Research on the real-time information fusion algorithm for GNSS/MIMU integrated navigation system

In real-time high-precision navigation applications such as unmanned aircraft automatic landing and intelligent robotic operations, the navigation system should not only maintain high precision in positioning and orientation, but also ensure good real-time performance and high reliability. When developing an actual high-accuracy GNSS /MIMU integrated navigation system, time-lag of navigation problem occurs due to the base station GNSS navigation information transmission delay, affecting the overall navigation performance seriously. For such time-delay effect, this paper researches on real-time information fusion method for the high-precision GNSS/MIMU integration, which combines precise relative positioning RTK (Real Time Kinematic) and very low-cost MEMS-IMU (MIMU). In order to solve the GNSS-RTK/MIMU integrated navigation delay effect, this paper designs a real-time correction algorithm with delayed measurement by improving the updating stage of Kalman filter suitable for real-time navigation applications. Based on the experimental data, delay-effect simulations have been carried out and the simulation results show that the improved real-time Kalman filtering can effectively solve the short-time delay of GNSS information within 1s, under the condition of GNSS-RTK 1Hz data output rate and using very low-cost MEMS-IMU.