Research On Autonomous Rendezvous Guidance And Control For Spacecraft

Based on the rendezvous and docking knowledge background and the requirements of rendezvous and docking (AR&D) mission, this dissertation puts much emphasis on the guidance and control approaches of far-distance rendezvous based on the impulse and the finite thrust, near-distance rendezvous and approach operations by applying rendezvous theories. The rendezvous safety and simulation system modeling issues are analyzed conceptually and methodologically.First, the rendezvous dynamic models are established. The GNC scheme system frame of the far-distance and near-distance rendezvous are designed respectively.Second, the far-distance rendezvous trajectory optimization and the guidance approaches are researched. (1) Two far-distance multi-impulse orbit optimal approaches are proposed: Adopting the general states variables, a multi-phase-multi-dimension dynamic programming optimizing algorithm is implemented, and the energy optimal solution of two-impulse rendezvous are deduced; For the multi-impulse optimal problem of the time and energy performance indexes, a niche evolution algorithm which has a rapid convergence performance is put forward. (2) For the finite thrust guidance problem, the velocity-gain-guidance and E guidance are respectively studied for application, the parameter selecting principles and optimizing methods are given, and the implement problem of E guidance under the condition of constant finite thrust is solved with the PWPF modulator. (3) A combined guidance project with initial, middle, terminal guidance phases and free flight phase are planned. The mission planning with impulsive conditions and guidance with finite thrust are combined compactly. A project implementation model with the velocity-gain-guidance as the initial guidance, the E guidance as the terminal guidance is given. The project shows good autonomous and robust performances from the simulation results.Third, the relative orbit control, attitude control and the rendezvous safety questions of near-distance rendezvous are studied. (1) In theory, the constrained time multi-impulse least norm solution and quadratic programming solution are given, and the general solution of non-constrained time nonlinear programming problem algorithm is put forward; A reference line-of-sight (LOS) multi-impulse rapid calculating guidance approach is studied, and the exponential and the power function transforms are put forward to optimize orbit kinetic characteristics; Applying the LOS guidance to the docking position operation, the parameter transformation methods and the guidance laws are designed. Based on the glidescope theory, the velocity control design approaches are proposed, and the concept of fast, exponential and slow approach orbits are defined; The approach phase orbit control is studied based on the sliding mode control, for the constant and non-constant thrust model, the control effects are analyzed under different control strategies; A gene-fuzzy control approach is studied for the fly-around and terminal approach phase, the modeling and optimization methods of the fuzzy table are given. Simulation results demonstrate the efficacy of the proposed approaches (2) For the relative attitude control problem, the attitude parameter invariable principle is proven under the parallel condition of the body and the docking panel coordinate system, and the transformation formulas of centroid motion parameters are deduced; The observability and controllability conditions of nonlinear attitude control system are proven; The phase variable model is attained by adopting the differential geometry theory, based on the algorithm of terminal sliding mode control, the attitude track is implemented when considering the disturbances. (3) The safety concept of the space rendezvous is improved, and several rendezvous strategies are given; Based on the rendezvous dynamic stochastic model, the computational equations of the collision probability are given and analyzed, and three kinds of simple models of collision avoidance are given.Finally, the space rendezvous simulation system modeling frame is studied; The logic modeling of GNC system are completed by using UML diagrams; Based on design pattern theory the simulation system is abstracted, and three oriented-object design patterns for GNC of AR&D are given.Combining theory with engineering practice, this dissertation proposes many approaches to solve the AR&D problems, and the performances of optimization, rapidness and precision are embodied in the design of the approaches. Some results and conclusions are significant and helpful to associate future space rendezvous researches.