Application of 3-Axis Magnetic Sensors for the Orientation Determination of Mobile Devices

In recent, most mobile devices such as smartphone come with embedded 3-axis magnetic sensor. The 3-components of earth magnetic field for the body axis of devices are essential to determine the orientation of the devices together with the 3-components of earth gravitational field. In this paper, we present in detail the algebraic process deriving the formulas to calculate the Yaw, Roll and Pitch angles, which specify the orientation of mobile devices, from the measured total 6-components of earth magnetic and gravitational fields. In addition, the derived formulas are verified by experiment with a simple apparatus and smartphone. Through this paper, we expect to provide a reference to developers of application software and sensor firmware who require calculating the orientation angles of mobile devices.