The Application Of Variable Structure Control In Attitude Maneuver Of Flexible Spacecraft

Nowadays, more and more light material is used in spacecraft, especia ly forsolar arrays. This material is easy to be exited conciliatorily, especially during themaneuver process. The development of astronautics needs the ability of satellitesimprovement, but the flexibility of solar arrays blocks it. The paper mostlyanalysisd and designd spacecraft control algorithm for attitude maneuver ofsatellites with huge solar arrays, especially based on the variable structure control.Firstly, flexible spacecraft attitude kinematics described by Euler angle andunit quaternion is presented. The dynamic equations of motion of the flexiblemulti-body spacecraft have been derived based on the Lagrange’s equations interms of quasi-coordinates. The environment disturbance is taken intoconsideration.Secondly, Euler-based PID control algorithm is designed, and its stability andapplication is analyzed. Unit quaternion-based PID control algorithm is designedusing Lyapunov function for attitude maneuver. VSC algorithm has also beendesigned and its parameters adjustment has been considered. Simulation showsVSC algorithm’s performance is much better than PID.Finally, taken many project constrains into consideration, numericalsimulations were presented and analyzed based on the proposed control laws.These simulations include thrust error, inertia error, frequency error, etc. Errorschanges between80%and120%. Simulation results show VSC algorithm’s strongrobustness for model errors. New technology about thrusts and wheels usingsimultaneity is presented and simulation show this algorithm greatly improve theperformance during attitude maneuver. But this algorithm is seldom used inpractice due to its sensitivity to model parameters.