Comparative studies of global and targeted control of walkway bridge resonant frequencies

Abstract

In this paper, three controllers are investigated for active vibration control (AVC) of a pedestrian walkway structure. They comprise of direct velocity feedback (DVF), observer-based and independent modal space (IMSC) controllers that are implemented in single-input single-output (SISO), multi-SISO and multiple-input multiple-output (MIMO) configurations. The objective of the SISO controller schemes is to compare vibration mitigation performances arising from global control versus selective control of structural resonant frequencies in a given frequency bandwidth. The objectives set out for the multi-SISO and MIMO controllers are to realise global control within the same frequency bandwidth considered in the SISO studies. A novel aspect of these latter studies is the independent control of selected resonant frequencies at different locations on the structure with the aim of imposing global control.Vibration mitigation performances are evaluated using frequency response function measurements and uncontrolled and controlled responses to a synthesized walking excitation force. In the SISO studies, selective control of specific resonant frequencies has a slight degradation in the global vibration mitigation performance although it reflects better performance around the target frequencies. For the multi-SISO and MIMO controller studies, the selective control of the two lowest and dominant frequencies of the structure at two different locations still offers comparative vibration mitigation performances with the controllers considered as global in the sense that they target both structural frequencies at both locations. Attenuations of between 10-35 dB are achieved.

Independent modal space phase‐lead velocity feedback control of floor vibration

“…Therefore, the control force for multiple modes, denoted by , is calculated by The response reduction effect for each mode is achieved by choosing a sufficiently large value of the control gain . However, it has been shown that the use of an actuator introduces a pair of high‐damped poles that substantially affect the dynamic property of the structural system 11,28 . Since the dynamics of the actuator or other involved components are not negligible in the whole control system, reduction of the modal response would be different depending on the mode j .…”

“…However, it has been shown that the use of an actuator introduces a pair of high-damped poles that substantially affect the dynamic property of the structural system. 11,28 Since the dynamics of the actuator or other involved components are not negligible in the whole control system, reduction of the modal response _ q j t ð Þ would be different depending on the mode j. It is often the case that the phase change caused by the actuator dynamics degrades the performance of the control strategy by the resulting decrease of the stability margin as well as the reduction of damping introduced by the active control system.…”

“…The advantages of AVC lie in a high level of effectiveness and the ease of implementation to deal with multiple modes. Many researchers showed the advantages of AVC by analysis and experiments using building floors 1,11–14 . In the previous research, Direct‐Output Feedback (DOFB) controllers are often used owing to the advantage in the ease of implementation, 1,12,15 and their robustness to the spillover effects.…”

“…Many researchers showed the advantages of AVC by analysis and experiments using building floors. 1,[11][12][13][14] In the previous research, Direct-Output Feedback (DOFB) controllers are often used owing to the advantage in the ease of implementation, 1,12,15 and their robustness to the spillover effects. However, when the sensors and actuators are not collocated and dynamics of actuators and sensors are considered, the latter merit is no longer guaranteed.…”

Response control of cable-stayed arch bridge using modified hanger system

“…Considering the investigated vibrational behavior of the cables and bridges, it is the engineering concern to control the vibration and dynamic responses of bridges. Numerous research studies have been carried out in this field such as using inclined suspenders (VGTU Report, 2003) or vibration and resonant frequency controllers (Caetano et al, 2010; Liu et al, 2010; Nyawako and Reynolds, 2016; Zhang et al, 2019). Among the structural control solutions, using dampers to reduce the vibration of cables and bridges has been an efficient method.…”