Mitigating Drift in Extraction of Joint Angle Measurements from Inertial Measurement Unit (IMU) Data

Inertial measurement unit (IMU) sensors are widely used in sports science to acquire motion-related data, such as joint angle measurements, and provide valuable insights into the performance of the athletes. These sensors can be used for specific purposes that needs regular calibration to compensate for drift since assessment of muscle stress rely on these devices. However, sensor-based systems may not always provide accurate joint angle measurements. This paper aims to mitigate the drift of the IMU data by pre-processing it with various sensor fusion algorithms: Complementary filter, Kalman filter, and Madgwick filter. The output of the calibrated IMU sensor device was compared with the data collected from the VICON motion capture system to validate its accuracy. Finally, the calibrated IMU sensor output is used to measure the joint angles. As a result, the complementary filter resulted in a better accuracy and reliability performance than the Kalman and Magdwick filter. The Kalman filter obtained a higher reliability and precision due to its lower variability and standard deviation of 37.68. Moreover, it also indicated that the complementary filter often yielded low error values, suggesting better performance as seen in its Root- Mean-Square Error (RMSE) of 9.75. An Analysis of Variance (ANOVA) test was done, indicating that the RMSE accepts the null hypothesis, H0, that there are no significant differences among the means of the metrics.