Journal of Mechatronics and Artificial Intelligence in Engineering
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Experimental study on vibration isolation performance of mining dump truck suspensions for improving ride comfort
Full text linkThis study addresses the challenge of reducing the transmission of low-frequency road excitation vibrations to the cab of mining dump trucks to enhance ride comfort. Given the harsh working conditions of these vehicles, a novel methodology combining experimental data collection and advanced signal processing techniques was developed. The research established a comprehensive vibration testing program aligned with earth-moving machinery standards, collecting vibration acceleration data under both idling and full-load operation at 35 km/h. To improve data accuracy, Singular Value Decomposition (SVD) was employed to denoise the experimental vibration data, effectively mitigating environmental interference. Subsequent Fourier transform analysis revealed the vibration energy transfer patterns of the vehicle suspension system in the frequency domain. The results indicated a significant vibration isolation rate of 89 % for the frame suspension system, contrasting with only 7 % for the cab suspension system. Notably, the cab seat suspension system was found to amplify low-frequency road excitations. Compared to previous methods, this study innovatively integrates SVD and Fourier transform techniques to provide a more accurate and detailed understanding of vibration transmission. The key result of achieving an 89 % vibration isolation rate for the frame suspension system demonstrates the effectiveness of the proposed methodology. This study offers practical optimization directions for improving suspension system performance and ride comfort in mining dump trucks, outperforming traditional approaches by providing a more comprehensive analysis and actionable insights for vibration isolation. The findings also serve as valuable references for addressing similar engineering challenges in heavy machinery
Numerical study of heat and mass transfer in a relief pipeline with variable diameter
Full text linkIn this work, a comprehensive numerical and analytical investigation of hydrodynamic and thermal processes in closed pipelines of variable diameter is carried out, taking into account the terrain profile and external temperature effects. The scientific novelty of the study lies in the development of an improved quasi-one-dimensional model that allows for an integral assessment of the influence of geometric parameters (diameter, inclination angle, internal surface roughness) and thermophysical properties (material thermal conductivity, ambient temperature) on the distribution of pressure and temperature along the pipeline. The developed model was validated by comparing it with numerical simulations based on the SST turbulence model and calculations using the Darcy-Weisbach equation. The maximum deviation between the results did not exceed 2 %, confirming the high accuracy of the proposed method. It was established that hydraulic losses are predominantly determined by the pipe diameter and flow velocity, whereas thermal losses depend mainly on the thermal conductivity of the material and the spatial orientation of the pipeline. The proposed approach provides a reliable and computationally efficient foundation for predicting the energy characteristics of liquid transportation systems, optimizing structural parameters, and improving the energy efficiency of industrial, municipal, and thermal networks
LSGAN-Transformer life prediction method for rolling bearings under few samples
Full text linkAiming at the problem that it is difficult to obtain a large amount of data for bearings with complex working conditions, which leads to the inability to accurately predict their life, a rolling bearing life prediction method based on few samples, LSGAN-Transformer, is proposed. A dropout layer is added to the LSGAN generator to avoid the overfitting phenomenon that often occurs during few-sample training. The normalization of each layer in the traditional Transformer model is moved forward to the input of the decoder and encoder submodules before the residual network, forming a direct gradient path from input to output, avoiding the problem of excessive expected gradient near the output layer that often occurs in the traditional Transformer network. Verification on the PHM2012 dataset and the XJTY-SY dataset shows that the MAE and RMSE of the proposed method are greatly improved; compared with other common prediction models, the MAE and RMSE of the proposed method are improved by 30.61 % and 35.93 % respectively
Research on coupling dynamic characteristics and parameter influence of TBM cutterhead system
Full text linkAs an important system of TBM, the host system bears the impact of unstable load from itself and the strong load of the rock in the geological layer during operation, which causes irregular vibration of the host system, resulting in low tunneling efficiency, and is more likely to cause cutterhead cracking and component damage. To this end, with the help of analysis software such as Matlab and Ansys, the intrinsic characteristics and vibration response of the host system are studied, and the specific parameters of the vibration influencing factors are discussed. The results show that the axial displacement of the center block of the cutterhead is the largest, reaching 0.85 mm, and the longitudinal displacement value is about 2-3 times of the transverse displacement; in the design stage, the mass of the central block should be controlled in the range of 50 %-55 %, and the rest of the cutterhead should be controlled in the range of 12.5 %-13.5 %; the vibration is the smallest under the uniform layout of the gear, the fluctuation of the solid short shaft connection of the motor is relatively stable, and the maximum vibration value does not exceed 3.5e-2 mm
Denoising for ECG signals based on VMD and RLS
Full text linkElectrocardiogram (ECG) signals often encounter various types of noise interference, which annihilates their waveform characteristics and exhibits strong instability. To facilitate clinical diagnosis and analysis, it is necessary to perform denoising processing in advance. A denoising method for ECG signals based on variational mode decomposition (VMD) and recursive least square (RLS) has been proposed. VMD was used for the modal decomposition of noisy ECG signals, and the recursive least square (RLS) algorithm was used for adaptive filtering of various intrinsic mode functions (IMFs) components. The problem construction, solution, and decomposition characteristics of VMD were analyzed. The IMFs filtered by RLS were reconstructed. This achieved the elimination of interference noise in the ECG signal. The Sym8 wavelet basis, LMS, NLMS, RLS, and VMD-RLS denoising method were compared by using ECG signals including Gaussian white noise, baseband drift, electrode motion, electromyographic interference, and electrical interference noise. The experimental results showed that the VMD-RLS denoising method has significantly better denoising performance than the other four methods, achieving better values in the quantitative evaluation indicators. This algorithm improved convergence speed and signal estimation accuracy, and it has good effectiveness, superiority, and practicality. Therefore, the VMD-RLS denoising method can enable doctors and researchers to analyze and diagnose ECG signals of heart diseases more accurately
Towards explainable artificial intelligence with potential games
Full text linkExplainable Artificial Intelligence (XAI) emerged when researchers attempted to identify methods that would interpret the models that are used to perform classification and predictions, in order to avoid having a black box just informing about the result. Methods of XAI are crucial to determine details of the model feature contribution towards the result. One of these methods is attributed to cooperative game theory and especially Shapley values. With this method the features are considered as players and the marginal contribution of the features are employed. In this paper, we take onboard the Potential Game paradigm to show the interconnection between them and the Shapley values. We show that the Shapley values are interlinked with the potential function. Moreover, we setup a game with the marginal contribution of the players as their utility functions and we prove that the game is a potential game. Finally, we show that the price of stability of this game is 1. We utilise the Simulated Annealing (SA) method to find the optimal solution
Construction of a mathematical model of the motion of a vibrating separator with pneumatic suspension
Full text linkThe mathematical model of the movement of an arbitrary point of the container of a vibrating separator with a pneumatic suspension is built in the article. For modeling, a vibrating separator with two independently driven unbalances and a pneumatic suspension was chosen, which has a number of advantages over other separators, is characterized by simplicity of construction and maintenance, and low sensitivity to the properties of the medium being separated. The developed unified parameterized model of a vibrating separator can be used by changing its parameters or zeroing them for a wide range of designs of vibrating separators. The use of data from ready-made unified mathematical models allows you to reduce the duration of research and design of vibrating separators, and reduce material costs in general
Energy analysis of living stumps slope based on Hilbert-Huang Transform and marginal spectrum
Full text linkA large-scale shaking table model test on a slope with living stumps was designed and conducted. Under various types of seismic waves and excitation intensities, acceleration data from monitoring points on both sides of the living stumps were collected. Hilbert-Huang Transform (HHT) was innovatively applied to study the dynamic response of slopes with living stumps under seismic loading, overcoming the limitations of traditional Fourier Transform and Wavelet Transform. The variation patterns of Hilbert energy and marginal spectral characteristics under different seismic excitations were analyzed, providing new insights from both time-frequency domain and energy perspectives. The research conclusion showed that: (1) Under different seismic waves, the horizontal peak acceleration inside the living stumps slope shows the elevation amplification effect, and increases with the intensity of excitation. Additionally, the existence of living stumps causes a difference in horizontal acceleration on both sides, and the absolute value of the difference is positively correlated with elevation and excitation intensity. (2) Under different seismic waves, Peak of Hilbert energy spectrum (PSHEA) is positively correlated with excitation intensity and elevation. With the increase of elevation, the increase of PSHEA increases gradually when the excitation intensity increases. PMSA is positively correlated with excitation intensity, but at low frequencies (1-3 Hz), Peak of marginal spectrum (PMSA) is negatively correlated with elevation; while at high frequencies (7-11 Hz), PMSA is positively correlated with elevation. (3) With increasing elevation and excitation intensity, the total seismic Hilbert energy continues to accumulate and reaches the maximum at the top of the slope. During the propagation of seismic waves, the living stumps and the rock-soil composite play the characteristics of filtering the low-frequency components and amplifying the high-frequency components, causing the total seismic Hilbert energy in the low-frequency (1-3 Hz) component to gradually decrease and transfer to the high-frequency (7-11 Hz) component, resulting in a significant increase in seismic Hilbert energy in the high-frequency component. (4) The superposition of incident wave and reflected wave near the living stumps, and the absorption of seismic Hilbert energy by the living stumps make the PSHEA, PMSA, and total seismic Hilbert energy on the outside of the living stumps always smaller than the inside, resulting in different dynamic responses on either side of the living stumps. The living stumps show attenuation effect on seismic Hilbert energy, and the attenuation degree increases with the increase of excitation intensity and elevation. The study provides a theoretical basis for the seismic design of living stumps slopes
Study on the variation mechanism of non-linear stiffness of rubber O-ring
Full text linkO-ring dampers can be used as vibration-damping elements for short-life, low-cost engines, and the selection of a suitable rubber superelastic-viscoelastic ontological model to study their stiffness and damping is an important prerequisite for determining their vibration-damping characteristics. The superelastic-viscoelastic constitutive model consists of two models, superelastic and viscoelastic, in which the superelastic model reflects the static characteristics of the O-ring. Therefore, it is the basis of the study of dynamic characteristics to carry out the research on the static stiffness of the O-ring and to select an accurate superelastic model to describe its deformation and recovery characteristics under different working conditions. Based on the fact that the O-ring is in a small deformation range in the damper and the applicability of finite element simulation, the Mooney-Rivilin superelastic constitutive model is selected in this paper. Establish a three-dimensional finite element model of the O-ring damper, focusing on the analysis of the effect of temperature on the O-ring material properties and damper structure, to reveal the mechanism of non-linear stiffness change of the O-ring damper. At the same time, the accuracy of the hyperelastic model is verified by the test method, which lays a foundation for the study of the dynamic stiffness and damping characteristics of the O-ring. The results show that in the pre-compression state, there is a large contact pressure between the O-ring and the inner and outer rings of the damper. The contact pressure increases linearly during the compression process, and the stiffness of the O-ring changes linearly. In the non-pre-compression state, the contact pressure is 0, the contact pressure increases nonlinearly during the compression process, and the stiffness of the O-ring shows obvious nonlinear characteristics. In addition, the static stiffness of the O-ring increases with the increase of pre-compression amount, increases with the increase of material hardness, and decreases with the increase of temperature. The above research provides a reference for selecting the appropriate O-ring material size and installation conditions in the project to ensure that the O-ring can effectively withstand pressure during use
Analysis of the structural performance of reinforced concrete under fire loading
Full text linkThis study examined the behavior of reinforced concrete structures when exposed to high temperatures resulting from fire. Deterioration in material strength due to fire exposure alters a reinforced concrete structure’s load-bearing capacity and overall behavior. Elevated temperatures negatively affect key material properties of reinforced concrete, including density, coefficient of thermal expansion, thermal conductivity, and elastic modulus. As a result, if a structure experiences fire either concurrently with or prior to an earthquake, these changes in material properties will significantly influence its dynamic performance. For the numerical simulation, the selected structure was designed with a formwork plan and load-bearing system in accordance with earthquake-resistant design principles. Based on this design, fixed and variable loads acting on the beams were assigned. By promoting resilient infrastructure capable of withstanding severe environmental conditions such as earthquakes and fires, this study contributes to the achievement of sustainable development goals. It underscores the necessity of integrating fire resistance into earthquake-resistant design to foster disaster-resilient urban development. The findings may encourage more flexible and sustainable construction practices aligned with SDGs 9 (Industry, Innovation and Infrastructure), 11 (Sustainable Cities and Communities), and 13 (Climate Action)