Design and experimental evaluation of indirect centralized and direct decentralized integration scheme for low-cost INS/GNSS system

Advances in Geomatics science and technologies such as global navigation satellite system (GNSS) as well as inertial navigation system (INS) make it possible to develop accurate navigation system relying on low-cost technologies. We concentrated on integrated INS/GNSS system as a significant development in modern navigation systems. The ultimate aim is to enhance the performance, reliability, and navigation accuracy of low-cost INS/GNSS system. To achieve this, we focus on configuration and integration mechanization in low-cost INS/GNSS system. Two configurations, called here indirect centralized (IC) and direct decentralized (DD) integration, are proposed and a detailed comparative evaluation of the proposed schemes is provided. A serious problem of the low-cost INS/GNSS is the system reliability during GNSS signal blockage. Based on motion velocity constraints, the auxiliary velocity-update approach is proposed to enhance the navigation accuracy during GNSS outages. The assessment of the proposed integration schemes is conducted in numerous land/flight tests in which the host vehicle undergoes different dynamical maneuverings. Experimental evaluation shows that the IC integrated INS/GNSS has better performance in orientation estimation, but DD integrated INS/GNSS results in better positioning accuracy.