隨著運動科技的進步，在現今棒球的訓練中也加入了不少軟硬體技術協助選手提升運動表現。而其中擊網打擊練習(Toss Batting)是選手對於打擊基礎訓練中不可或缺的一塊，但這項訓練卻還是以人工拋球的方式，鮮少有與運動科技的結合。

因此本研究致力於打造一個基於六軸機械手臂的智慧拋球系統，能夠根據打者身高制定對應的好球帶範圍，讓選手能夠選擇拋球的落點位置，增加擊網練習的多元性及實用性。透過制定一套機械手臂的拋球姿勢，針對特定關節的參數調整並用影像紀錄棒球拋到自製拋球板的位置，共有11種的高低位置參數組合，每一種高度再搭配約8至11組的左右位置參數，每組參數進行6次拋球取其平均位置，最終整理出一份參數與落點位置的對照表。

將整體拋球姿勢分為前段的蓄力階段及後段的發力階段兩者。透過第一關節的角度調整決定拋球起始位置，影響落點的左右位置。第二級第三關節的旋轉角度影響落點的高低位置及出球點距離打者的遠近。第四關節的角度則用來做為末端夾爪釋放球體的時機判定。將身高從165公分至185公分，5公分為身高級距的好球帶分別均分成九宮格，根據參數對照表每個位置挑選三組範圍內最佳的參數，每組參數進行3次投擲並使用加權準度分數的方式進行準度測試。整體的準確度為79.51\%，若將落點位置區分成內角、紅中及外角三個區域，準確度分別為75.93\%、80.00\%、82.59\%，若將落點位置區分成高處、中間及低處三個區域，準確度分別為77.41\%、78.52\%、82.59\%，本系統的訓練便利性及多元性已具有一定的實戰訓練價值。

With advancements in sports technology, modern baseball training has incorporated various software and hardware tools to enhance athletes' performance. Among these, toss batting practice is an essential component of foundational training for hitters. However, this practice is still primarily conducted manually, with limited integration of sports technology.

Thus, this study aims to develop an intelligent tossing system based on a six-axis robotic arm, capable of adjusting the strike zone according to the batter's height. This system allows the player to select the target location for tosses, enhancing both the versatility and practicality of toss batting practice. A specific pitching posture for the robotic arm is established, with adjustments made to key joint parameters. Using video analysis, the position where the baseball lands on a custom toss board is recorded. There are a total of 11 height parameter combinations, and each height is paired with approximately 8 to 11 horizontal position parameters. For each set of parameters, six tosses are performed, and the average landing position is calculated. A reference table is then compiled, correlating the parameters to the landing positions.

The entire tossing posture is divided into two stages: the initial power-gathering phase and the subsequent release phase. The first joint's angle determines the starting position of the toss, which influences the horizontal position of the landing spot. The second and third joint angles affect the height of the toss and the distance of the release point from the batter. The fourth joint’s angle is used to determine the timing for the gripper to release the ball. The strike zone is divided into a 3x3 grid for five height ranges, spanning from 165 cm to 185 cm. For each grid position, three optimal parameter sets are selected from the reference table, and each set is used for three tosses. Accuracy is assessed using a weighted scoring system. The overall accuracy achieved is 79.51\%. When dividing the target areas into inside, center, and outside zones, the accuracy rates are 75.93\%, 80.00\%, and 82.59\%, respectively. When categorized by height, upper, middle, and lower zones, the accuracy rates are 77.41\%, 78.52\%, and 82.59\%, respectively. The system demonstrates substantial value in terms of practicality and versatility for real-world training.

[1] A. D. Morris, Colonial project, national game: A history of baseball in Taiwan. Univ of California Press, 2010, vol. 6.
[2] A. Kos, Y. Wei, S. Tomažič, and A. Umek, “The role of science and technology in sport,” Procedia Computer Science, vol. 129, pp. 489–495, 2018.
[3] D. M. INC., “Sport specific – event detection during complex movements.” https://darimotion.com/post/sport-specific-event-detection-during-complex-movements/, 2024.
[4] J. A. Kincaid, F. Gong, T. Jia, H. Z. Tan, C. Kohr, and G. Bertoline, “A study on vr training of baseball athletes,” in
International Conference on Human-Computer Interaction. Springer, 2021, pp. 187–204.
[5] Z. Farrel, A. R. Cocco, E. J. Dichiara, P. C. Jones, B. C. Skutnik, R. L. Crotin, E. Rimer, P. Ivey, and J. F. Caruso, “Pitch release speed predictors for division i collegiate baseball players,”
Isokinetics and Exercise Science, vol. 31, no. 4, pp. 19–328, 2023.
[6] C.-H. Lin, H.-C. Shih, and W.-Y. Wang, “Evaluations of flight dynamic parameters for smart baseballs,” in 2019 IEEE 8th Global Conference on Consumer Electronics (GCCE). IEEE, 2019, pp. 553–554.
[7] R. Cross, “The sweet spot of a baseball bat,” American Journal of Physics, vol. 66, no. 9, pp. 772–779, 1998.
[8] H.-J. Chen, H.-J. Wang, W.-T. Yang, and J.-H. Zhang, “棒球揮擊動作對打擊表現之影響-以國中選手為例,” 運動教練科學, no. 21, pp. 57–66, 2011.
[9] T. S. Inc., “Trajekt arc™,” https://www.trajektsports.com/, 2024.
[10] G. Vecsey, Baseball: A history of America’s favorite game. Modern Library, 2008, vol. 25.
[11] J. Mizels, B. Erickson, and P. Chalmers, “Current state of data and analytics research in baseball,” Current reviews in musculoskeletal medicine, vol. 15, no. 4, pp. 283–290, 2022.
[12] D. Kagan and A. M. Nathan, “Statcast and the baseball trajectory calculator,” The Physics Teacher, vol. 55, no. 3, pp. 134–136, 2017.
[13] M. Henshon, “Sports, mobile devices, and the new player mobility,” Scitech Lawyer, vol. 16, no. 2, pp. 16–19, 2020.
[14] K. Middleton, M. Connolly, N. Busuttil, and M. Cianciosi,“Accuracy of the motusbaseballtm wearable sensor,” ISBS Proceedings Archive, vol. 41, no. 1, p. 79,2023.
[15] G. E. Barre, The Ultimate Hitting Training Guide: Building Rome Series - Step by Step Coaching Guides To Training Great Ballplayers - Baseball and Fastpitch Softba. Independently published, 2020.
[16] S. Spot, “Softball hitting drills,” https://www.softball-spot.com/, 2024.
[17] B. Motion, “Blast baseball swing analyzer,”https://store.blastmotion.com/store/products/baseball/, 2024.
[18] T. Newcomb, “Tech bit: Zepp builds advanced smart bat for mlb superstar mike trout,” https://www.si.com/edge/2016/02/29/mike-trout-baseball-training-zepp-smart-bat-swing-tracking, 2016.
[19] K-VEST, “K-baseball,” https://www.k-motion.com/k-shop/technology/k-baseball/, 2024.
[20] B. N. Marty, “Automatic base-ball-pitching machine.” Patent, 1916.
[21] Y.-T. Cheng, Y.-H. Chang), W.-A. Chuang, W.-H. Chen, and C. Liu, “不同棒球發球機在發球落點與速度穩定性之比較,” 華人運動生物力學期刊, vol. 12, no. 1, pp. 39–44, Apr 2015.
[22] S. Sakai and H. Nakayama, “Optimization and improvement of throwing performance in baseball pitching machine using finite element analysis,” Finite Element Analysis—Applications in Mechanical Engineering, 2012.
[23] S. Sakai, J. Oda, S. Yonemura, K. Kawata, S. Horikawa, and H. Yamamoto, “Research on the development of baseball pitching machine controlling pitch type using neural network,”
Journal of System Design and Dynamics, vol. 1, no. 4, pp.682–690,2007.
[24] S. Sakai and J.-X. Shi, “Development of new baseball pitching machine with four-roller throwing mechanism,” in Proceedings, vol. 49, no. 1. MDPI, 2020, p. 8.
[25] 金龍機械有限公司, “揮臂式棒球發球機,”http://klm104.com/product_detail.asp?p_id=179, 2024.
[26] A. Sports, “M3x 2.0 baseball traning machine - on tripod,” https://www.atecsports.com/en-us/product/m3x-baseball-on-tripod-2-0-wba7429#axis=91701, 2024.
[27] F. INC., “Ftm-240,” https://www.fieldforce-ec.jp/, 2024.
[28] A. Gasparetto and L. Scalera, “From the unimate to the delta robot: the early decades of industrial robotics,” in Explorations in the History and Heritage of Machines and Mechanisms: Proceedings of the 2018 HMM IFToMM Symposium on History of Machines and Mechanisms. Springer, 2019, pp. 284–295.
[29] A. Gasparetto, L. Scalera et al., “A brief history of industrial robotics in the 20th century,” Advances in Historical Studies, vol. 8, pp. 24–35, 2019.
[30] V. Patidar and R. Tiwari, “Survey of robotic arm and parameters,” in 2016 International Conference on Computer Communication and Informatics (ICCCI), 2016,pp. 1–6.
[31] X. Jiang and W.-F. Huang, “六軸機械臂之控制理論分析與應用,”
機械工業, vol. 277 民 95.04, pp. 057–073, 2006.
[32] J. Tebbe, Y. Gao, M. Sastre-Rienietz, and A. Zell, “A table tennis robot system using an industrial kuka robot arm,” in
Pattern Recognition: 40th German Conference, GCPR 2018, Stuttgart, Germany, October 9-12, 2018, Proceedings 40. Springer, 2019, pp. 33–45.
[33] J. Tian, H. Liu, S.-L. Dai, and C. Yang, “A real-time football goalkeeper robot system based on fuzzy logic control,” in
2021 China Automation Congress (CAC). IEEE, 2021, pp. 3258–3263.
[34] S. Mori, K. Tanaka, S. Nishikawa, R. Niiyama, and Y. Kuniyoshi, “High-speed humanoid robot arm for badminton using pneumatic-electric hybrid actuators,”IEEE Robotics and Automation Letters, vol. 4, no. 4, pp. 3601–3608, 2019.
[35] T. Xu and L. Tang, “Adoption of machine learning algorithm-based intelligent basketball training robot in athlete injury prevention,”
Frontiers in Neurorobotics, vol. 14, p. 620378, 2021.
[36] T. Senoo, A. Namiki, and M. Ishikawa, “High-speed throwing motion based on kinetic chain approach,” in 2008 IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE, 2008, pp. 3206–3211.
[37] J.-S. Hu, M.-C. Chien, Y.-J. Chang, S.-H. Su, and C.-Y. Kai, “A ball-throwing robot with visual feedback,” in 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2010, pp. 2511–2512.
[38] L. Chen, W. Lu, K. Zhang, Y. Zhang, L. Zhao, and Y. Zheng, “Tossnet: Learning to accurately measure and predict robot throwing of arbitrary objects in real time with proprioceptive sensing,” IEEE Transactions on Robotics, vol. 40, pp. 3232–3251, 2024.
[39] A. Zeng, S. Song, J. Lee, A. Rodriguez, and T. Funkhouser, “Tossingbot: Learning to throw arbitrary objects with residual physics,” 2019.
[40] H.-J. H. Jyhhow Huang, “Approximating strike zone size and shape for baseball umpires under different conditions,” International Journal of Performance Analysis in Sport, vol. 20, no. 2, pp. 001–017, 2020.
[41] T. R. INC., “Techman robot information.” https://www.tm-robot.com/zh-hant/tm14/, 2024.
[42] O. Inc., “Onrobot 3fg15 datasheet,” https://onrobot.com/zh-hant/
[43] ——, “Weblogic simple programming,”https://learn.onrobot.com/en/weblogic-simple-programming, 2024.
[44] T.-Y. Luo, B.-Y. Zhuang, and J.-H. Zhang, “不同層級大專棒球選手揮擊不同高度位置之揮棒動作分析,” 華人運動生物力學期刊, vol. 16, no. 2, pp. 001–011,2019.
[45] I. Inc., “What an mlb strike zone really looks like and why players are always so mad about it,”https://www.businessinsider.com/mlb-strike-zone-2014-9, 2014.