Active Vibration Control of the Axially Moving String in the S Domain

1991 ◽  
Vol 58 (1) ◽  
pp. 189-196 ◽  
Author(s):  
B. Yang ◽  
C. D. Mote

A new method is presented for active vibration control of the axially moving string, one of the most common models of axially moving continua. The control is formulated in the Laplace transform domain. The transfer function of a closed-loop system, consisting of the plant, a feedback control law and the dynamics of the sensing and actuation devices, is derived. Analysis of the root loci of the closedloop system gives two stability criteria. Stabilizing controller design is carried out of both collocation and noncollocation of the sensor and actuator. It is found that all the modes of vibration can be stabilized and that in principle the spillover instability can be avoided. Also, the steady-state response of the stabilized string to periodic, external excitation is presented in closed form.

Author(s):  
C. H. Chung ◽  
C. A. Tan

Abstract Active vibration control of an axially moving string by wave cancellation is presented. The control problem is formulated in the frequency domain. An exact, closed-form expression for the transfer function of the closed-loop system, consisting of the flexible structure, a feedback control law and the dynamics of the sensing and actuation devices, is derived. It is shown that all vibration modes can be stabilized and that the controlled system has no resonance. Moreover, the designed controller is applicable to the control of the string transverse vibration under various kinds of loading and constraint conditions. Results for the response of the controlled string under different excitations are presented and discussed along with the wave propagation and cancellation characteristics.


1995 ◽  
Vol 117 (1) ◽  
pp. 49-55 ◽  
Author(s):  
C. H. Chung ◽  
C. A. Tan

Active vibration control of an axially moving string by wave cancellation is presented. The control problem is formulated in the frequency domain. An exact, closed-form expression for the transfer function of the controlled system, consisting of the flexible structure, a feedback control law and the dynamics of the sensing and actuation devices, is derived. It is shown that all vibration modes can be stabilized and that the controlled system has no resonance. Moreover, the designed controller is applicable to the control of the string transverse vibration under various kinds of loading and constraint conditions. Results for the response of the controlled string under different excitations are presented and discussed along with the wave propagation and cancellation characteristics.


1996 ◽  
Vol 118 (3) ◽  
pp. 306-312 ◽  
Author(s):  
S. Ying ◽  
C. A. Tan

Active vibration control of an axially moving string using space feedforward and feedback controllers is presented. Closed-form results for the transverse response of both the uncontrolled and controlled string are given in the s domain. The space feedforward controller is established by employing the idea of wave cancellation. The proposed control law indicates that vibration in the region downstream of the control force can be cancelled. With the space feedforward control, the mode shapes of the axially moving string are changed such that the free response tends to zero in the downstream region. An interesting physical interpretation is that the control force acts effectively as a holder (active support) which limits the vibration of the string to the upstream region and eliminates any vibration in the downstream region. Simulation results show that the response of the string to both sinusoidal and random excitations is suppressed by applying the space feedforward control. The feedback controller is introduced to attenuate the response of the string due to undesired disturbances in the downstream.


1999 ◽  
Vol 121 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Rong-Fong Fung ◽  
Chun-Chang Tseng

This paper presents the active vibration control of an axially moving string system through a mass-damper-spring (MDS) controller at its right-hand side (RHS) boundary. A nonlinear partial differential equation (PDE) describes a distributed parameter system (DPS) and directly selected as the object to be controlled. A new boundary control law is designed by sliding mode associated with Lyapunov method. It is shown that the boundary feedback states only include the displacement, velocity, and slope of the string at RHS boundary. Asymptotical stability of the control system is proved by the semigroup theory. Finally, finite difference scheme is used to validate the theoretical results.


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.


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.


1993 ◽  
Author(s):  
S. Jagannathan ◽  
A. B. Palazzolo ◽  
A. F. Kascak ◽  
G. T. Montague

A novel frequency-domain technique, having its roots in Quantitative Feedback Theory (QFT), has been developed to design controllers for active vibration control (AVC). The advantages are a plant-based design according to performance specifications, and the ability to include structured uncertainties in the critical plant parameters like passive bearing stiffness or damping. In this paper, we describe the background theory of single-input, single-output (SISO) and multi-input, multi-output (MIMO) QFT design, followed by development of the theory adapted for AVC. Application examples are considered next, outlining the design method for both cases. Simulation results for the systems studied are presented showing the effectiveness of the technique in attenuating vibration.


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