Research On Angles-Only Relative Navigation And Autonomous Control For Space Rendezvous

The autonomous rendezvous and docking technology is crucial for on-orbit service, space-assembly, propellant supply, space debris clearance, and deep-spaced exploration. Based on measurements of optical camera, the methods of relative navigation, closed-loop covariance analysis, optimal multi-objective rendezvous trajectory design, and guidance and control of close range rendezvous are researched. The main results achieved in this dissertation are summarized as follows.The angles-only relative navigation and its degree of observability (DOO) models are formulated, and the latent range information and the active maneuvering strategy are employed to enhance the DOO of angles-only relative navigation. 1) According to relative dynamics equations, angles-only relative navigation model is formulated under the condition that optical camera is the only available sensor for relative measurement. 2) DOO model of angles-only relative navigation is obtained based on the Newton iterative method, and then the observability of navigation is quantificational. 3) The latent range information of orbital maneuver is analyzed, and is employed to enhance the DOO of angles-only relative navigation. 4) According to the performance index of DOO, the optimal maneuvering strategy is designed for chaser to enhance the observability of angles-only relative navigation.The covariance of autonomous rendezvous under closed-loop control is analyzed on basis of angles-only relative navigation. 1) Based on the assumptions of impulsive control and angles-only relative navigation, error dispersion equations during the process of propagation, update and correction are derived, and the closed-loop control covariance of relative navigation and relative trajectory control are obtained. 2) According to the linear covariance analysis method, the closed-loop control covariance of angles-only relative navigation and trajectory control are calculated, and the effectiveness of the covariance result is validated by Monte Carlo simulations.According to the performance indexes of propellant consumption, relative position robustness and relative velocity robustness, the method of optimal multi-objective trajectory design based on closed-loop control is proposed. 1) According to linear covariance analysis method, the closed-loop control covariance of autonomous rendezvous with angles-only relative navigation is analyzed, and expressions of propellant consumption, relative position robustness and relative velocity robustness are formulated. 2) Considering these performance indexes, the multi-objective optimization algorithms of NSGA-II and Physical Programming are employed to solve the optimal multi-objective rendezvous problem respectively, and the effectiveness of the optimization results are testified by Monte Carlo simulations.New guidance and control algorithms are developed for closing, flyaround and approach during the close range rendezvous. 1) Line-of-sight guidance law is formulated, which is proposed for the closing trajectory control perturbed by measurement and control noise. 2) The propellant consumptions of the in-plane and horizontal fast flyaround are analyzed, and the fuzzy controller is proposed for the flyaround trajectory control. 3) Fuzzy, PID and Fuzzy/PID hybrid controllers are designed for final approach trajectory control respectively, and their robustness and propellant consumptions are analyzed and compared. 4) The relative position and attitude dynamics equations are formulated, which are suitable for spacecraft with arbitrary eccentricity. The reference trajectory and attitude for the chase approaching the uncontrolled rotating target are designed, and adaptive sliding mode controller is proposed for the six degree of freedom position and attitude control. The simulation results show that the reference trajectory and attitude are reasonable and the adaptive sliding mode controller is robust.The relative navigation and control based on optical camera for autonomous rendezvous are researched in this dissertation, and the technologies such as the angles-only relative navigation, the close-looped covariance analysis, the optimal multi-objective rendezvous trajectory design, and the guidance and control of close range rendezvous are developed. Some new approaches and significant conclusions of the relative navigation and control are obtained, which are useful for autonomous rendezvous mission design.