Research On SINS/GPS Integrated Navigation Algorithm Based On Low-cost MEMS

SINS has totally autonomy, but is not suitable for working long and alone. GPS has high long-term accuracy, but it is so vulnerable to outside interference that can’t position. By using the technology of integrated navigation, SINS and GPS can be combined to make use of their advantages and learn from each other, so this technology is the main research content of the navigation technology area now. In recent years, MIMU which based on MEMS technology has been widely used in SINS because of its small volume and low cost, especially having great importance to make navigation, guidance and control of micro flying carrier come true. Therefore, this paper use MIMU and navigation computer as experimental subjects, which are independently designed by the laboratory, and research on the SINS/GPS integrated navigation algorithm.First, according to the basic principles of SINS and its common coordinate systems, the updates of attitude, speed and location in the SINS navigation algorithm are been inferred, and the simulation of the SINS algorithm is completed by using MATLAB. The simulation results verify the correctness of the SINS algorithm.Second, according to the composition and positioning principle of GPS navigation system, the causes of the GPS measurement error are analyzed. And the algorithm and simulation of satellite coordinates calculated by GPS prediction ephemeris are completed. The simulation results show that this algorithm provide certain theory foundation to reduce positioning time and improve positioning accuracy.Again, according to the error model of SINS/GPS integrated navigation, the state equation and observation equation under different combination models are established. And the extended kalman filter and unscented kalman filter are used to simulate the combination by using MATLAB. The simulation results show that UKF has better effect on the nonlinear system filter than EKF and the tight coupling is better than the loose coupling too.Finally, the three-axis turntable experiment and the car experiment are designed to test every parts algorithms and program codes of the SINS/GPS integrated navigation system. The results show that every parts of the integrated navigation programs are viable and the algorithm can suppress the divergence of the SINS results with certain engineering significance.