The Research On The Simulation Platform Of Ultra-Tightly Coupled SINS/GPS Integration System In High Dynamic Conditions

With the fast development of military modernization, the high dynamic performance of the modern weapons is much better than ever, so how to navigation and positioning in high dynamic conditions becomes the focus problem in the field. As the error characteristics of the SINS and GPS are complementary, when the information from SINS and GPS are fused, the SINS can provide high bandwidth attitude, position and velocity estimates which is needed in the GPS receiver tracking loops. In turn, the GPS position and velocity estimates can be used to calibrate the SINS sensors errors. In this way, the SINS/GPS integration navigation system becomes the most effective way to solve the navigation problem in high dynamic conditions.Funded by the National Natural Science Foundation, a thorough study on the simulation platform of the ultra-tightly coupled SINS/GPS integration navigation system is conducted this dissertation. The main work and key contributions includes:1. As the comprehensive and actual navigation data is hard to get, a SINS sensors signal simulator and a GPS intermediate frequency signal simulator are developed based on the vehicle’s high dynamic movement. As to inertial measurement unit (IMU) signal simulator, a reverse calculation method is proposed, which uses the attitude, position and velocity data to calculate the inertial sensors data. The mathematical models of the gyroscope and the accelerometer are established, and the error models have been analyzed comprehensively. As for the GPS IF signal simulator, combining the satellite ephemeris with the vehicle’s movement information, the corresponding satellite signal mathematic models are established, and both the user defined parameters and signal transmission errors are calculated either. The flexibility of the parameter setting facilitates the algorithms performance analysis and error analysis.2. The relationships among satellite signal tracing parameters, the quadrature signals (I/Q) and the inertial sensor errors, including the position, velocity and attitude errors, are established. Considering the restriction relation of the thermal noise and dynamic stress error, the SINS aided GPS receiver tracking loops is proposed, which can remove the impact of Doppler shift much better. The new designed tracking loop can both reduce the tracking loop bandwidth and improve the ability to resist the high dynamic stress. Besides that, a tracking loop bandwith optimization algorithm is proposed, which can minimize the phase error to a small value, so that the tracking loop can work much better.3. The design of ultra-tight integration navigation system based on the vector tracking loops. Comparing with the tranditional tracking loops, the vector tracking loops can take full use each channel’s data, so that high dynamic signal and weak signal can be processed much better. As for the information fusion of the ultra-tight SINS/GPS integration navigation system, a distributed information fusion algorithm based on the unscented Kalman filter is proposed. The algorithm includes two parts: one is the estimation of the aided tracking loop parameters, which is the sub-filer, and the other one is the main filer, which is based on the SINS and GPS error model. The simulated data and actual data are both processed in the dissertation, and the experiment shows that ultra-tight SINS/GPS integration system can navigation much better than the traditional receiver.