scholarly journals Active Vibration Control of Cantilever Beam by Using Optimal LQR Controller

2018 ◽  
Vol 24 (11) ◽  
pp. 1
Author(s):  
Hadeer Abd UL-Qader Mohammed ◽  
Hatem Rahem Wasmi

Many of mechanical systems are exposed to undesired vibrations, so designing an active vibration control (AVC) system is important in engineering decisions to reduce this vibration. Smart structure technology is used for vibration reduction. Therefore, the cantilever beam is embedded by a piezoelectric (PZT) as an actuator. The optimal LQR controller is designed that reduce the vibration of the smart beam by using a PZT element.   In this study the main part is to change the length of the aluminum cantilever beam, so keep the control gains, the excitation, the actuation voltage, and mechanical properties of the aluminum beam for each length of the smart cantilever beam and observe the behavior and effect of changing the length of the smart cantilever beam. A cantilever beam with piezoelectric is modeled in Mechanical APDL ANSYS version 15.0 and verified this by using experimental work. The AVC was tested on a smart beam under different control gains in experimental work and chose the best control gain depending on FEM results for each length of the smart beam. The response of the smart beam is noticed to be different for every length and the reduction percentage for settling time was different for every length.  

2020 ◽  
Vol 10 (6) ◽  
pp. 6549-6556
Author(s):  
K. G. Aktas ◽  
I. Esen

The aim of this study is to design a Linear Quadratic Regulator (LQR) controller for the active vibration control of a smart flexible cantilever beam. The mathematical model of the smart beam was created on the basis of the Euler-Bernoulli beam theory and the piezoelectric theory. State-space and finite element models used in the LQR controller design were developed. In the finite element model of the smart beam containing piezoelectric sensors and actuators, the beam was divided into ten finite elements. Each element had two nodes and two degrees of freedom were defined for each node, transverse displacement, and rotation. Two Piezoelectric ceramic lead Zirconate Titanate (PZT) patches were affixed to the upper and lower surfaces of the beam element as pairs of sensors and actuators. The location of the piezoelectric sensor and actuator pair changed and they were consecutively placed on the fixed part, the middle part, and the free end of the beam. In each case, the design of the LQR controller was made considering the first three dominant vibratory modes of the beam. The effect of the position of the sensor-actuator pair on the beam on the vibration damping capability of the controller was investigated. The best damping performance was found when the sensor-actuator pair was placed at the fixed end.


Author(s):  
Hao Jiang ◽  
Xinhua Long ◽  
Guang Meng

In this paper, a study on the active control of vibration for peripheral milling is presented. Different from the control for the vibrations of cutting tool or workpiece, in this effort, the relative vibration between the workpiece and tool is selected as the control target. To reduce the relative vibration, a two-axis active work-holding stage, which is droved by two piezo-actuators, is designed and the control system synthesis method is used to determine the control gain. By this method, the dynamical stage is considered as plant while the complicated cutting process is treated as disturbance. The cutting vibration control can be considered as a robust disturbance rejection problem (RDRP), and the controller design is based on robust servo-mechanism method. Without the requirement on the model of disturbance, this method simplifies the vibration control problem and only the knowledge of frequencies of disturbance is required. Numerical results indicate the implemented system works well in cutting vibration cancellation.


2018 ◽  
Vol 51 (25) ◽  
pp. 441-446
Author(s):  
Peng Wang ◽  
Gerard Scorletti ◽  
Anton Korniienko ◽  
Manuel Collet

2017 ◽  
Vol 28 (18) ◽  
pp. 2603-2616 ◽  
Author(s):  
Asif Khan ◽  
Hyun Sung Lee ◽  
Heung Soo Kim

In this article, the effect of a sensor-debonding failure on the active vibration control of a smart composite plate is investigated numerically. A mathematical model of the smart structure with a partially debonded piezoelectric sensor is developed using an improved layerwise theory, a higher-order electric-potential field that serves as the displacement field, and the potential variation through the piezoelectric patches. A state-space form that is based on the reduced-order model is employed for the controller design. A control strategy with a constant gain and velocity feedback is used to assess the vibration-control characteristics of the controller in the presence of the sensor-debonding failure. The obtained results show that sensor-debonding failure reduces the sensor-output, control-input signal, and active damping in magnitude that successively degrades the vibration attenuation capability of the active vibration controller. The settling time and relative tip displacement of the controlled structure increase with the increasing length of partial debonding between the piezoelectric sensor and host structure. Furthermore, a damage-sensitive feature along with multidimensional scaling showed excellent results for the detection and quantification of sensor-debonding failure in the active vibration control of smart structures.


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