Adaptive predictive feedback control of circular plate vibrations

2008 ◽  
Vol 123 (5) ◽  
pp. 3728-3728
Author(s):  
Lucyna Leniowska ◽  
Pawel Kos
Keyword(s):  
Feedback Control ◽  
Circular Plate ◽  
Plate Vibrations

Large Amplitude Vibrations of Circular Plate on a Uniform Elastic Foundation

1972 ◽  
Vol 94 (1) ◽  
pp. 43-49 ◽  
Author(s):  
R. Bolton
Keyword(s):  
Circular Plate ◽  
Elastic Foundation ◽  
Normal Modes ◽  
Single Mode ◽  
Linear Mode ◽  
Mode Amplitude ◽  
Plate Vibrations ◽  
Edge Conditions ◽  
Large Amplitude Vibrations ◽  
Mode Response

Herrmann’s equations, the dynamic analogues of the von Karman equations, are solved for a circular plate on a linear elastic foundation by assuming a series solution of the separable form involving unknown time functions. The spatial functions include both regular and modified Bessel functions and are chosen to satisfy the linear mode shape distributions of the plate as well as the usual edge conditions. Total differential equations governing the symmetric plate motions are derived using the Galerkin averaging techniques for a spatially uniform load. By extending the concept of normal modes to nonlinear plate vibrations, comparisons between normal mode response and single mode response, as functions of the first mode amplitude, are shown for different values of the elastic foundation parameter. Results are obtained for plates with simply supported and clamped edges and with both radially moveable and immoveable edges. These results are used to discuss the limitations of single-mode response of circular plates, both with and without an elastic foundation.

The Application of xPC Target Platform for a Circular Plate Vibration Control

2016 ◽  
Vol 248 ◽  
pp. 135-141 ◽  
Author(s):  
Mariusz Sierżęga ◽  
Lucyna Leniowska
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Circular Plate ◽  
Pole Placement ◽  
Separate Experiment ◽  
Control Procedure ◽  
Control Input ◽  
Plate Vibrations ◽  
Xpc Target ◽  
Target Platform

The goal of this work is to describe a control procedure that simplifies the implementation and improves the performance of feedback active control on a planar structure. The article presents a design, development and experimental verification of an active feedback vibration control system of circular plate with the application of xPC Target platform. Vibrations of the plate are measured using MFC sensors. The control input is applied to the plate by a MFC disk, attached to the plate in its center. The plate vibrations were excited by a loudspeaker or by a second MFC actuator placed at a certain distance from the center of the disc.The basic philosophy is the off-line identification of the best model for the controlled process [1] and the subsequent synthesis of the controller. There are many classical strategies that can be used when a mathematical model is available, for instance, poles allocation or optimal control (LQR), used also by the authors [2, 3]. This article proposes an approach to design an effective controller for vibration suppression of a circular plate with the use of the pole placement method. For the considered system a linear discrete model obtained by parametric identification method for the data measured in a separate experiment has been designated. This model was used to develop the 6-th order digital controller which was implemented on xPC Target platform. Before implementation of the chosen control law design on real plant the simulations in Simulink/Matlab were performed. In order to investigate the influence of the implemented controller on the plate vibrations suppression the 3D scanning vibrometer has been used. The obtained simulation and experimental results, corresponding to the developed active vibration control system have been presented, compared and analyzed.

MFC Sensors and Actuators in Active Vibration Control of the Circular Plate

2015 ◽  
Vol 40 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Lucyna Leniowska ◽  
Dominik Mazan
Keyword(s):  
Circular Plate ◽  
Laser Scanning ◽  
Vibration Suppression ◽  
Active Vibration Control ◽  
Sampling Period ◽  
Linear Feedback ◽  
System Response ◽  
Sensors And Actuators ◽  
Control Effort ◽  
Plate Vibrations

Abstract In this paper, the MFC sensor and actuators are applied to suppress circular plate vibrations. It is assumed that the system to be regulated is unknown. The mathematical model of the plate was obtained on the base of registration of a system response on a fixed excitation. For the estimation of the system’s behaviour the ARX identification method was used to derive the linear model in the form of a transfer function of the order nine. The obtained model is then used to develop the linear feedback control algorithm for the cancellation of vibration by using the MFC star-shaped actuator (SIMO system). The MFC elements location is dealt with in this study with the use of a laser scanning vibrometer. The control schemes presented have the ability to compute the control effort and to apply it to the actuator within one sampling period. This control scheme is then illustrated through some numerical examples with simulations modelling the designed controller. The paper also describes the experimental results of the designed control system. Finally, the results obtained for the considered plate show that in the chosen frequency limit the designed structure of a closed-loop system with MFC elements provides a substantial vibration suppression.

scholarly journals Optimized design of adaptable vibrations suppressors in semi-active control of circular plate vibrations

2018 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Navid Asmari Saadabad ◽  
Hamed Moradi ◽  
Gholamreza Vossoughi
Keyword(s):  
Circular Plate ◽  
Active Control ◽  
Optimized Design ◽  
Plate Vibrations

Use of vent stack temperature as a feedforward variable for dissolver total titratable alkali (TTA) control

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 261-269
Author(s):  
Wei Ren ◽  
Brennan Dubord ◽  
Jason Johnson ◽  
Bruce Allison
Keyword(s):  
Feedback Control ◽  
Current Practice ◽  
Feedforward Control ◽  
Control Variable ◽  
Indirect Measurement ◽  
Tight Control ◽  
Transfer Lines ◽  
Green Liquor ◽  
Process Dynamics ◽  
Downstream Processes

Tight control of raw green liquor total titratable alkali (TTA) may be considered an important first step towards improving the overall economic performance of the causticizing process. Dissolving tank control is made difficult by the fact that the unknown smelt flow is highly variable and subject to runoff. High TTA variability negatively impacts operational costs through increased scaling in the dissolver and transfer lines, increased deadload in the liquor cycle, under- and over-liming, increased energy consumption, and increased maintenance. Current practice is to use feedback control to regulate the TTA to a target value through manipulation of weak wash flow while simultaneously keeping dissolver density within acceptable limits. Unfortunately, the amount of variability reduction that can be achieved by feedback control alone is fundamentally limited by the process dynamics. One way to improve upon the situation would be to measure the smelt flow and use it as a feedforward control variable. Direct measurement of smelt flow is not yet possible. The use of an indirect measurement, the dissolver vent stack temperature, is investigated in this paper as a surrogate feedforward variable for dissolving tank TTA control. Mill trials indicate that significant variability reduction in the raw green liquor TTA is possible and that the control improvements carry through to the downstream processes.

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