H ∞ Robust Control of Flexible Beam Vibration by Using a Hybrid Damper

1996 ◽  
Vol 118 (3) ◽  
pp. 643-648 ◽  
Author(s):  
Chong-Won Lee ◽  
Won-Ho Jee
Keyword(s):  
Robust Control ◽  
Laboratory Test ◽  
Cantilever Beam ◽  
Large Amplitude ◽  
Vibration Absorber ◽  
Flexible Beam ◽  
Test Rig ◽  
Control Scheme ◽  
Large Amplitude Vibrations ◽  
Hybrid Damper

A new hybrid damper is proposed to suppress the vibration of a flexible cantilever beam at its free end. It consists of an active piezoelectric-type servo-damper and a passive dampled vibration absorber to effectively suppress both the small and large amplitude vibrations. The H∞ control scheme is successfully applied to a laboratory test rig equipped with the hybrid damper when its overhung length is continually changed.

Development of Laboratory Model of Wind Turbine's Tower-Nacelle System with Magnetorheological Tuned Vibration Absorber

2013 ◽  
Vol 208 ◽  
pp. 40-51 ◽  
Author(s):  
Paweł Martynowicz
Keyword(s):  
Laboratory Test ◽  
Mr Damper ◽  
Laboratory Model ◽  
Vibration Absorber ◽  
Model Parameters ◽  
Test Rig ◽  
Development Stages ◽  
Modes Of Vibration ◽  
System Uncertainties ◽  
Tuned Vibration Absorber

The paper addresses the consecutive development stages of laboratory model of wind turbines tower-nacelle system with horizontally aligned tuned vibration absorber at its top. To cope with system uncertainties and possibly multiple modes of vibration, tuned vibration absorber is equipped with MR damper instead of passive viscous one. Several laboratory model constraints have to be fulfilled. Discrete frequency-based and Comsol-Simulink analyses were conducted to determine and verify model parameters. Finally, sketch of laboratory test rig design was presented.

Design of a Passive/Active Autoparametric Cantilever Beam Absorber With PZT Actuator for a Building-Like Structure

2013 ◽  
Author(s):  
H. F. Abundis-Fong ◽  
G. Silva-Navarro ◽  
B. Vazquez-Gonzalez
Keyword(s):  
Cantilever Beam ◽  
Primary Structure ◽  
Internal Resonance ◽  
Active Vibration Control ◽  
Parametric Uncertainty ◽  
Vibration Absorber ◽  
Control Scheme ◽  
Active Vibration ◽  
Stiffness And Damping ◽  
Sinusoidal Excitation

An experimental and theoretical investigation is carried out on a system consisting of a primary structure coupled with a passive/active autoparametric vibration absorber. The primary structure consists of a building-like mechanical structure with two rigid floors connected by flexible columns made from aluminium strips, while the vibration absorber consists of a cantilever beam with a PZT patch actuator cemented and actively controlled through an acquisition card installed on a PC running on a Matlab/Simulink platform. The overall system is then a coupled nonlinear oscillator subjected to sinusoidal excitation, obtained from an electromechanical shaker, in the neighborhood of its external and internal resonance. The addition of the PZT patch actuator to the cantilever beam absorber, cemented to the base of the beam, makes active the autoparametric vibration absorber, thus enabling the possibility to control the effective stiffness and damping associated to the passive absorber and, as a consequence, the implementation of an active vibration control scheme able to preserve, as possible, the autoparametric interaction as well as to compensate varying excitation frequencies and parametric uncertainty.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

2021 ◽  
pp. 095441002110136
Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Computationally Efficient ◽  
Control Scheme ◽  
Control Schemes ◽  
Adaptive Laws ◽  
Unknown Disturbances ◽  
The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

A nonlinear model of thick shells for large-amplitude vibrations

2021 ◽  
Vol 130 ◽  
pp. 103668
Author(s):  
Hamid Reza Moghaddasi ◽  
Mojtaba Azhari ◽  
Mohammad Mehdi Saadatpour ◽  
Saeid Sarrami-Foroushani
Keyword(s):  
Nonlinear Model ◽  
Large Amplitude ◽  
Large Amplitude Vibrations ◽  
Thick Shells

Parametrically Excited Electrostatic MEMS Cantilever Beam With Flexible Support

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Mark Pallay ◽  
Shahrzad Towfighian
Keyword(s):  
Cantilever Beam ◽  
Large Amplitude ◽  
Chaotic Behavior ◽  
Signal To Noise Ratio ◽  
Mass Sensors ◽  
Flexible Support ◽  
Sensing Applications ◽  
Electrostatic Mems ◽  
Fringe Fields ◽  
Steady State Amplitude

Parametric resonators that show large amplitude of vibration are highly desired for sensing applications. In this paper, a microelectromechanical system (MEMS) parametric resonator with a flexible support that uses electrostatic fringe fields to achieve resonance is introduced. The resonator shows a 50% increase in amplitude and a 50% decrease in threshold voltage compared with a fixed support cantilever model. The use of electrostatic fringe fields eliminates the risk of pull-in and allows for high amplitudes of vibration. We studied the effect of decreasing boundary stiffness on steady-state amplitude and found that below a threshold chaotic behavior can occur, which was verified by the information dimension of 0.59 and Poincaré maps. Hence, to achieve a large amplitude parametric resonator, the boundary stiffness should be decreased but should not go below a threshold when the chaotic response will appear. The resonator described in this paper uses a crab-leg spring attached to a cantilever beam to allow for both translation and rotation at the support. The presented study is useful in the design of mass sensors using parametric resonance (PR) to achieve large amplitude and signal-to-noise ratio.

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