文章基本信息

标题：Profiling of a Pitcher’s Performance with a Smart Baseball: A Case Report
本地全文：下载
作者：Batdelger Doljin ; Kwangyul Jeong ; Young-Kwan Kim 等
期刊名称：Proceedings
电子版ISSN：2504-3900
出版年度：2020
卷号：54
期号：36
页码：103
DOI：10.3390/proceedings2020049103
语种：English
出版社：MDPI AG
摘要：A pitcher’s action, when delivering a fastball, was analyzed from the data provided by a smart baseball. The spin rate at the release of the ball was merely 15.7 rps, however, the peak torque was excessively high, namely 0.396 Nm. The reason why the pitcher was not able to translate the torque entirely to angular kinetic energy and this to the spin rate was that the spin axis changed its direction suddenly three times when moving across the ball’s surface. This resulted in angles between torque and angular velocity vectors of greater than 90°, high precession and precession torque, and negative spin torques, causing a very low efficiency (5.4%) and a slow spin rate at the release of the ball.