Online Calibration Technology Of Fiber Gyros Inertial Navigation System Based On Strong Tracking CKF

In the process of using SINS, due to its error accumulation over time characteristic, it is necessary to remove the device from the carrier for re-calibration from time to time, this is not only a waste of manpower and material resources,but also let the navigation system not meet the requirement of long time sailing.Especially in recent years, China's navy is at an important period of strategic transformation,national defense and construction requirements the navigation system of naval must have high accuracy and long autonomous navigation capability,therefore develop online SINS self-calibration technology is imperative. In this paper,regard the STF-CKF filtering algorithm as the core, use the ship's main INS assist its son INS to make the process of online calibration,its main contents include:1. Analysis of the principle of the inner lever arm of the SINS and the outer lever arm of the main and son INS, and the calibration methods of two lever arm error were discussed in detail.Among them, the calibration of the inner lever arm use the linear error model and use the traditional Kalman filtering method; the calibration of the outer lever arm use the non-linear error model and use the UKF filtering method. Finally, base on the theoretical analysis conducte the computer simulation.2. For the problem of information transmit .delay between the main INS and the son INS,the time delay is divided into: fixed delay and random delay, then analysis the errors characteristics and the error compensation method. The fixed delay time error compensation method is let the son INS information inside interpolated to the time of main INS information generate, then make the Kalman filtering process again;The random delay time error compensation method is add an additional observation noise to the Kalman filtering equivalent.Finally, let the indoor system calibration method as an example to verify the effectiveness of the method described in this chapter.3. For the problem of the system error equivalent non-linear during the warship sailing,from the system observability analysis to start, then discuss the IMU parameter errors's observability of warship in the state of stilling and the state of sailing. Secondly, this paper analyzes the strong tracking CKF filtering method to improve the ability of track the system model and the ability of robustness. Finally, carriy out the computer simmulation to verify the effectiveness of the online calibration method for inertial navigation system.4. On the basis of several studies discussed before, this paper carry out the Songhua River test experiment, this experiment let the Phins navigation equipment which from French IXSEA company as the main INS to online calibration SINS which from our lab. Selecting such stable experimental data use in the process of STF-CKF filter after the experiment. The filtering results show that every error parameter has a good convergence, and reduce the system's position and velocity error after error compensation. Thereby, the experiment results verify the effectiveness of the online calibration method and provide a theoretical basis for the practical application of the online calibration technology.