Research On Multi-source Heterogeneous Adaptive Integrated Navigation Technology In Complex Environment

Satellite navigation and positioning technology is a high-precision navigation and positioning method with wide application and perfect technology.When the GNSS signal is received normally,the navigation and positioning accuracy of the system can reach centimeter level.But in some complex environment,such as tunnel,city,forest and some signal blocked environment,the positioning accuracy of GNSS navigation system will decline sharply.At the same time,the stability is not only affected by the system model,but also related to various unknown faults.When the external environment changes dramatically,GNSS navigation system will be reduced accordingly.Therefore,the traditional single GNSS sensor navigation system and simple GNSS/SINS integrated navigation system can't meet the needs of people for high precision,high real-time,seamless navigation and positioning.This paper focuses on the research of multi-sensor integrated navigation.At the same time,in the process of sensor fusion,fault detection,isolation and recovery algorithms are combined to build a multi-source heterogeneous multi-sensor fault-tolerant integrated navigation and positioning system.The main research work is as follows:(1)Based on the analysis of the existing navigation and positioning system and its corresponding algorithm,a multi-source and heterogeneous fault-tolerant integrated navigation structure is proposed.At the same time,the SINS error is corrected by using the position information of the satellite navigation system,the velocity information of the Doppler velocity and the attitude information of the astronomical navigation system.This integrated navigation system makes full use of the advantages of each sensor,which can effectively eliminate the sudden failure of each navigation and positioning module in complex environment.Meanwhile,its application scope is wider and its accuracy is higher.(2)An effective fault detection,isolation and recovery(FDIR)algorithm is studied,which is combined with integrated navigation system.This paper discusses the state chi square test and a kind of BP neural network as the FDIR algorithm of the system,which can ensure that the system operate orderly and effectively when a subsystem fails,and run stably in complex environment and when the environment changes dramatically.Part of the output results of the two FDIR algorithms are introduced into the federated filter for information allocation and fusion.This method accurately reflects the state of each subsystem,tracks its state changes,and makes each subsystem provide different"contributions" in the final fusion stage to obtain the optimal fusion results.(3)By studying multi-source heterogeneous integrated navigation system model and fault detection,isolation and recovery algorithm,the SINS/GNSS/DVL/CNS integrated navigation mechanism based on adaptive fault-tolerant federated filtering is developed.It provides a feasible solution for high-precision navigation and positioning in complex environment.Meanwhile its effectiveness and reliability are verified by system simulation experiment.