Active Vibration Control of the Axially Moving String by Wave Cancellation

1993 ◽  
Author(s):  
C. H. Chung ◽  
C. A. Tan
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Closed Form Expression ◽  
Control Law ◽  
Closed Loop System ◽  
Controlled System ◽  
Axially Moving String ◽  
Active Vibration ◽  
Axially Moving ◽  
Actuation Devices

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.

Active Vibration Control of the Axially Moving String by Wave Cancellation

1995 ◽  
Vol 117 (1) ◽  
pp. 49-55 ◽  
Author(s):  
C. H. Chung ◽  
C. A. Tan
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Closed Form Expression ◽  
Control Law ◽  
Vibration Modes ◽  
Controlled System ◽  
Axially Moving String ◽  
Active Vibration ◽  
Axially Moving ◽  
Actuation Devices

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.

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
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Active Vibration Control ◽  
Stabilizing Controller ◽  
Axially Moving String ◽  
The Laplace Transform ◽  
Modes Of Vibration ◽  
Active Vibration ◽  
Axially Moving ◽  
Actuation Devices

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.

Active Vibration Control of the Axially Moving String Using Space Feedforward and Feedback Controllers

1996 ◽  
Vol 118 (3) ◽  
pp. 306-312 ◽  
Author(s):  
S. Ying ◽  
C. A. Tan
Keyword(s):  
Vibration Control ◽  
Feedforward Control ◽  
Active Vibration Control ◽  
Upstream Region ◽  
Control Force ◽  
Feedback Controllers ◽  
Axially Moving String ◽  
Downstream Region ◽  
Active Vibration ◽  
Axially Moving

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.

Boundary Control of an Axially Moving String Via Lyapunov Method

1999 ◽  
Vol 121 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Rong-Fong Fung ◽  
Chun-Chang Tseng
Keyword(s):  
Boundary Control ◽  
Lyapunov Method ◽  
Sliding Mode ◽  
Semigroup Theory ◽  
Active Vibration Control ◽  
Nonlinear Partial Differential Equation ◽  
Distributed Parameter ◽  
Axially Moving String ◽  
Active Vibration ◽  
Axially Moving

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.

scholarly journals MIMO Active Vibration Control of Magnetically Suspended Flywheels for Satellite IPAC Service

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Junyoung Park ◽  
Alan Palazzolo ◽  
Raymond Beach
Keyword(s):  
Vibration Control ◽  
Attitude Control ◽  
High Frequency ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Control Law ◽  
Frequency Noise ◽  
Active Vibration ◽  
Simulation Results ◽  
And Control

Theory and simulation results have demonstrated that four, variable speed flywheels could potentially provide the energy storage and attitude control functions of existing batteries and control moment gyros on a satellite. Past modeling and control algorithms were based on the assumption of rigidity in the flywheel’s bearings and the satellite structure. This paper provides simulation results and theory, which eliminates this assumption utilizing control algorithms for active vibration control (AVC), flywheel shaft levitation, and integrated power transfer and attitude control (IPAC), that are effective even with low stiffness active magnetic bearings (AMBs) and flexible satellite appendages. The flywheel AVC and levitation tasks are provided by a multiple input–multiple output control law that enhances stability by reducing the dependence of the forward and backward gyroscopic poles with changes in flywheel speed. The control law is shown to be effective even for (1) large polar to transverse inertia ratios, which increases the stored energy density while causing the poles to become more speed dependent, and for (2) low bandwidth controllers shaped to suppress high frequency noise. Passive vibration dampers are designed to reduce the vibrations of flexible appendages of the satellite. Notch, low-pass, and bandpass filters are implemented in the AMB system to reduce and cancel high frequency, dynamic bearing forces and motor torques due to flywheel mass imbalance. Successful IPAC simulation results are presented with a 12% initial attitude error, large polar to transverse inertia ratio (IP∕IT), structural flexibility, and unbalance mass disturbance.

Active Wave Cancellation of the Axially Moving String

2001 ◽  
Author(s):  
Chin An Tan ◽  
Shenger Ying
Keyword(s):  
Boundary Conditions ◽  
Initial Conditions ◽  
General Boundary ◽  
Closed Form Expression ◽  
Control Law ◽  
General Boundary Conditions ◽  
Axially Moving String ◽  
Axially Moving ◽  
Active Wave ◽  
Control Forces

Abstract The active wave control of the linear, axially moving string with general boundary conditions is presented in this paper. Considerations of general boundary conditions are important from both practical and experimental viewpoints. The active control law is established by employing the idea of wave cancellation. An exact, closed-form expression for the transverse response of the controlled system, consisting of the flexible structure, the wave controller, and the sensing and actuation devices, is derived in the frequency domain. Two actuation forces, one upstream and one downstream of an excitation force, are applied. The proposed control law shows that all modes of the string are controlled and the vibration in the regions upstream and downstream of the control forces can be cancelled. However, these results are based on ideal conditions and the assumption of zero initial conditions at the non-fixed boundaries. Effects of non-zero boundary motions at the instant of application of the control forces are examined and the control is shown to be effective under these conditions. The stability and robustness of the control forces are improved by the introduction of a stabilization coefficient in the control law. The effectiveness, robustness and stability of the control forces are demonstrated by simulations and verified by experiments on axially moving belt drive and chain drive systems.

Vibration Control of a Beam Using the Nearly Optimal Control Algorithm with a Disturbance Force Observer

2001 ◽  
Vol 17 (4) ◽  
pp. 173-177
Author(s):  
Der-An Wang ◽  
Yii-Mai Huang
Keyword(s):  
Optimal Control ◽  
Feedback Control ◽  
Vibration Control ◽  
Feedforward Control ◽  
Active Vibration Control ◽  
Asymptotic Properties ◽  
Control Law ◽  
Flexible Beam ◽  
Active Vibration ◽  
Modal Space

ABSTRACTActive vibration control of a flexible beam subjected to arbitrary, unmeasurable disturbance forces is investigated in this paper. The concept of independent modal space control is adopted. Both the feedforward and feedback control is implemented here to reduce the beam vibration. Because of the existence of the disturbance forces, the feedforward control is applied by employing the idea of force cancellation. A modal space disturbance force observer is then established in this paper to observe the disturbance modal forces for the feedforward control. For obtaining the feedforward and feedback control gains with the optimal sense, the nearly optimal control law is derived, where the modal disturbance forces are regarded as additional states. The vibration control performances and the asymptotic properties of the control law are discussed.

Substructuring Dynamic Modeling and Active Vibration Control of a Smart Parallel Platform

2004 ◽  
Author(s):  
Xiaoyun Wang ◽  
James K. Mills
Keyword(s):  
Vibration Control ◽  
Dynamic Model ◽  
Motion Control ◽  
Dynamic Models ◽  
Active Vibration Control ◽  
System Dynamic ◽  
Control Law ◽  
Active Vibration ◽  
Parallel Platform ◽  
Simulation Results

A substructuring approach to derive dynamic models for closed-loop mechanisms is applied to model a flexible-link planar parallel platform with Lead Zirconate Titanate (PZT) transducers. The Lagrangian Finite Element (FE) formulation is used to model flexible linkages, in which translational and rotary degrees of freedom exist. Craig-Bampton mode sets are extracted from these FE models and then used to assemble the dynamic model of the planar parallel platform through the application of Lagrange’s equation and the Lagrange multiplier method. Electromechanical coupling models of surface-bonded PZT transducers with the host flexible linkages are introduced to the reduced order dynamic models of flexible linkages. The assembled system dynamic model with moderate model order can represent essential system dynamic behavior and maintain kinematic relationships of the planar parallel platform. A Proportional, Integral, and Derivative (PID) control law is used as the motion control law. Strain rate feedback (SRF) active vibration control is selected as the vibration control law. Motion control simulation results with active vibration control and simulation results without active vibration control are compared. The comparison shows the effectiveness of active vibration control.

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