Formation Control And Simulation Of Satellites Formation Flying

The formation flying of satellites can make several satellites work together toform a huge "virtual satellite" which performs the same functions as a single bigspacecraft with the large aperture or the long baseline. Moreover, it can not only bringdown the cost and risk obviously, but also eliminate the impact of the satellitemalfunction on the space mission. More and more people pay much attention to theresearch of it now. It will play an important role in many fields such as the electronicreconnaissance, three-dimensional imaging, satellite remote sensing, navigation etc.Researching work as follows about the formation flying of satellites has been done inthe thesis.Relative dynamical models of formation flying were introduced, and Hillequations were deduced based on the circular reference orbit. Several commonformations and their initial conditions under the Hill equations were presented. Theresult shows that the formation flying can't keep chronically stable, if the initialorbital elements of the deputy satellite were obtained through the Hill equations andorbital elements of the reference satellite. So a correction to the semi-axis of the initialconditions was adopted in the thesis based on circular formation to improve thestabilization of the formation flying.Formation flying was destroyed after a long period due to all kinds ofperturbations, so a controller was needed to keep the formation flying stable.Linear-quadratic regulator based on Hill equations was presented here and asimulation method based on STK for the formation keeping control was realized. Thecontrol forces calculated by the control strategy of the formation keeping were addedinto the STK orbit propagator, which is realized through the STK plug-in. It is showedthat the stable condition of the controlled formation flying satellite is not only to keepthe control state stable, but also to let the semi-axis of the deputy satellite equal to thatof the reference satellite. It is the key problem to reduce the energy cost for the long-term formationkeeping control. In the thesis, ω t is replaced by the argument of Periapsis and theinitial true anomaly, which were subtracted from the argument of the latitude. Thiscorrection could reduce the error of the relative motion model, and at the same timeresult in the reduction of energy cost. Several of simulations were performed fordifferent formation keeping control strategies. The control precision and energy costwere analyzed for each control strategy As for the formation flying reconfiguration, one strategy was presented on theassumption that the phase angle for every deputy satellite keeps the same before andafter reconfiguration. Linear-quadratic regulator was adopted to perform theformation flying reconfiguration.