Research On The Coupede Mode And Fusion Algorithm Of GPS/INS Integrated Navigation

GPS/INS has become a focused theme because of the merits on complementation between GPS and INS. This dissertation has made research on the GPS/INS loose-coupled, tight-coupled and deep-coupled navigation in terms of data processing. Based on the analysis of characteristic in the three integrated navigation, the corresponding control methods to make tracking loop closed has gave in detail. The frequency information from INS-aided has adopted to design the tight-coupled navigation system which cut down the mean time and the signal width in the tracking loop which make the signal of high jerk carrier quickly acquired and stably tracked.Considering the filter extrapolation, the data synchronization programs have proposed to solve the data update at different rate in the integrated navigation which is the key technology to close the coupling loop. The standard UPF has been advanced and adopted to the information fusion in GPS/INS deep-coupled navigation which satisfies the need of the positioning.The research works and innovation points as follows:(1) According to the characteristic of structure in the GPS/INS loose-coupled navigation, the data processing in GPS and INS is mutual independent. In order to make satellite signals acquired, the length of data, searching methods and acquisition algorithm including the processing of the implement have been determined. Then the synchronization scheme based on Kalman fiter extrapolation has been desiged. Furthermore, the second order tracking loop has designed to get the phase of the PRN and carrier. The experiments using testing data have carried out to validate signal acquisition and tracking capacity.(2) The dissertation gives the implemental methods to acquire and track GPS signals with INS-aid using frequency which is got by Doppler calculation.Then the synchronization scheme based on UKF fiter extrapolation has been desiged. In terms of the high dynamic carrier, acquisition INS-aided frequency has proposed, meantime, the third order tracking loop is designed. Furthermore, the experiments show that: on the condition of cold start acquisition which is not aided by INS has the same detection capacity with the GPS INS-aided, and the mean acquisition time is cut by 20%. Under the circumstances of the jerk at 10 g and the C/N0 at 25 dB-Hz, the tracking loop width is set to 2Hz, which is enough to make tracking error at the range of±15°.(3) The data processing of GPS/INS deep-coupled navigation based on tracking structure vector has analyzed so that deep coupling with federation structure has been determined. Then the nonlinear model of preset filter in each channel has given. In order to make the tracking loop closed the method on computing control parameter of NCO and the data synchronization scheme of CIC with extrapolation have been told. The expriments show that the phase error of PRN and carrier of deep-coupled navigation desingded in the dissertation at the range of ±0.1chip and ±0.1rad, respectly,that means the tracking loop locked.(4)The UPF filter has adopted to deep-coupled navigation for fusing information from GPS and INS. In terms of the shortcomings of the standard UPF filtering, two improvements has presented: on the one hand, definite treatment has adopted to solve the problem of the estimation error covariance non-positive definite in UKF; on the other hand, MCMC has adopted to solve the problem the diversity of particles reduced which caused by resembling in the particle filter.The expriments show that the advanced UPF can solve the problem of non-linear in fusion system which produced higher accurary than EKF and UKF.