Vibration Suppression Of System Research Articles

Stair‐Stepping Mechanical Metamaterials with Programmable Load Plateaus

AbstractMaterials with target load plateaus offer the potential for developing innovative vibration suppression and isolation systems for applications such as satellite platforms, submarines, and electric vehicles. However, implementing these materials can pose significant challenges. In this study, stair‐stepping mechanical metamaterials with programmable load plateaus are presented, which are created via a three‐level (unit, module, and 3D object) construction strategy. The strategy inspired by the inverse design concept achieves tunability in the number and properties of load plateaus within the force–displacement profiles of the metamaterials. This approach even yields appealing stair‐stepping response patterns, as validated by experiments and finite element simulations. Promisingly, programming the unit from its initial configuration to a “zero stiffness” configuration enables these metamaterials excellent vibration isolation performance. Furthermore, two reversible methods are proposed for switching among various unit configurations, namely shape memory programming and supporting payload. This innovative design strategy for programmable load plateaus opens up new possibilities for creating metamaterials with customized force–displacement responses. It also provides opportunities to incorporate multimodal vibration isolation capabilities into precision devices.

A multi-objective trajectory planning approach for vibration suppression of a series–parallel hybrid flexible welding manipulator

Although the series–parallel hybrid welding manipulator has advantages over the traditional series manipulator, its must run continuously and smoothly according to a specific trajectory at the rated velocity. Considering a flexible manipulator with a complex series–parallel hybrid structure as the research object, this paper proposes a multi-objective approach to indirectly suppress the vibration. In view of the complex flexible mechanism with a multi-kinematic pair arrangement and a multi-motor drive, a system comprehensive elastodynamics model is established, and the effectiveness of the model is verified through the hammer test method. To achieve synchronous and coordinated planning of the end position and attitude, the spatial arc welding trajectory is planned on the basis of the synchronous planning controller and the dual-S velocity profile interpolation function. Then, a multi-objective optimization model considering the travel time, energy consumption and terminal amplitude fluctuations is proposed, the trajectory planning problem is transformed into a parameter optimization problem in the interpolation function, and then the elite non-dominated sorting genetic algorithm (NSGA-II) is employed to determine the optimal trajectory. The optimal trajectory thus obtained effectively suppresses the vibration of the system. Finally, compared with the classic fifth-degree polynomial trajectory planning method, the system vibration suppression effect is significant, which verifies the effectiveness and feasibility of the proposed method and provides a theoretical basis for further realizing real-time control.

Analyzing Vertical Earthquake Vibrations and Moving Vehicle Loads for Structural Health Monitoring and Vibration Suppression in Bridges

The design of bridges often overlooks the vertical component of earthquakes or considers it of secondary importance, despite compelling evidence indicating specific structural damage caused by primary earthquake waves. Conversely, during the operational phase, the combined influence of ground motion and moving loads from vehicles can significantly impact the structural health monitoring (SHM) of bridges. This study aims to evaluate the simultaneous effect of vertical earthquake vibrations and moving vehicle loads on simply supported bridges. The research employs a practical methodology based on the eigenfunction expansion method to analyze change of deflection due to the effect of these concurrent forces under seven different earthquake records. It is shown that within a realistic range of vehicle mass and velocity, the average of changing the maximum deflection at the mid-span of the main beam (denoted as M_n) reaches up to 163% under various scenarios. Subsequently, the seismic parameters influencing this phenomenon are identified through a statistical analysis of set of 100 different earthquake records with unique features. A linear regression equation is presented to predict the M_n based on the earthquake specific properties. Additionally, to control the vertical vibration of bridge systems, a novel vibration suppression system utilizing steel pipe dampers is introduced, and its reliability is examined across a broad spectrum of bridge flexural rigidity. The results indicate that the system's efficiency depends on M_n and the soil type of the bridge construction, enabling a reduction in structural sections (up to 27%) while achieving the same maximum target deflection in the initial state. This efficiency leads to a more economical design solution, emphasizing the potential benefits of the proposed system for practical application.

Model Prediction and Optimization of Belt Drive System Vibration Suppression Based on Industrial Robot Joints

Addressing the vibration issues caused by torsional angle changes in the belt transmission systems of industrial robots during practical applications, this paper introduces a control strategy that integrates a Model Predictive Control (MPC) compensation mechanism. By applying the Lagrangian method, a dynamic mathematical model correlating torsional angle and torque was established, and an algorithm design combining MPC with its compensatory controller was developed. This strategy was validated in a MATLAB simulation environment. Simulation results demonstrate that, compared to traditional sliding mode control, the newly proposed controller significantly improved response speed in tracking the torsional angle's position and angular velocity, achieving enhancements of approximately 2 seconds and 1 second, respectively. This led to higher tracking accuracy and faster convergence speed, effectively enhancing the vibration suppression performance of industrial robot joint belt transmission systems.

An analytical vibration model of a one-dimensional two-stage periodic isolation system for the broadband vibration suppression of an underwater glider

Periodic isolation system is effectively applied in broadband vibration control. To further enhance the broadband vibration attenuation effect, the paper proposes a two-stage periodic isolation system for an underwater glider. The analytical model of the one-dimensional two-stage periodic isolation system is developed through the multi-degree of freedom spring mass model method. For illustrating the superiority of the proposed two-stage periodic isolator, the force transmission ratio and the wave propagation constant of the SDOF isolator, the single-stage periodic isolator, and the two-stage periodic isolator are calculated and compared. In order to obtain the dynamic parameter influences on the vibration isolation performances as the design guidelines of the two-stage periodic isolator, the parametrical study is carried out based on the analytical model. Furthermore, a two-stage periodic isolator is designed for an underwater glider. The application effect of the two-stage periodic isolator is investigated through analytical modeling and finite element method, comparing to the single-stage periodic isolator. The research results from the analytical models show the proposed two-stage periodic isolator could strength the broadband vibration suppression. The parametrical study results demonstrate the vibration attenuation bandgap and attenuation amount are greatly influenced by the designed dynamic parameters, such as the mass unit and the spring unit of the periodic isolator, the intermediate mass of the two-stage isolator, and the number of the periodic cells. In application study of an underwater glider, the finite element results verify that the two-stage periodic isolator has more vibration attenuation effect than the single-stage periodic isolator. The vibration isolation assessment according to the proposed analytical model gives good predictive performance before the finite element model verification.

Numerical and Experimental Investigations of Particle Dampers Attached to a Pipeline System

The structure of pipeline systems is complex, and the working environment is harsh. Under the excitation of the engine equipment foundation and pump fluid, it is easy to generate excessive vibration, which seriously affects the safe operation of the equipment. Particle damping achieves structural vibration suppression through the principle of particle collision dissipation. Due to the drawbacks of traditional pipeline vibration reduction methods, this article introduces a particle damping technology for pipeline system vibration suppression and designs particle dampers based on the structural characteristics of pipelines. We analyzed the energy dissipation mechanism of particle damping, revealed the influence of the materials, structure, external excitation, and other parameters of the pipeline particle dampers on the energy dissipation characteristics of the particle damping, established a pipeline vibration reduction test system with particle damping, and verified its effectiveness in pipeline system vibration reduction. This study can provide a technical reference for vibration reduction in pipeline systems.

Reliability evaluation and optimization design method of piezoelectric actuator vibration suppression system

As an effective means of structural vibration suppression, piezoelectric actuator vibration suppression system(PAVSS) has been gradually applied in structural vibration control. However, the performance degradation or failure of piezoelectric actuator under long service life will lead to the degradation of service reliability of PAVSS, so the scheme obtained by deterministic optimization method is difficult to ensure the service reliability. Aiming at the reliability evaluation and optimal design of PAVSS in service, the failure mechanism considering of the performance degradation or failure of piezoelectric actuator is analyzed, and the reliability evaluation method based on nested sampling and weighted statistics is constructed, which solves the reliability evaluation problem of PAVSS with the characteristics of load-sharing and redundancy. A reliability-based optimization method based on master-slave parallel genetic algorithm is proposed to optimize the position and angle of the actuators. At last, the feasibility and effectiveness of the proposed method are proved by an example, which not only provides a theoretical basis for the high reliability design of PAVSS in service, but also provides a new solution for the engineering problem of structural vibration control.

Seismic mitigation performance evaluation of linked buildings with a vibration-suppression layer

Linked buildings (LBs) have been widely used in urban areas because of their aesthetic quality and versatility. As LBs are vulnerable to damage under earthquake excitation, undesired vibrations should be suppressed. The use of weak connections is an effective approach to improve the seismic performance of LBs; however, they are inapplicable to LBs with inherently strong connections. In this study, a novel control system—a LB with a vibration-suppression layer (LBVSL)—is proposed to reduce the seismic responses of the LBs with strong connections. The LBVSL system is implemented by introducing a vibration-suppression system into one of the buildings. To extensively investigate the seismic mitigation performance of the LBVSL, a parametric study is conducted to evaluate the trends of its mean vibration energy with the control and structural parameters based on a simplified calculation model. The control parameters include the equivalent stiffness and damping of the vibration-suppression system, and the structural parameters include the stiffness and mass of the LBs. To understand the damping effect of the LBVSL, several numerical examples are studied. The analytical results suggest that the LBVSL has substantially reduced vibration energy and responses compared to the plain LBs. For instance, the LBVSL with the optimal parameters achieves a vibration energy reduction of 69% and a stochastic seismic response decrease of 30–50% relative to those of plain LBs. Additionally, the LBVSL achieves better damping performance and robustness when the vibration-suppression layer is placed on a lower floor. Furthermore, the simplified model provides an alternative for effectively optimizing critical parameters in the preliminary design stage.

An active piezoelectric damping vibration control system for the sting used in wind tunnel

In wind tunnel tests, the cantilever sting supporting system often suffers from low-frequency and large-amplitude resonance due to its inherent low structural damping characteristic, resulting in the degradation of data quality and structural safety. To improve wind tunnel testing safety and data accuracy, this paper is dedicated to establish an active vibration control system using piezoelectric stack actuators. A novel methodology of vibration monitoring based on modal transformation, which uses measured strain and a Strain-to-Displacement Transformation (SDT) matrix to reconstruct dynamic displacement field, is proposed herein. Meanwhile, strain sensor positions are optimized by an improved Particle Swarm Optimization (PSO) algorithm to reduce systematic estimation errors of this method. Furthermore, a Back-Propagated Neutral Network (BPNN) is established to implement a self-adaptive control strategy. A series of verification tests are performed to demonstrate the validity of the proposed system. Experimental results indicate that the relative Root Mean Square Error (RMSE) between estimated vibration displacement and measured vibration displacement is less than 3%, and a vibration attenuation of over 14 dB/Hz is achieved in ground tests, proving the superiority of this intelligent active vibration suppression system.

Multidomain Synthesis of Optimal Vibration Suppression Systems

Abstract There are numerous design possibilities for vibration–suppression systems considering components from multiple domains (e.g., mechanical, hydraulic, pneumatic, electrical). Traditional vibration absorber design approach could only explore limited possibilities, of which the performance is away from optimal. Since the 2000s, network synthesis-based approach has been applied. It allows identification of optimal absorber properties represented by networks consisting of modeling elements (stiffness, damping, inertance), providing significant theoretical performance improvements. However, such improvements have not yet been realized in industry. This is because the following questions have not been answered: (1) What are the network-represented properties of the conventional absorber? (2) How can the optimal network-represented properties be realized considering multidomain physical components? This article provides a method for answering these questions by proposing a novel multidomain synthesis technique, allowing bidirectional transformation between networks and multidomain components. Building on this technique, a vibration–absorber design methodology is proposed, which can construct physical realizations of optimal absorbers considering multidomain components. Another contribution of this work is to propose a novel component, providing a hydraulic realization of compliance ‘embedded’ in a hydraulic network. This methodology is demonstrated using an automotive case study, where the constructed optimal hydraulic suspension provides 23% ride comfort enhancement over the conventional one.

Bandgap and wave attenuation optimization of tetra-chiral metamaterial using PSO algorithm

The development of vibration suppression systems with desired efficiency and low cost is one of the significant challenges in engineering. In this study, a parametric lattice model is considered to analyze the wave mitigation features in the metamaterial based on a tetra-chiral topology of the periodic cell equipped with internal resonators. Bloch wave theorem and finite element method are employed to explore the bandgap of the structure and its wave mitigation features. Since the unit cell geometry can be designed to open and shift bandgaps, particle swarm optimization algorithm is used to find the largest possible gap in the desired frequency range. The optimization method is programmed using MATLAB combined with an in-house finite element solver, considering the parameters' ranges to ensure geometric compatibility. In all studied cases, the optimized geometry leads to superior vibration suppression and larger complete bandgaps.

Intelligent vibration control for ultra-high-speed elevators: A type 2 variable universe fuzzy neural network method with input saturation

When elevators accelerate to ultra-high speed, the horizontal vibration suppression is significantly challenged by the complex coupled excitation and uncertain time-varying parameters. Therefore, this paper proposes an intelligent control method with type 2 variable universe fuzzy neural network considering input saturation. Firstly, considering the multilevel relationship of the guide rails, guide shoes, frame and car, a horizontal vibration dynamic model is constructed. To improve the tolerance and adaptability of the control system to the uncertain parameters, the type 2 variable universe fuzzy control is used as the main controller. The discourse of universe is adjusted by the T-S fuzzy neural network, and the anti-saturation controller is designed to compensate for the over-saturation problem aggravated by the networks. The non-parametric inverse model of intelligent adjustable dampers represented by the magnetorheological damper is constructed to accurately calculate the ideal output damping force. The effectiveness of the proposed control method is verified by the elevator experimental data and the bidirectional gas-solid coupling aerodynamic excitation. The results show that the proposed intelligent control method can significantly improve the mean values, peak values and comfort indexes of the horizontal vibration acceleration and tilt angle acceleration of the elevator car. The research provides a new intelligent control scheme for high-speed/ultra-high-speed elevators and other similar vibration suppression systems.

Research on longitudinal vibration suppression of underwater vehicle shafting based on particle damping

A particle damper is applied to suppress the longitudinal vibration of underwater vehicle shafting in order to reduce vibration level and improve silence and stealth of underwater vehicles. The model of rubber-coated steel particle damper was established with discrete element method and PFC3D simulation software, the damping energy consumption law of collision and friction between particle and damper and between particle and particle investigated, the effects of particle radius, mass filling ratio, cavity length, excitation frequency, excitation amplitude, rotating speed and both stacking and motion states of particles on the system vibration suppression were discussed, and the bench test was carried out to verify the law. It revealed the mechanism of longitudinal vibration suppression of particle damping, established the intrinsic relationship between of total energy consumption of particle and vibration of system, and put forward the evaluating method of longitudinal vibration suppression effect by total energy consumption of particle and vibration reduction ratio. The research results show that the mechanical model of particle damper is reasonable and the simulation data is reliable; the rotating speed, mass filling ratio and cavity length have significant effects on the total energy consumption of particle and vibration reduction ratio.

Modeling and control analysis of electric driving system considering gear friction based on dual-inertia system

In the electric driving system, the measurement of the motor speed error becomes more and more important, which has an impact on the system vibration suppression. In this paper, based on the single-neuron adaptive PID control method, the dual-inertia system considering gear friction torque is modeled and studied. Firstly, the dual-inertia system with gear friction is established, and dynamic differential equations of it are derived; Then, the comprehensive meshing stiffness and the time-varying friction torque of the gear system are deduced; Next, the Ziegler-Nichlos frequency domain response method is adopted to obtain the parameters of the PID controller. The control methods including the PID, Fuzzy-PID with DOB and single-neuron adaptive PID are utilized to adjust the motor speed of the system; Finally, the effects of gear friction, the moment of inertia of load and control methods on motor speed and system error are analyzed.

Dynamic characteristic reconfiguration of a fixture-workpiece system for vibration suppression in milling of thin-walled workpieces based on MR damping fixture

Dynamic characteristic reconfiguration of a fixture-workpiece system for vibration suppression in milling of thin-walled workpieces based on MR damping fixture

Online Control Strategy for Radial Vibration Suppression of PMSM by Multiharmonic Current Injection Method

In the radial vibration suppression of the motor, the current harmonic injection method is an effective method. The radial force model of surface permanent magnet synchronous machine (SPMSM) is analyzed, and the relationship of the frequency, amplitude and phase between harmonic current and radial vibration harmonic is obtained. A current harmonic injection method is derived by using the current closed-loop transfer function in vector control, which can adjust the frequency, amplitude and phase of current harmonics to realize the change in the amplitude of radial vibration harmonics. one current harmonic is selected to suppress one even-order radial vibration harmonic, and the gradient descent method is adopted to online calculate the frequency amplitude and phase of the current harmonics injected at the minimum amplitude of radial vibration harmonics. In order to avoid the influence of the single current harmonic on the high radial vibration harmonics, a sequential vibration suppression method is proposed to realize the comprehensive suppression of every low-even-order vibration harmonics. Finally, an on-line control system for the radial vibration suppression of SPMSM with multi-current harmonics injection is designed. The prototype is a 750W SPMSM, the amplitude of all low-even radial vibration harmonics are suppressed significantly by this method, which verifies the correctness and effectiveness of this method.

Research on the Mechanism and Control Characteristics of Vehicle-Track Beam Coupling Vibration for Medium-Speed Maglev Vehicle

In the maglev transportation system, the track beam may vibrate under the dynamic levitation force of the maglev vehicle due to its own elastic characteristics, which may cause the vehicle to vibrate. At present, the general method of suppressing vibration is to improve the stiffness, density, damping of the bridge, and the accuracy of track installation, which will result in higher construction costs. In this article, the simulation analysis of the vehicle-rail coupling vibration is carried out from the perspective of suspension control characteristics. Through theoretical derivation, a mathematical model is established, and the mechanism of the vehicle-bridge coupling system vibration is analyzed through simulation. The internal influence of the main parameters of the controller on the system vibration is discussed. Theoretical analysis and simulation research show that the mismatch between the structural parameters of the track beam and the controller parameters will cause coupled vibration, while adjusting the parameters to match the track beam structure can suppress vibration to a certain extent. Taking the 25-m simply supported beam of Changsha Maglev Express as the research object, the vehicle-bridge coupled vibration characteristics test under 75–140-km/h operating speed is carried out, and the dynamic response of the vehicle and the bridge frame is obtained. Dynamic experiments show that proper controller parameters can maintain a stable suspension of the vehicle. This research provides theoretical and experimental references for vehicle-track coupled vibration suppression and maglev transportation system optimization.

Nonlinear oscillator design based on phase reduction method for closed‐loop system

SummaryTo widely utilize the synchronization properties of nonlinear oscillators in the control and signal processing engineering field, a common design method for a nonlinear oscillator model would be helpful. The output response of a nonlinear oscillator excited by a periodic signal implicitly includes the information of both the instantaneous phase and the amplitude of the input signal. Explicitly expressing the dynamics of both phase and amplitude with the phase reduction method, and organizing them by the number of events in one period, could enable the design of a nonlinear oscillator model in the same manner that can synchronize with an arbitrary cyclic phenomenon in a broad sense. Assuming the cyclic phenomenon is a single periodic signal, the property of the generalized nonlinear oscillator model has the role as a common‐dimensional observer to attain the pseudo‐property of both iso‐damping and flat‐gain. Thus, this article determines the essential role of the nonlinear oscillator inserted in the closed‐loop system through investigating the input–output characteristic of the generalized nonlinear oscillator model. As a result of the numerical simulation using a simple vibration excitation and suppression system, it was found that using the generalized nonlinear oscillator model enables us to easily build the closed‐loop system including the pseudo‐property of both iso‐damping and flat‐gain.

Spacecraft attitude control and vibration suppression using magnetically suspended control & sensitive gyroscope and radial basis function network adaptive sliding mode control

For the sake of improving the agility and super-static performance of spacecraft under external disturbances, this paper puts forward an idea for using pyramid configuration of the Magnetically Suspended Control & Sensitive Gyroscope to realize dual control of attitude maneuver and vibration suppression of spacecraft. The RBF neural network is used to reduce the chattering in sliding mode control through adaptively learning the non-linear part of the system. A band-pass filter is designed to divide the attitude deviation signal fed back by the sensors into high-frequency and low-frequency parts. The control laws of gyro gimbal and magnetic suspension rotor are designed, respectively, to realize the attitude maneuver and vibration suppression simultaneously. The adaptive laws of parameters avoid the saturation of rotor deflection angle while speeding up the attitude maneuver process of spacecraft. Compared with the traditional sliding mode control methods, the proposed one not only improves the accuracy and speed of attitude control but also improves the robustness of the spacecraft attitude control and vibration suppression system. Semi-physical simulation results show the effectiveness and superiority of the proposed method.

A Practical Approach for the Mitigation of Seismic-Induced Vibrations in Slender Metallic Structures through Magnetorheological Fluid Dampers

The mitigation of seismic-induced vibrations is essential for the effective protection of buildings and occupants during earthquakes. This especially applies to slender buildings with metallic frames; in this case, the structure’s geometrical layout and relatively low damping properties favor an excessive and potentially catastrophic oscillatory response to a seismic event. Semiactive systems for energy dissipation are among the most commonly used strategies to control this oscillatory response. They offer the right balance between the reliability of passive devices and the versatility and adaptability of fully active systems. In this work, a vibration-suppression system based on dissipative bracings that integrate commercial magnetorheological fluid dampers (MRDs) was designed and validated through experimental tests on a true-scale structural model that was representative of a five-story slender building with a metallic frame. A practical and robust approach was proposed for: (1) The definition of the MRD type in compliance with a predefined mitigation target for seismic-induced accelerations on each floor of the structure; (2) The modeling of the MRDs, contribute to the dynamic response of the structural system. The approach involves a linearized formulation of the characteristic damping curves of the MRDs at different values of the activating current. By relying upon this linearization, a rapidly converging iterative process was set up to simulate the seismic response of the structure in the case of activated or deactivated dampers. The reference structure and the vibration-suppression system were then manufactured and tested on a sliding table, which provided realistic seismic excitation. The good correlation levels between the numerical predictions and the experimental measurements proved the effectiveness of the conceived system and of the approaches that were used for its design and simulation.