Research On Calibration Technique Of Shipborne CNS/INS Integrated Navigation System

Navigation system is a key component of modern military equipment,its reliability determines whether the combat mission can be completed or not,and its accuracy directly determines the speed and quality of ships’ completing navigation missions.Ships need navigation system with better performance,for they often have to carry out long-endurance or long-range missions,which mostly dependents on satellite navigation.Since inertial navigation system(INS)alone will not satisfy their requirements,the combination of celestial navigation system(CNS)with INS,which is characterized by high precision,reliability,autonomy and concealment,is then introduced here to reduce the dependence of satellite navigation and improve the performance of INS,and then improve the survivability of battleships.Under the project of “the development and application of 24-hour high precision starlight orientation instrument on marine platform”,which belongs to the development of National Major Scientific Instruments and Equipment,the integrated navigation system is studied from theoretical analysis and project realization as well.The corresponding general and system calibration schemes are designed based on marine environment and different combinations,and the combined alignment and system reset schemes as well as the designed prototype under this project are introduced here.This research mainly focuses on the following aspects:(1)General design scheme.The requirements on general design of the starlight navigation is given based on marine environment;the development and trends of star navigation equipment are discussed;the different configurations for shipborne starlight navigation equipment are put forward from spectral band selection,optical parameters and circuit design of star sensor;the work modes and the overall technical features of combined system are compared under different cases.(2)System calibration scheme.The basic principles of celestial and inertial navigations are introduced to set the theoretical basis for follow-up relative technology studies and the corresponding error models are established.The system calibration scheme is proposed for celestial/inertial integrated navigation system,which focuses on the calibration methods of horizontal and azimuth deviation between subsystems.At last,the calibration errors are analyzed and simulated.(3)Combined model and filtering algorithm.Since strapdown CNS needs INS to offer horizon attitude as horizontal reference,the influence of horizontal INS attitude errors on CNS precision is analyzed and simulated.Several typical celestial/inertial integrated navigation system models and corresponding filtering algorithms are introduced,and a combined model based on two parallel filters with master-slave structure is then proposed.At last,simulation validation is finally carried out for it.(4)Integrated alignment and system reset scheme.The self-alignment principle for shipborne INS in moorage is introduced.In order to reduce alignment time and assure the alignment accuracy,a rapid integrated alignment scheme is designed for INS based on CNS assistance under mooring or sailing conditions,and the corresponding simulation analysis is completed.As for INS level damp work mode,a CNS/INS integrated reset scheme based on INS level damp is proposed and the simulation analysis is done as well.(5)Experimental analysis of CNS/INS integrated prototype.The composition,operation mode and control process of the project prototype are introduced,and integrated navigation experiment is carried out for it,and finally the test data is analyzed.