Estimation of baseball bat trajectory during a practice swing using a Kalman filter for velocity compensation. (June 2023)

• Record Type: Journal Article
• Authors: Shibata, Shohei; Hirose, Kiyoshi; Naruo, Takeshi; Shimizu, Yuichi
• Other Names: Seo Kazuya guest-editor.
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 237:Number 2(2023)
• Page Start: 96
• Page End: 101
• Publication Date: 2023-06
• Subjects: Inertial sensor -- microelectromechanical systems -- baseball swing -- Kalman filter -- time integration of backward direction -- bat trajectory -- motion analysis; Sports sciences -- Periodicals; Sporting goods -- Design and construction -- Periodicals; Sports -- Technological innovations -- Periodicals; Biomechanics -- Periodicals; 613.71
• DOI: 10.1177/1754337119871436
• Languages: English
• ISSNs: 1754-3371

Abstract

This study aimed to (a) develop an algorithm that could estimate a baseball bat trajectory from the beginning of the swing to the follow-through phase during a practice swing without a ball and (b) evaluate the accuracy of the proposed method using a three-dimensional motion capture system. The sensor fusion using the adaptive Kalman filter for compensating velocity decreased the error of acceleration integration during the follow-through phase. Further, the three-dimensional bat trajectory in a global coordinate was estimated by combining the sensor fusion and compensation by motion characteristics. The three-dimensional bat trajectory from the swing beginning to the follow-through phase estimated by the proposed method was compared with the three-dimensional bat trajectory obtained by the three-dimensional motion capture system. The proposed method achieved a root mean square of the error of 7.72 km/h for velocity, which was less than the root mean square of the error (8.91 km/h) obtained by simple time integration of forward direction. These results indicate that the error by acceleration integration during the follow-through phase is compensated. The proposed method is, thus, deemed effective and can be used to evaluate baseball swing, including the follow-through phase, with high accuracy.