Two-stage strategy for simultaneous slewing and vibration suppression of flexible structures Original Research Article

This paper presents an open loop near-minimum-time solution for simultaneous slewing and vibration suppression of flexible structures. The problem is formulated as an open-loop, minimum-system energy and/or control effort optimal control problem in modal space. With parametric control law, a two-level problem-solving strategy is presented. In the first stage, a sequence of rigid mode-based time-optimal control problems is solved and the minimum maneuver time is found by gradually reducing the maneuver time until the solution converges. In the second stage, the optimal parameters of the control law are evaluated using nonlinear programming with prescribed performance index as its objective function. The proposed strategy, through time-optimal control of the rigid mode combined with the parametric quadratic control of the clastic modes, determines the control profiles which give both minimum maneuver time and desired value of performance index. As an example, the optimal control of a slewing flexible beam is presented, and high performance slewing maneuver is achieved.