Abstract
This study is devoted to investigate slew maneuver of a flexible space structure. The flexible space structure treated in the present study is a rigid body equipped with a flexible aluminum bean, and the control scheme is defined as a method to minimize the bending-moment at the root of the flexible appendage during slew maneuver. The hierarchical gradient algorithm is employed to obtain the optimal control profile. Original of the algorithm can only treat inequality constraints on the state variables, and not on the maximum value of control input. It is necessary in the present problem formulation to take into consideration constraints on the control input since maximum value of control input is naturally limited. This paper proposes a method to improve the hierarchical algorithm so that constraints on the control input can be treated. The method is analyzed numerically to verify the present modified algorithm, and to show that constraints both on the control input and bending-moment are satisfied. The resulting control profile is implemented in an experiment to verify its feasibility. Results of experiments show that bending-moment is effectively reduced in the case that constraint on the maximum value of bending moment is considered.
