Incorporating a disturbance observer with direct velocity feedback for control of human-induced vibrations

Abstract

Feedback control strategies are desirable for disturbance rejection of human-induced vibrations in civil engineering structures as human walking forces cannot easily be measured. In relation to human-induced vibration control studies, most past researches have focused on floors and footbridges and the widely used linear controller implemented in the trials has been the direct velocity feedback (DVF) scheme. With appropriate compensation to enhance its robustness, it has been shown to be effective at damping out the problematic modes of vibration of the structures in which the active vibration control systems have been implemented.The work presented here introduces a disturbance observer (DOB) that is used with an outer-loop DVF controller.Results of analytical studies presented in this work based on the dynamic properties of a walkway bridge structure demonstrate the potential of this approach for enhancing the vibration mitigation performance offered by a purely DVF controller. For example, estimates of controlled frequency response functions indicate improved attenuation of vibration around the dominant frequency of the walkway bridge structure as well as at higher resonant frequencies. Controlled responses from three synthesized walking excitation forces on a walkway bridge structure model show that the inclusion of the disturbance observer with an outer loop DVF has potential to improve on the vibration mitigation performance by about 3.5% at resonance and 6-10% off-resonance. These are realised with hard constraints being imposed on the low frequency actuator displacements.

Passive, semi-active, active and hybrid mass dampers: A literature review with associated applications on building-like structures

“…Aghajanian et al (2017), and Hillis (2010) implemented the Luenberger observer in their control schemes. Moreover, the use of the disturbance observer can be found in the control scheme of Nyawako et al (2016). Alt et al (2000) reported that, during an earthquake, the measured signals from the sensors may deviate from the real ones and this could result to a detrimental effect on the controlled structure.…”

Vibration Control Strategies for Cancelling Floor Vibrations via Inertial Mass Dampers

“…Finally, more complex control strategies also have been proposed. For example, multi-loop vibration controller, disturbance observer introduced into an outer-loop DVFC and other dynamic compensators are investigated in recent researches [47,48,49]. However, these features and new control components undoubtedly complicate the practical implementation and its likelihood of success.…”