Research On Relative State Estimation Method Of Non-cooperative Maneuvering Spacecraft

In order to ensure the safety of spacecraft in orbit and effectively deal with the abnormal approach of non-cooperative maneuvering targets in space,this dissertation focuses on the research about tracking a non-cooperative maneuvering spacecraft in the context of space situational awareness and pursuit-evasion game.The method of relative state estimation to target with impulsive thrust maneuver,continuous thrust maneuver and in the orbit pursuit-evasion game are studied respectively.Finally,the semi-physical simulation experiments are carried out to verify the proposed methods.The main contributions are summarized as follows.The method for tracking a non-cooperative spacecraft with impulsive thrust maneuver based on improved adaptive IMM algorithm is proposed.Aiming at the problem that the maneuvering time and size are unknown,the white noise model is combined with the extended Kalman filter(EKF)algorithm,the non-maneuvering model EKF1 and the maneuvering model EKF2 with large process noise are designed as the IMM algorithm model set.A new correction function is proposed to overcome the singularity problem when simply using the model likelihood function to correct the markov probability transition matrix,and then an improved adaptive IMM-EKF estimation method is proposed.The effectiveness of the proposed method is verified by simulation examples,and the results show that the improved model transition probability adaptive IMM algorithm has better estimation accuracy than other methods.The method for tracking a non-cooperative spacecraft with continuous thrust maneuver based on the current statistical jerk(CSJerk)model is proposed.The total relative jerk between spacecraft is modeled based on the current statistical jerk model,and the maneuvering acceleration model of target is derived.Combining the idea of residual-normalized orthogonalization with the CSJerk-based EKF algorithm improves the robustness of the tracking algorithm at the start or end time of the unknown maneuvers.Based on this,the IMM algorithm model set is designed and the adaptive tracking algorithm for continuous thrust maneuvering targets is proposed.The effectiveness of the proposed method is verified by simulation examples,the results show that the proposed method can effectively track constant thrust and time-varying thrust maneuvering targets,and the convergence speed of traditional current statistical jerk filtering after maneuvering is improved.The method for tracking maneuvering target in orbital pursuit-evasion game based on extended dimension estimation is proposed.Aiming at the problem of state estimation that the observation platform and the target are both maneuvering in orbital pursuit-evasion game,the CW equation is used as the basic dynamic model while the target maneuvering jerk with unknown information is modeled based on the current statistical jerk model,and then an extended dimension compensation estimation algorithm is proposed.By solving the orbit parameters of osculating circular to update the reference point,the problem that the orbit parameters vary real time caused by the maneuvering of the observation spacecraft,which does not meet the assumption that the reference orbit is near-circle,is solved.An extended dimension estimation for tracking maneuvering target in orbital pursuit-evasion game then is proposed.The effectiveness of the proposed method is verified by simulation examples,the results show that the proposed method can effectively overcome the problem of filtering accuracy degradation caused by the maneuvering of the observation spacecraft on which the reference frame established,and can accurately track the target state changes in the orbital pursuit-evasion game.The semi-physical simulation experiments for the verification of proposed maneuvering target tracking method are carried out.Based on the system’s composition and experimental requirements,the scheme of the experiment is designed and the similarity criterion of the system is derived by the similarity principle.Based on the design of scale factors such as length and time,experiments are carried out to verify the continuous thrust maneuvering target tracking method based on the current statistical jerk model and the method for tracking maneuvering target in orbital pursuit-evasion game based on extended dimension estimation.The relative state estimation method for non-cooperative maneuvering spacecraft proposed in this dissertation can effectively expand the theoretical system of space situation awareness technology,provide efficient and high-precision situation input for the control strategy design in the process of orbital pursuit-evasion game,and support the development of space defense technology,which is of great significance for improving the survivability of the on-orbit spacecraft.