Article
Acoustics
Yisheng Zheng, Xinong Zhang, Yajun Luo, Shilin Xie, Yahong Zhang
Summary: In this study, a six-degrees-of-freedom quasi-zero-stiffness isolation platform constructed using compressed-spring structures is proposed. Static and dynamic analysis show that the presence of static load results in linear cross-coupling effects, affecting the isolation performance of the platform in coupling directions.
JOURNAL OF VIBRATION AND CONTROL
(2021)
Article
Engineering, Mechanical
Guilin Wen, Junfeng He, Jie Liu, Yu Lin
Summary: This study aims to expand the effective displacement range of quasi-zero stiffness systems through a semi-active control strategy. A novel vibration isolation system based on oblique springs and a coil spring is proposed, along with a feedback displacement strategy for stiffness adjustment. Theoretical analysis and virtual prototype simulation results show significant advantages in low-frequency vibration isolation performance for the proposed system.
NONLINEAR DYNAMICS
(2021)
Article
Construction & Building Technology
Tao Liu, Aiqun Li, Hengyuan Zhang
Summary: Compared with the linear isolation system, the quasi-zero-stiffness (QZS) nonlinear isolation system has better low-frequency vibration isolation performance due to its high static stiffness and low dynamic stiffness. To optimize the isolation performance, a new isolation device based on the parallel connection of oblique springs and vertical springs was proposed, which can expand the interval of quasi-zero-stiffness through parameter optimization design. The vibration isolation performance of the QZS system was analyzed and compared with the linear system through a shaking table test.
STRUCTURAL CONTROL & HEALTH MONITORING
(2023)
Article
Engineering, Mechanical
Song Zuo, Dayang Wang, Yongshan Zhang, Quantian Luo
Summary: This paper investigates a parabolic cam-roller (PCR) quasi-zero stiffness (QZS) vibration isolator, which outperforms circular cam-roller (CCR) isolator in terms of vibration isolation performance. Experimental results show that the proposed PCR QZS isolator can withstand larger amplitudes of excitation and has lower stiffness and transmissibility around the equilibrium position compared to the CCR QZS isolator.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Ming Li, Wei Cheng, Ruili Xie
Summary: This paper introduces a passive quasi-zero-stiffness vibration isolator using a cam mechanism, which can generate ideal simplest restoring force directly and eliminate approximation errors. Experimental results confirm the proposed design principle and show the advantages of the QZS isolator in vibration tests, with wider isolation frequency bandwidth and weaker resonance effect compared to linear counterparts. The specific isolation efficiency and the effect of excitation amplitudes on vibration attenuation performance are comprehensively compared.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Acoustics
Yishen Tian, Xiaoyun Zhang, Chao Chen, Bo Fang, Dengqing Cao
Summary: This study investigates the nonlinear transverse vibration of a beam with one end free and the other end simply supported with a torsion spring. A torsional quasi-zero-stiffness vibration isolator is employed at the fixed end of the beam for vibration isolation. Differential equation of motion and natural characteristics of the beam are obtained using Hamilton's principle. The quasi-zero-stiffness vibration isolation system shows superior performance compared to the linear torsion spring, reducing the first resonant frequency and providing wide effective isolation range at low frequency.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Acoustics
Ge Yan, Zhi-Yuan Wu, Xin-Sheng Wei, Sen Wang, Hong-Xiang Zou, Lin-Chuan Zhao, Wen-Hao Qi, Wen-Ming Zhang
Summary: Various quasi-zero stiffness (QZS) vibration isolators have been successfully applied in low-frequency vibration isolation in recent years. However, the current approach is limited to compensating the negative stiffness of bistable structures using linear springs. This study proposes a nonlinear compensation method and verifies its effectiveness through a confirmatory system.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Mechanical
Junhan An, Guoping Chen, Xi Deng, Chen Xi, Tao Wang, Huan He
Summary: This paper examines the dynamic phenomenon of a pneumatic QZS isolator with mistuned mass and analyzes the amplitude-frequency relationship and force transmissibility. The results show that, in the case of a large mass mistuning, the system exhibits possible response periods and chaos phenomena. Mass detuning leads to a more complex nonlinear response of the QZS isolator, and the dynamic response becomes more sensitive to changes in parameters such as external excitation frequency, amplitude, and damping ratio. These findings are helpful for improving the structure of the pneumatic QZS vibration isolator and determining the applicable working frequency.
NONLINEAR DYNAMICS
(2022)
Article
Engineering, Mechanical
Chun Cheng, Yan Hu, Ran Ma, Weiping Wang
Summary: A displacement-velocity feedback control method is proposed to improve the isolation performance of a quasi-zero-stiffness vibration isolator (QZS-VI). The study considers the effect of time delay and analyzes its impact on system stability and frequency response. The results show that the proposed control method can effectively suppress vibration in the resonant region without affecting the performance in the isolation region.
NONLINEAR DYNAMICS
(2023)
Article
Mechanics
Yanqi Liu, Wen Ji, Erjie Deng, Xin Wang, Chunfang Song
Summary: This study presents a two degree-of-freedom quasi-zero stiffness (QZS) vibration isolator based on the anti-resonance characteristics of a multi-degree-of-freedom system. Nonlinear inclined springs (NIS) are used to achieve the nonlinear stiffness, with both linear and cubic stiffness terms. The effects of various mechanical and structural parameters on the stiffness characteristics are analyzed, and the dynamic response and force transmissibility are numerically discussed. The results show that the system can achieve smaller stiffness and wider low-stiffness range near equilibrium position by using smaller structural parameters and nonlinear inclined springs with softening stiffness.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Engineering, Mechanical
Tengfei Chen, Yuxuan Zheng, Linhui Song, Xiumin Gao, Zhiming Li
Summary: This paper proposes a quasi-zero-stiffness (QZS) isolator with a new design of positive stiffness configuration, which exhibits beneficial nonlinearity and enhances the vibration isolation performance compared to previous designs.
NONLINEAR DYNAMICS
(2023)
Article
Chemistry, Multidisciplinary
Quan Zhang, Dengke Guo, Gengkai Hu
Summary: A new design strategy for a programmable quasi-zero-stiffness (QZS) mechanical metamaterial is proposed in this research, which can achieve tailored stair-stepping force-displacement curves with multiple QZS working ranges and ultra-low frequency vibration isolation capability. The mechanism solely depends on the structural geometry of curved beams and is materials-independent, opening up a new avenue for innovating compact and scalable QZS isolators.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Engineering, Mechanical
Kan Ye, J. C. Ji
Summary: In this study, an origami-inspired vibration isolator with quasi-zero-stiffness (QZS) property is proposed using a truss-spring based stack Miura-ori (TS-SMO) structure. The unique structure uses coil spring sets to replace deformable creases, improving physical realization in engineering applications. Nonlinear force response and QZS feature are achieved through geometric nonlinearity and specific Poisson's ratio profile, with isolation performance discussed under variable viscous damping effects.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Instruments & Instrumentation
G. L. Leandri, A. Sunderland, J. Winterflood, L. Ju
Summary: The novel design allows column springs in Euler buckling mode to be laterally stable, providing vibration isolation in six degrees of freedom. The stiffness was analytically modeled to achieve resonant frequencies of 1.13 Hz vertically, 1.68 Hz horizontally, and 2.58 Hz in roll. A prototype vibration isolator demonstrated a 2x reduction in vertical vibration at 2 Hz, and a 100x reduction in vertical, horizontal, and roll vibrations above 20 Hz.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Acoustics
Nur Afifah Kamaruzaman, William S. P. Robertson, Mergen H. Ghayesh, Benjamin S. Cazzolato, Anthony C. Zander
Summary: This paper compares passive and active stability analyses of a six degree of freedom quasi-zero stiffness magnetic levitation vibration isolation system. The study shows that increasing passive stability has a minimal impact on isolation performance, but control benefits from improved passive stability. The designed control system demonstrates robustness to uncertainties with a large stability margin dominating the closed-loop response.
JOURNAL OF SOUND AND VIBRATION
(2021)
Article
Chemistry, Analytical
Jinsong Sang, Hongbin Sun, Lei Kou
Summary: Microgrids face challenges such as small-scale volatility, uncertainty, intermittency and demand-side uncertainty of distributed energy resources (DERs). Traditional microgrids are unable to meet the flexible energy dispatch between complex demands and microgrids. This paper proposes an overall environment approach for microgrid control, which ensures power supply for flexible loads and minimizes input costs by considering the response priority of each component.
Article
Mathematics
Jiawei Yin, Agung Julius, John T. Wen, Zhen Wang, Chuanlin He, Lei Kou
Summary: This paper addresses the optimization of light exposure and sleep schedules to improve alertness, using a three-process hybrid dynamic model to simulate circadian rhythm and predict alertness. By adjusting sleep and wake times based on individual differences, the impacts of light and sleep schedules on alertness are evaluated using variational calculus, and an optimal solution is determined using a gradient descent algorithm.
Article
Physics, Multidisciplinary
Fangfang Zhang, Zhe Huang, Lei Kou, Yang Li, Maoyong Cao, Fengying Ma
Summary: In this paper, a new 9-dimensional complex chaotic system with quaternion is proposed for the encryption of smart grid data. Pseudo-random sequences generated by the new chaotic system are used to encrypt power data. The verification results show that the proposed encryption scheme is technically feasible and available for power data encryption in smart grid.
Article
Engineering, Industrial
Jian Wang, Shibin Gao, Long Yu, Dongkai Zhang, Chenlin Xie, Ke Chen, Lei Kou
Summary: In this paper, a data-driven Bayesian network (BN) approach with spatiotemporal fragility model is proposed to predict the lightning-related failure risk of overhead contact lines (OCLs) in high-speed railways. The approach integrates multiple key lightning parameters to capture the uncertainty in lightning occurrence and intensity, examines the impacts of lightning strike on OCL failure probability using a spatiotemporal fragility model, and achieves better prediction performance compared to other methods.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Article
Engineering, Multidisciplinary
Zhen Wang, Lei Kou, Wende Ke, Yuhan Chen, Yan Bai, Qingfeng Li, Dongxin Lu
Summary: In this paper, the Linear Quadratic Regulator (LQR) method is used to track the center of mass (COM) of a robot, and the whole-body-control method and value function generated in the process of tracking COM are used to construct the quadratic programming (QP) model of a biped robot. The torque feedforward of the robot is obtained in the Drake simulation platform, and the torque feedforward information is transformed into position feedforward information by spring compensation. The experimental results show that the spring compensation method is both reasonable and effective for improving the motion performance of a low-cost biped robot.
Article
Engineering, Industrial
Jian Wang, Shibin Gao, Long Yu, Chaoqun Ma, Dongkai Zhang, Lei Kou
Summary: In this study, a data-driven integrated predictive probabilistic risk analytics framework based on dynamic Bayesian network is proposed to comprehensively investigate the associated risks in overhead contact lines (OCLs). By exploiting weather-driven analytics for failure probability prediction and developing an integrated failure probability modelling for OCL components, the framework can dynamically model and evaluate risks of failure patterns that expose to OCLs.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Article
Environmental Sciences
He Xu, Bin Lv, Jie Chen, Lei Kou, Hailin Liu, Min Liu
Summary: Water quality is crucial for marine pasture farming, and its parameters exhibit time series characteristics with instability and nonlinearity. To overcome the limitations of previous models, this study proposes an LSTM-BP combined prediction model that utilizes long short-term memory (LSTM) and backpropagation (BP) neural networks. The model is evaluated using RMSE, MAE, and NSE, showing superior performance compared to other models. The LSTM-BP model effectively captures time series characteristics and nonlinear mapping capabilities, offering a new method for water quality parameter prediction in marine ranching and promoting intelligent and sustainable development.
Article
Green & Sustainable Science & Technology
Hongbin Sun, Xinmei Sun, Lei Kou, Wende Ke
Summary: Against the background of the 30 x 60 target, this study proposes an optimal dispatching model for a park-level integrated energy system considering flexible load and Power-to-Gas (P2G) participation in the carbon trading market. The results demonstrate the importance of considering the operational cost of P2G and the feasibility of integrating operating economy and wind power accommodation ability in integrated energy systems.
Article
Engineering, Multidisciplinary
Yuhan Chen, Qingfeng Li, Dongxin Lu, Lei Kou, Wende Ke, Yan Bai, Zhen Wang
Summary: Continuous exploration of the ocean has led to the emergence of numerous CNN-based underwater image enhancement methods. However, the existing methods have limited feature-learning abilities and fail to meet the requirements of both suitable enhancement effects and real-time performance. In this study, we propose an optimal underwater image-enhancing composite backbone network (OECBNet) to achieve better enhancement effects and shorter running time. A comprehensive investigation of different composite architectures was conducted, resulting in a CBNet with optimal performance. Experimental results demonstrate that our optimized network outperforms existing CNN-based methods in generating enhanced images.
Article
Engineering, Multidisciplinary
Qingfeng Li, Yuhan Chen, Yijie Pang, Lei Kou, Dongxin Lu, Wende Ke
Summary: Ear image segmentation and identification using image processing technology improves the diagnosis and treatment of intelligent traditional Chinese medicine ear acupoints. An AAM-based method for ear acupoint segmentation divides the ear's acupoints precisely. This method can be used for intelligent disease diagnosis and has the same abilities as experienced doctors.
Article
Computer Science, Artificial Intelligence
Lei Kou, Fangfang Zhang, Luobing Chen, Wende Ke, Quande Yuan, Junhe Wan, Zhen Wang
Summary: This paper proposes a cellular automata with weights (CAW) algorithm, which connects the updated cell and its neighbors using weights to determine the output of each cell. The error correction algorithm is then used to find the correct transition rules by adjusting weights. Mathematical analysis and simulation show that the proposed algorithm has the ability to find correct transition rules.
INTERNATIONAL JOURNAL OF BIO-INSPIRED COMPUTATION
(2023)
Article
Energy & Fuels
Hongbin Sun, Xinmei Sun, Lei Kou, Benfa Zhang, Xiaodan Zhu
Summary: In this study, a low-carbon economic operation optimization model is constructed to improve the utilization efficiency of multi-energy coupling in park-level integrated energy system (PIES), promote wind power consumption, and reduce carbon emissions. The model incorporates flexible load and carbon trading mechanism, considers load response characteristics, and gives the basic architecture of PIES. By introducing a ladder-type carbon trading mechanism and minimizing the total operating cost, the low-carbon economic operation optimization model of PIES is established. Simulation results show that the participation of electrical and thermal coupled scheduling and flexible electric or thermal loads can significantly reduce the system operating cost, reduce the load peak-to-valley difference, and relieve peak power consumption pressure.
Article
Engineering, Industrial
Jian Wang, Huiyuan Liu, Shibin Gao, Long Yu, Xingyang Liu, Dongkai Zhang, Lei Kou
Summary: This paper proposes a robust deep Gaussian process (DGP)-based uncertainty-aware trustworthy prediction approach to the fog-haze-caused pollution flashover (FHPF) risk of overhead contact line (OCL) insulators. The key parameters affected by fog-haze on insulator surface contamination are identified, and a sampling-based inference method is used to handle uncertainty. Experimental results demonstrate the effectiveness and superiority of the proposed method compared to other predictive classification methods.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Computer Science, Artificial Intelligence
Lei Kou, Jinbo Wu, Fangfang Zhang, Peng Ji, Wende Ke, Junhe Wan, Hailin Liu, Yang Li, Quande Yuan
Summary: An encryption algorithm for offshore wind power based on two-dimensional lagged complex logistic mapping (2D-LCLM) and Zhou Yi eight trigrams is proposed. The algorithm demonstrates resistance to common attacks and has excellent encryption performance.
INTERNATIONAL JOURNAL OF BIO-INSPIRED COMPUTATION
(2023)
