Study On SINS/SNSS/CNS Integrated Nvaigation Systems Based On Inofrmation Fusion

SINS/GNSS/CNS integrated navigation is a common method in the high-precision navigation of high-altitude-long-endurance fly vehicle,such as long-range ballistic missiles,cruise missiles,and UAV(unmanned aerial vehicles).Using the information fusion theory and setting UAV as the moving carrier,the filtering algorithm and the simulation of SINS/GNSS/CNS Integrated Navigation System are researched in this paper.The main job is constituted of the following aspects:Firstly,the paper defines the coordinate systems and their conversion relations used for SINS.Taking the position,velocity and attitude into account,a flight program is designed in the navigation frame;the trajectory generator is studied;and a nominal trajectory of carrier was simulated.Secondly,bsaed on the work principle of strapdown inertial navigation system,satellite navigation system and celestial navigation system,the error model of attitude,velocity and position of the strapdown inertial navigation system and the error model of the satellite navigation receiver are established.The observation data of three kinds of navigation systems are simulated.According to its principle and its observation data,each navigation results(position vector,velocity and attitude of the carrier)are solved,respectively.Thirdly,the filtering algorithm and information fusion method of integrated navigation system are studied.The Kalman filtering algorithm,extended Kalman filtering algorithm and federated filtering algorithm are introduced.In view of the requirements of high precision,real-time performance and fault tolerance requirements,the application of information fusion theory in integrated navigation system is discussed.An information factor al ocation algorithm for adaptive federated filter is founded.Finally,the system state equation and the observation equation of SINS/GNSS,SINS/CNS integrated navigation system are deduced.SINS/GNSS,SINS/CNS and SINS/GNSS/CNS integrated navigation system are simulated after the establishment of the adaptive federated filter,respectively.The contrast and analysis of simulation results show that the SINS/GNSS/CNS integrated navigation system based on federated filter enjoy the full advantages of the three navigation systems.Inhibiting the accumulation of errors due to gyro drift effectively,having better fault-tolerant performance,the SINS/GNSS/CNS integrated navigation system can satisfy the high-precision requirement and the high-reliability needs during long endurance navigation.