Article

Genetic algorithms based adaptive active vibration control of a flexible structure

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Abstract

This paper investigates the development of an active vibration control (AVC) mechanism for a flexible plate structure using a genetic modelling strategy where the utilisation of genetic algorithms (GAs) for dynamic modelling of the system is considered. The global search technique of GAs is used to obtain a dynamic model of a flexible plate structure based on one-step-ahead (OSA) prediction and verified within the AVC system. The GA based AVC algorithm thus developed is implemented within a flexible plate simulation environment and its performance in the reduction of deflection at the centre of the plate is assessed. The validation of the algorithm is presented in both the time and frequency domains. An assessment of the results thus obtained is given in comparison to the AVC system using conventional recursive least squares (RLS) method. Investigations reveal that the developed GA based AVC system performs better in the suppression of vibration of a flexible plate structure compared to an RLS based AVC system.

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... Force is applied at distance, x, from the fixed end at time, t, and the resulting deflection from its stationary position is denoted by u(x,t) and y(x,t) respectively. The motion of the beam in transverse vibration is formulated by fourth-order partial differential equation (PDE) that yields the following equation [9] and [19]: ...
... Finite difference (FD) method is chosen to obtain the numerical solution of the PDE in Eq. (1). Simulations of flexible plate and beam via FD method are easy to implement and the method has been proven effective in investigating dynamics behavior of structures [4], [5], [9], [19] and [20]. The beam is discretized into a finite number of equal-length sections (segments), each of length, Δx, and the deflection of beam at the end of each segment is sampled at a constant time, Δt. ...
Article
This paper presents the development of dynamic model of a flexible beam structure using finite difference method. A Simple Proportional (P) control scheme is applied to suppress vibration at the tip of the flexible beam. The performance of P controller is studied by gradually increasing manually the proportional gain until significant attenuation of the vibration is observed. Then the controller is further extended to self-tune the proportional gain by using an intelligent mechanism known as Proportional Iterative Learning Algorithms (P-type ILA). The robustness of both controllers in suppressing the vibration is investigated by changing the beam's physical parameter, applying disturbance at different segments and amplitudes respectively. The simulation results clearly revealed the effectiveness and robustness of a self-tuning proportional control over conventional P control scheme as active vibration control of a flexible beam.
... Force is applied at distance, x, from the fixed end at time, t, and the resulting deflection from its stationary position is denoted by u(x,t) and y(x,t) respectively. The motion of the beam in transverse vibration is formulated by fourth-order partial differential equation (PDE) that yields the following equation [9] and [19]: ...
... Finite difference (FD) method is chosen to obtain the numerical solution of the PDE in Eq. (1). Simulations of flexible plate and beam via FD method are easy to implement and the method has been proven effective in investigating dynamics behavior of structures [4], [5], [9], [19] and [20]. The beam is discretized into a finite number of equal-length sections (segments), each of length, Δx, and the deflection of beam at the end of each segment is sampled at a constant time, Δt. ...
Article
Full-text available
This paper presents the development of dynamic model of a flexible beam structure using finite difference method. A Simple Proportional (P) control scheme is applied to suppress vibration at the tip of the flexible beam. The performance of P controller is studied by gradually increasing manually the proportional gain until significant attenuation of the vibration is observed. Then the controller is further extended to self-tune the proportional gain by using an intelligent mechanism known as Proportional Iterative Learning Algorithms (P-type ILA). The robustness of both controllers in suppressing the vibration is investigated by changing the beam's physical parameter, applying disturbance at different segments and amplitudes respectively. The simulation results clearly revealed the effectiveness and robustness of a self-tuning proportional control over conventional P control scheme as active vibration control of a flexible beam.
... GAs are computationally simple and are not limited by assumptions about the search space (Goldberg, 1989). GAs have been successfully applied to engineering search and optimization problems such as system identification (Kristinsson and Dumont, 1992; Li, 1999; Puangdownreong, 2006) and control (Darus, 2004; Hossain et al., 1995; Ghaffari et al., 2007). ...
... GAs are computationally simple and are not limited by assumptions about the search space (Goldberg, 1989). GAs have been successfully applied to engineering search and optimization problems such as system identification (Kristinsson and Dumont, 1992; Li, 1999; Puangdownreong, 2006) and control (Darus, 2004; Hossain et al., 1995; Ghaffari et al., 2007). ...
Article
This paper focuses on an identification technique based on genetic algorithms (GAs) with application to rectangular flexible plate systems for active vibration control. A real coded GA with a new truncation-based selection strategy of individuals is developed, to allow fast convergence to the global optimum. A simulation environment characterizing the dynamic behavior of a flexible rectangular plate system is developed using the central finite difference (FD) techniques. The plate thus developed is excited by a uniformly distributed random disturbance and the input–output data of the system acquired is used for black-box modeling the system with the GA optimization using an autoregressive model structure. Model validity tests based on statistical measures and output prediction are carried out. The prediction capability of the model is further examined with unseen data. It is demonstrated that the GA gives faster convergence to an optimum solution and the model obtained characterizes the dynamic system behavior of the system well.
... The motion of the beam in transverse vibration is, thus, governed by the well-known fourth-order partial differential equation (PDE) [14], [18] ...
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Yes This correspondence presents an investigation into the comparative performance of an active vibration control (AVC) system using a number of intelligent learning algorithms. Recursive least square (RLS), evolutionary genetic algorithms (GAs), general regression neural network (GRNN), and adaptive neuro-fuzzy inference system (ANFIS) algorithms are proposed to develop the mechanisms of an AVC system. The controller is designed on the basis of optimal vibration suppression using a plant model. A simulation platform of a flexible beam system in transverse vibration using a finite difference method is considered to demonstrate the capabilities of the AVC system using RLS, GAs, GRNN, and ANFIS. The simulation model of the AVC system is implemented, tested, and its performance is assessed for the system identification models using the proposed algorithms. Finally, a comparative performance of the algorithms in implementing the model of the AVC system is presented and discussed through a set of experiments.
... The motion of the beam in transverse vibration is, thus, governed by the well-known fourth-order partial differential equation (PDE) [14], [18] ...
Article
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Thesis
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