scholarly journals Active Vibration damping of Smart composite beams based on system identification technique

2018 ◽  
Vol 5 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Kouider Bendine ◽  
Zouaoui Satla ◽  
Farouk Benallel Boukhoulda ◽  
Mohammed Nouari

Abstract In the present paper, the active vibration control of a composite beam using piezoelectric actuator is investigated. The space state equation is determined using system identification technique based on the structure input output response provided by ANSYS APDL finite element package. The Linear Quadratic (LQG) control law is designed and integrated into ANSYS APDL to perform closed loop simulations. Numerical examples for different types of excitation loads are presented to test the efficiency and the accuracy of the proposed model.

Author(s):  
A. H. Daraji ◽  
J. M. Hale

This paper concerns optimal placement of discrete piezoelectric sensors and actuators for active vibration control, using a genetic algorithm based on minimization of linear quadratic index as an objective function. A new method is developed to get state space matrices for simple and complex structures with bonded sensors and actuators, using the ANSYS finite element package taking into account piezoelectric mass, stiffness and electromechanical coupling effects. The state space matrices for smart structures are highly important in active vibration control for the optimisation of sensor and actuator locations and investigation of open and closed loop system control response, both using simulation and experimentally. As an example, a flexible flat plate with bonded sensor/actuator pairs is represented in ANSYS using three dimensional SOLID45 elements for the passive structure and SOLID5 for the piezoelectric elements, from which the necessary state space matrices are obtained. To test the results, the plate is mounted as a cantilever and two sensor/actuator pairs are located at the optimal locations. These are used to attenuate the first six modes of vibration using active vibration reduction based on a classical and optimal linear quadratic control scheme. The plate is subject to forced vibration at the first, second and third natural frequencies and represented in ANSYS using a proportional derivative controller and compared with a Matlab model based on ANSYS state space matrices using linear quadratic control. It is shown that the ANSYS state space matrices describe the system efficiently and correctly.


2020 ◽  
Vol 53 (3-4) ◽  
pp. 531-540
Author(s):  
Tao Lai ◽  
Junfeng Liu

In order to improve the vibration responses of rotor system, this paper presents an active vibration control technique for a rotor-bearing-actuator system with the use of robust eigenvalue placement method. By analyzing the characteristics of the piezoelectric stack actuator, bearing and rotor, a rotor-bearing-actuator system is modeled. Based on this dynamical model, a reduced-order technique is used to establish the state equation in the modal space. A robust eigenvalue placement method, which can enhance the robustness of system to model error and uncertain factors by optimizing the close-loop eigenmatrix with a small condition number, is proposed to carry out the active vibration control for system. The good results indicate that the eigenvalue can be placed to precise position, and the displacement responses get effectively suppressed with the proposed method. Meanwhile, the optimized close-loop eigenmatrix can possess a small condition number, which means the system has achieved excellent robustness.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yi Yu ◽  
Xing Shen ◽  
Yun Huang

In wind tunnel tests, the cantilever sting is usually used to support aircraft models because of its simple structure and low aerodynamic interference. However, in some special conditions, big-amplitude and low-frequency vibration would occur easily on the model not only in the pitch direction but also in the yaw direction, resulting in inaccurate data and even damage of the supporting structure. In this paper, aiming at suppressing the vibration in pitch and yaw plane, a multidimensional system identification and active vibration control system on the basis of piezoelectric actuators is established. A vibration monitoring method based on the strain-displacement transformation (SDT) matrix is proposed, which can transform strain signals into vibration displacements. The system identification based on chirp-Z transform (CZT) is applied to improve the adaptability and precision of the building process for the system model. After that, the hardware platform as well as the software control system based on the classical proportional-derivative (PD) algorithm is built. A series of experiments are carried out, and the results show the exactness of the vibration monitoring method. The system identification process is completed, and the controller is designed. Vibration control experiments verify the effectiveness of the controller, and the results indicate that vibrations in pitch and yaw directions are attenuated apparently. The spectrum power is reduced over 14.8 dB/Hz, which prove that the multidimensional identification and active vibration control system has the capability to decline vibration from different directions.


2008 ◽  
Vol 47-50 ◽  
pp. 137-140 ◽  
Author(s):  
Jung Woo Sohn ◽  
Seung Bok Choi

In this paper, active vibration control performance of the smart hull structure with Macro-Fiber Composite (MFC) is evaluated. The governing equations of motion of the hull structure with MFC actuators are derived based on the classical Donnell-Mushtari shell theory. Subsequently, modal characteristics are investigated and compared with the results obtained from finite element analysis and experiment. The governing equations of vibration control system are then established and expressed in the state space form. Linear Quadratic Gaussian (LQG) control algorithm is designed in order to effectively and actively control the imposed vibration. The controller is experimentally realized and control performances are evaluated.


2017 ◽  
Vol 28 (15) ◽  
pp. 2074-2081 ◽  
Author(s):  
Chunyou Zhang ◽  
Lihua Wang ◽  
Xiaoqiang Wu ◽  
Weijin Gao

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.


2019 ◽  
Vol 224 ◽  
pp. 05010
Author(s):  
Yi Ye ◽  
Miaoxian Guo

In this paper, an active vibration control platform is developed for milling processes. In this system, the workpiece is driven by a specially designed active platform to control the relative vibration between the tool and workpiece during milling processes. Numerical simulations are carried out to validate the effectiveness of the control platform. Results indicate that maximum stress of the hinge mechanism of the platform is far less than the yield limit of the material, and the designed platform can meet the use requirements in terms of the maximum displacement and natural frequency.


Author(s):  
Zhang Xianmin ◽  
Song Li ◽  
Liu Jike

Abstract In this paper, a mathematical model for flexible robot manipulators with smart links featuring piezoelectric films is developed in conjunction with the finite element method. The dynamics of piezoelectric actuators and strain gage sensors bonded on the flexible links are presented for beam model. Theory and measures of active vibration control for flexible manipulators are studied based on the modal and modern control theory, and the correspondent optimal control scheme is proposed. The robust control low is formulated based on the modified independent modal control method and the Linear Quadratic theory. The computational method for the actual control moments and the control voltages are also presented.


Author(s):  
Nurul Bahiah Mohd Noor ◽  
Mohd Ridzuan Ahmad

Actuators based on smart materials such as piezoelectric actuators (PEAs) are widely used in many applications to transform electrical signal to mechanical signal and vice versa. However, the major drawbacks for these smart actuators are hysteresis nonlinear, creep and residual vibration. In this paper, PEAs are used for active vibration application. Therefore, a model of PEA must be established to control the vibration that occurs in the system. The frequencies of 1 Hz, 20 Hz and 50 Hz were tested on the PEAs. The results obtained from the experimental were used to develop transfer function model by employing system identification technique. Meanwhile, the model validation was based on level of models fitness to estimation data, mean squared error (MSE), final prediction error (FPE) and correlation test. The experimental result showed that the displacement of the actuator is inversely proportional to the frequency. The following consequences caused the time response criteria at 50 Hz achieved smallest overshoot and fastest response of rise time and settling time.


2012 ◽  
Vol 479-481 ◽  
pp. 1490-1494 ◽  
Author(s):  
Wen Bo Li ◽  
Xiao Ran Li ◽  
Zhi Gang Zhao ◽  
You Yi Wang ◽  
Yang Zhao

To solve the problem of active vibration control for satellite antenna reflector, which is weak damping and closely spaced modes, the optimal actuators/sensors deployment and controller designing need to be considered. Firstly, the optimal criterions of controllability and observability are designed according to the specificity of Gram Matrix eigenvalue in satellite antenna system equations. Secondly, based on the above criterions, piezoelectric materials (as sensors and actuators) and genetic algorithm are utilized to optimize the deployed locations of sensors and actuators. Finally, to suppress the vibration of satellite antenna reflector, a Linear Quadratic Gaussian (LQG) controller is designed under the impulse and white noise excitation respectively. The simulate results show the effectively deployed locations of sensors and actuators, and the correctness of designed LQG controller.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xing Shen ◽  
Yuke Dai ◽  
Mingxuan Chen ◽  
Lei Zhang ◽  
Li Yu

In wind tunnel tests, cantilever stings are often used as model-mount in order to reduce flow interference on experimental data. In this case, however, large-amplitude vibration and low-frequency vibration are easily produced on the system, which indicates the potential hazards of gaining inaccurate data and even damaging the structure. This paper details three algorithms, respectively, Classical PD Algorithm, Artificial Neural Network PID (NNPID), and Linear Quadratic Regulator (LQR) Optimal Control Algorithm, which can realize active vibration control of sting used in wind tunnel. The hardware platform of the first-order vibration damping system based on piezoelectric structure is set up and the real-time control software is designed to verify the feasibility and practicability of the algorithms. While the PD algorithm is the most common method in engineering, the results show that all the algorithms can achieve the purpose of over 80% reduction, and the last two algorithms perform even better. Besides, self-tuning is realized in NNPID, and with the help of the Observer/Kalman Filter Identification (OKID), LQR optimal control algorithm can make the control effort as small as possible. The paper proves the superiority of NNPID and LQR algorithms and can be an available reference for vibration control of wind tunnel system.


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