On the accuracy of IMUs for human motion tracking: a comparative evaluation

Inertial Measurement Units (IMUs) are becoming more and more popular in human motion tracking applications. Among the other advantages, wearability, portability, limited costs, and accuracy are the main drivers of their increasing use. These devices are nowadays well-established commercially available products, ranging from few to hundreds of Euros. The main purpose of this study is to investigate the potentialities and the limits of IMUs belonging to different commercial segments in providing accurate orientation estimates within the operating conditions characterizing the human motion. These are simulated by means of a direct drive servomotor, in order to ensure accuracy and repeatability of the whole assessment pipeline. Both static and dynamic conditions are analyzed, the latter obtained by varying frequency and amplitude of a sinusoidal motion, thus evaluating the performances for a broad set of movements. IMUs orientations are estimated through proprietary filters, when available, and then compared with the well-established Madgwick's filter, to effectively investigate the performances of the on-board sensors. Results show that the low-cost IMUs are suited for applications requiring low bandwidth, while the comparison through Madgwick's filter did not highlight appreciable differences among the IMUs