Experimental Study on Arrangements of Setting Points of an Actuator and Sensor for the Vibration Control of Flexible Structures

1994 ◽  
Vol 6 (4) ◽  
pp. 292-297
Author(s):  
Kazuto Seto ◽  
◽  
Katsuhiko Ezure ◽  
Keyword(s):  
Experimental Study ◽  
Vibration Control ◽  
Vibration Mode ◽  
Controller Design ◽  
Flexible Structures ◽  
Reduced Order Model ◽  
Displacement Sensor ◽  
Order Model ◽  
Reduced Order ◽  
Dynamic Absorber

This paper proposes an experimental study on the arrangements between the setting points of an actuator and sensor for the vibration control of a flexible structure, when a vibration controller is mounted at an arbitrary position on the structure. The important vibration mode of the structure to be controlled is its first mode, because it is excited most sensitively by strong winds. It is therefore necessary to make a reduced-order model represented by a one-degree-of-freedom system at an arbitrary location, in consideration of preventing spillover instability. In this paper, non-observability is used for making the reduced-order model, and the LQ control theory is used for controller design. For controlling vibration, a reduced-order model is constructed at the setting point of a hybrid dynamic absorber, and a displacement sensor is set at the vibration node of the second vibration mode. Then, the setting point of the sensor is changed to compare control effects by means of this model. It is demonstrated experimentally that a hybrid dynamic absorber, designed by this method, is capable of controlling vibration well without causing spillover instability. In addition, it is considered that the setting point of the sensor influences the robustness of the control system.

Vibration Control Method and Adaptability for Flexible Structures With Distributed Parameters Using a Hybrid Dynamic Absorber

1995 ◽  
Author(s):  
Kazuto Seto ◽  
Susumu Kondo ◽  
Katsuhiko Ezure
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Controller Design ◽  
Flexible Structures ◽  
Vibration Modes ◽  
Order Model ◽  
Reduced Order ◽  
Distributed Parameters ◽  
Dynamic Absorber ◽  
Lq Control

Abstract This paper examines the vibration control of a flexible structure using a hybrid dynamic absorber. A new method for modeling flexible structures with distributed parameters using a reduced-order model with lumped parameters is specified. Both prevention of spillover and physical correspondence at the modeling points are taken into consideration. Due to restrictions of controller design it is necessary to employ reduced-order models of flexible structures when using LQ control theory to control vibration. By ignoring higher mode orders model reduction may invite vibration instability called spillover. In order to prevent spillover nodes of higher-order vibration modes are selected as modeling points. The effectiveness of this method is demonstrated by applying vibration control to a flexible tower-like structure. In addition the robustness of the control system is tested by placing the sensors and absorbers at points different from those selected by the model.

Solving Vibration Control Problems Using Reduced Order Models for Flexible Structures: A Genetic Algorithm Approach

1997 ◽  
Author(s):  
Sourav Kundu ◽  
Kentaro Kamagata ◽  
Shigeru Sugino ◽  
Takeshi Minowa ◽  
Kazuto Seto
Keyword(s):  
Genetic Algorithm ◽  
Vibration Control ◽  
Controller Design ◽  
Fitness Function ◽  
Flexible Structures ◽  
Design Solution ◽  
Reduced Order Models ◽  
Reduced Order ◽  
Fitness Value ◽  
Genetic Algorithm Approach

Abstract A Genetic Algorithm (GA) based approach for solution of optimal control design of flexible structures is presented in this paper. The method for modeling flexible structures with distributed parameters as reduced-order models with lumped parameters, which has been developed previously, is employed. Due to some restrictions on controller design it is necessary to make a reduced-order model of the structure. Once the model is established the design of flexible structures is considered as a feedback search procedure where a new solution is assigned some fitness value for the GA and the algorithm iterates till some satisfactory design solution is achieved. We propose a pole assignment method to determine the evaluation (fitness) function to be used by the GA to find optimal damping ratios in passive elements. This paper demonstrates the first results of a genetic algorithm approach to solution of the vibration control problem for practical control applications to flexible tower-like structures.

Reduced-Order Model-Based Feedback Control of Flow Over an Obstacle Using Center Manifold Methods

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Coşku Kasnakoğlu ◽  
R. Chris Camphouse ◽  
Andrea Serrani
Keyword(s):  
Boundary Control ◽  
Center Manifold ◽  
Controller Design ◽  
Tracking Error ◽  
Reduced Order Model ◽  
Order System ◽  
Linear Quadratic ◽  
Order Model ◽  
Control Effort ◽  
Reduced Order

In this paper, we consider a boundary control problem governed by the two-dimensional Burgers’ equation for a configuration describing convective flow over an obstacle. Flows over obstacles are important as they arise in many practical applications. Burgers’ equations are also significant as they represent a simpler form of the more general Navier–Stokes momentum equation describing fluid flow. The aim of the work is to develop a reduced-order boundary control-oriented model for the system with subsequent nonlinear control law design. The control objective is to drive the full order system to a desired 2D profile. Reduced-order modeling involves the application of an L2 optimization based actuation mode expansion technique for input separation, demonstrating how one can obtain a reduced-order Galerkin model in which the control inputs appear as explicit terms. Controller design is based on averaging and center manifold techniques and is validated with full order numerical simulation. Closed-loop results are compared to a standard linear quadratic regulator design based on a linearization of the reduced-order model. The averaging∕center manifold based controller design provides smoother response with less control effort and smaller tracking error.

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