Reduced order H∞ controller synthesis for flexible structures control

This paper presents new control laws synthesis methods which can be applied to the attitude control of flexible structures. These methods are based on the structured H∞ synthesis and the acceleration sensitivity formulation which is here extended to mechanical systems with non-actuated flexible modes. These methods are applied on an academic spring-masses example, which is representative of a flexible structure. The proposed approach is compared with classical proportional-derivative control and full order H∞ control in terms of closed-loop dynamics. A particular attention is drawn on the avoidance of pole-zero cancellations and the fact that the required bandwidth is close to the flexible dynamics.