Damping Control System Research Articles

Combined repetitive control system for active damping of forced vibrations

Combined repetitive control system for active damping of forced vibrations

Examination of a Magnetorheological Damper Control System with Vibration Energy Harvesting

Abstract The study deals with the experimental examination of a magnetorheological (MR) damper control system with vibration energy harvesting using a specially engineered electronic unit (EU). Unlike a typical MR damper control system, which requires an external energy source, the developed system is powered exclusively by energy extracted from a vibrating structure (mechanical system with one-degree-of freedom) and processed through the EU. The work describes the structure and functions of the EU, presents the test rig and the control algorithm implementation, and discusses the test results of the control system under harmonic kinematic excitations of low frequency range.

Performance monitoring and redesign of power system stabilizers based on system identification techniques

To maintain stable power system operation, damping control systems are used in conventional power plants, known as Power System Stabilizers (PSS). However, to derive suitable controller parameters, the current methods require dynamic models that are difficult to maintain and update, and in some cases, might not be available. This makes it challenging for grid operators to maintain system stability when the system is under stringent operating conditions or undergoes the loss of major transmission corridors, which would require a new stabilizer design to provide adequate damping.Leveraging the availability of real-time measurements and “probing” technologies, this paper provides a complementary approach that does not require power system simulation models, but is based on system identification techniques that allow to derive simple and accurate models based on data collected on the system. The proposed method allows to monitor the performance of damping controllers and even to perform redesign based on the models derived with system identification. The resulting redesign could be used to update PSS parameters and improve damping without the need of removing existing damping control systems from service.

Coupled Torsional–Transverse Vibration Reduction in Marine Propulsion Dynamics with Novel Approach Using Magnetorheological Damping and Adaptive Control System

Coupled Torsional–Transverse Vibration Reduction in Marine Propulsion Dynamics with Novel Approach Using Magnetorheological Damping and Adaptive Control System

Study on the effect of semi-active control method matching for truck cab and seat suspension on driver comfort

This paper proposes a novel solution for addressing the challenges of whole-body vibrations in the heavy truck industry. Despite the substantial growth in this industry, excessive fatigue, back pain, neck pain, and other illnesses caused by rough and bumpy roads remain a major concern for truck drivers. To mitigate these issues, this study develops a comprehensive vibration reduction system based on a near-zero stiffness seat suspension system and a semi-active ON-OFF damping control system for the cab and seat. The study also evaluates the sensitivity of seat and cab suspension to vibration comfort by developing a nonlinear vibration system mathematical model. Simulation analysis results demonstrate that the proposed system can significantly reduce whole-body vibration experienced by the driver, potentially enhancing driver comfort and reducing the risk of illness and injury. However, further experimental validation and optimization are needed to fully evaluate the system's effectiveness and feasibility in practice.

Research on a novel displacement-dependent semi-active valve damping control mechanism used in the seat suspension system

The passive suspension seats have been widely used in off-road vehicles, but the drivers still suffer from the greater vibration and shock transmitted from the rough road, adversely affecting the drivers’ health and vehicle handling safety. Although active suspension seats have been researched and developed in engineering and academia for more than 30 years, they have rarely been applied in the industry due to the complex electrical structures and high costs. In this paper, a novel valve damping control system (VDCS) used in the off-road vehicle seat suspension is proposed and studied, which is a mechanical semi-active damping control system without ECUs and sensors. Firstly, the structures and working principles of VDCS are described in detail. Then, the dynamics model of the seat suspension system with VDCS is established, and simulation and experimental research are performed to evaluate its shock and vibration isolation performance. The results show that a seat suspension with VDCS is much better for isolating vibrations and shocks than one with a traditional manual adjustment damper in the whole workspace.

Model of a Quarter Car Suspension with a Damper Containing Magnetorheological Fluid and with Damaged Parts Controlled by Backstepping Method

The work focuses on the minimization of the body deflection from its equilibrium position after a deflection by force applied to the wheel with the task of simulating obstacles encountered by the wheel. The model presents a quarter of the car’s suspension with a nonlinear spring and a damper with magnetorheological fluid, by which the damping of the suspension is modified. The system was created in harmony with Lyapunov’s stability. The model was designed using Matlab-Simulink. The model was designed for testing many different damaged parts of the suspension, for example, a spring or a damper. In further attempts, the model was tested for numerous damaged parts, and the sequence of events was different. The model was tested for different characteristics of springs and dampers and variable method deflection wheel from its equilibrium position such as force and displacement. This work discusses the detection of damage to the suspension along with the possibility of adapting the MR damper control system to avoid reducing the comfort and safety of the vehicle.

Research and numerical analysis of floating offshore wind turbine based on a novel extended tuned mass damper

Offshore wind turbines will be developed from shallow water to deep water to meet the rapid growth of wind power generation. Floating offshore wind turbine (FOWT) faces complex load challenges, which endanger its safety and service life. Hence, it is urgent to develop a novel damping device to improve the stability of FOWT. In this paper, a novel extended tuned mass damper (ETMD) is proposed. On this basis, a linear quadratic regulator is added to realize the design and simulation of the extended active tuned mass damper (EATMD) control system to reduce the surge response of FOWT. Numerical analysis shows that under the control of ETMD, the surge response of the tower is reduced by 73%, and the frequency modulation width is increased by 55%. Here, under the control of EATMD, the displacement, velocity, and acceleration of the surge response of the tower are decreased by 47.0%, 30.7%, and 24.2%, respectively.

Wide-area damping control system for large wind generation with multiple operational uncertainty

• Illustrates the contribution of wind generation, and investigates the influence of the grid-forming mode-based VSWT-DFIGs. • Coordinated design of wide-area damping controller for utility-scale wind generation power plants considering time delays uncertainty. • Optimization is used to optimize the parameters of damping controller. • Contains case studies on a large power system, including FACTS, and wind generation. • MATLAB/Simulink-based nonlinear simulations are performed, for variable wind speed, 3-phase faults, and dynamic load model. The large integration of wind generation resources into power systems may causes low-frequency oscillations and deterioration in power system stability. This paper presents a novel coordinated approach-based Wide-Area Damping Control System (WADCS) for large wind generation integrated power system, while taking into consideration of the operational uncertainties. The coordinated WADCS approach is used to enhance the damping of inter-area oscillations while maintaining the voltage and frequency in the prescribed range. In a coordinated WADCS, a wide-area damping controller is coordinated with the rotor side converter model of wind generation resources (WGRs). The Static compensator (STATCOM) is used to enhance voltage and reactive power support for WGRs. To provide the additional damping, a static synchronous series compensator (SSSC) is also employed with the WADCS. The geometric measures of controllability/observability and residues method is utilized to select the appropriate input control signals and optimal location of wide-area damping controller. A multi-objective grey wolf optimizer (MOGWO) algorithm is used to optimize the parameters of the wide-area damping controller to enhance the damping. MATLAB/Simulink-based nonlinear simulations are performed considering operational uncertainties such as variable wind speed, 3-phase faults, variable load, and time delays to demonstrate the efficacy of the proposed coordinated control for modified WGRs integrated test power system.

Spontaneous electricity and electromagnetic damping control system for fitness equipment

Strength quality can reflect the physical quality, strength forging plays a positive role to maintain a strong body and abundant energy. The transmission system of traditional fitness equipment, such as electric treadmill and bicycle fitness device, are difficult to achieve the force training effect of simulating the rapid change of resistance like wind gust change and slope change automatically according to the pre-programmed curve changes in real time or speed. Combined with the current situation and existing problems of fitness equipment at home and abroad, this paper develops a self-generating power generation and electromagnetic damping control system that does not require external power supply, also has intelligent charge and discharge function, which can adjust the resistance output in real time. The system, which takes permanent magnetic synchronous generator as the resistance source, can replace the complex mechanical resistance structure and some electric resistance structure, and is widely used in the fitness equipment such as treadmill and bicycle trainer.

Advanced Prototype of an Electrical Control Unit for an MR Damper Powered by Energy Harvested from Vibrations

The work deals with a newly developed prototype of an electrical control unit (ECU) for a magnetorheological (MR) damper powered by energy harvested from vibrations. The ECU, consisting of a rectifying bridge, a driver unit, a microcontroller, and an internal power supply system, is an advanced version of the specially designed processing system for energy harvested from vibrations and the use of this energy to control the MR damper. Unlike a typical MR damper control system in which electrical circuits are powered from an external energy source, the ECU is powered by a part of the energy extracted from a vibrating system using an electromagnetic harvester. However, the excess amount of energy recovered over that necessary to power the MR damper and electrical circuits can be collected in harvested energy storage. The study presents the design concept of the ECU, computer simulations of the in-built driver unit (DU), the method of connecting the ECU with the harvester, the MR damper and displacement sensors, and also describes experimental tests of the engineered unit applied in a vibration reduction system (VRS) with an energy recovery function.

Effect of Control–Structure Interaction Using Torsional Servomotor for Active Tuned Mass Damper Control System

The control–structure interaction (CSI) affects the performance and robustness of protective structures in active control system, and it is important to consider the CSI effect to achieve high performance in structural vibration control. In this paper, the electro-mechanical model of the torsional servomotor is derived by establishing dynamic voltage equilibrium equation. Three different active control models (non-CSI, reduced-order CSI, and higher-order CSI model) which considering different accuracy requirements of the electro-mechanical relationship are established to investigate the influence of the CSI on active tuned mass damper (ATMD) control system. The frequency- and time-domain responses of a three-story steel frame structure during different excitations are investigated, and as a comparison, the responses of the uncontrolled and tuned mass damper (TMD) control system are also studied. It can be concluded that the control performance of the active control system is reduced due to the CSI effect, especially at resonance frequency region of the structure (around 2.7 Hz, 8.2 Hz, and 13.2 Hz). The input voltage, velocity of the top floor, velocity of active mass, and higher-order of control forces have an important influence on the servomotor output control force. Furthermore, it can be found that, to achieve the same control effect, the required control voltage has been significantly increased due to the CSI effect.

The true potential of nonlinear stiffness for point absorbing wave energy converters

A spherical point absorbing wave energy converter was simulated in floating and submerged conditions for regular and irregular waves. A nonlinear stiffness was included to augment a linear stiffness and damper control system. The linear control parameters were optimised for each regular and irregular wave condition. The optimal linear control stiffness for the floating system was negative to counteract the hydrostatic stiffness. The nonlinear stiffness was shown to increase the converted power if no linear control stiffness was used, and reduce the converted power if optimal linear control parameters were used for regular waves. Similarly, for irregular conditions, nonlinear stiffness degrades the performance of the system when compared to optimised parameters, but enhances the robustness of the system to changing sea states and stochastic phases. Therefore, a nonlinear stiffness mechanism may improve the power output for poorly tuned control systems arising from plant uncertainty for point absorbing wave energy converters.

Control damping for elastic vibrations of a distributed system with the sensor - actuator overcharge

This project develops the modal control system for vibration damping of an elastic object with distributed parameters. Non-controllable upper modes excitement sets a limit on control efficiency of individual lowest elastic mode damping. The study tests the control operability in relation to the changing sensor - actuator number while the feedback loops remains the same. Simulation results show spillover effect degradation in case the sensor - actuator overcharge. Control algorithm includes of identification procedure instead of de signing with the object model assistance. The present procedure puts the modal matrices to separate the inherent object modes from the sensor signals and to suppress the modes using the actuators.

Venice Keeps Adriatic at Bay [Engineering flood defence

Hydraulics company Enerpac created caissons for three of the four barriers. It developed a damping and levelling control system, with four cylinders at each corner of the caisson and hydraulic accumulators, which absorb forces as the huge structure is placed onto metal sliding plates mounted on concrete mats positioned on the seabed. The control system cushions the momentum caused by lowering the caisson and an algorithm stops residual wave momentum from dislodging the caisson while it is being positioned. A watertight seal between caissons allows a service tunnel for maintenance once the project is complete. Construction work for the MOSE project began in 2003 and was scheduled to be completed in 2011, but delays - from environmental and conservationist challenges as well as bribery and corruption scandals, have resulted in a 10-year slippage and an increase in budget from euro1.6bn to euro5.5bn (around £4.8bn). Raising the gates takes 30 minutes and they remain closed for around four to five hours each time. The barriers have been tested every day since December last year, when they proved effective against high tides of 1.35m. The barriers are raised when there is a forecast of high water above 1.3m. In December 2020, incorrect forecasts of 1.2m-high tides meant that the gates were not raised and 1.37m-high waters flooded parts of the city. At the time, Venice's mayor, Luigi Brugnaro, said that the project is still being tested and that protocols would be developed to activate the defence system sooner. It was activated again shortly afterwards to protect the city from a 1.2m tide the following week. MOSE is scheduled to be fully operational by the end of this year to protect historic buildings and Venetians' businesses from the Adriatic Sea.

Study on human-induced vibration of a cable-stayed bridge without backstays located in abrupt valley

This research aims to assess the pedestrian comfort and to control human-induced vibration of an arch tower cable-stayed bridge without backstays located in canyon. Dynamic simulations of human-induced vibration were carried out with a mode-by-mode approach, and the results indicated that a total of seven lateral and vertical modes of the bridge may suffer from excessive vibrations at the design crowd density. Based on the periodic walking force, the structure response under pedestrian loads was evaluated performing dynamic analyses with two Finite Element models of the footbridge. A single tuned mass damper (STMD) control system was developed for control of human-induced vibration, which consisted of four tuned mass dampers mounted on the mid-span of bridge to enhance damping ratios of lively modes. The results indicate that the maximum acceleration for the first-order lateral and second-order vertical vibration at the design crowd density exceed the associated threshold values referring to the comfort level 1 (CL1) Criteria. The critical pedestrian number of lateral dynamic instability estimated by the Dallard’s empirical formula is much smaller than the dynamic design pedestrian number; and the Dallard’s empirical formula is applicable to estimate the critical pedestrian number of lateral dynamic instability for this bridge by comparing with Pedroe Inês footbridge. The damping ratios for both the vertical and lateral modes increase appreciably after installing the tuned mass dampers and no evidence of large-amplitude vibrations has been observed, leading to the realization of satisfactory comfort levels, which can provide reference for vibration reduction design of this kind of bridge.

Performance-based optimization of LQR for active mass damper using symbiotic organisms search

The linear-quadratic regulator (LQR) has been applied to structural vibration control for decades; however, selection of the weighting matrices of an LQR mostly depends on trial and error. In this study, a novel metaheuristic optimization method named as symbiotic organisms search (SOS) algorithm is applied to tuning LQR weighting matrices for active mass damper (AMD) control systems. A 10-story shear building with an active mass damper installed at the top is adopted as a benchmark for numerical simulation in order to realize the optimization performance considering three objective functions for mitigation of structural acceleration. Two common optimization methods including genetic algorithm (GA), and particle swarm optimization (PSO) are also applied to this benchmark for comparison purposes. Numerical simulation results indicate that SOS is superior to GA and PSO on searching the minimized solution of the three objective functions. Meanwhile, minimizing the square root of the sum of the squares of peak modal acceleration achieves the best control performance of structural acceleration among the three objective functions. In addition, force saturation is proposed and applied in the optimization process such that the control force level is close to the force capacity of AMD under specified earthquake intensity. Furthermore, the control performance of the optimized LQR is compared with that of the LQR designed by applying three common weighting selection methods when the 10-story building is subjected to various earthquake excitations. Simulation results demonstrate that the optimized LQR significantly outperforms the three LQRs on structural acceleration responses as expected and reduces story drift slightly better than the three LQRs. Finally, the performance-based optimized LQR is experimentally validated by conducting shake table testing in the laboratory. The experimental results and structural control performance are discussed and summarized thoroughly.

Research on Automatic Control System of MR Damper Based on Neural Network Algorithm

The use of MR dampers can achieve the absorption of harmful vibrations such as seismic waves that affect the structure of the building itself. The current control of the MR damper generally uses a pulse width modulation system to control the current input to the MR damper, thereby controlling the MR damper. But this is a semi-automatic control method, and the error is relatively large. This article introduces an MR damper control system that introduces a neural network algorithm. The system uses a half-bridge drive circuit for output current control in the circuit part and uses the Shen BP network algorithm for numerical prediction and fitting. The experimental research and tests conducted in the project show that the use of this fuzzy algorithm can make the MR damper achieve good damping effects under different conditions, and can well improve the original semi-automatic control method.

Parameter identification of Bouc-Wen model for Magnetorheological (MR) fluid Damper by a Novel Genetic Algorithm

In this research, novel genetic algorithm (nGA) is proposed for Bouc-Wen modle parameters esstimation for magnetorheological (MR) fluid dampers. The optimization efficiency is improved by modifying the crossover and mutation steps of a GA. In the crossover stage, the probability of reproducing offspring from the same parent (same mother and father chromosome) is done to be zero, which may happen in the standard GA, and the probability of a chromosome to be selected for mating is based on error rank weighting of the chromosomes. Additional fitness evaluation of chromosomes will take place in between the crossover and mutation steps to save the best chromosome found so far, which is not implemented in the standard genetic algorithm (GA). The model is validated by comparing its simulation output force ( Fsim) with experimentally generated MR damper force ( Fexp). The mean absolute error, standard deviation and number of generations for convergence are taken as a criterias for performance evaluation. With these ctriterias, the proposed novel GA outperform better than the other researches. The accuracy is improved by 46.67% compared to standard GA. The proposed novel GA for Bouc-Wen model parameter identification can be used for any MR damper control system with better accuracy.

The Dynamic Models, Control Strategies and Applications for Magnetorheological Damping Systems: A Systematic Review

The magnetorheological (MR) damping devices have attracted an increasing amount of attention in the field of vibration control for their excellent performance of the vibration absorption. Systematically, the constitutive mechanical models of the MR fluids affect the control accuracy for the control strategies and the applications of the MR dampers. This work elaborately gives a systematic review on the control issues with the MR devices, thus, covering the dynamic models of the MR dampers, the state-of-the-art research, and the damping control strategies and its applications, which provide the necessary fundamental theories and the references for the damping control design of an MR damping device. According to the advanced degree of the control algorithms that are discussed in detail, they can be classified into three categories, namely, the classical control algorithms, the advanced control algorithms, and the intelligent control algorithms. The damping control strategies determine the control quality, which is the soul of an MR damping control system. There is still room to improve the algorithm for the controller for MR dampers. Employing the smart algorithms of machine learning, the work directs much more attention to the foundational research on the application of the artificial intelligence algorithms in damping control, outlining a perspective to combine the advantages of the individual different intelligent algorithms that could be an alternative solution to control of an MR damping device for the complex problems.