無線微機電感測器系統應用於羽球高反拍擊球之球拍振動分析

THE RACKET VIBRATION ANALYSIS OF WIRELESS MEMS SENSORS USED IN BADMINTON HIGH BACKHAND STROKE

目的：本研究利用無線微機電感測器，分析羽球高反拍擊球動作時球拍振動的差異。對象：優秀選手目前世界排第11名；次優選手目前最佳成績是100年全國排名賽乙組第三名。方法：在拍面下端放置一個無線微機電感測器；內含有三軸加速規，取樣頻率為3333Hz，在擊反拍高點長球時擷取感測器的記錄來做分析比對。結果：一、無配戴與有配戴感測器，無顯著差異(顯著水準為0.05)。二、球拍加速度頻譜振動頻率次數分佈，發現優秀選手有較高的振動頻率。三、球拍振動時間，經檢定後發現優秀與次優秀選手在XYZ軸，有顯著差異。四、球拍加速度頻域資料經Ｆ和ｔ檢定之後，發現三軸總功率有顯著差異。五、在球拍時域分析時，發現Ｚ軸優秀和次優秀選手的最大和最小平均值皆有顯著差異，且優秀選手皆大於次優秀選手。結論:一、有無配戴感測器不會影響選手的表現。二、優秀選手球拍振動頻率較高，擊球點明顯集中於甜區。三、優秀選手在XYZ軸振動時間較短，在瞬間擊球後放鬆握把，節省體力。明顯優於次優秀選手。四、球拍加速度頻域資料之三軸總功率平均值優秀選手大於次優秀選手。五、在球拍時域，發現Ｚ軸最大和最小平均值優秀選手皆大於次優秀選手。

Purpose: This research explored the use of Wireless Micro Electro Mechanical systems (MEMS) Sensors to analysis of racket vibration of badminton high backhand striking. Subjects: The elite athlete is ranked number 14 in the world and the sub-elite are ranked the third of group B in this Taiwan. Methods: Underneath the racket is placed a wireless MEMS sensor which includes a tri-axis accelerometer. The sample is taken on the frequency of 3333Hz. When players strike backhand high racket， sensors capture measuring point of numerical data， and statistical analysis. Result: 1. Two of the contestants not worn and wear sensors in ball speed， no significant differences (The significant difference of α is 0.05 ). 2. From the acceleration spectrum， it is found that the elite athlete has more frequencies. 3. Significant differences are found between the two athletes on the vibrating time of the racket. 4. After the examination of the F and t testing， the total tri-axis power has obviously difference. 5. The analysis of racket time zone， both of the elite and sub-elite athletes have the obviously difference during the max and min average values on Z axis. Conclusions: 1. The performances of the athletes not worn and wear sensors are not affected. 2. The vibrating frequencies of the elite athlete are higher with the hitting points focused on the sweet spots. 3. The vibrating time of the elite athlete on the tri-axis is shorter than the sub-elite because the former releases the handle soon after hitting the ball. 4. The average of total tri-axis power in racket acceleration spectrum， the elite athlete’s data is better than the sub-elite athlete. 5. The racket time domain， the elite athlete’s data is better than the sub-elite athlete with the max and min average values on Z axis.