Research On Key Techniques Of Adm/sinsintegrated Navigation System

Since the 20 th century, navigation system plays an essential role in the economic and military acitivities. With the increasing diversity and complexity of unmanned aerial vehicles(UAVs) tasks, higher demands of accurate, reliable and autonomous navigation systems are proposed in the practical applications. At present, INS/GPS integrated navigation system is commonly used. The precision of the integrated navigation system is degraded in the absence of GPS signal since the INS navigation precision degrades rapidly with time. In recent years, the autonomous navigation techniques in the absence of GPS signal have became a research hotspot.Aircraft dynamic model(ADM)-aided navigation technique is studied as a new kind of autonomous navigation method. ADM produces navigation information with strong autonomy, low cost and wide application range. Aimed at enhancing the precision and autonomy of navigation system effectively during GPS outages, the research of the key techniques in ADM-aided INS has been carried out in this paper. The research provides a certain reference value for the application and promotion of ADM-aided navigation technology.Firstly, the aerodynamic characteristics of fixed-wing UAVs are analyzed in this paper. With the basis of six degrees of freedom ADM, this paper gives a research on the calculating process of navigation information in ADM. Meanwhile, the error propagation equations of this calculating process are deduced after systematically analyzing the error sources effects in ADM.Secondly, in order to eliminating the sensitivity to the errors of aerodynamic parameters, a parameter identification algorithm based on extended kalman filter(EKF) is designed. This algorithm effectively improves the accuracyof ADM.Then, two different data fusion schemes of ADM/INS integrated navigation system are put forward to optimize the use of ADM and the performance of the ADM-aided INS. According to the schemes, the system state model and observation model are established completely. The results of these two schemes show that different scheme has different effect on the ADM-aided INS.Eventually, a simulation platform is established in Matlab/Simulink in order to verify the ADM/INS technology and compare the performance of the two data fusion schemes in this paper. This platform consists of trajectory generating module, GNC module and display module. It can simulate the ADM, airborne sensors and integrated navigation system. By using this simulation platform, the feasibility and effectiveness of data fusion schemes in ADM/INS integrated navigation are verified. The simulation platform in the research of ADM-aided navigation technique has a good supporting role.ADM-aided navigation technique is a multidisciplinary technique which involves navigation, control and aerodynamics. Aimed at providing theoretical basis for the development of ADM-aided technique, the basic research of error propagation in ADM and data fusion schemes in ADM-aided INS are carried out in this paper.