Developing Innovative Inertial Systems based on advanced MEMS sensors

Abstract

Current technological improvements allow for the realization of MEMS inertial sensors that have several advanced peculiarities such as low production cost, wide bandwidth, high-reliability, small-size, low-power consumption, and lightweight configuration. These advantages combined with new generation MEMS higher levels of accuracy and the development of innovative algorithms is allowing MEMS technology to replace expensive, bulky, heavy and power requiring Fiber Optic Gyroscopes in most applications. This thesis deals with the development of various innovative MEMS-based inertial systems suitable to accomplish different tasks. First, a low-cost Inertial Navigation System solution composed of industrial-grade inertial sensors, magnetometer and GNSS antenna/receiver suitable for Unmanned Aircraft Systems applications is shown. Such aeronautical platforms require attitude determination capabilities more enhanced than the standard attitude measurement accuracy FAA requirements. Then, a land navigator system built around an Inertial Measurement Unit with quasi-tactical level gyroscopes linked with a GNSS equipment and an odometer is exposed. Both civil and military applications are demanding for self-contained, dead-reckoning systems able to provide a continuous and reliable Position, Velocity and Timing solution even in GNSS denied and degraded environments. Finally, a ZUPT algorithm able to accurately initialize a MEMS-based INS navigation state and north-finding activities employing tactical-grade MEMS gyroscopes are described. Each inertial navigation system shall be accurately initialized before navigation in order to improve its performance. Attitude initialization is the most difficult task to satisfy and heading self-initialization has been not considered possible for many years utilizing MEMS gyroscopes.