scholarly journals SEMI-ACTIVE PREDICTIVE CONTROL OF STRUCTURES WITH CONTROLLED STIFFNESS DEVICES AND VARIABLE FRICTION DAMPER SYSTEM

2010 ◽  
Vol 13 (4) ◽  
pp. 64-73
Author(s):  
Thang Quoc Chu ◽  
Hoa Nhan Pham ◽  
Ben Van Tran
Keyword(s):  
Active Control ◽  
Predictive Control ◽  
Control Algorithms ◽  
Friction Damper ◽  
Velocity Feedback ◽  
Numerical Examples ◽  
Acceleration Feedback ◽  
Variable Friction ◽  
Instantaneous Control

This paper presents two active control algorithms (Instantaneous Control with Displacement and Velocity Feedback (ICDVF) and Instantaneous Control with Velocity and Acceleration Feedback (ICAVF)) to control the structures eqquiped Controlled Stiffness Devices and Variable Friction Damper System. The numerical examples aim to evaluate the effect structure’s response reductions between the two algorithms as well as the principal and accessory role.

Control Concepts of Semi-Active Friction Dampers

2009 ◽  
Author(s):  
Lothar Gaul ◽  
Jens Becker
Keyword(s):  
Active Control ◽  
Relative Displacement ◽  
Structural Vibration ◽  
Control Algorithms ◽  
Friction Damper ◽  
Control Laws ◽  
Friction Dampers ◽  
Closed Loop Systems ◽  
Major Interest ◽  
Improving Accuracy

Reduction of structural vibrations is of major interest in mechanical engineering for lowering sound emission of vibrating structures, improving accuracy of machines and increasing structure durability. Besides design optimization and passive damping treatments, active structural vibration control can be applied to reduce unwanted vibrations. In this contribution, two semi-active control laws for control of friction dampers are derived and investigated in simulations and experiments. Thereby, semi-active control concepts have the advantage over active control to yield intrinsically stable closed-loop systems and low energy consumption. In the experimental implementation, the control makes use of piezoelectric stack actuators to apply adjustable normal forces between structure and attached friction dampers. The control uses an observer based on reduced finite-element models to estimate the unknown relative displacement beneath the normal force actuator from acceleration measurements. Experimental results of the control algorithms for a structure with attached friction damper show the effectiveness of the proposed control algorithms.

scholarly journals Development and Validation of Advanced Nonlinear Predictive Control Algorithms for Trajectory Tracking in Batch Polymerization

ACS Omega ◽  
2021 ◽  
Author(s):  
Prajwal Shettigar J ◽  
Kshetrimayum Lochan ◽  
Gautham Jeppu ◽  
Srinivas Palanki ◽  
Thirunavukkarasu Indiran
Keyword(s):  
Predictive Control ◽  
Trajectory Tracking ◽  
Control Algorithms ◽  
Nonlinear Predictive Control ◽  
Development And Validation

The Use of Damping Based Semi-Active Control Algorithms in the Mechanical Smart-Spring System

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Wander Gustavo Rocha Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Vibration Reduction ◽  
Flow Analysis ◽  
Coupled Systems ◽  
Control Technique ◽  
Control Algorithms ◽  
Control Techniques ◽  
Spring Mechanism

In recent decades, semi-active control strategies have been investigated for vibration reduction. In general, these techniques provide enhanced control performance when compared to traditional passive techniques and lower energy consumption if compared to active control techniques. In semi-active concepts, vibration attenuation is achieved by modulating inertial, stiffness, or damping properties of a dynamic system. The smart spring is a mechanical device originally employed for the effective modulation of its stiffness through the use of semi-active control strategies. This device has been successfully tested to damp aeroelastic oscillations of fixed and rotary wings. In this paper, the modeling of the smart spring mechanism is presented and two semi-active control algorithms are employed to promote vibration reduction through enhanced damping effects. The first control technique is the smart-spring resetting (SSR), which resembles resetting control techniques developed for vibration reduction of civil structures as well as the piezoelectric synchronized switch damping on short (SSDS) technique. The second control algorithm is referred to as the smart-spring inversion (SSI), which presents some similarities with the synchronized switch damping (SSD) on inductor technique previously presented in the literature of electromechanically coupled systems. The effects of the SSR and SSI control algorithms on the free and forced responses of the smart-spring are investigated in time and frequency domains. An energy flow analysis is also presented in order to explain the enhanced damping behavior when the SSI control algorithm is employed.

Frequency Shaped Semi-Active Control for Magnetorheological Fluid-Based Vibration Control Systems

2013 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Active Control ◽  
Control Algorithm ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Model Parameters ◽  
Mr Fluid ◽  
Control Current ◽  
Active Vibration

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.

Passive Variable Friction Damper for Increased Structural Resilience to Multi-Hazard Excitations

2018 ◽  
Author(s):  
Austin Downey ◽  
MohammadKazem Sadoughi ◽  
Liang Cao ◽  
Simon Laflamme ◽  
Chao Hu
Keyword(s):  
Structural Control ◽  
Seismic Event ◽  
Active Damping ◽  
Friction Damper ◽  
Strength Based ◽  
Story Drift ◽  
Variable Friction ◽  
Wind Events ◽  
Better Than ◽  
Damping Systems

Structural control systems, including passive, semi-active and active damping systems, are used to increase structural resilience to multi-hazard excitations. While semi-active and active damping systems have been investigated for the mitigation of multi-hazard excitations, their requirement for real-time controllers and power availability limit their usefulness. This work proposes the use of a newly developed passive variable friction device for the mitigation of multi-hazard events. This passive variable friction device, when installed in a structure, is capable of mitigating different hazards from wind and ground motions. In wind events, the device ensures serviceability, while during earthquake events, the device reduces the building’s inter-story drift to maintain strength-based motion requirements. Results show that the passive variable friction device performs better than a traditional friction damper during a seismic event while not compromising any performance during wind events.

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