無線微機電感測器系統應用於羽球正拍擊長球之球拍振動分析

WIRELESS MEMS SENSORS SYSTEM APPLIED TO BADMINTON FOREHAND STRIKING CLEAR RACKET VIBRATION ANALYSIS

本研究是在探討利用無線微機電感測器系統來分析羽球正拍擊長球的動作。目的：是來探討國內優秀選手(全國甲組)與次優秀選手(全國乙組)的正拍長球回擊動作之差異性及穩定性。對象：優秀選手目前世界排第14名(參加2012倫敦奧運會)；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：以無線微機電感測器在球拍放置一個測量點；內含有三軸加速規，取樣頻率為3333Hz，在擊正拍長球時擷取各測量點的運動數值來做分析。結果：一、無配戴與有配戴無線感測器做成對t檢定結果發現兩者無顯著差異，所以有配戴感測器是不會影響到擊球動作。二、加速度振動頻譜資料，來做均方根誤差計算結果發現，X軸和Y軸誤差較大。三、球拍加速度頻譜振幅次數15次回擊中，於球拍X、Z軸的振動頻譜分析時，發現優秀選手在振動頻率443~482Hz之間有較多的次數；於球拍Z軸的振動頻譜分析時，發現次優秀選手在振動頻率299~417Hz之間有較多的次數。四、球拍時域三軸最大值比較，經F和t檢定結果發現優秀選手與次優秀選手在X軸和Y軸都有明顯的差異。五、球拍振動時間經F和t檢定(P值<.05)後發現優秀選手與次優秀選手在X、Z軸向有明顯的差異，優秀選手振動時間短於次優秀選手。結論：一、從本實驗可看出在加速度的頻域和時域球拍振動對X軸與Y軸有較大的差異性。二、球拍加速度頻譜振幅次數中，發現優秀選手與次優秀選手的振動特性不同。三、從加速度時域資料可觀察出優秀選手施力大於次優秀選手。四、球拍振動時間可觀察出優秀選手施力時間較短，次優秀選手施力時間較長，所以可看出優秀選手在擊球後握拍的地方就放鬆，而次優秀選手還握的很緊。

This research explored the use of Wireless MEMS Sensors System to analysis of badminton forehand striking clear racket vibration. Purpose: analysis of the domestic player “national group A” and the second best player “group B” striking forehand clear racket of the divergence and the stability. Objects: the player from currently under test world rank 14 – participation in 2012 the 30th London Olympic Games - and the second best player currently rant match in group B third place. Method: to place sensor wireless MEMS sensors in the racket points; each measurement point contains three-axis acceleration sensor chip. When players strike forehand clear racket， each chip captures sensor measuring point of numerical data， and statistical analysis. Result: 1. two of the contestants not worn and wear sensors in ball speed， paired t- testing， no significant differences. 2. The number racket acceleration spectrum amplitude， x axis is inaccuracy with y axis. 3. in 15 times racket acceleration spectrum amplitude， the national group A player has more vibration between 443 to 482 Hz and group B player gets vibration between 299 to 417 Hz. 4. the max compare of three-axis area， the group A player and the group B player have obviously difference. 5. The racket vibrating time of F and T testing， group A player’s vibrating time is shorter than group B’s. Conclusions: 1. the racket acceleration spectrum amplitude and the racket vibration have their diverseness. 2. Group A player and group B player have different characteristics of vibration.3. Group A player has powerful force than group B player. 4. From the vibration of the racket， it showed that group A player forces the power shorter than group B player， which means group A player release power after she hit but didn’t group B player.