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.

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.

Towards Academic Successor Selection Modelling with Genetic Algorithm in Multi-Criteria Problems

2018 ◽  
Vol 7 (4.33) ◽  
pp. 130
Author(s):  
Atiqa Zukreena Zakuan ◽  
Shuzlina Abdul-Rahman ◽  
Hamidah Jantan ◽  
. .
Keyword(s):  
Genetic Algorithm ◽  
Decision Making ◽  
Succession Planning ◽  
Fitness Function ◽  
Academic Staff ◽  
Fitness Value ◽  
Selection Decision ◽  
The University ◽  
Hierarchy Process

Succession planning is a subset of talent management that deals with multi-criteria and uncertainties which are quite complicated, ambiguous, fuzzy and troublesome. Besides that, the successor selection involves the process of searching the best candidate for a successor for an optimal selection decision. In an academic scenario, the quality of academic staff contributes to achieving goals and improving the performance of the university at the international level. The process of selecting appropriate academic staff requires good criteria in decision-making. The best candidate's position and criteria for the selection of academic staff is the responsibility of the Human Resource Management (HRM) to select the most suitable candidate for the required position. The various criteria that are involved in selecting academic staff includes research publication, teaching skills, personality, reputation and financial performance. Previously, most studies on multi-criteria decision-making adopt Fuzzy Analytical Hierarchy Process (FAHP). However, this method is more complex because it involved many steps and formula and may not produce the optimum results. Therefore, Genetic Algorithm (GA) is proposed in this research to address this problem in which a fitness function for the successor selection is based on the highest fitness value of each chromosome.    

Robust vibration control of flexible panel: modeling and simulation

2017 ◽  
Vol 14 (5) ◽  
pp. 433-442
Author(s):  
Aalya Banu ◽  
Asan G.A. Muthalif
Keyword(s):  
Robust Control ◽  
Vibration Control ◽  
Controller Design ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Parametric Uncertainty ◽  
Design Algorithm ◽  
Content Type ◽  
And Performance

Purpose This paper aims to develop a robust controller to control vibration of a thin plate attached with two piezoelectric patches in the presence of uncertainties in the mass of the plate. The main goal of this study is to tackle dynamic perturbation that could lead to modelling error in flexible structures. The controller is designed to suppress first and second modal vibrations. Design/methodology/approach Out of various robust control strategies, μ-synthesis controller design algorithm has been used for active vibration control of a simply supported thin place excited and actuated using two piezoelectric patches. Parametric uncertainty in the system is taken into account so that the robust system will be achieved by maximizing the complex stability radius of the closed-loop system. Effectiveness of the designed controller is validated through robust stability and performance analysis. Findings Results obtained from numerical simulation indicate that implementation of the designed controller can effectively suppress the vibration of the system at the first and second modal frequencies by 98.5 and 88.4 per cent, respectively, despite the presence of structural uncertainties. The designed controller has also shown satisfactory results in terms of robustness and performance. Originality/value Although vibration control in designing any structural system has been an active topic for decades, Ordinary fixed controllers designed based on nominal parameters do not take into account the uncertainties present in and around the system and hence lose their effectiveness when subjected to uncertainties. This paper fulfills an identified need to design a robust control system that accommodates uncertainties.

A Natural Evolution Based Numerical Optimisation Framework to Develop and Enhance Airfoil-Slat Arrangement

2019 ◽  
Author(s):  
Sushrut Kumar ◽  
Priyam Gupta ◽  
Raj Kumar Singh
Keyword(s):  
Genetic Algorithm ◽  
Fitness Function ◽  
Fuel Efficiency ◽  
Optimal Solution ◽  
Leading Edge ◽  
Initial Population ◽  
Invasive Weed ◽  
Fitness Value ◽  
Leading Edge Slats ◽  
Dynamics Simulations

Abstract Leading Edge Slats are popularly being put into practice due to their capability to provide a significant increase in the lift generated by the wing airfoil and decrease in the stall. Consequently, their optimum design is critical for increased fuel efficiency and minimized environmental impact. This paper attempts to develop and optimize the Leading-Edge Slat geometry and its orientation with respect to airfoil using Genetic Algorithm. The class of Genetic Algorithm implemented was Invasive Weed Optimization as it showed significant potential in converging design to an optimal solution. For the study, Clark Y was taken as test airfoil. Slats being aerodynamic devices require smooth contoured surfaces without any sharp deformities and accordingly Bézier airfoil parameterization method was used. The design process was initiated by producing an initial population of various profiles (chromosomes). These chromosomes are composed of genes which define and control the shape and orientation of the slat. Control points, Airfoil-Slat offset and relative chord angle were taken as genes for the framework and different profiles were acquired by randomly modifying the genes within a decided design space. To compare individual chromosomes and to evaluate their feasibility, the fitness function was determined using Computational Fluid Dynamics simulations conducted on OpenFOAM. The lift force at a constant angle of attack (AOA) was taken as fitness value. It was assigned to each chromosome and the process was then repeated in a loop for different profiles and the fittest wing slat arrangement was obtained which had an increase in CL by 78% and the stall angle improved to 22°. The framework was found capable of optimizing multi-element airfoil arrangements.

A Study on the Use of Reduced Order Models for Unsteady Fluid Dynamic Analysis of Flexible Structures

2012 ◽  
Author(s):  
L. Ebrahimnejad ◽  
H. Yadollahi Farsani ◽  
D. T. Valentine ◽  
K. D. Janoyan ◽  
P. Marzocca
Keyword(s):  
Dynamic Analysis ◽  
Cross Sections ◽  
Fluid Dynamic ◽  
Flexible Structures ◽  
Reduced Order Models ◽  
Computationally Efficient ◽  
Reduced Order ◽  
Long Span ◽  
Long Span Bridge ◽  
Unsteady Fluid

Reduced order models (ROMs) are computationally efficient techniques, which have been widely used for predicting unsteady aerodynamic response of airfoils and wings. However, they have not been applied extensively to perform unsteady fluid dynamic analysis of flexible structures in civil engineering. This paper discusses the application of reduced order computational fluid dynamics (CFD) model based on the eigensystem realization algorithm (ERA) in the aerodynamic analysis of flexible structures with arbitrary shaped cross sections. As an example of a civil structure we examine the GBB long-span bridge for which there are published experimental data. The aerodynamic impulse responses of the GBB Bridge are used to construct the ROM, and then the aerodynamic forces due to arbitrary inputs are evaluated and compared to those of the model coupled with an advanced CFD code. Results demonstrate reasonable prediction power and high computational efficiency of the technique that can serve for preliminary design, optimization and control purposes. The methodology described in this paper has wide application in many offshore engineering problems where flexible structures interact with unsteady fluid mechanical phenomena.

scholarly journals Genetic Algorithm for Scheduling of Laboratory Personnel

2001 ◽  
Vol 47 (1) ◽  
pp. 118-123 ◽  
Author(s):  
James C Boyd ◽  
John Savory
Keyword(s):  
Genetic Algorithm ◽  
Medical Center ◽  
Fitness Function ◽  
Visual Basic ◽  
Work Environments ◽  
Skilled Workers ◽  
Laboratory Personnel ◽  
Work Shift ◽  
Work Tasks ◽  
Genetic Algorithm Approach

Abstract Background: Staffing core laboratories with appropriate skilled workers requires a process to schedule these individuals so that all workstations are appropriately filled and all the skills of each worker are exercised periodically to maintain competence. Methods: We applied a genetic algorithm to scheduling laboratory personnel. Our program, developed in Visual Basic 4.0, maximizes the value of a fitness function that measures how well a given scheduling of individuals and their skills matches a set of work tasks for a given work shift. The user provides in an Excel spreadsheet the work tasks, individuals available to work on any given date, and skills each individual possesses. The user also specifies the work shift to be scheduled, the range of dates to be scheduled, the number of days that an individual stays on a given workstation before rotating, and various parameters for the genetic algorithm if they differ from the default values. Results: For >22 months, the program matched individuals to those tasks for which they were qualified and maintained personnel skills by rotating job duties. The schedules generated by the program allowed supervisory personnel to anticipate dates far in advance of when worker availability would be limited, so staffing could be adjusted. In addition, the program helped to identify skills for which too few individuals had been trained. This program has been well accepted by the staff in the clinical laboratories of a 670-bed university medical center, saving 37 h of labor per month, or approximately $11 000 per year, in time that supervisory personnel have spent developing work schedules. Conclusions: The genetic algorithm approach appears to be useful for scheduling in highly technical work environments that employ multiskilled workers.

scholarly journals GENETIC ALGORITHM-BASED CALIBRATION OF REDUCED ORDER GALERKIN MODELS

2011 ◽  
Vol 16 (1) ◽  
pp. 233-247 ◽  
Author(s):  
Witold Stankiewicz ◽  
Robert Roszaka ◽  
Marek Morzyńskia
Keyword(s):  
Genetic Algorithm ◽  
Bluff Body ◽  
Calibration Procedure ◽  
Galerkin Projection ◽  
Reduced Order Models ◽  
Data Set ◽  
Reduced Order ◽  
Low Dimensional ◽  
Fluid Behaviour ◽  
Proper Orthogonal

Low-dimensional models, allowing quick prediction of fluid behaviour, are key enablers of closed-loop flow control. Reduction of the model's dimension and inconsistency of high-fidelity data set and the reduced-order formulation lead to the decrease of accuracy. The quality of Reduced-Order Models might be improved by a calibration procedure. It leads to global optimization problem which consist in minimizing objective function like the prediction error of the model. In this paper, Reduced-Order Models of an incompressible flow around a bluff body are constructed, basing on Galerkin Projection of governing equations onto a space spanned by the most dominant eigenmodes of the Proper Orthogonal Decomposition (POD). Calibration of such models is done by adding to Galerkin System some linear and quadratic terms, which coefficients are estimated using Genetic Algorithm.

A novel optimal configuration of sensor and actuator using a non-linear integer programming genetic algorithm for active vibration control

2017 ◽  
Vol 28 (15) ◽  
pp. 2074-2081 ◽  
Author(s):  
Chunyou Zhang ◽  
Lihua Wang ◽  
Xiaoqiang Wu ◽  
Weijin Gao
Keyword(s):  
Genetic Algorithm ◽  
Integer Programming ◽  
Vibration Control ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Linear Quadratic ◽  
Linear Integer Programming ◽  
Optimal Criterion ◽  
Non Linear ◽  
Active Vibration

Due to widespread applications of a large number of flexible structures, to obtain the best dynamic control performance of a system, optimal locations of the actuators and sensors are necessary to be determined. This article proposes a novel optimal criterion for the actuators or sensors ensuring good controllability or observability of a structure, and also considering the remaining modes to control the spillover effect. Based on the proposed optimization criteria, a non-linear integer programming genetic algorithm is employed to achieve the optimal configurations. Active vibration control is investigated for a cantilever plate with the actuators in optimal positions to suppress the specified modes utilizing linear quadratic regulator controller. Several simulation results validate the efficiency and feasibility of the proposed optimal criteria.

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