Tennis Hit-point Positioning Method Based On Acoustic Source Location

The position of tennis hit-point is the main factor that affects the quality of the receive a service,it is of great significance for the athletes to find the best position of tennis hit-point,and to enhance the predicting ability of the best hit-point,which is important to improve tennis technological level.With the problems of the errors and high price of recent location methods,this paper applied acoustic source location technology into tennis hit-point location,with the two key technologies of microphone arrays and source localization methods,tennis hit-point positioning method was advanced researched.The main contents were as follows:(1)The princples and characteristics of several common time delay estimation algorithms were discussed.The theory of cross correlation time delay estimation was deduced and analyzed in detail.The performance of the algorithms was compared by experiments.The time delay estimation by the cross correlation method based on wave transform was proposed to improve the accuracy.It was verified by the simulation results that the cross correlation method based on wave transform was much more accurate and stable,in addition,several methods which can improve the accuracy of time delay estimation were also studied.(2)A research on localization algorithm by five-element microphone array had been done,the factors which affected the accuracy of localization were analyzed,due to the matter that the five-element microphone array existed,a localization algorithm by solid seven-element microphone array was proposed,its model was designed,as well as error model,meanwhile,the quadrant decision criterion for acoustic source was presented.It proved that the proposed algorithm could effectively solve the location ambiguity problem and the accuracy problem affected by the sound source orientation.(3)Experimental apparatuses were built,location device performance was conceived by analyzing the results,it turned out that the accuracy of the tennis hit-point positioning method based on acoustic source location could meet the request,which was up to 95%.In the meantime,the factors which affected the results also were analyzed.This paper will not only explore new applications for tennis hit-point positioning methods,but also take on active meanings for the new application field of acoustic source localization.