Research On Ship Fiber Optic Gyro Strapdown Attitude Measurement System

In the 21 st century,the ocean has once again become the focus of all countries in the world with its vast area and unique resources.With the development of fiber optic gyroscope technology,high-precision attitude measurement technology with fiber optic gyroscope as the core inertial measurement unit has become a research hotspot.At present,marine attitude measurement techniques based on GPS,stellar reference,star map recognition,and magnetic sensors have problems that are susceptible to cloud weather and human interference,which leads to the poor anti-interference ability and work limitations.Therefore,the fiber optic gyroscope strapdown attitude measurement technology with autonomy and independence is particularly important in the attitude measurement of surface ships.In this paper the marine fiber optic gyro strapdown attitude measurement system is designed under the traction of the horizontal project.The paper mainly includes the following aspects:First of all,the basic principles of strapdown inertial attitude measurement is studied and analyzed.The common coordinate system,coordinate transformation and attitude measurement methods are analyzed and compared.The initial alignment attitude error of the ship,the coarse alignment of the inertia of the sway base,and the fine alignment of the sway base are studied and analyzed.The attitude calculation algorithm is designed according to the ship attitude measurement solution.Then,according to the actual design requirements of the system,the shell structure of the system is designed.A hardware circuit platform including power supply,fiber IMU,parameter setting,and data storage module with FPGA + DSP as the core processing unit is built.The supporting PC software for manipulating the system and displaying and processing the attitude measurement data in real time is designed.Finally,based on the resources available in the laboratory,a test platform for the attitude measurement and verification of the system is built using an external power supply and a high-precision three-axis position rate swing temperature control turntable.According to the designed attitude test scheme,the test is conducted.The results show that the measurement accuracy of the heading,roll and pitch attitude angle can reach ±0.20° in the single and comprehensive tests respectively,which can meet the practical engineering application.