Research On Initial Alignment/Evaluation Of The Inertial Sensor Error And Comprehensive Correction For Shipboard Single-axial Rotary Fiber-Gyroscope Inertial Navigation System

According to the development of high-accuracy inertial navigation system of`warshipwith long time running. It is necessary to substitute the platform inertial navigation system byoptic gyro strapdown inertial navigation system(SINS). In order to increase navigationperformance with limited cost increase and considering the structure and costs of the inertialnavigation system at the same time, single-axis rotary SINS become one of the importantdevelopment directions of ship’s inertial navigation systems. Some crucial techniques forfiber optical gyroscope inertial navigation system are studied in theoretical and engineeringaspects in this article. The test device is made up of turntable and the inertial measurementunit(IMU). IMU is made up of optical gyroscopes and flexible quartz accelerometers, and thetechnologies proposed in this paper are verified. The main works arc as fo11ows:In order to provide theoretical basis to the relevant technical programmes, firstly, thecontinual coordinate frame is defined in this paper. The error auto-compensation princip1e ofrotary SINS is also studied. The four-position single axis indexing scheme is proposed, theinfluence of SINS error caused by the size effect and turntable’s error is analyzed. Then, theeffect of modulation when the carrier is still and swing are expatiated. Then, the tests and theprofound research are carried out.The test device made up of turntable and the IMU. Then，the four-position single axisindexing scheme simulation and test results under a variety of movement condition arecompared. The results show that the test device can meet the test requirements for relatedtechnology.In order to shorten the time of initial alignment of inertial navigation system, the fastalignment method for single single-axis rotary SINS is proposed. For marine inertialnavigation system in moorage, the traditional transformation matrix calculation method isimproved. A leveling+inertial alignment method with single-axis turntable’s assisted isproposed. On the basis of study above, the reverse attitude algorithm is carried out to shortenthe time of initial alignment. Then, the error of alignment method proposed in this paper isanalyzed. The tests are carried out to verified the validity of the alignment method.To improve the navigation accuracy of single-axis inertial navigation system, This articleanalyses the inertial sensors’ error which is need to be evaluation and compensationaccording to the effect of modulation and the initial alignment error. Using alignmentheading-effect and single-axis turntable’s assisted, the four-position+compass loopalgorithm for inertial sensors’ error measurement is proposed. the tests are carried out in the end.To ensure long-term accuracy of inertial navigation system, on the basis of thecomprehensive calibration method for platform inertial navigation system, the two-point andthree-point comprehensive calibration method for SINS based on the OEPQ frame areproposed. The limitations of the comprehensive calibration methods based on the OEPQframe are pointed out. Then, the comprehensive calibration method based on the inertialframe is proposed. This method does not need to limit maneuvering and sailing of the ship. Atlast, the comprehensive calibration methods with and without azimuth information forsingle-axis rotary SINS are proposed, the tests are carried out in the end.