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

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.

[1]  Takaaki Hagiwara,et al.  The parametrization of all disturbance observers for plants with input disturbance , 2009, 2009 4th IEEE Conference on Industrial Electronics and Applications.

[2]  G. R. Allen,et al.  Ride quality and international standard ISO 2631 (Guide for the evaluation of human exposure to whole-body vibration) , 1975 .

[3]  Vicente Feliú Batlle,et al.  Position control of very lightweight single-link flexible arms with large payload variations by using disturbance observers , 2012, Robotics Auton. Syst..

[4]  Ferruccio Resta,et al.  A modal disturbance estimator for vibration suppression in nonlinear flexible structures , 2011 .

[5]  Paul Reynolds,et al.  Observer-based controller for floor vibration control with optimization algorithms , 2017 .

[6]  Linda M. Hanagan,et al.  Active Control Approach for Reducing Floor Vibrations , 1997 .

[7]  E. Schrijver,et al.  Design of disturbance observers for the compensation of low-frequency disturbance , 2000 .

[8]  H. Nijmeijer,et al.  Equivalence of disturbance observer structures for linear systems , 2000, Proceedings of the 39th IEEE Conference on Decision and Control (Cat. No.00CH37187).

[9]  Der-An Wang,et al.  Modal space vibration control of a beam by using the feedforward and feedback control loops , 2002 .

[10]  Paul Reynolds,et al.  Potential benefits of incorporating active vibration control in floor structures , 2013 .

[11]  Paul Reynolds,et al.  Enhancing active vibration control of pedestrian structures using inertial actuators with local feedback control , 2012 .

[12]  M. H. Mickle,et al.  Disturbance estimation and compensation in linear systems , 1990 .

[13]  Carl J. Kempf,et al.  Disturbance observer and feedforward design for a high-speed direct-drive positioning table , 1999, IEEE Trans. Control. Syst. Technol..