Research And Simulation Of SINS/GPS Integrated Navigation System For Semi-submersible Floating Platform

With the proposal of the strategy of marine power in recent years,it has become a hot research issue to enhance the observation capability of ocean vehicles such as semi-submersible floating platforms.Insufficient autonomous navigation capability of a semi-submersible floating platform is one of the important factors limiting its observation capability.Stable navigation with a high precision will directly promote the semi-submersible floating platform's range of motion and maneuverability,thereby strengthening its ability to observe the sea.Integrated navigation can greatly improve the navigation quality.Therefore,the research on integrated navigation technology of semi-submersible floating platform has significance of practical value for improving its ability to observe the sea and even promote the construction of marine power.The integrated navigation technology of Strapdown Inertial Navigation System and Global Positioning System is one of the hottest directions in the field of navigation.The combination of the two enables the navigation system not only to obtain the parameters such as attitude and speed of the aircraft in real time,but also to overcome the disadvantage that the navigation error of the inertial navigation system increases with time,which can to some extent guarantee the accuracy and reliability of the system.In this paper,the semi-submersible floating platform is used as the system algorithm application object.Matlab/Simulink mathematics software is used as the main simulation tool to study and analyze the basic theory of SINS/GPS integrated navigation system.Firstly,the SINS numerical update algorithm is deduced,the influencing factors of the cause of error in the navigation process are analyzed and then the error equation is derived.The specific implementation methods of coarse alignment and fine alignment are given by studying the SINS initial alignment technique.The designed strapdown inertial navigation algorithm is simulated in a static state,which proves the conclusion of the theoretical analysis that the error will increase with time when using inertial navigation independently.Secondly,in this paper,the Kalman Filter algorithm is systematically studied for the phenomenon that multiple signals are affected by noise during the navigation process.Compared with the state estimation effects of various nonlinear Kalman Filters,by taking the target tracking problem as an example,attests that the estimation effect of the Unscented Kalman Filter is better under the same conditions.In order to ensure the estimation effect of the semi-submersible floating platform in the maneuvering state,The basic structure and principle of the Interactive Multi-model algorithm are studied.The Interactive Multi-model Kalman Filter is designed based on Unscented Kalman Filter to estimate the state of the floating platform motion.The simulation results prove that the Interactive Multi-model Kalman Filter has better robustness,suitably serving as a parameter state estimator in SINS/GPS integrated navigation algorithm.Based on the above research,the coupling mode and correction mode between subsystem SINS and GPS are discussed.Loose coupling and feedback correction are selected as the basic combination form.The SINS/GPS integrated navigation algorithm is derived based on the error equation.Combined with the actual motion form of the floating platform,the track generator and inertial sensor simulator are designed on the basis of idealization,and generates the input data of the combined navigation algorithm under the set motion state.The simulation of the integrated navigation system algorithm under dynamic conditions can provide a basis for the subsequent engineering design of the navigation system.On the basis of completing the mathematical model of the integrated navigation algorithm,Matlab/Simulink mathematics software is used as the main research tool for joint programming.The final result proves that the integrated navigation overcomes the disadvantage that the position error increases with time,and its effect is better than the single GPS navigation effect,which can guarantee the long-term navigation needs of the semi-submersible floating platform.