Performance Comparison of Sensor Implemented in Smartphones with X-IMU

In this paper a comparison of inertial sensors in smartphones and X-IMU (Inertial Measurement Unit) is presented. The goal of the experiment is to compare the performance of inertial sensors implemented in smartphones with special IMU. The orientation of the devices will be compared. Measuring data from accelerometer and gyroscope provide orientation estimation in three dimensional space and for this purpose orientation in all three axes is needed. Accelerometer measures acceleration and gyroscope measures angular velocity. Orientation can be calculated by using one sensor, but both are affected by negative parameters which make estimation imprecise. Accelerometers measure all forces acting on it including gravitation. This fact can be used to estimate orientation, however, output data of accelerometer are quite noisy. Another possibility how to obtain orientation estimate is integration of gyroscopes data, but this estimation is insufficient due to bias. Combination of output data from both sensors, more precise orientation estimation can be obtained. Combination of sensors is called sensor fusion and is done by using Complementary filter based on Euler angles.