An Experimental Study on Measurement Errors of Inertial Sensors in Smartphones

In recent years, inertial sensors in smartphones are used more and more widely, and play great roles in navigation, human movement monitoring and other applications. Hence, it is significant to understand accuracies of smartphone sensors. Many researchers pay much attention on how to reduce or compensate measurement errors of sensors, but the characteristics of measurement errors produced by the inertial sensors in smartphones are still unclear. In this paper, the measurement errors of the inertial sensors embedded in smartphones are carefully investigated through an experimental study. To do so, extensive experiments have been carried out to collect inertial measurements from both the smartphones and a motion tracking system (i.e. Xsens MTw) that delivers much higher precision than the smartphone. In the first place, the experiments demonstrate that the error distribution is dependent on smartphone's motions. Specifically, when the smartphone is stationary, the measurement errors of the inertial sensors satisfy the t Location-Scale distribution and the Gaussian distribution; while the smartphone moves at a low speed, the distribution can be approximated as the Gaussian distribution; while the smartphone moves quickly, the distribution also satisfies the t Location-Scale distribution. Our studies establish a basis for future studies in establishing error models of the inertial sensors.