Active Vibration Control of a 3-PRR Flexible Parallel Manipulator With PZT Actuators and Sensors

Author(s):  
Xuping Zhang ◽  
James K. Mills ◽  
William L. Cleghorn

This paper presents an experimental study on active vibration control of a moving 3-PRR parallel manipulator with three flexible intermediate links, with bonded lead zirconate titanate (PZT) actuators and sensors. Experimental modal tests are conducted to identify structural vibration mode shapes and natural frequencies used. These modal tests provide guidance to design the filter and determine the location of PZT transducers. A PZT actuator controller is developed based on strain rate feedback (SRF) control. A state-space model is formulated with the control input voltage applied to PZT actuators, and output generated from PZT sensors. Then, the design of an optimal active vibration controller is presented based on SRF for the parallel manipulator with flexible links with multiple bonded PZT transducers. Active vibration control experiments are conducted to demonstrate that the proposed active vibration control strategy is effective. Power spectral density (PSD) plots of vibrations illustrate that the structural vibration of flexible links is reduced effectively when the proposed vibration control strategy is employed.

Author(s):  
Xuping Zhang ◽  
James K. Mills ◽  
William L. Cleghorn

This paper addresses the control of structural vibrations of a 3-PRR parallel manipulator with three flexible intermediate links, bonded with multiple lead zirconate titanate (PZT) actuators and sensors. Flexible intermediate links are modeled as Euler-Bernoulli beams with pinned-pinned boundary conditions. A PZT actuator controller is designed based on strain rate feed control (SRF). Control moments from PZT actuators are transformed to force vectors in modal space, and are incorporated in the dynamic model of the manipulator. The dynamic equations are developed based on the assumed mode method for the flexible parallel manipulator with multiple PZT actuator and sensor patches. Numerical simulation is performed and the results indicate that the proposed active vibration control strategy is effective. Frequency spectra analyses of structural vibrations further illustrate that deformations from structural vibration of flexible links are suppressed to a significant extent when the proposed vibration control strategy is employed, while the deflections caused by inertial and coupling forces are not reduced.


Robotica ◽  
2008 ◽  
Vol 26 (5) ◽  
pp. 655-665 ◽  
Author(s):  
Xuping Zhang ◽  
James K. Mills ◽  
William L. Cleghorn

SUMMARYThis paper addresses the dynamic simulation and control of structural vibrations of a 3-PRR parallel manipulator with three flexible intermediate links, to which are bonded lead zirconate titanate (PZT) actuators and sensors. Flexible intermediate links are modelled as Euler–Bernoulli beams with pinned-pinned boundary conditions. A PZT actuator controller is designed based on strain rate feedback (SRF) control. Control moments from PZT actuators are transformed to force vectors in modal space and are incorporated in the dynamic model of the manipulator. The dynamic equations are developed based on the assumed mode method for the flexible parallel manipulator with multiple PZT actuator and sensor patches. Numerical simulation is performed and the results indicate that the proposed active vibration control strategy is effective. Spectral analyses of structural vibrations further illustrate that deformations from structural vibration of flexible links are suppressed to a significant extent when the proposed vibration control strategy is employed, while the deflections caused by inertial and coupling forces are not reduced.


2004 ◽  
Author(s):  
S. Carra ◽  
M. Amabili ◽  
R. Ohayon ◽  
P. M. Hutin

A rectangular plate bolted to a thick Plexiglas rectangular container is investigated in the case of empty and water-filled tank. A modal analysis is firstly realized in order to verify the effects of different water levels and of the free surface waves on the modal parameters and on the modal shapes. A filtered-x LMS (least mean square) adaptive feedforward algorithm is then applied to the perturbed system realizing structural vibration control in linear field with a SISO approach. Five piezoelectric PZT actuators apply the secondary control input in a nearly-collocated configuration. Their positioning is based on the knowledge on the deformation energy of the plate. The present study investigates primarily the control of the first vibration mode, but second and third modes are also experimentally studied. Satisfactory reductions (up to about 45 dB on the second mode measured on Channel 4) are reached for vibration amplitude of the three modes investigated in absence of water. For each modal shape, a particular effectiveness of the optimally placed actuators clearly appears. The introduction of water in the tank reduces the effectiveness of control of the first mode (maximum 5.5 dB of reduction of the vibration amplitude), but the five control channels show a more global uniform effectiveness.


2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Quan Zhang ◽  
Chaodong Li ◽  
Jiantao Zhang ◽  
Jiamei Jin

This paper addresses the active vibration control and coupled vibration analysis of a planar parallel manipulator (PPM) with three flexible links. Multiple piezoelectric ceramic transducers are integrated with the flexible links to constitute the smart beam structures, and hence the vibration of the flexible link can be self-sensed and self-controlled. To prevent the spillover phenomena and improve the vibration control efficiency, the independent modal space control combined with an input shaper is developed to suppress both the structural and the residual vibration of the flexible links. The coupled vibration features between rigid and elastic motions and the interaction effects among three flexible links are theoretically analyzed based on the one-pass rigid-flexible dynamic models. Numerical simulation and experiment results show that the vibration of the three flexible links is coupled through the moving platform and the vibration suppression efficiency is getting improved with the number of controlled flexible links increased.


Author(s):  
Fumio Doi ◽  
Kazuto Seto ◽  
Mingzhang Ren ◽  
Yuzi Gatate

Abstract In this paper we present an experimental investigation of active vibration control of a scaled bridge tower model under artificial wind excitation. The control scheme is designed on the basis of a reduced order model of the flexible structures using the LQ control theory, with a collocation of four laser displacement sensors and two hybrid electro-magnetic actuators. The experimental results in the wind tunnel show that both the bending and the twisting vibrations covering the first five modes of the structure are controlled well.


2013 ◽  
Vol 744 ◽  
pp. 528-531
Author(s):  
Feng Xing ◽  
Jian Guo Cao ◽  
Jing Wang ◽  
Chang Yong Deng

This paper analyses the active vibration control technology on the piezoelectric ceramics car-body pieces in fuzzy control Strategy. Adaptive controllers, based on fuzzy logics, are synthesized for the control of vibration of body structure. Piezoelectric element, control system and body structure have been combined to be a intelligent response system to external drive and it’s own vibration. This system can effect reducing body structure’s reaction from environmental load with external energy. The availability of the control strategy has been confirmed by experiments.


2018 ◽  
Vol 148 ◽  
pp. 11005 ◽  
Author(s):  
Darren Williams ◽  
Hamed Haddad Khodoparast ◽  
Chenyuang Yang

Within robot systems the use of flexible links could solve many issues raised by their rigid counterparts. However, when these flexible links are integrated within systems which include moving parts their main issue lies in the vibrations experienced along their length due to disturbances. Much research effort has been made to solve this issue, with particular attention being paid to the application of piezoelectric patches as actuators within active vibration control (AVC). The study will consist of accurate models of a flexible link and two surface bonded piezoelectric patches, where the link and the piezoelectric patches will be modelled through the use of Euler-Bernoulli beam theory (EBT). The link will be subject to an initial displacement at its free end, and the resulting displacement of this end of the beam is to be controlled using a classic proportional-differential (PD) controller. The voltages to be applied across each of the actuators is to be controlled in accordance with the displacement of the free end of the beam, the actuators will then induce a strain upon the link opposing the movement of the tip. This research outlines this general method, obtains the best location of the piezoelectric patches and the control gains to be used, and proves that the method can be used to attenuate the vibrations experienced by a flexible link.


2017 ◽  
Vol 28 (18) ◽  
pp. 2603-2616 ◽  
Author(s):  
Asif Khan ◽  
Hyun Sung Lee ◽  
Heung Soo Kim

In this article, the effect of a sensor-debonding failure on the active vibration control of a smart composite plate is investigated numerically. A mathematical model of the smart structure with a partially debonded piezoelectric sensor is developed using an improved layerwise theory, a higher-order electric-potential field that serves as the displacement field, and the potential variation through the piezoelectric patches. A state-space form that is based on the reduced-order model is employed for the controller design. A control strategy with a constant gain and velocity feedback is used to assess the vibration-control characteristics of the controller in the presence of the sensor-debonding failure. The obtained results show that sensor-debonding failure reduces the sensor-output, control-input signal, and active damping in magnitude that successively degrades the vibration attenuation capability of the active vibration controller. The settling time and relative tip displacement of the controlled structure increase with the increasing length of partial debonding between the piezoelectric sensor and host structure. Furthermore, a damage-sensitive feature along with multidimensional scaling showed excellent results for the detection and quantification of sensor-debonding failure in the active vibration control of smart structures.


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