Semi-active Vibration Control Research Articles

Decoupled Semiactive Vibration Control of Electrically Interconnected Suspension Based on Disturbance Compensation

Decoupled Semiactive Vibration Control of Electrically Interconnected Suspension Based on Disturbance Compensation

An Electromagnetic Negative Stiffness Spring With High Response Speed and Its Semiactive Vibration Control

An Electromagnetic Negative Stiffness Spring With High Response Speed and Its Semiactive Vibration Control

Pneumatické pružné hriadeľové spojky v pohonoch mechanických sústav

The article presents a newly developed pneumatic flexible shaft coupling with hose flexible element usable, among other applications, in drives of mechanical systems. The presented coupling uses a hose-shaped flexible element winding between the supporting surfaces of coupling’s driving and driven hub. As the torque transfer is ensured with compressed air, the torsional stiffness of coupling can be adapted to actual operating parameters (rotational speed) with change or air pressure inside the flexible elements. This makes the presented coupling suitable for semi-active torsional vibration control. A patent was also granted for the presented coupling design. The design of hose-shaped element enables reliable sealing of compression volume and it is also easy to assembly and dismantle.

Real-Time Integration of Identification and Semiactive Optimization Control for Mass Damper-Building Combined Systems under Known/Unknown Seismic Excitations

The integration of structural identification and vibration optimal control has been studied. Since the semiactive optimization vibrational control of civil structures needs to be implemented by massive control devices such as mass dampers, it is necessary to investigate the real-time integration of identification and semiactive optimization vibration control for mass damper-building combined systems. However, there is a lack of such studies in the literature. In this paper, a methodology is presented for real-time integration of identification and semiactive optimization vibration control of the mass damper-building combined system under known/unknown seismic excitations. For the combined system under known seismic excitations, the identification is implemented by the extended Kalman filter (EKF) using only partial structural acceleration responses. The identified structural state and parameters of mass damper-building systems are integrated in real time for the optimal control of systems by the linear-quadratic regulator (LQR) control algorithm and the Hrovat semiactive optimization control strategy via semiactive optimization mass dampers (SAMD). Then, it is extended to the scenario of unknown seismic excitations. The partially measured structural acceleration responses are absolute ones in this case, so the generalized extended Kalman filter with unknown input (GEKF-UI) developed by the authors is used to identify the structural input-state parameters of the mass dampers-building combined systems. The identification results are also integrated in real time for the semiactive optimization control of the combined system via SAMD. Two numerical simulation examples are used to test the proposed integration methods. It is shown that the proposed integration methods can reach almost the same optimal control effects as the conventional semiactive optimization control with known parameters of the mass damper-building combined systems under known/unknown seismic excitations.

Response Characteristics and Suppression of Transverse Vibrations of Mine Hoisting Conveyances Excited by Multiple Faults

The failures of steel guides can excite complex and intense transverse oscillations of hoisting containers in the mine hoisting process. The present paper mainly contributes to reveal the response characteristics of the transverse oscillations of mine conveyances excited by various faults such as interface misalignment, local bulge, orbital gap, bending deformation, and orbital tilt. First, a rigid-flexible coupled virtual prototype model between the conveyance and the steel guide was established. Subsequently, the vibration response characteristics of the container under various single and coupling excitations were simulated and analyzed. Eventually, a new type of roller cage shoe with a magnetorheological damper was put forward to decrease the transverse impact responses. Based on the hyperbolic tangent model of magnetorheological dampers, a semiactive fuzzy PID method was studied to explore the vibration suppression of the container. The results showed the fuzzy PID method can play a good role in the vibration reduction. This paper can give a fine scheme for the virtual simulation and semiactive vibration control of the mine hoisting system.

Enhanced Semi-active piezoelectric vibration control method with shunt circuit by energy dissipations switching

Piezoelectric vibration control holds the advantages of lightweight and anti-electromagnetic interference, and has broad application prospects in fields such as aerospace and mechanical engineering. A semi-active control method based on a piezoelectric smart cantilever beam with a passive shunt circuit is proposed for vibration control. The contribution is that the proposed semi-active control method is used to achieve energy dissipations switching by changing the piezoelectric electrical boundary conditions. The open-circuit state of piezoelectric materials corresponds to higher stiffness and dissipation of elastic potential energy, while the short-circuit state is accompanied by lower stiffness and dissipation of electrical energy. Firstly, the stiffness difference of different electrical boundary conditions of the piezoelectric materials is derived and its effect on the vibration characteristics is analyzed. Then, the proposed passive shunt circuit for the vibration control principle is analyzed, and the modeling of the piezoelectric smart cantilever beam with the passive shunt circuit is developed. Finally, a prototype is manufactured and the measurement system is constructed. The correctness and the feasibility of the semi-active vibration control method are verified by experiments, and the logarithmic damping coefficient is 0.8919. The superiority of the proposed shunt circuit is demonstrated experimentally with the comparison groups including depolarized comparison group and the common shunt circuits.

Application of metal rubber for semi-active vibration control of mechanical transmission systems

This study proposes a novel semi-active vibration control technique for mechanical transmission systems. The backbone of current research technology is the adaptive stiffness and damping properties of metal rubber (MR) which plays the role of tuning to the vibrational system eigenmodes. The adaptive properties of MR material were proved by a previous study, but the present research investigates the effect of this feature on the structural response and designs an MR-based semi-active vibration controller for industrial application. For this purpose, the semi-active control strategy is created based on an optimal tuning using experimental harmonic test results. The control strategy is applied in practice using a linear actuator controlled by a double pole double throw (DPDT) relay, and National Instruments hardware and software for reading data and writing the control task. The isolator attachment position is defined through the analysis of eigenmode shapes that are predetermined by numerical simulation. A maximum isolation rate of 55.17% is measured near the vibration isolator position. It is observed that the isolation position has a prominent effect on structure vibration behavior where the elastic wave has been reduced in amplitude by passing the isolator position. The effectiveness of the MR-based semi-active control approach is eminent and its application for vibration isolation of commercial mechanical transmission systems could be studied in the future.

Design and optimization of a new flow-mode magnetorheological mount with compact structure and extended workable force

Magnetorheological-fluid-based mount (MR mount) is a useful type of semi-active vibration control device that is extensively used in automotive, construction, and medical applications. However, these applications are usually limited by the workable force range of the MR mount. This paper proposed a new design of MR mount using multiple magnetic poles based on a compact valve structure. Then, a three-step optimization process with evaluation is applied into this mount design to find out the optimal mount design through a cost function damping-force-to-volume ratio (DFVR). Simulation results showed that this proposed MR mount obtained an excellent DFVR of 3.23×107 N m−3, which is significantly higher than those of other MR mounts. According to the high DFVR of this MR mount, it is obvious that this MR mount has compact structure and dimension, and high workable force. The proposed MR mount has strong potential for its utility in commercial applications.

Multi-Physics Simulation and Experimental Verification of Magnetorheological Damper with Additional Stiffness

Single-rod magneto-rheological dampers (MRD) have the advantages of a simple mechanism, high reliability, and broad application range. They are widely used in various semi-active vibration control fields. However, their working mode requires a compensating mechanism to perform volume compensation on the rod, leading to additional stiffness for the system. Ignoring this point makes it tough to establish an accurate mechanical model to describe its performance in the design stage, affecting its application. To address this issue, this study proposes a multi-physics simulation model based on gas compensation for single-rod MRD to characterize their mechanical performance accurately. Firstly, the mechanism and mechanical model of the single-rod gas compensation MRD are introduced. Secondly, considering that its performance is affected by the coupling effect of multiple physical fields, including magnetic, flow, and solid mechanics fields, the control equations and boundary conditions of each field are analyzed separately, and a multi-physics coupling simulation model is established by COMSOL. In particular, the gas compensation unit is considered in the multi-physics simulation model. The effect of the compensating mechanism on the mechanical performance of the damper under different excitation speeds, currents, and initial pressures is analyzed. Finally, the accuracy of the proposed method is verified through the demonstration power test. The results show that the simulation can describe the additional stiffness in the damper. The average error between experimental value and simulation value is 7%. This demonstrates the degree of agreement between the experiment and simulation.

Semi-active structural vibration control with magnetorheological damper based on hybrid fuzzy sliding mode controller

Recently, structural vibration control has proved its capacity to save lives and keep structures safe during earthquakes. Furthermore, there is a wealth of research in both numerical and experimental studies. As a result, due to its simplicity and performance in mitigating structural vibrations generated by ground motions, semi-active control played a significant role in the majority of these studies. Nonetheless, the magnetorheological damper is the most often used semi-active device. In particular, the rheological fluid properties have gained adequate attention in earthquake energy dissipation and structural vibrations management, particularly in the civil engineering field. The semi-active control of three scaled excited structures is addressed in this study. A magnetorheological damper operated by a hybrid fuzzy sliding mode controller ensures the proposed control. However, to provide the appropriate current for the damper to operate, this proposed intelligent controller is combined with a clipped optimum algorithm. Otherwise, the numerical simulation results of the seismic excited scaled structure demonstrate the resilience of the suggested controller. As a result, four time-scaled seismic data are applied to the tested structure. Finally, the usefulness of the suggested semi-active control technique in mitigating earthquake structural vibration is demonstrated clearly in the compared controlled and uncontrolled responses.

Development of integrated semi-active adaptive vibration control system for bridges subjected to traffic loads

Nowadays, the fluid viscous damper is the most conventional energy dissipation system implemented in bridge structures to control the vibrations due to traffic loads. However, to effectively protect the bridge against frequent and severer vibrations, it is required to adapt the function of the damper according to the variable traffic loads. In this research, an Integrated Semi-Active Adaptive Vibration Control System is developed for the bridge structures. This control system consists of a Semi-Active Bypass Fluid Damper (SABFD), a programmable logic controller (PLC), pressure transducers, and displacement sensors. Semi-Active Bypass Fluid Damper is a hydraulic cylinder with a pair of external bypass pipes with motorized electric flow control valves which are installed in the middle of pipes to control the flow rate of the fluid. A programmable logic controller (PLC) is implemented to manage the operation of motorized valves according to the movement of the bridge.Therefore, the integrated control system is able to function as a real-time controller during its operation. To develop the control system, the performance of the SABFD device has been assessed through analytical model of the various control valve positions. Then, according to the structure response, a fuzzy control algorithm has been adapted in the PLC controller.Afterward, the prototypes of the SABFD and the PLC controller have been fabricated and a series of cyclic load tests have been conducted by using a dynamic actuator. The outcomes of the numerical analysis and results of the experimental tests revealed that the developed device is capable of generating a wide range of forces during device operation. The developed fuzzy control algorithm is then implemented to the finite element model of the bridge equipped with SABFD, and the results proved that the real-time control system effectively limits the bridge displacements according to the pre-defined fuzzy control rules.

Semi-Active Vibration Control of Seat Suspension Equipped with a Variable Equivalent Inertance-Variable Damping Device

The seat suspension has a significant influence on riding comfort in many practical applications, such as heavy duty vehicles, military vehicles, and high-speed crafts. This paper proposes a seat suspension equipped with a variable equivalent inertance-variable damping (VEI–VD) device and a novel semi-active vibration control strategy. The VEI–VD device can control its equivalent inertance and damping by controlling two external resistors in its electric circuit. Especially, the VEI part of the device can store and release vibration energy via the inside flywheel, which enables the seat suspension to have a four-quadrant controllable capability in the available force–velocity diagram, similar to an active system. First, the dynamic model of the VEI–VD device is built, and a prototype is developed and tested to identify the model parameters and verify its characteristics. Then, a semi-active vibration control method is proposed for the VEI–VD seat suspension. The control method uses a sliding mode controller to acquire the desired control force for reducing vibration; then, according to the desired force and system states, the VEI–VD device is tuned by a force-tracking scheme to generate a real force. In the numerical validation, the vibration transmissibility of VEI–VD seat suspension around its natural frequency is tested with different states. The effectiveness of force-tracking control strategies for different types of suspensions is verified. In the random excitation test, the root means square acceleration of the VEI–VD seat is reduced by 30.72% compared with a passive seat. The VEI–VD seat suspension shows great potential in applications.

Research on Structure Design and Control Method of Magnetorheological Suspension Based on Improved Fruit Fly Optimization Algorithm

To reduce engine vibration, a semi-active controlled magnetorheological suspension is designed. First, the magnetic circuit of the new magnetorheological suspension is simulated. Furthermore, the non-parametric forward and inverse dynamic models of the magnetorheological suspension with the Elman neural network are established, where the modeling results and accuracy are analyzed. Second, according to the characteristics of semi-active vibration control of engine suspension, an improved fruit fly optimized proportional-integral-differential (PID) controller is proposed. Compared with the original fruit fly optimized PID controller and particle swarm optimization PID controller, the control strategies based on the proposed methods are simulated by MATLAB. Then, a vibration control experiment is carried out under different control strategies. The simulation and experiment results show that the PID controller based on the improved fruit fly optimization algorithm has the advantages of short adjustment time and fast dynamic response.

Intelligent Control Methodology for Smart Highway Bridge Structures Using Optimal Replicator Dynamic Controller

Control algorithms are an essential part of effective semi-active vibration control systems used for the protection of large structures under dynamic loading. Adaptive control algorithms, which are data-driven methods, have recently been developed to replace model-based control algorithms, thus improving efficiency. The dynamic parameters of semi-actively controlled infrastructures will change after significant vibration loading. As a result, these structures require real-time, effective control actions in response to changing conditions, which classical controllers are unable to provide. To improve the efficiency of the semi-active controller, the optimal control algorithm was developed in this study. The algorithm is the integration of the replicator dynamics with an improved non-dominated sorting genetic algorithm (NSGA), which is NSGA-II. The optimal parameters of replicator dynamics (total resources, growth rate, and fitness function), which represent the behavior of the actuators, were obtained through a multi-objective optimization process. The new control system was then used to reduce the vibrations of the isolated highway bridge, which is equipped with semi-active control devices known as MR dampers. Moreover, the current study improved the performance of the structural control system with minimum energy consumption by assigning a specific growth rate to each control device. In order to reduce the vibrations of the highway bridge, the results show that the performance of the optimal replicator controller is better than the performance of the classical control algorithms. Doi: 10.28991/CEJ-2023-09-01-01 Full Text: PDF

A Review Paper on Comparative Analysis on RCC Structure with Energy Dissipation Device and Composite Structure

Abstract: In recent years considerable attention has been paid to research and development of structural vibration control devices with particular emphasis on mitigation of wind and seismic response of buildings. Many vibration-control measures like passive, active, semi-active and hybrid vibration control methods have been developed. Base isolation is a passive vibration control system. The isolator partially reflects and partially absorbs input seismic energy before it gets transmitted to the superstructure. Lead rubber bearing isolators are placed between the superstructure and foundation, which reduces the horizontal stiffness of the system. It thereby increases the time period of the structure and decreases the spectral acceleration of the structure. The superstructure acts like a rigid body, thus inter storey drift is reduced. This study is concerned with the effects of various vertical irregularities on the seismic response of a structure and controls this response using base isolation. The objective of the study is to carry out response spectrum analysis. The predominant lateral loads acting upon building structures are earthquake and wind induced forces. If wind load is much greaterthan earthquake load, the lateral force resisting system required to tackle wind loading may be enough to resist the smaller earthquake load. In this situation, a seismic base isolator will not bring any benefit to the building system. Furthermore, if time period of a building without isolator is greater, incorporation of isolator will not bring much difference to the building behavior with respect to seismic load. Additionally, for buildings with lowerstructural time periods, incorporation of an isolator will greatly alter the seismic behavior

Design and evaluation of an MRF damper for semi-active vibration control of the machining processes

Cutting forces and vibrations generated during machining significantly affects the cutting tool and the integrity of the workpiece surface. Therefore, it is necessary to control or reduce those vibrations. Among the different vibration control methods, semi-active and active vibration control approaches are more effective than traditional methods. Also, with recent advancements in smart fluids and materials, the Magnetorheological fluid has gained attention in semi-active vibration control. In the present study, the novel monotube MRF damper is designed, fabricated, and evaluated for use in an end-milling process. The MRF damper has higher radial dimensions to develop a large damping force and reduce system complexity. The performance of a developed MRF damper is analyzed using the Bouc-Wen model, whose parameters are tuned for the developed MRF damper and validated experimentally under the different excitation currents, frequencies, and amplitude. The experimental and simulated damping forces are well agreed with each other, having a range of 13%–17%. The damper provides a maximum damping force of 1700 N under the excitation current of 2 A, and a frequency of 1 Hz at the amplitude of 8 mm. Moreover, it was also observed that the excitation current has a higher influence on the damping force than the frequency and amplitude. Thus, the developed MRF is further used in end-milling to reduce the cutting forces generated during the material removal, which shows that vibration damping significantly reduces 40%–65% of the cutting forces generated during the normal end-milling operation.

Vibration Suppression for Flexible Plate with Tunable Magnetically Controlled Joint Stiffness/Damping

Large flexible solar panels have the properties of light weight, low stiffness, and weak damping, which leads to low-frequency and large-amplitude vibrations. The existing vibration control methods of solar panels mainly adopt intelligent piezoelectric structures. However, the disadvantage is that the large stroke drive and control are limited. In the present study, a semi-active vibration control approach is proposed for flexible space solar panels based on magnetically controlled joints. The magnetic stiffness comes from the linear relationship between the joint output torque and rotation angle. The magnetic damping stems from the eddy current damping resulting from the relative motion between the permanent magnet rotor and the stator core of the joint. Firstly, the coupling dynamic modeling of a flexible plate and magnetic joints is established by adopting the Lagrange equation and the assumed mode approach. Secondly, semi-active vibration control simulations of the coupled system are performed. Meanwhile, the influence of the variable joint stiffness on the system frequency-shift effect is studied. Finally, the experimental platform is built, and simultaneously, non-contact permanent magnets and airflow are used to simulate single- and multi- frequency excitations, respectively. The experimental results indicate that, in the range of 0.06–0.343 Hz, magnetic damping is the leading factor with magnetic stiffness being the auxiliary. Additionally, it is also experimentally verified that the dual joint actuation has good synchronization. This study provides a new solution for the low-frequency vibration control of large flexible space structures.

Real-time neural network based semiactive model predictive control of structural vibrations

Semiactive model predictive control (sMPC) can be very effective, but its computational cost due to the inherent mixed-integer quadratic programming (MIQP) optimization precludes its use in real-time vibration control. This study proposes training neural networks (NNs) to predict in real-time only the MIQP’s integer variables’ values, called a strategy, for a given structure state. Because the number of strategies is exponential in the number of sMPC horizon steps, the resulting NN can be massive. This study proposes to reduce the NN dimension by exploiting the homogeneity-of-order-one nature of this control problem and, using state vector statistics, to efficiently choose training samples. The single large NN is proposed to be split into several much smaller NNs, each predicting a strategy grouping, that together uniquely and efficiently predict the strategy. Given the strategy’s integer values, the MIQP optimization reduces to a quadratic programming (QP) problem, solved using a fast QP solver with proposed adaptations: exploiting optimization efficiencies and bounding sub-optimality; using several NN predictions; and reverting to a simpler (suboptimal) semiactive control algorithm upon occasional incorrect NN predictions or QP solver nonconvergence. Shear building examples demonstrate significant online computational cost reductions with control performance comparable to the conventional MIQP-based control.

Semi-active control for 1 story building via a magnetorheological damper

This paper presents the development of semi-active vibration control via a magnetorheological damper of a seismically-excited 1-story building structure. The control scheme is based on a Proportional Integral Derivative Controller (PID) due to its solid performance and robustness in a wide variety of operating conditions. The PID goal is to reduce the displacement of the building through a magnetorheological damper installed between the first floor and the ground. Furthermore, this control law includes an online algebraic observer that estimates the unmeasured displacement and velocity. Indeed, the obtained expressions depend only on integrals of the measured acceleration output and the control input, which is useful for practical purposes. This approach is robust to measurement noise and provides the estimated states required by the PID controller. Simulation results validate the performance of the proposed scheme.

Semiactive vibration control for vibration reduction in buildings through ADRC

In this paper an Active Disturbance Reflection Control (ADRC) technique is proposed for semi-active vibration control for building structures. The ADRC objective is to reduce the displacement of the building, regulating the force of a magnetorheological damper to provide rigidity to the structure and thus cancel the effects of seismic disturbances. In addition, an algebraic state estimator is proposed to estimate the displacement and velocity required by the ARDC. Simulation results validate the performance of the proposed scheme.