Research On Multi-source Dynamic Celestial Navigation Of Spacecraft

China is in the transition period from a " aerospace big country " to a " aerospace powerful country ".With the continuous enrichment and development of space technology,China has carried out more and more intensive space launch missions.With the increase of space vehicles in orbit,the burden of ground telemetry and control becomes heavier,and the cost and complexity of ground navigation service increases with the increase of distance.With the deepening of deep space exploration,spacecraft navigation is developing from earth-based telemetry and control to automation,which can guide spacecraft without human-computer interaction or human assistance.In order to realize the autonomous navigation of space vehicle in earth orbit and even deep space exploration,it is necessary to study the navigation technology composed of various celestial navigation technologies.In order to broaden the application scope of navigation system and improve dynamic adaptive capacity,this paper carries out multi-source dynamic celestial navigation exploration,and tries to form a high-precision,strong autonomy and anti-interference spacecraft navigation scheme.X-ray pulsar navigation(XPNAV)is a new direction in the study of celestial navigation,which provides the possibility of autonomous navigation in the solar system and even in the Milky Way.Once the XPNAV scheme is established,it can be a general scheme in the field of near earth and even deep space.In view of the problem that it is difficult to maintain the "visibility" of pulsars for a long time under dynamic environment,this paper analyzes the visible conditions of pulsars and establishes a pulsar selection scheme to ensure the continuity and effectiveness of pulse signals.The time delay caused by pulse signal propagation in space is analyzed and modeled,the arrival time conversion model of pulse photon is constructed,and the pulsar observation data is used to generate the pulse radiation profile.The theoretical system of XPNAV is constructed and verified by simulation.In order to solve the problem that the pulsar navigation observation period is long and it is difficult to provide continuous and real-time navigation information,the starlight navigation method is introduced to improve the real-time and disturbance resistance of the navigation system.To meet the requirements of ground navigation experiments,a starlight navigation simulation system was established to simulate the data processing process of star sensors.In order to solve the problem of fuzziness of star map imaging in dynamic environment,a research on star map preprocessing technology is carried out to improve the accuracy of star extraction and attitude estimation of fuzzy star map.The nonlinear filtering algorithms are used to combine the pulsar navigation system and starlight navigation,and the dynamic information distribution coefficients algorithm based on the system error covariance norm is used to further improve the adaptive capacity of the integrated navigation system.A inertial/celestial integrated navigation system is proposed,which can restrain the error accumulation of inertial navigation system,and increase the frequency of navigation information update effectively.The integrated navigation system improves the navigation precision significantly,and has better robustness and dynamic adaptability in the case of system failure,measurement loss and other emergencies.In this paper,we study the multi-source dynamic celestial navigation method,which make full use of pulsars,starlight,inertial navigation information.This method ensures that the navigation system can maintain a high level of autonomy under the dynamic environment,provides a stable and efficient navigation information for the spacecraft,greatly improves the spacecraft response and survival capability,meets the earth's orbit and deep space mission to the navigation requirements.