Inertial measurement units inside smartphones: Performances future steps

Inertial measurement units (IMUs) are one of the most common sensors available today in smartphones. Generally, cell phones are equipped with particular inertial sensors that may vary among different brands and models. Their characteristics, in terms of precision and accuracy, are not important for smartphone operations but they become fundamental for some activities, such as positioning and navigation. In this context, it is interesting to analyse the characteristics of different inertial platforms installed today in these mobile devices. In this chapter, the performance of different IMU mass-market platforms present in mobile devices will be analysed, considering different positioning modes available in the literature. All tests are conducted in a laboratory, considering free magnetic field conditions. To identify the flicker noise, white noise, and random noise in each device, the Allan variance of each sensor will be computed. Each dataset (acceleration and angular velocity) has also been analysed with NaveGo, a software tool, with the purpose of performing the Allan Variance procedure to quantify the level of inertial sensor stochastic errors. A brief overview of future applications will be provided at the end of this chapter.