Analysis of the Accuracy and Usefulness of MEMS Chipsets Embedded in Popular Mobile Phones in Inertial Navigation

By using inertial sensors embedded in modern telephones, such as a three-axis accelerometer and a gyroscope, it is possible to determine the position of the user in all conditions, regardless of the place, time or surrounding terrain obstacles. For this purpose, it is necessary to determine the starting coordinates, speed and orientation of the device. The system determining the position of the user on the basis of indications of inertial sensors is called the Inertial Navigation System (INS) and is a part of dead reckoning navigation. The accuracy of the position determined in this way depends mainly on the class, stability and quality of the sensors used. The accelerometers, gyroscopes and magnetometers used in cell phones are made in the MEMS (Micro Electro-Mechanical System) technology, which has been developing dynamically since the end of the 20th century. Sensors, despite their miniature dimensions and weight, are cheap in production and more and more accurate. The article attempts to determine the accuracy and usefulness of popular mobile phones in navigation using the IMU (Inertial Measerument Unit) by determining the coordinates of the user's route. A special script in the Matlab environment was written for comparison analyses of IMU route with the indications from the GNSS receiver. It should be noted that positions calculated on the basis of data from IMU devices were not integrated with the GNSS system in any way. In the practical part, two modern cell phones operating under the Android system, i.e. Sony Xperia M2 Aqua and Samsung Galaxy Note 3 were used to create an inertial navigation system. The measurement was carried out simultaneously with two telephones in three different scenarios. Based on data collected using sensors (accelerometers and gyroscope), subsequent user positions in the geocentric coordinates were determined using the Matlab script. The conducted research has shown to what extent a modern mobile phone can be used to create an inertial navigation system. The achieved results are presented, analysed and discussed.