Inertial Sensors and Inertial Measurement Units

This chapter focuses on the inertial sensors and inertial measurement units (IMUs) in context of their operating principles. Inertial sensors are the hardware basis for inertial navigation. Inertial sensors are sensors based on inertia and relevant measuring principles. There are two types of inertial sensors: accelerometers and gyroscopes, measuring the specific forces and rotations, respectively. Accelerometers can typically be categorized into two classes: static accelerometers and resonant accelerometers. Gyroscope is a kind of sensor that measures rotation. Some of the gyroscope classes include mechanical gyroscopes, optical gyroscopes, nuclear magnetic resonance (NMR) gyroscopes, and micro electro mechanical systems vibratory gyroscopes. The chapter introduces some of the commonly used technologies to combine individual inertial sensors into a single IMU. IMU miniaturization approach is through vertical chip stacking. There is no IMU technology that is best for all applications, and therefore, a proper selection of the technology is needed for various application scenarios.