Research On SINS/CNS Integrated Navigation Technique Of Long-range And Long-endurance Vehicle

The long flight time and long flight distance of long-range and long-endurance vehicle impose particular high requirements on the autonomy,long endurance reliability and accuracy of its navigation system.Because replying solely on inertial navigation system cannot meet the accuracy requirements of positioning and attitude determination,long-range and long-endurance vehicle often uses integrated navigation technology to improve the performance of the navigation system.The commonly used navigation method,SINS/GPS integrated navigation system,can provide high-precision navigation information,but its autonomy is often affected by electromagnetic interference,its reliability of navigation information cannot be guaranteed in the future battlefield.As a result,it is of great significance to develop a completely independent navigation system for long-range and long-endurance vehicle.Taking its flight characteristics into account,a study of key SINS/CNS integrated navigation technology is carried out in this thesis in the hope of providing a highly accurate SINS/CNS integrated navigation programs and algorithms for long-range and long-endurance vehicle and providing the theoretical foundation and method reference for the long-range and long-endurance vehicle's high-precision navigation.During the long time and long distance flight process,guide stars observed by celestial navigation system change over time,affecting the performance of celestial positioning and astronomical attitude determining.Considering this,a scheme of astronomical positioning and attitude determining under the condition of variable starlight is designed in this thesis,including celestial positioning method and orientation method of single star and traditional celestial positioning method and attitude determination method of multiple guide stars.The mathematical model of astronomical positioning and attitude determining under the condition of variable starlight is also established,to ensure the continuity of navigation information of CNS.Because of this,the scope of using celestial navigation system is expanded.Based on the above scheme and mathematical model,the error characteristics of astronomical positioning and attitude determining methods are analyzed in this paper.As for using the position and heading information of celestial navigation system to correct the inertial navigation error,a SINS/CNS position and orientation integrated navigation scheme is proposed.A heading correction method for inertial navigation system with the aid of celestial information is devised,by using the two-order damping correction circuit,heading error of inertial navigation system can be rectified.The dynamic equation of the SINS/CNS position integrated navigation system is deduced,and the error of the inertial navigation system is further corrected,which would effectively improve the performance of SINS/CNS integrated navigation system.Normally,the drift errors and fixed errors of gyroscope have a great influence on the performance of inertial navigation system.While the traditional SINS/CNS attitude integrated navigation system will contain location errors.Therefore,aiming at the above two problems,an online calibration scheme of gyro errors based on astronomical attitude observation under inertial coordinate is presented in this thesis.By building the gyro error model,inertial attitude calculation model,online calibration filtering model of gyro errors based on astronomical attitude observation under inertial coordinate,the drift error,installation errors and scale factor errors of gyro are calibrated and corrected online,and the attitude calculation precision of inertial navigation system under geographic coordinate is effectively improved.Finally,based on the studies above,a scheme of SINS/CNS integrated navigation system for long-range and long-endurance vehicle is proposed,and a SINS/CNS integrated navigation simulation platform based on STK and MATLAB simulation software is also created in this thesis.It can provide a good platform to test the SINS/CNS integrated navigation technology for long-range and long-endurance vehicle.