Attitude and orbit coupled control and simulation of spacecraft formation by using intelligent adaptive control based on characteristic model
Regarding to the relative attitude and orbit of spacecraft formation flying, a nonlinear dynamic model of six degree of freedom coupled with attitude and orbits established, with the help of characteristic model, this paper mainly analyzes the factors of the spatial perturbation and multiple disturbance torques, a kind of intelligent adaptive controller is designed based on the combination of RBF neural network and the golden section adaptive control. Later, the simulation platform Jade is used to simulate and analyze the Multi-Agent system of spacecraft formation. The results show that the spacecraft formation can run along in the ideal orbit, the effect of the control system has good robustness, fault tolerance and intelligence.
Coupled-distributed-adaptive-coordinated control for relative orbit and attitude of multiple spacecrafts
According to the consensus theory, the coupled-cooperative control for relative orbits and attitudes of a multispacecraft system is investigated under a directed communication topology. Considering the nonlinear equations for the relative orbits of near-earth spacecraft and the attitude motion equations in terms of the modified Rodriguez parameters(MRP), we build six-degrees-of-freedom(6DOF) motion equations with coupled control input and unknown nonlinearities and external disturbance. When the reference state(label of the leader spacecraft) is available only to a partial number of the follower spacecrafts, we develop an adaptive gain control algorithm based on Chebyshev neural networks, which can let a fleet of followers rendezvous at a point with the same attitude. The proposed distributed algorithm for each following spacecraft is only dependent on the information of itself and its neighboring spacecraft. Because the relative velocities and relative angular velocities among the follower spacecrafts are difficult to be measured, we propose a distributed-coupledadaptive-control algorithm without using neighboring velocities and angular velocities, so that all follower spacecrafts maintain a desired formation and relative attitudes. Simulation results of the formation-flight of six spacecrafts are carried out to study the effectiveness of the proposed control scheme.
Space Vehicle Dynamics and Control
"Space Vehicle Dynamics and Control, Second Edition" continues to provide a solid foundation in dynamic modeling, analysis, and control of space vehicles featuring detailed sections covering the fundamentals of controlling orbital, attitude, and structural motions of space vehicles. A new Part 5 is a collection of advanced spacecraft control problems and their practical solutions obtained by applying the fundamental principles and techniques emphasized throughout the book.The textbook highlights a range of orbital maneuvering and control problems: orbital transfer, rendezvous, and halo orbit determination and control. Rotational maneuvering and attitude control problems of space vehicles under the influence of reaction jet firings, internal energy dissipation, or momentum transfer via reaction wheels and control moment gyros are treated in detail. It also covers the analysis and design of attitude control systems in the presence of structural flexibility and/or propellant sloshing. New topics include control moment gyros for agile imaging satellites, solar sail dynamics and control, solar sail missions for asteroid deflection, and attitude and orbit control of a large geostationary solar power satellite.This text requires a thorough knowledge of vector and matrix algebra, calculus, ordinary differential equations, engineering mechanics, and linear system dynamics and control. The first two chapters provide a summary of such necessary background material. Since some problems may require the use of software for the analysis, control design, and numerical simulation, readers should have access to computational software (i.e., MATLAB[registered]) on a personal computer. MATLAB is a registered trademark of The MathWorks, Inc.