Structural control using a deployable autonomous control system

Structural control devices facilitate the construction of lightweight structures by suppressing excessive vibrations that arise from the reduced self-weight. Most of the current structural control systems are permanent installations designed to control particular structural properties and are hence specific to a particular application. This paper presents a novel concept of a deployable, autonomous control system (DACS) targeting specific applications where short-term vibration mitigation is desired. These applications may include control of existing structures during predictable extreme loading events or temporary structures where the need for vibration mitigation depends on usage characteristics. This control system consists of an electromechanical mass damper (EMD) mounted on an unmanned ground vehicle (UGV) equipped with vision sensors. The mobility of the UGV combined with on-board vision sensors facilitates autonomous positioning of the device at any desired location of the structure. This allows the device to update its position on the structure as required, through a simultaneous localization and mapping (SLAM) solution, to effectively control different structural modes. The performance of the SLAM solution is evaluated using a full-scale pedestrian bridge while the ability of the proposed system to re-position itself to control various modes of vibration is studied through real-time hybrid simulation (RTHS). The experimental results confirm the ability of the proposed system to effectively control large amplitude motion in slender bridges, while being able to position itself at the appropriate locations for multi-modal control. The concept of the overall system presents promising results for applications where temporary control is desired.