A simple strategy for active structural control against control–structure–excitation effects: Concept, framework, and experiments

Abstract

Active control is among the most effective control techniques for mitigating structural vibrations. Control–structure interaction (CSI) plays a significant role in modeling a control system. Popular methods incorporate the actuator dynamics and structure into the control system to account for CSI. The transfer function of the actuator can be identified through frequency response tests without physical modeling. However, this method ignores the effects of the excitation. Another approach is to create a physics‐based model of the actuator and include it in the control design, but its implementation may be challenging and requires a thorough understanding of the complex control system. In this study, the concept of control–structure–excitation effects (CSEE) is presented to account for the effects of the control, structure, and excitation on the transfer function of the actuator. In contrast to the existing control methods that consider CSI in system modeling, an improved control framework is proposed to eliminate the influence of CSI/CSEE on the control performance and thus decouple the tracking control of the actuator from the control design of the structure. This is achieved by introducing the control floor acceleration into the actuator controller and transforming the tracking of the absolute control force into that of the relative acceleration. The control strategy is simple and easy to implement based on conventional actuator control algorithms, such as three‐variable control. Frequency response tests and shake table tests were performed on a two‐story small‐scale structure to evaluate the effectiveness of the control strategy. It was confirmed that the improved control framework shows good tracking performance with respect to the control force and thus allows for ideal structural response control.