IMU acceleration drift compensation for position tracking in ambulatory gait analysis

This study is a part of a project where we target determining discriminative features to define diseases that cause disorders in the human vestibular system. For this purpose we aim to analyze the gait of the person. Among a number of parameters used for gait analysis, some make use of the foot- and knee positions. Hence the exact determination of position is of great importance. Here we use inertial sensors (IMU) placed on foot and knee in order to calculate the displacement by double integrating the free acceleration output data of the sensor. Thus, the overall position accuracy is highly dependent on the accuracy of the acceleration data where the offset and drift play great role in its corruption. We propose a method to minimize the error due to sensor offset and drift by utilizing the fact that there are gait intervals where the foot rests. The results are promising that the calculated average error is low; though the standard deviation needs some further amendment.