A Basic Test of Calibration Methods for Measurement of Three-Dimensional Movements of Lower Limbs with Inertial Sensors

Abstract

Three calibration methods were examined in estimation of 3D angles of a rigid body model under 8 attachment conditions of IMU. Difference of the IMU attachment conditions increased significantly RMSE values of estimated angles. Since two methods using static postures showed almost same RMSE values as in the case that there is no difference of the coordinate system, the methods were considered to be practical calibration method. However, one method using movement in the sagittal plane could not decrease RMSE values in many cases. Performing movement in a plane might be difficult in practical use.