Approach For Active Vibration Control Research Articles

Data-driven model reduction approach for active vibration control of cable-strut structures

The cable-strut structures have the features of low stiffness and weak damping, resulting in large vibration response under dynamic excitation. The vibration response of the cable-strut structures can be reduced by active control methods. However, many traditional active control methods need to build a state-space model (SSM) based on finite element model (FEM), and solving the active control force for the high-dimensional SSM is time-consuming. In this paper, the dynamic mode decomposition with control (DMDc) method is proposed to achieve a data-driven reduced-order SSM for active vibration control of cable-strut structures. This proposed method only uses the data of structural response and control force input to build reduced-order SSM and does not rely on the FEM. Linear quadratic regulator (LQR) design using the DMDc-based reduced-order SSM (DMDc-LQR) is more computationally efficient than that using the FEM-based SSM (FEM-LQR). The relationship between the design parameters of the DMDc-LQR controller and the FEM-LQR controller is established, which ensures that the control performance indexes of the DMDc-LQR controller and the FEM-LQR controller are equal. The effectiveness of the proposed DMDc-LQR method is validated using numerical Kiewitt cable dome and tensegrity grid under wind and seismic loads. The results show that the DMDc-LQR controller maintains similar control effect to that of the FEM-LQR controller and has advantage of high computing efficiency as well. In addition, the influence of critical parameters (i.e., data noise and model order) on vibration control effect is comprehensively explored. It is found that increasing the model order is effective to mitigate the noise influence on the DMDc-based reduced-order SSM and ensures the effectiveness of the DMDc-LQR controller.

Vibration Control of a Multi-Disc Rotor System with Active Lateral Bearings and Disturbance Estimation

A rotor system used in a wide range of engineering applications generally consists of a rotor shaft, multiple discs, blades and other essential components, generating a multi-disc rotor arrangement. System uncertainties caused by unbalanced discs and disc mass variation, compounded with external disturbances under different operating conditions, can lead to a variation in rotor-dynamic characteristics with multiple structural resonances, potentially causing an excessive level of rotor lateral vibration. Therefore, to effectively suppress lateral vibration for such a multi-disc rotor system, an active vibration control approach using active lateral bearings with disturbance estimation is presented in this work. The utilized active lateral bearings can generate necessary bearing displacement regulations to eliminate the bearing forces so to effectively control the lateral vibration of the rotor system. The disturbance estimation approach is used to estimate the unknown uncertainties associated with the system's internal dynamics and external disturbances affecting the rotor system, incorporating an extended state observer (ESO). Utilizing the total disturbance estimated by the ESO to cancel out the effects of the disturbance using active lateral bearings, the rotor lateral vibration can be satisfactorily suppressed with sufficient control robustness against uncertainties in the rotor internal dynamics, particularly associated with the degree of mass unbalance of rotor discs, demonstrating the effectiveness of the active vibration control approach for suppressing vibration in a rotor system.

A New Method for Controlling Vibration in Automotive Applications: Circular Force Generator Technology

Automotive Noise Vibration and Harshness (NVH) continues to be critical to address in passenger vehicles, especially as new vehicles today emphasize the use of lighter weight materials that create even more challenging NVH issues. NVH can negatively impact drivability and comfort, as well as perceived vehicle quality. Moreover, with the development of increased driver ergonomic technologies and capabilities (audible or otherwise), NVH continues to be key in allowing these technologies to be fully effective. Both passive and active control technologies are used extensively to improve automotive NVH. The use of active noise and vibration control has become a standard solution approach in vehicles, especially to mitigate low-frequency noise and vibration inside the vehicle. Linear actuators have been used in active engine mounts as well as frame vibration control to mitigate passenger cabin NVH. This paper introduces a new lightweight approach for active vibration control for automotive applications. Controllable Circular Force Generator (CFG) technology is introduced to displace the use of larger, heavy linear electromagnetic technology, and is shown to provide improved performance with lower weight and cost.

Singular System-Based Approach for Active Vibration Control of Vehicle Seat Suspension

Abstract This paper proposes a singular system-based approach for active vibration control of vehicle seat suspensions, where the drivers' acceleration is augmented into the conventional seat suspension model together with seat suspension deflection and relative velocity as system states to make the suspension model as a singular system. In this novel seat suspension system, all the system states are easy to measure in real-time. A friction observer is applied to estimate the real system friction and an H∞ controller is designed to achieve the optimal ride comfort performance with consideration of the friction compensation, actuator saturation, and time delay issues. The cone complementarity linearization (CCL) algorithm is applied to solve the nonlinear constraints. The experimental results show that good ride comfort performance can be achieved by the proposed controller in both the time and frequency domain compared with the uncontrolled seat suspension.

Experimental verification of model-free active vibration control approach using virtually controlled object

The purpose of this study is to develop a simple and practical controller design method without modeling controlled objects. In this technique, modeling of the controlled object is not necessary and a controller is designed with an actuator model, which includes a single-degree-of-freedom virtual structure inserted between the actuator and the controlled object. The parameters of the virtual structure are determined so that indirect active vibration suppression is effectively achieved by considering the frequency transfer function from the vibration response of the controlled object to that of the virtual structure. Since the actuator model, which includes a virtually controlled object, is a simple low-order system, a controller with high control performance can be designed by traditional model-based optimal control theory. In this research, a mixed controller is designed considering both control performance and robust stability. The effectiveness of the proposed method is validated experimentally. The robustness of the controller is demonstrated by applying the same controller to various structures.

Novel approach for active vibration control of a flexible missile

This paper investigates the feasibility of using an active dynamic vibration absorber (ADVA) for active vibration control of a flexible missile system through simulation. Based on the principles of a dynamic vibration absorber (DVA), a ring-type ADVA is first designed to attenuate the elastic vibration of the flexible missile, and the design of the active controller adopts the proportional-integral-derivative (PID) control algorithm. The motion equations of a flexible missile with an ADVA, which is subjected to follower thrust at its aft end, are derived using the Lagrangian approach. Taking the minimum of the root mean square (RMS) of the lateral displacement response of the center of mass as the objective function, a genetic algorithm (GA) is used to optimize the parameter of the DVA and PID controller. The numerical calculations show that the ADVA and DVA are effective in suppressing the vibration and provide approximately 41.2% and 17.6% improvement, respectively, compared with the case of no DVA. The ADVA has better performance than the DVA. When the missile is subjected to follower thrust, the effect of vibration reduction is more effective than the case without follower thrust. It is feasible to reduce vibration and improve the stability of flexible missiles by means of the ADVA.

Observer based active vibration control of flexible space structures with prescribed performance

This paper proposes an active vibration control approach to solve the vibration suppression problem of flexible space structures in the presence of external disturbances and parameter uncertainties. Based on the independent modal space control method, each mode can be decoupled and controlled separately. To meet the case that the velocity sensors are not available on the flexible structures, a neural network based state observer is designed for the estimation of the modal velocity. The neural network approximation is introduced into the observer design which can effectively deal with the disturbances and uncertainties in order to obtain more accurate observation results. Further, the controller and the adaptive law are derived by using the backstepping technique and prescribed performance control method with the stability of the whole closed-loop system analyzed via Lyapunov theory. Simulation results illustrate the effectiveness and vibration control performance of the proposed method.

A magnetostrictive active vibration control approach for rotating functionally graded carbon nanotube-reinforced sandwich composite beam

Vibration of a rotating functionally graded carbon nanotube-reinforced sandwich composite beam was controlled using two magnetostrictive actuator layers. A closed-loop velocity proportional feedback control approach was employed to mitigate the vibration amplitude. The Timoshenko beam theory (TBT) as well as the Hamilton’s principle were used to derive the equations of motion. The differential quadrature method was implemented to solve the governing equations. Some convergence and comparison studies were performed to assess the stability and accuracy of results. The effects of distribution type and volume fraction of the carbon nanotubes (CNTs) and angular velocity on vibration suppression of different modes of the sandwich beam were investigated. Overshoot response of the rotating sandwich beam was significantly affected by the volume fraction and distribution type of CNTs.

An Active Vehicle Suspension Control Approach with Electromagnetic and Hydraulic Actuators

An active vibration control approach from an online estimation perspective of unavailable feedback signals for a quarter-vehicle suspension system is introduced. The application of a new signal differentiation technique for the online estimation of disturbance trajectories due to irregular road surfaces and velocity state variables is described. It is assumed that position measurements are only available for active disturbance suppression control implementation. Real-time signal differentiation is independent of detailed mathematical models of specific dynamic systems and control force generation mechanisms. Active control forces can be supplied by electromagnetic or hydraulic actuators. Analytical and simulation results prove the effective and fast dynamic performance of the online signal estimation as well as a satisfactory active disturbance attenuation on a quarter-vehicle active suspension system.

A combined approach for active vibration control of fluid-loaded structures using the receptance method

A combined experimental–numerical approach for the pole assignment of fluid-loaded structures using the receptance method is proposed in this paper. The in-air measurements of structural receptances and numerically simulated fluid loading computed using acoustic boundary element analysis are combined to obtain the receptances of the fluid-loaded structures. It does not require evaluating the fluid-loaded model which usually contains errors, and it does not require receptance measurements of the fluid-loaded structure which are usually difficult and time-consuming. A partial pole assignment can also be achieved with the combined approach. The accuracy and efficiency of the proposed combined approach are demonstrated on a water-loaded plate. Numerical results indicate that the chosen poles of the water-loaded plate can be assigned to the predetermined values with the proposed approach, and the in-air mode shapes may represent the water-loaded mode shapes in the combined approach for suppression of spillover.

A novel approach to enhance the accuracy of vibration control of Frames

All structures built within known seismically active regions are typically designed to endure earthquake forces. Despite advances in earthquake resistant structures, it can be inferred from hindsight that no structure is entirely immune to damage from earthquakes. Active vibration control systems, unlike the traditional methods which enlarge beams and columns, are highly effective countermeasures to reduce the effects of earthquake loading on a structure. It requires fast computation of nonlinear structural analysis in near time and has historically demanded advanced programming hosted on powerful computers. This research aims to develop a new approach for active vibration control of frames, which is applicable over both elastic and plastic material behavior. In this study, the Force Analogy Method (FAM), which is based on Hook’s Law is further extended using the Timoshenko element which considers shear deformations to increase the reliability and accuracy of the controller. The proposed algorithm is applied to a 2D portal frame equipped with linear actuator, which is designed based on full state Linear Quadratic Regulator (LQR). For comparison purposes, the portal frame is analysed by both the Euler Bernoulli and Timoshenko element respectively. The results clearly demonstrate the superiority of the Timoshenko element over Euler Bernoulli for application in nonlinear analysis.

Saturated Output Regulation Approach for Active Vibration Control of Thin-Walled Flexible Workpieces With Voice Coil Actuators

Thin-walled flexible workpieces are known to be the most commonly used flexible elements in mechanical structures and machines in the industries of aerospace, national defense, petrochemistry, and so on. Workpiece machining vibrations induced by machining tools greatly worsen the efficiency and accuracy of milling processes, and hence, vibration attenuation has become a bottleneck for improving the machining quality of thin-walled flexible workpieces. An active vibration control system is hereby established to attenuate vibration by using laser displacement detectors and voice coil motors (VCMs). In this paper, we reveal that the vibration attenuation problem can be theoretically formulated as an output regulation problem subject to saturated actuation of VCMs. Within the formulation, a saturated output regulation algorithm is successfully implemented and its effectiveness is extensively examined by experiments.

Experimental study on active structural acoustic control of rotating machinery using rotating piezo-based inertial actuators

In this paper, two Piezo-Based Rotating Inertial Actuators (PBRIAs) are considered for the suppression of the structure-borne noise radiated from rotating machinery. As add-on devices, they can be directly mounted on a rotational shaft, in order to intervene as early as possible in the transfer path between disturbance and the noise radiating surfaces. A MIMO (Multi-Input−Multi-Output) form of the FxLMS control algorithm is employed to generate the appropriate actuation signals, relying on a linear interpolation scheme to approximate time varying secondary plants. The proposed active vibration control approach is tested on an experimental test bed comprising a rotating shaft mounted in a frame to which a noise-radiating plate is attached. The disturbance force is introduced by an electro-dynamic shaker. The experimental results show that when the shaft spins below 180rpm, more than a 7dB reduction can be achieved in terms of plate vibrations, along with a reduction in the same order of magnitude in terms of noise radiation.

Consensus positive position feedback control for vibration attenuation of smart structures

This paper presents a new network-based approach for active vibration control in smart structures. In this approach, a network with known topology connects collocated actuator/sensor elements of the smart structure to one another. Each of these actuators/sensors, i.e., agent or node, is enhanced by a separate multi-mode positive position feedback (PPF) controller. The decentralized PPF controlled agents collaborate with each other in the designed network, under a certain consensus dynamics. The consensus constraint forces neighboring agents to cooperate with each other such that the disagreement between the time-domain actuation of the agents is driven to zero. The controller output of each agent is calculated using state-space variables; hence, optimal state estimators are designed first for the proposed observer-based consensus PPF control. The consensus controller is numerically investigated for a flexible smart structure, i.e., a thin aluminum beam that is clamped at its both ends. Results demonstrate that the consensus law successfully imposes synchronization between the independently controlled agents, as the disagreements between the decentralized PPF controller variables converge to zero in a short time. The new consensus PPF controller brings extra robustness to vibration suppression in smart structures, where malfunctions of an agent can be compensated for by referencing the neighboring agents’ performance. This is demonstrated in the results by comparing the new controller with former centralized PPF approach.

Finite element based model predictive control for active vibration suppression of a one-link flexible manipulator

This paper presents a unique approach for active vibration control of a one-link flexible manipulator. The method combines a finite element model of the manipulator and an advanced model predictive controller to suppress vibration at its tip. This hybrid methodology improves significantly over the standard application of a predictive controller for vibration control. The finite element model used in place of standard modelling in the control algorithm provides a more accurate prediction of dynamic behavior, resulting in enhanced control. Closed loop control experiments were performed using the flexible manipulator, instrumented with strain gauges and piezoelectric actuators. In all instances, experimental and simulation results demonstrate that the finite element based predictive controller provides improved active vibration suppression in comparison with using a standard predictive control strategy.

Fuzzy Logic Based Active Vibration Controller

This paper presents fuzzy logic approach for active vibration control of composite shell structure using collocated piezoelectric sensor/actuator. The vibratory response of piezolaminated composite shell is modeled using degenerated finite shell element. Modeling is based upon first order shear deformation theory and linear piezoelectric theory. The fuzzy IF-THEN rules are established on analysis of the motion traits of laminated composite shell. The fuzzy logic controller (FLC) is designed using the sensor voltage and its derivative as inputs and actuator voltage as output. The simulation results illustrate that this controller has more superiority than the conventional controller.

Robust Nominal Model-Based Sliding Mode Robust Control for Vibration of Flexible Rectangular Plate

In this paper, we developed an approach for active vibration control of flexible rectangular plate structures using control theory. The flexible rectangular plate system is firstly modelled and simulated via a finite element method; and secondly, a new type of modelling method, and the state-space model are involved in the development of the equation of motion in state-space, which is efficiently used for the analysis of the system and design of control laws with a modern control framework. Then, the validity of the obtained new model is investigated by comparing the plate natural frequencies and forced vibration response analysis predicted by the finite element model with the calculated values obtained from new model. After validating the model, nominal model-based sliding mode robust MIMO controller is applied to the plate dynamics via the MATLAB/Simulink platform. The simulation results clearly demonstrate an effective vibration suppression capability that can be achieved using nominal model-based sliding mode robust MIMO controller.

ADAPTIVE ITERATIVE LEARNING CONTROL FOR VIBRATION OF FLEXURAL RECTANGULAR PLATE

In this paper, we developed an approach for active vibration control of flexible rectangular plate structures using control theory. The flexible rectangular plate system is firstly modeled and simulated via a finite element method; and secondly, a new type of modeling method, and the state-space model are involved in the development of the equation of motion in state-space, which is efficiently used for the analysis of the system and design of control laws with a modern control framework. Then, the validity of the obtained new model is investigated by comparing the plate natural frequencies, mode shapes, statical analysis and forced vibration response analysis predicted by the finite element model with the calculated values obtained from new model. After validating the model, adaptive iterative learning MIMO controller is applied to the plate dynamics via the MATLAB/Simulink platform. The simulation results clearly demonstrate an effective vibration suppression capability that can be achieved using adaptive iterative learning MIMO controller.http://dx.doi.org/10.5755/j01.mech.17.5.724

Model predictive control based on mixed ℋ2/ℋ∞ control approach for active vibration control of railway vehicles

This paper investigates the application of model predictive control technology based on mixed ℋ2/ℋ∞ control approach for active suspension control of a railway vehicle, the aim being to improve the ride quality of the railway vehicle. Comparisons are made with more conventional control approaches, and the applicability of the linear matrix inequality approach is illustrated via the railway vehicle example.

Active robust vibration control of flexible structures

Flexible structures are extensively used in many space applications, for example, space-based radar antennae, space robotic systems, and space station, etc. The flexibility of these space structures results in problems of structural vibration and shape deformation, etc. In recent years, active control methods have been developed to suppress structural vibration and improve the performance of these flexible space structures. In this paper, we developed an approach for active vibration control of flexible structures with integrated piezoelectric actuators using control theory. First, dynamic models for a flexible circular plate with integrated piezoelectric actuators and sensors are derived using the Rayleigh–Ritz method. An active robust controller is designed to suppress vibration of the circular plate. Robustness of the control system of the circular plate is discussed for the model parameter uncertainty. This active robust vibration control method is tested via experimental implementation. The experimental results show that the proposed robust active control method is efficient for active vibration suppression.