Experimental Study on the Arrangement between Setting Points of Actuator and Sensor for Vibration Control of Flexible Structures.

Abstract

This paper proposes an experimental study on the arrangement between setting points of an actuator and a sensor for vibration control of a flexible structure, when a vibration controller is mounted at an arbitrary position on the structure. The important vibration mode of the structure to be controlled is the first one, because it is excited most sensitively by strong wind. Therefore, it is necessary to make the reduced-order model represented by the one-degree-of-freedom system at the arbitrary position, considering prevention of the spillover instability. In this paper, the unobservability is used for producing the reduced-order model, and the LQ control theory is used for controller design. For controlling vibration, reduced-order model is made at the setting point of a hybrid dynamic absorber, and a displacement sensor is set at the vibration node of the second vibration mode. Then, the setting point of the sensor is moved to compare the control effect, using this model. It is demonstrated experimentally that the hybrid dynamic absorber designed by this method is able to control vibration well, without spillover instability. Furthermore, it is considered that the setting point of the sensor influences the robustness of the control system.