Novel Non-Contact Technique for Detecting Sports Motion on the Basis of Current Generated by Electrostatic Induction

• Published in: Nihon Kikai Gakkai rombunshuu. C hen Vol. 78; no. 789; pp. 1420 - 1427
• Main Authors: YAMASHIMA, Takahito, KURITA, Koichi
• Format: Journal Article
• Language: Chinese; English; Japanese
• Published: The Japan Society of Mechanical Engineers 2012
• Subjects: Contact; Current Measurement; Electric potential; Electrodes; Electrostatic Induction; Electrostatics; Grounds; Human body; Mechanical engineers; Non-Contact Detection; Sports Motion; Time measurements
• ISSN: 0387-5024; 1884-8354
• DOI: 10.1299/kikaic.78.1420

In this study, we develop an effective noncontact technique for analyzing sports motion. We propose a new method for detecting sports motion by measuring the current generated due to a change in the capacitance between a given electrode and the human body. The technique involves the detection of electrostatic induction current of the order of approximately sub-picoamperes flowing through the electrode that is placed at a distance of 3 m from a subject. An occurrence model is proposed for the electrostatic induction current generated due to a change in the electric potential of the human body. This model can be used to effectively explain the behavior of the electrostatic induction current flowing through the measurement electrode. We apply the noncontact technique to detect the timing of athlete's foot contact or off with the ground during pitching and batting motions in baseball. Thus, we could quantitatively estimate the timing of contact and noncontact of an athlete's foot with the ground from the time of occurrence of the peaks. Our technique enables easy in-situ detection of the timing of contact and noncontact of an athlete's foot with the ground during pitching and batting motions.