| Summary: | 碩士 === 國立海洋大學 === 機械與輪機工程學系 === 84 === Spacecraft attitude control and momentum management is a
highly nonlinearcontrol problem. The first objective of this
thesis is to extend the result ofthe feedback linearization for
spacecraft attitude control and momentum manage-ment problem on
principal axes to body axes. Basically, feedback linearizationis
an extension of pole placement for linear system to nonlinear
systems. Simplified feedback linearizing controllers such as,
linearized first ordercontroller and second order nonlinear
controller will be obtained. The compari-son of the performance
of these controllers will be conducted. The singularityand the
stability problem of the control systems will be discussed.
Due to the limitations of the application of feedback
linearization tech-nique to control systems, the second
objective of this research is to investi-gate the application of
approximate feedback linearization developed by Krenerto the
spacecraft nonlinear control problem. There are two advantages
in thisscheme: it can be easily applied to to the controller
design of arbitrary order; and it only need to solve a set of
linear partial differential equations todetermine nonlinear
coordinate change and state feedback. The simulation
results indicate the performance of the high order non-linear
controller is closer to the performance of the feedback
linearizing controller than the linearized one. Moreover, the
stability of the control system with the feedback linearizing
controller is guaranteed inside the validregion of state
transformation. However, the approximate controllers may
causethe stability problem of the control systems. This will be
demonstrated bysimulations.
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