Research Of The Ship Deformation Measurement Method Base On FOG Strapdown Inertial System

For the use of the technology of the inertial device measures hull deformation, this paperproposes the use of fiber optic gyroscope strapdown inertial device measures hull deformationangle. Angle degree of information can be the most direct reaction of the angular velocity, sothe proposed use of the angular velocity of the fiber optic gyroscope output Kalman filteringtechnique estimates hull deformation angle. Through the establishment of the Kalman filtermodel, theoretical simulation and the real ship sea trials. Simulation and the real ship testresults to verify the effectiveness of the method, and to lay the foundation for further study ofthe measurement of the hull deformation technology. The main contents are as follows:First of all, a brief introduction the basic principles of hull deformation measured basedon angular velocity matching hull deformation used some basic knowledge, and determinationof the introduction. Determined based on the angular velocity matching hull deformation oftwo methods: Kalman filter methods and iterative methods. Kalman filter measurement hulldeformation the filtered model; the calculation process of iterative algorithm. Through thecomparison of the two methods and theoretical simulation, the result of simulation shows thattwo algorithms can be estimated on the hull deformation angle; iterative algorithm affected bygyro drift error factors, and the presence of error accumulation; Kalman filter algorithm caneffectively filter out confounding factors such as gyro drift optimal estimation of hulldeformation angle.Secondly, the study of the impact of hull deformation measurement accuracy factors, andanalyzed the choice of the coefficient of dynamic deformation angle model and consider thequasi-static hull deformation angle measurement model. In the actual measurement of hulldeformation test and found that the fiber optic gyroscope of the crystal over time, the drift ofthe crystal, thereby causing the test data collected by the system time is not synchronized,which will largely affect the deformation measurement system accuracy. To solve thisproblem, propose program for GPS second pulse tame gyro crystal, to eliminate gyro crystaldrift time synchronization to improve the accuracy of the measurement of the deformationmeasurement system. In addition, analysis of the sampling frequency of the fiber opticgyroscope measuring the hull deformation angle accuracy, improve using frequency will helpimprove the measurement accuracy of the deformation system.Finally, deformation measurement system as well as the structural characteristics of theship itself, the laboratory since the inquiry fiber strapdown system as the main measurement instrument design offshore sea trial, and the offshore sea trial. The sea trials verify the validityof the deformation measurement system as well as the deformation measurement solutions.Learned through trial conclusions the associated hull deformation and state of motion of theship, the deformation angle by the ship’s navigation status greater impact. Hull dynamicdeformation angle reflects the characteristics of elastic deformation; hull static deformationangle reflects the characteristics of the non-elastic deformation.