology, find the new law, improve and prefect the discus throw technological optimization.