Abstract
We consider the attitude tracking problem of the axisymmetric underactuated spacecraft. It is known that the asymptotic stabilization of the system to any state is possible, and that the system admits flat output. Thus, the asymptotic model matching problem to itself is solvable. However, its flat output given in [6] include a singularity so that the control input which generates the state trajectory may not be unbounded. Tsiotras et al proposed a third order polynominal-type parametarization of the output trajectory which avoids the singularity. In this paper, the authors give a condition such that the given analytic output trajectory can avoid the singularity. Based on the result, we can use the broader class of output trajectories.
