Benefits of a Tightly-coupled GNSS/INS Real-Time Solution in Urban Scenarios and Harsh Environments

The paper deals with the development of a Robust Position Unit (RPU) based on the real-time implementation of an advanced positioning algorithm. The RPU uses a tightly-coupled technique between a mass market single frequency GNSS chipset with a low cost Inertial Measurement Unit (IMU) based on Micro Electro-Mechanical Systems and an odometer. The tight integration algorithm has been obtained through the design of a complex Extended Kalman Filter (EKF). Its performance has been verified running the designed real-time algorithm in different challenging environments: an urban scenario characterized by narrow streets, few satellites in view and tree-lined avenues. A second harsh environment is represented by a mountain area where the vehicle has driven through long tunnels, overpasses and sharp road bends. The tests showed how a tight integration algorithm, designed by using raw data from only low-cost sensors, can provide real advantages at a price of careful customizations and adaptations that take into account the particular use and environment.