Tight Coupling of GNSS and IMU using Extended Kalman Filtering

This paper presents a tightly coupled approach to fuse Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) data with a low-cost Inerial Measurement Unit (IMU) using an Extended Kalman Filter (EKF) to improve navigational accuracy. Offline simulations were conducted by using data sets from u-blox NEO-M8T Global Navigation Satellite System (GNSS) receiver and Xsens MTi-300 IMU. The results demonstrate that an accuracy of up to centimeter level can be attained by tight integration of multiple GNSS constellations (GPS and BDS) with a Micro Electro-Mechanical Systems (MEMS) based IMU. Furthermore, this paper establishes the efficacy of the tightly coupled multi-constellation system against Single Point Positioning (SPP), by performing SPP on the data from the GNSS receiver. The results in this paper also highlight the superiority of using multiple constellations over any standalone system. The proposed technique of tightly coupling a multi-constellation GNSS with IMU contributes to the field of navigation by providing a robust scheme that enables pinpoint positioning for a wide variety of applications like precision agriculture, autonomous cars and land surveying.