由於棒球是我們的國球，因此我們希望透過科學的方式，來協助運動員跟教練在訓練時可以有量化的數據供參考。在這篇論文中，我們設計一個智慧棒球，可以幫助選手量測手指力度、投擲的速度和轉速、飛行時軌跡的變化。我們將訊號透過微控制器整合，再使用藍牙低功耗將資料傳送至電腦，最後在電腦進行信號處理。
在這個裝置中，我們提供了兩種不同的操作模式，讓使用者可以依照需求選擇感測器的配置。在訊號量測方面，手指力度最大可量測到111牛頓，速度和轉速分別可以提供至每小時100公里和每分鐘600轉以上的量測範圍。感測裝置提供高取樣率，足以應付訊號在0.01秒內快速變動的情況。
我們開發了一種訊號處理方法，用來計算球速。應用低通濾波器和重力補償，再把加速度做積分獲得球速。
我們進行了兩種實驗的比較。實驗一是縮短投補距離為14公尺，限制球速在每小時80公里。計算結果與測速槍的量測結果之間均方根誤差為每小時4.2305公里。實驗二是標準投捕距離為18.4公尺，限制球速大約在時速90公里。計算結果與測速槍的量測結果之間均方根誤差為每小時6.4398公里。在低速的情況下，計算誤差約為5%。在高速的情況下，計算誤差約為6%。而我們也從實驗數據中發現指力與球速之間的關係，指力增加約9牛頓，球速會增加約每小時10公里。

Since baseball is Taiwan's national ball game, we hope to help players and coaches with quantitative data during training in a scientific way. In this thesis, we design a smart baseball that can help players measure finger force, ball speed and spin rate, and flight trajectory changes. We integrate signals through microcontroller, and then use Bluetooth Low Energy (BLE) to transfer data to personal computer (PC), and then conduct subsequent signal processing on PC.
In this device, we provide two different modes of operation, allowing the user to select the sensor configuration according to the requirements. In terms of signal measurement, the maximum finger force can be measured to 111 N, and the maximum measurement range of ball speed and spin rate can reach 100 km/h and 600 rpm. The sensor provides a high sampling rate sufficient to cope with rapid signal changes in 0.01 seconds.
We developed a signal processing method to calculate the ball speed. Apply low-pass filter and gravity compensation, then integrate the acceleration to get the ball speed.
We compared the two experiments. Experiment one is to shorten the throwing distance to 14 m and limit the ball speed to 80 km/h. The root-mean-square error (RMSE) between the calculation result and the radar gun measurement result is 4.2305 km/h. In the second experiment, the standard throwing distance was 18.4 m and limit the ball speed to 90 km/h. The RMSE between the calculation result and the radar gun measurement result is 6.4398 km/h. At low speeds, the calculation error is about 5\%. At high speeds, the calculation error is about 6\%. We also found the relationship between finger force and ball speed from the experimental data. The finger force increased by about 9 N and the ball speed increased by about 10 km/h.

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