Research On The Key Technologies Of SINS/GPS Deeply Coupled Navigation System

As one development direction of the navigation system, the integrated navigation system is under increasing attention in the field of aviation, navigation and weapons. The combination of two or more navigation system and the same system in different combination ways become a research focus at home and abroad. The domestic GPS and SINS integrated navigation system is mainly loose coupled and tight coupled system. There are the defects of weak anti-interference ability and poor dynamic performance. The deeply coupled system using GPS and SINS mutually supportive way improve the anti-jamming and dynamic performance of the integrated navigation system. A feasible method is provided when realizing the characteristics of small size, low power and high precision in integrated navigation system and using for the work environment of high dynamic and large maneuver.Based on the "863" special project "low-cost domestic production CORS base station receiver technology" and taken the engineering development of "small, smart and combinatorial guided bomb" as the background, research has been done on the key technologies of GPS/SINS deeply coupled navigation system around the application for guided bomb and guided artillery in highly dynamic and highly integrated environment. And numerical simulation, semi-physical simulation, simulation-bombing test by the car, high-dynamic tests, bomb hanging fly and bombing test have been carried through.The main work includes the following aspects:(1) Research on baseband of sofeware GPS receiver. Including signal acquisition, carrier tracking, code tracking and performance analysis of the receiver loop with SINS aided. On this basis, the improved algorithms of acquisition and tracking and its applications in the loop are proposed.(2) Research on the model of GPS/SINS deeply coupled navigation system. Not only a mathematical model of the system is established, but also the observability and testability of the model are analysed.(3) To solve the nonlinear problem of the model in GPS/SINS deeply coupled navigation system, the UKF (Unscented Kalman Filter) and the PF (Partical Filter) algorithm are introduced. According to the feature of deeply coupled system that state equation is linear and the observation equation is nonlinear, a new simplified UKF is proposed. And using genetic manipulation to replace the simple resampling, a GA (Genetic Algorithm)-aided PF is designed to improve the filtering performance of the PF. Enhancing the function of real time and localsearch through adding self adaptive operator and parallel handling in GA.(4) To solve the uncertainties of the noise in GPS/SINS deeply coupled navigation system, two new multiple model hybrid estimation algorithms are correspondingly presented based on the simplified UKF and the GA-aided PF. Through modeling for the uncertain noise factors and the calculation of the model probability, obtaining the final fusion output.(5) Establishing the hardware experimental platform of GPS/SINS deeply coupled navigation model. A design of GPS software receiver based on FPGA and DSP is presented to import the imformation of SINS into receiver loop. And the time synchronization between the GPS and the SINS is solved.(6) Numerical simulation and semi-physical simulation are carried out for the deeply coupled system, and on this basis, simulation-bombing test by the car, high-dynamic tests, bomb hanging fly and bombing test have been carried through. Bomping test has a success. And verifying the correctness and feasibility of the GPS/SINS deeply coupled navigation system in the guided bombs.