Vol. 11, Issue 10, Part B (2025)

Abstract
Currently, various measures of physical ability have been developed and used to improve the physical ability of athletes in the sports world. Circular activity is a very important and fundamental data for assessing the physical performance of most sports athletes, and studies are being conducted on various measures and methods to accurately measure this level of vigor. Several methods have been proposed and used using photodiodes, lasers, and high-speed cameras. In addition, devices for measuring instantaneous power using inertial sensors have been proposed and used. The inertial sensor has a very large error due to its measurement bias, and to overcome this, a Kalman filter is used. However, we design a Kalman filter that compensates for errors with only the IM without additional measurement, and we propose algorithms and measurement methods to achieve high accuracy even for low-cost IMs such as MPU9250, and then build a measurement device based on it. The results of the experiments show that the instantaneous force is measured accurately even for low-cost inertial sensors.