SINS/GPS Deeply Integrated Receiver Signal Tracking Method Study

Integrated navigation system is new developed achievements of modern navigation technology theory.Based on the principle of Inertial navigation system(INS)and global positioning system(GPS).Because they have good complementary information,function characteristics also have complementary.Strapdown inertial navigation system(SINS)/ GPS deeply integrated navigation can overcome the shortcoming of SINS error accumulated over time,effectively strengthen the anti-jamming ability of GPS,and enhance tracking accuracy and performance of the integrated navigation system in complex environment.Our country is building Beidou second generation satellite navigation system at the momend,can achieve global navigation position output and communication around 2020.Development of the low cost Beidou / INS integrated navigation system will be better beneficial to the development of our country navigation enterprise,high precision navigation system will serve the economic construction and social development of our country.In this paper,the basic principle of SINS and GPS is analyzed,which GPS signal form and receiver tracking loop is studied.The receiver carrier loop and code loop discriminator is analysis,and different types of identify phase method is listed,and its working character and phase detector performance is given.Then three kinds of typical architecture form of the deeply integrated navigation is introduced,and internal data fusion algorithm of integrated navigation is discussed.Deeply integrated navigation system design for SINS-aided GPS tracking loop,which makes it has strong anti-interference capability.Non-related deeply integrated navigation using the frequency discriminator and phase detector in the tracking loop,through the proportion of summation operation get pseudorange and pseudorange rate measurement values.And sent them to the integrated navigation filter as the measurement information.Related deeply integration system left the tracking loop discriminator,directly used I/Q branch output information as the measurment of pre filter,and comprehensive estimate the state of the tracking loop,effectively improve signal parameters estimated precision.Based on the deeply integrated technology comprehensive analysis and classification,proposes the deeply integration algorithm based on tracking loop UKF filter measurements,which using the distributed filtering structure,effectively improve the complexity of the deeply integrated system design,pre filter and main filter model is deduced in detail.And the carrier phase,carrier frequency and code phase signal parameter of tracking loop is simulation analysis.The pre-filter use the loop coherent integration as measurements and utilize UKFfilter algorithm to modeling analysis.Resolve the nonlinear relationship between the system measurement and state variables,and the derivation process of the core equation of UKF filtering algorithm is given.Employ the SINS/GPS output location,speed,clock skew and clock frequency difference as the main filter state estimation,effectively reduce the estimation error of the state in the tracking loop,improve the function of the integration navigation system.Based on the building of semi-physical emulation bench,for the sake of appraise the tracking capability of the deeply integration algorithm,the SINS/GPS deeply combination tracking performance has been carried on the comprehensive research and analysis in weak signal and high dynamic environment.The simulation results show that the proposed deeply integrated scheme is more superior performance than separate navigation systems.