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.
Nonlinear golden-section adaptive control
For high order linear systems with unknown parameters and a group of complicated nonlinear systems,in order to design a low order controller which can meet the requirements of transient process performance of different systems,a new nonlinear golden section adaptive control method is proposed in this paper,which is based upon the linear golden section adaptive control method.At first,the design principle and the features of the new control method and characteristic model of controlled system are introduced.Next,the stability of the closed loop system composed of the nonlinear golden section adaptive controller and the controlled plant,which can be described with a second order slowly time varying difference equation is proved.At the end of the paper,a typical simulation example is give to demonstrate the efficiency and advantages of the nonlinear golden section adaptive method.
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.