Active vibration control by using the wave control concept

AbstractIn the paper, a theoretical analysis regarding foundation forces caused by dynamic air gap torques of converter-driven induction motors, influenced by active vibration control, is shown. Based on a plane model, where actuators are placed between the motor feet and steel frame foundation and where the vertical motor feet accelerations are controlled, a mathematical description in the time domain, Laplace domain, and Fourier domain is presented, as well as a block diagram for numerical simulation. A numerical example is shown, where a 2-pole induction motor (2 MW) is analyzed for different cases—motor directly mounted on a steel frame foundation (case 1), actuators between motor feet and foundation, operating passively (case 2) and actively (case 3). It could be shown, that with the presented active vibration control concept the foundation forces due to dynamic air gap torques can be clearly reduced.

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Active Vibration Control of a Double-Curved Shell Structure Using the Example of Stuttgart Smartshell

Volume 4: Dynamics, Control and Uncertainty, Parts A and B ◽

10.1115/imece2012-87803 ◽

2012 ◽

Cited By ~ 3

Author(s):

Martin Weickgenannt ◽

Oliver Sawodny ◽

Stefan Neuhaeuser ◽

Werner Sobek

Keyword(s):

Vibration Control ◽

Control Strategy ◽

Shell Structure ◽

Active Vibration Control ◽

Optimal Control Strategy ◽

Present Contribution ◽

Control Concept ◽

Hydraulic Cylinders ◽

Active Vibration ◽

System States

The present contribution deals with concepts for active vibration control of a thin double-curved shell structure. The structure, Stuttgart SmartShell, is located at the University of Stuttgart. It is made of softwood and is equipped with strain gages to determine the state of static and dynamic loading. Furthermore a force input is provided at the supports of the structure using hydraulic cylinders. Here a model-based two-degree-of-freedom control concept for vibration damping is presented which is based on a dynamical model derived from Finite Element simulations. The control strategy uses modal decoupling of the system states to enable the manipulation and damping of single eigenmodes. An optimal control strategy is chosen to dampen oscillations as quickly as possible while considering limitations on the force input and peak stresses. The proposed control algorithms are applied to the shell structure under consideration and their applicability is demonstrated by simulation and experimental results.

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Hybrid Wave/Mode Active Vibration Control of a Timoshenko Beam

Design Engineering and Computers and Information in Engineering, Parts A and B ◽

10.1115/imece2006-16344 ◽

2006 ◽

Author(s):

C. Mei

Keyword(s):

Vibration Control ◽

Timoshenko Beam ◽

Active Vibration Control ◽

Hybrid Approach ◽

Wave Mode ◽

Pole Placement ◽

Modal Control ◽

Hybrid Wave ◽

Active Vibration ◽

Wave Control

A hybrid approach to active vibration control is described in this paper. It combines elements of both wave and mode approaches to active control and is an attempt to improve on the performance of these approaches individually. In the proposed hybrid approach, wave control is first applied at one or more points in the structure. It is designed on the basis of the local behavior of the structure and is intended to absorb vibrational energy, especially at higher frequencies. Then modal control is applied, being designed on the basis of the modified global equations of motion of the structure-plus-wave-controller. These are now normally non-self-adjoint. Because the higher order modes are relatively well damped, hybrid control improves the model accuracy and the robustness of the system and gives better broadband vibration attenuation performance. Hybrid wave/mode active vibration control is described with specific reference to the control of bending vibrations in a Timoshenko beam. The particular case considered is that of collocated, point force/sensor feedback wave control combined with modal control designed using pole placement. Numerical results are presented.

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