Horizontal Vibration Acceleration Research Articles

Improved nonlinear active disturbance rejection control based on hierarchical expected improvement for high-speed elevator horizontal vibration suppression

In this paper, an improved NADR control method based on hierarchical expected improvement (HEI) optimization is studied to suppress the horizontal vibration of high-speed elevator car under complex coupled disturbances to improve high-speed elevator ride comfort. First, a nonlinear 8-DOF dynamic model for the horizontal vibration of the high-speed elevator car is constructed. Then, a 4-level parallel NADR main control system based on the fal-function is designed to observe the total disturbance in real time, which can be quickly compensated by fuzzy sliding mode control. Meanwhile, the adaptive law is used to adjust fuzzy rules and sliding mode switching term coefficients to ensure the stability and adaptability of the control system. To address the problem of multiple bandwidth parameters and high sensitivity of the observer in the NADR control system, the comprehensive RMS experimental data fusion model based on hierarchical Gaussian process is constructed. With the goal of achieving the optimal value of comprehensive RMS, a hierarchical expectation improvement search strategy that balances exploratory and developmental aspects is studied to improve the optimization accuracy of bandwidth parameters. Finally, the results show that the proposed method can reduce the horizontal vibration acceleration and tilt angle acceleration of the car system by more than 68%.

Research on Optimal Fast Terminal Sliding Mode Control of Horizontal Vibration of High-speed Elevator Car System

An optimal fast terminal sliding mode control strategy is proposed to suppress effectively the horizontal vibration of the high-speed elevator car system is caused by uncertainties such as rail unevenness, elevator load variation, and component friction and wear. Firstly, considering the elevator's composition structure and vibration characteristics, a 4-degree-of-freedom car system horizontal vibration active control model with a symmetric distribution of the control center is established. Secondly, considering the nonlinear factors of the rolling guide shoe and the external excitation, an optimal fast terminal sliding mode controller (PFTSMC) based on the sliding mode variable structure control is designed to eliminate the horizontal vibration of the car, define the nonsingular terminal sliding mode surface, and introduce the fast terminal convergence law based on the fast terminal attractor to ensure the accessibility of the sliding mode motion and reduce the jitter vibration. In addition, optimization of controller parameters using random weight particle swarm algorithm (RNW-PSO) to improve the controller's vibration suppression performance and robustness. Finally, the proposed controller can achieve more than 51.2% attenuation of horizontal vibration acceleration and displacement, showing that PFTSMC can effectively reduce the horizontal vibration of high-speed elevator car systems and improve ride comfort.

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.

Analysis of the horizontal vibration response under gas–solid coupling throughout the entire high-speed elevator operating process

High-speed elevator cars affected by external excitations exhibit complex horizontal vibration responses during their entire operating processes. To accurately explore the horizontal vibration response of a car and the response differences between the operating processes, a gas–solid coupling model for the entire high-speed elevator operating process was developed based on the finite volume method, Lagrange’s theorem, and the external excitations obtained from dynamic mesh technology and the time-variant guideway excitation simulation method. The differences in the car’s horizontal vibration acceleration and the effect of the fluid load disturbance during different high-speed elevator operating processes were analyzed by considering the different operating characteristics of the car during its acceleration–uniform speed–deceleration process. The feasibility of the model and modeling method were verified by testing an actual 7 m/s high-speed elevator. The results showed that the horizontal vibration acceleration of the car reached its maximum value during the uniform speed process, and the shaft fluid pressure load had the most significant effect on the horizontal vibration response of the car during the deceleration process.

Dynamic Characteristics of the Helical Planetary Transmission System considering the Installation Error of Shaft

The helical planetary transmission system (HPTS) is widely used in wind power, hydropower, and shield machine, which operating conditions are extremely complicated, and the existence of component installation errors will result in response deviations to the theoretical design. A dynamic model for slice type bending-torsional-pendulum of the HPTS is established in the lumped parameter method considering the installation error of shaft (IEOS) for the 1st planet gear, helical meshing characteristics, and bearing support characteristics. The vibration response characteristics of the HPTS under the IEOS for the 1st planet gear are studied. The results have shown that the FFT amplitudes for the horizontal vibration acceleration of the sun gear increased by 8.3%, and the axial vibration acceleration of the ring gear increased by 11.5%, respectively. The maximum magnitude increase of FFT amplitude for the vibration acceleration under a positive 0.13 mm IEOS for the 1st planet gear is the axial direction of the ring gear. The results indicate that the IEOS needs to be thoroughly introduced into the HPTS to simulate the actual operating conditions of the system.

High-speed elevator car system semi-active horizontal vibration reduction method based on the improved particle swarm algorithm

As the field of modern high-rise buildings advances, the demand for the high-speed elevator increases. The high-speed elevator car vibration directly affects the riding comforts, among which the high-speed elevator car horizontal vibration has the most pronounced effect. Previous researches indicate that the semi-active vibration reduction method is an effective horizontal vibration reduction method for elevator car, which has the characteristics of low energy consumption, suitable for high-speed elevator, while its adaptability is relatively weak. To address the adaptability issue, we proposed a semi-active high-speed elevator car horizontal vibration reduction method based on the improved particle swarm algorithm. To verify the feasibility of the proposed method, it is applied with a magneto-rheological damper in the KLK2-type elevator from Canny Elevator Co, Ltd The horizontal vibration results are compared with ones of the passive vibration reduction method and other algorithm-based vibration reduction methods. The vibration reduction method proposed in this paper is superior to all other mentioned methods in terms of the peak-to-peak value and the A95 value of the vibration acceleration. The horizontal vibration acceleration performance of the HSEC is improved by about 70%.

The multi-component coupling horizontal vibration modeling technology of the high-speed elevator and analysis of its influencing factors

Horizontal vibration of a high-speed elevator can seriously influence the safety, stability, and ride comfort of the elevator during the operation. The construction of an accurate and robust dynamic model for horizontal vibration is the key to vibration control and suppression. In this article, the modeling and influencing factor analysis of the horizontal vibration of the high-speed elevator car are performed considering multi-component coupling. The rigid flexible coupling of the traction ropes and the elevator car system, the rigid irregularity perturbation generated by the manufacturing and installation errors of the guide rails, and the vibration inconsistency between the elevator car and car frame are considered in the modeling process. Based on the coupling system of the traction rope, elevator car, elevator car frame, guide rails, and rolling guide shoes, the kinematic horizontal vibration equation is established by using the generalized Hamilton’s principle. The solution of the horizontal vibration of the elevator car is derived based on the Galerkin method and MATLAB/Simulink software, and the influence of the perturbation frequency, irregularity perturbation type, and operating velocity on the horizontal vibration of the elevator car is analyzed. The KLK2 high-speed elevator is taken as a case study. Compared with the measured data, the mean absolute percentage error (MAPE) of the proposed model for maximum peak-to-peak (max [Formula: see text]) and [Formula: see text] peak-to-peak ([Formula: see text] [Formula: see text]) of the horizontal vibration acceleration is 6.08% and 5.16%, respectively, while the MAPE of a four degree-of-freedom model for the two is 16.74% and 7.35% and the MAPE of a distributed-parameter model for the two is 10.66% and 6.97%, respectively. The effectiveness of the proposed model is verified.

Horizontal vibration response analysis of ultra-high-speed elevators by considering the effect of wind load on buildings

Abstract. At present, the wind-induced vibration effects of super-high-rise buildings caused by wind loads can no longer be ignored. The wind-induced vibration effect of super-high-rise buildings will inevitably cause the vibration of ultra-high-speed elevators. However, for the study of the vibration characteristics of ultra-high-speed elevators, the wind-induced vibration effect of the ultra-high-speed elevator is often ignored. Based on Bernoulli–Euler theory, the forced vibration differential equation of elevator guide rail was established, and the vibration equation of elevator guide shoe and car was established by using the Darren Bell principle. The coupled vibration model of the guide rail, guide shoes, and car can be obtained through the relationship of force and relative displacement among these components. Based on the model, the effects of wind pressure and building height on the horizontal vibration of the ultra-high-speed guideway and passenger comfort were analyzed. The results showed that the influence of the wind load on the vibration of ultra-high-speed elevator can no longer be disregarded, and the maximum horizontal vibration acceleration of the guide rail is positively correlated with the height of building. The vibration acceleration of the same height rail increases with the increase in wind pressure. The vibration dose values (VDVs) increase with the increase in wind pressure and building height, respectively.

Analysis of the gas-solid coupling horizontal vibration response and aerodynamic characteristics of a high-speed elevator

To accurately explore the horizontal vibration response and aerodynamic load variation law of high-speed elevator with gas-solid interaction coupling in real environment, a mathematical and a three-dimensional calculation model of the coupling vibration of the shaft airflow and car body were established based on the arbitrary Lagrange-Euler method and the finite volume method. Additionally, the rationality of the coupling calculation model was verified by taking the working condition of 7 m/s as the test object. Then, the aerodynamic load and the horizontal vibration acceleration of the car body for different speed conditions were solved using unidirectional and bidirectional fluid-structure coupling numerical simulation methods, and the influences of the two coupling methods on the horizontal vibration response of the car body were compared and analyzed. The results showed that the aerodynamic load on the car body fluctuated greatly due to its horizontal vibration under the bidirectional coupling effect, and the peak value of the fluctuation was proportional to the second power of the running speed. When the running speed was greater than 7 m/s, the influence of the bidirectional coupling on the horizontal vibration of the car body became more prominent. The typical digital characteristics of the vibration acceleration increased by 129.70%–226.84%, and the maximum amplitude of the low-frequency vibration of the car body increased significantly. This study provides an effective method for the analysis of the gas-solid coupling characteristics of a high-speed elevator, and it provides theoretical guidance for the development of an optimal vibration damper for a high-speed elevator.

Variable Universe Fuzzy Control of High-Speed Elevator Horizontal Vibration Based on Firefly Algorithm and Backpropagation Fuzzy Neural Network

To effectively suppress the horizontal vibration of a high-speed elevator car caused by uncertainties such as the irregularity of guide rails and the piston wind in the hoistway, this paper proposes a new variable universe fuzzy control method for semi-active guide shoes with magnetorheological (MR) dampers based on the firefly algorithm and backpropagation (FA-BP) algorithm fuzzy neural network (FNN). First, the dynamic model of a car system is constructed, and the FNN system based non-parametric model of the MR damper is established with the original MR damper data collected from experiments. Then, a variable universe fuzzy main controller is presented to control the input current of the MR damper. As for its variable universe contraction-expansion factors, another FNN auxiliary controller is designed to accurately adjust the universe. Furthermore, the FA-BP algorithm is utilized to train the FNN auxiliary controller. Finally, the elevator experiment is carried out to analyze the characteristics of horizontal vibration, and simulation tests are conducted using the measured excitation signal and two kinds of simulated excitation signals, respectively. The results show that the proposed controller has a lower horizontal vibration acceleration, tilt angle acceleration and other index values than the passive controller or the FNN controller, indicating that the proposed control method can effectively suppress the horizontal vibration of a high-speed elevator. This study can provide the technical foundation for intelligent vibration control of high-speed elevators.

Assessment on the crash risk factors of a typical long-span bridge using oversampling-based classification method and considering bridge structure movement

Abstract In comparison to ordinary highways, traffic accidents on long-span bridges have unique characteristics due to large percentages of large trucks, inclement weather conditions, and dynamically moving bridge structures. Presently, there is a research significant gap in the existing literature about the traffic safety of long-span bridges due to those difficulties. Meanwhile, the structure movement data of bridge is difficult to obtain. In this paper, real-time data related to the bridge crashes including surrounding environment, traffic status and especially structural movement were obtained from monitoring system of a long-span bridge. An oversampling-based classification method was utilized to explore the risk factors of the long-span bridge crashes. The results indicate that higher maximum wind speed and volume prior to a crash tend to increase the likelihood of the occurrences of the crash, while higher temperature, humidity, average vehicle speed and truck percentage are found to decrease the likelihood. Moreover, the structure movement indicators including horizontal vibration acceleration and deformation are found to have significant adverse effects on the traffic safety of the long-span bridge, and we recommend that those factors should be considered at the design stage.

Modelling Ambient Vibration Responses Induced by Operation of Metro Train on Curved Rail Segment with Small Curvature Radius

The torsional effect of the tracks on curved segment intensifies the ambient vibration response induced by Metro operation. This paper studies the ambient vibration responses induced by the operation of the Metro train on curved rail segments. By taking the curved segment of Hangzhou Metro Line 1 of China as an example, the wheel-rail model employing the multibody dynamics is demonstrated; the dynamic wheel-rail force of a B-type vehicle passing through a 350 m radius curved segment is also calculated. A finite element method model of the track-tunnel-soil-building is developed and verified by comparing the measured results with the simulated ones. Then, we analyzed the ambient vibration responses induced by the Metro operation. The results show that the horizontal vibration induced by the Metro train, on curved segments, cannot be ignored. When propagating on the ground, the variation trend of the horizontal vibration acceleration is greater than that of the vertical vibration. The horizontal vibration attenuates faster than the vertical vibration. The secondary vibration along the horizontal direction yields a significant amplifying effect upon the building. The vibration level increases with the height of the building, along the horizontal direction, but the vertical vibration level changes negligibly. The insight exhibits the influence level of the horizontal action of the Metro train wheels to the tracks, which can be referred by the practitioners for the planning and operation.

A Vibration-Related Design Parameter Optimization Method for High-Speed Elevator Horizontal Vibration Reduction

High-speed elevator horizontal vibration (HsEHV) is a problem that seriously affects ride comfort. To solve this problem, a design parameter optimization method for HsEHV reduction was studied. A dynamic equation of HsEHV was established, and its response value was calculated using a precise integration method. The influence of the design parameters on horizontal vibration was also analyzed. An optimization model of the design parameters for HsEHV reduction was constructed, and the response surface model of objective function (the peak-to-peak value of horizontal vibration acceleration) was constructed using Latin hypercube sampling. We adopted a multiobjective genetic algorithm to optimize the design parameters for horizontal vibration reduction and used the min-max standardization method to select an optimal solution set. Finally, a KLK2 high-speed elevator made by Canny Elevator Co., Ltd., was utilized as an example to analyze the influencing factors of HsEHV, optimize the design parameters to reduce horizontal vibration, and verify the optimized results using numerical calculation and prototype testing.

Study on horizontal vibration characteristics of high-speed elevator with airflow pressure disturbance and guiding system excitation

This paper aims to study the horizontal vibration dynamic characteristics of high-speed elevator by considering the combined effect of airflow and guiding system. The relationships of lateral force and overturning moment with horizontal displacement, deflection angle displacement and rated speed of the car are mathematically solved, and the horizontal vibration dynamic model of the car under the two excitations is established. For case model, the natural frequency and horizontal vibration response of the car are studied, and the guide-rail excitation frequency and car natural frequency are compared and analyzed. The results indicate that the higher the rated speed is, the more obvious the resonance phenomenon between the guide-rail and car will be in a certain range; the effect of airflow on horizontal vibration acceleration of the car with a speed lower than 6 m/s is small, but when the speed is over 6 m/s, the airflow will greatly affect the single-peak value of horizontal vibration acceleration, which is approximately a quadratic relationship; the deflection angle displacement has an increasing influence on horizontal vibration dynamic response with the increasing speed. The conclusions provide a theoretical guidance for the research and control on the horizontal vibration of high-speed elevator.

HVSRMS localization formula and localization law: Localization diagnosis of a ball bearing outer ring fault

Abstract The angle position of the outer ring fault has a significant influence on the residual life and the operation performance of ball bearing. Therefore, the realization of the localization diagnosis of the outer ring fault is of great importance to the bearing performance degradation assessment and the life prediction. In this paper, a novel localization diagnosis method, named horizontal–vertical synchronized root mean square (HVSRMS) localization law and localization formula, is developed to diagnose the angle position of outer ring fault accurately. Firstly, based on the established nonlinear contact model of the bearing system, the detailed change law of static contact force when the angle position of the outer ring fault is on both sides of 270° is studied, which lays a theoretical foundation for the discovery of localization law. Subsequently, the vibration acceleration signal and dynamic contact force of the outer ring fault are synchronously analyzed through theoretical research, and the new feature for localization diagnosis is presented as: the prime impact direction of horizontal vibration acceleration (IPDoHVA). Therefore, the outer ring fault localization law of ball bearing is proposed. On this basis, the HVSRMS localization formula is improved by combining it with the localization law. Thus the one-to-one mapping relationship between HVSRMS and outer ring fault angle position is determined. Finally, experiments are carried out to validate the accuracy and feasibility of the proposed localization law and localization formula. The research results provide a new approach and method for localization diagnosis and the residual life prediction of a defective bearing.

Transient loads and their influence on the dynamic responses of trains in a tunnel

Using compressible, unsteady and sliding meshing technologies, the aerodynamic loads including transient pressure, lateral force, and overturning moment that are caused by a single train moving through a double-track tunnel or two trains passing each other in a tunnel were calculated. The dynamic response generated by applying these loads to a train body was also analysed. The results show a large difference in the pressure on both sides of the vehicle nose when a single train moves through a double-track tunnel and when two trains pass each other in a tunnel. The pressures at the symmetric measuring points on both sides of the middle of the train body are approximately the same except at the moment of passing. When the train passes the measuring points, the pressure change at the symmetric measuring points on the tunnel wall closer to the train is obviously larger than that farther from the train; the pressure changes are approximately the same at all other times. Therefore, the propagation of the pressure wave in the tunnel has good one-dimensional characteristics. Under dynamic loads in the tunnel, especially those generated by two trains passing each other in the tunnel, the lateral and vertical displacements of the underframe and side walls all increase significantly. The lateral acceleration on the roof is significantly greater than that of the underframe, which has a rolling movement below the centre of gravity. For the measuring points on both the side wall and underframe, the vertical accelerations at both ends are larger than that in the middle of the body because of a pitching motion. The horizontal and vertical vibration acceleration for a train passing another train in a tunnel are 33.8% and 47.2% larger than those for a train operating in open air, respectively.

Microscopic analysis of particle detachment from an obliquely oscillating plate

Particle detachment from an obliquely oscillating plate was studied experimentally and theoretically. The plate was placed in a horizontal position, and vibrations were applied in the horizontal and vertical directions by piezoelectric vibrators. The frequency of vibration was constant at 280Hz. The amplitude of vibration increased with time and approached a constant value in each experiment. The movement of micrometer-sized spherical particles was analyzed using images captured by a high-speed microscope camera, which showed that the particles rolled on the plate before detaching from the surface, and that the rolling significantly reduced the adhesive force between the particles and surface. Furthermore, the removal efficiency, defined by the number ratio of detached particles to total particles, was analyzed as a function of the horizontal and vertical vibration accelerations. It was found that the removal efficiency was significantly affected by the horizontal vibration acceleration. These experimental results can be explained by the force and moment balance model.

The Numerical Analysis of Gravel Pile Reinforcing Liquefiable Silt

A three-dimensional numerical simulation about gravel pile reinforcing liquefiable silt foundation was built, and the influence of gravel pile on the liquefiable silt anti-liquefaction was discussed. Results show that under seismic load, gravel pile has obvious cushioning effect, and compared with natural foundation, the maximum horizontal vibration acceleration of the gravel pile composite foundation surface layer is obviously decreased; drainage effect of gravel pile is very significant and the larger is the gravel pile permeability coefficient, the better is the drainage effect; as earthquake intensity largens, silt liquefaction scope increases; of both natural foundation and composite foundation, the pore pressure ratio variation with depth is that the middle is bigger than the top and bottom, and middle layers are more likely to be liquefied; the greater is the seismic acceleration, the larger is the shear stress.

Time-Frequency Analysis of Horizontal Vibration for Vehicle-Track System Based on Hilbert-Huang Transform

Relationship between track alignment irregularity and car body horizontal vibration acceleration is analyzed by using Hilbert-Huang Transform (HHT). Actual measured alignment irregularity and car body horizontal vibration acceleration are decomposed by empirical mode decomposition (EMD) to obtain intrinsic mode function (IMF). By comparing IMF waveform and energy spectrum of the irregularity and vibration acceleration, there is the definitive correspondence of IMFs, and the adverse section of irregularity can be identified from car body horizontal vibration acceleration. Finally, regression analysis is taken for measured sample of track inspection car on Beijing-Guangzhou line; the quantitative relationship between track alignment irregularity and car body horizontal vibration acceleration is established with a wavelength between 1.5 m and 50 m.

Model Test Study on Vibration Transferring of Dynamic Compaction and the Measures of Reducing Vibration

Dynamic compaction method was widely used in various engineering foundation reinforcement, the research of influence to surrounding environment from dynamic compaction and the measures of reducing vibration was not complete. In this paper, the decay laws of dynamic compaction vibration acceleration in horizontal direction was got through the model test, the attenuation formula of horizontal vibration acceleration was fitted, which provides theory basis for determining the influence scope of dynamic compaction; And the depth and filling materials two influence factors of vibration isolation ditch were researched by model tests, which provide important basises for the application of vibration isolation ditch.