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Observer-Based Adaptive Robust Precision Motion Control of a Multi-Joint Hydraulic Manipulator

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1213-1226页

作者： Zheng Chen Shizhao Zhou Chong Shen Litong Lyu Junhui Zhang Bin Yao State Key Laboratory of Fluid Power and mechatronic systems Zhejiang UniversityHangzhou 310027 Ocean College Zhejiang UniversityZhoushan 316021China School of Mechanical engineering Shijiazhuang Tiedao UniversityShijiazhuang 050000 State Key Laboratory of Fluid Power and mechatronic systems Zhejiang UniversityHangzhou 310027China School of Mechanical engineering Purdue UniversityWest LafayetteIN 47907 USA

Hydraulic manipulators are usually applied in heavy-load and harsh operation ***,when faced with a complex operation,the traditional proportional-integral-derivative(PID)control may not meet requirements for high control ***-based full-state-feedback control is an effective alternative,but the states of a hydraulic manipulator are not always available and reliable in practical applications,particularly the joint angular velocity *** that it is not suitable to obtain the velocity signal directly from differentiating of position measurement,the low-pass filtering is commonly used,but it will definitely restrict the closed-loop bandwidth of the whole *** avoid this problem and realize better control performance,this paper proposes a novel observerbased adaptive robust controller(obARC)for a multi-joint hydraulic manipulator subjected to both parametric uncertainties and the lack of accurate velocity ***,a nonlinear adaptive observer is first designed to handle the lack of velocity measurement with the consideration of parametric ***,the adaptive robust control is developed to compensate for the dynamic uncertainties,and the close-loop system robust stability is theoretically proved under the observation and control ***,comparative experiments are carried out to show that the designed controller can achieve a performance improvement over the traditional methods,specifically yielding better control accuracy owing to the closed-loop bandwidth breakthrough,which is limited by low-pass filtering in fullstate-feedback control.

关键词： handle Observer filtering

Numerical modeling and experimental investigation of a two-phase sink vortex and its fluid-solid vibration characteristics

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第1期25卷 47-62页

作者： Zichao YIN Yesha NI Lin LI Tong WANG Jiafeng WU Zhe LI Dapeng TAN College of Mechanical engineering Zhejiang University of TechnologyHangzhou310014China State Key Laboratory of Fluid Power and mechatronic systems Zhejiang UniversityHangzhou310058China

A sink vortex is a common physical phenomenon in continuous casting,chemical extraction,water conservancy,and other industrial processes,and often causes damage and loss in ***,the real-time monitoring of the sink vortex state is important for improving industrial production ***,its suction-extraction phenomenon and shock vibration characteristics in the course of its formation are complex mechanical dynamic factors for flow field state *** address this issue,we set up a multi-physics model using the level set method(LSM)for a free sink vortex to study the two-phase interaction ***,a fluid–solid coupling dynamic model was deduced to investigate the shock vibration characteristics and reveal the transition mechanism of the critical flow *** numerical results show that the coupling energy shock induces a pressure oscillation phenomenon,which appears to be a transient enhancement of vibration at the vortex penetration *** central part of the transient enhancement signal is a high-frequency *** on the dynamic coupling model,an experimental observation platform was established to verify the accuracy of the numerical *** water-model experiment results were accordant with the numerical *** above results provide a reference for fluid state recognition and active vortex control for industrial monitoring systems,such as those in aerospace pipe transport,hydropower generation,and microfluidic devices.

关键词： Free sink vortex Fluid-solid coupling Level set method(LSM) Multi-physics model Vibration characteristics

A laser-engraved wearable gait recognition sensor system for exoskeleton robots

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Microsystems & Nanoengineering 2024年第2期10卷 269-277页

作者： Maowen Sun Songya Cui Zezheng Wang Huayu Luo Huayong Yang Xiaoping Ouyang Kaichen Xu State Key Laboratory of Fluid Power and mechatronic systems School of Mechanical EngineeringZhejiang UniversityHangzhou310027China School of Information and Electrical engineering Hangzhou City UniversityHangzhou310015China

As a reinforcement technology that improves load-bearing ability and prevents injuries,assisted exoskeleton robots have extensive applications in freight transport and health *** perception of gait information by such robots is vital for their *** information is the basis for motion planning in assistive and collaborative ***,a wearable gait recognition sensor system for exoskeleton robots is *** sensor arrays based on laser-induced graphene are developed with flexibility and *** sensor units are integrated into an insole to detect real-time pressure at key plantar *** addition,the circuit hardware and the algorithm are designed to reinforce the sensor system with the capability of gait *** experimental results show that the accuracy of gait recognition by the proposed system is 99.85%,and the effectiveness of the system is further verified through testing on an exoskeleton robot.

关键词： hardware robot skeleton

Investigation of Adhesive Perception Based on Friction and Brain Activation

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Journal of Bionic engineering 2024年第4期21卷 1862-1877页

作者： Xingxing Fang Wei Tang Shousheng Zhang Tengfei Zhuang School of mechatronic engineering China University of Mining and TechnologyXuzhou221116JiangsuChina

The enhancement of adhesive perception is crucial to maintaining a stable and comfortable grip of the skin-touch *** study the tactile perception of adhesive surfaces,subjective evaluation,skin friction and vibrations,and neurophysiological response of the brain activity were investigated *** materials,which are commonly used for bionic materials and skin-touch products,were chosen for the tactile *** results showed that with the increasing of surface adhesion,the dominant friction transferred from a combination of adhesive friction and deformation friction to adhesive *** friction coefficient and vibration amplitude had strong correlations with the perceived adhesion of *** parietal lobe and occipital lobe were involved in adhesive perceptions,and the area and intensity of brain activation increased with the increasing surface *** with larger adhesion tended to excite a high P300 amplitude and short latency,indicating that the judgment was faster and that more attentional resources were involved in adhesive ***,the electroencephalograph signals of the adhesive perception were simulated by the neural mass *** demonstrated that the excitability and intensity of brain activity,and the connectivity strength between two neural masses increased with the increasing surface *** study is meaningful to understand the role of surface adhesion in tactile friction and the cognitive mechanism in adhesive perception to improve the tactile experience of adhesive materials.

关键词： Surface adhesion Tactile perception Friction Brain activation Neural mass model

Leakage and diffusion characteristics of underground hydrogen pipeline

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Petroleum 2024年第2期10卷 319-325页

作者： Wenkang Zhang Guanghui Zhao School of mechatronic engineering Southwest Petroleum UniversityChengdu610500China

Soil corrosion and hydrogen embrittlement are the main factors of hydrogen pipeline failure. The gas escapes, diffuses and accumulates in the soil and enters the atmosphere when leak occurs. The mechanism of gas diffusion in buried pipelines is very complicated. Mastering the evolution law of hydrogen leakage diffusion is conducive to quickly locating the leakage point and reducing the loss. The leakage model of the underground hydrogen pipeline is established in this paper. The effect of leakage hole, soil type, pipeline pressure, pipeline diameter on hydrogen leakage diffusion were investigated. The results show that when the hydrogen pipeline leaks, the hydrogen concentration increases with the increase of leakage time, showing a symmetrical distribution trend. With the pipeline pressure increase, hydrogen leakage speed is accelerated, and longitudinal diffusion gradually becomes the dominant direction. As the leakage diameter increases, hydrogen leakage per unit of time increases sharply. Hydrogen diffuses more easily in sandy soil, and its diffusion speed, concentration, and range are higher than that in clay soil. The research content provides a reference and basis for the detection and evaluation of buried hydrogen pipeline leakage.

关键词： Buried pipeline Hydrogen leakage Diffusion characteristics Numerical simulation

An improved lightweight network based on deep learning for grape recognition in unstructured environments

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Information Processing in Agriculture 2024年第2期11卷 202-216页

作者： Bingpiao Liu Yunzhi Zhang Jinhai Wang Lufeng Luo Qinghua Lu Huiling Wei Wenbo Zhu School of mechatronic engineering and Automation Foshan UniversityFoshan 528000China

In unstructured environments,dense grape fruit growth and the presence of occlusion cause difficult recognition problems,which will seriously affect the performance of grape picking *** address these problems,this study improves the YOLOx-Tiny model and proposes a new grape detection model,YOLOX-RA,which can quickly and accurately identify densely growing and occluded grape *** proposed YOLOX-RA model uses a 3×3 convolutional layer with a step size of 2 to replace the focal layer to reduce the computational *** CBS layer in the ResBlock_Body module of the second,third,and fourth layers of the backbone layer is removed,and the CSPLayer module is replaced by the ResBlock-M module to speed up the *** auxiliary network(AlNet)with the remaining network blocks was added after the ResBlock-M module to improve the detection *** depth-separable convolutions(DsC)are used in the neck module layer to replace the normal convolution to reduce the computational *** evaluated the detection performance of SSD,YOLOv4 SSD,YOLOv4-Tiny,YOLO-Grape,YOLOv5-X,YOLOX-Tiny,and YOLOX-RA on a grape test *** results show that the YOLOX-RA model has the best detection performance,achieving 88.75%mAP,a recognition speed of 84.88 FPS,and model size of 17.53 *** can accurately detect densely grown and shaded grape bunches,which can effectively improve the performance of the grape picking robot.

关键词： YOLOX Grape recognition Depthwise separable convolution Res Block-M AINet

Recent progress in self-propelled particles

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Journal of Hydrodynamics 2024年第1期36卷 61-77页

作者： Zhen-yu Ouyang Jian-zhong Lin Laboratory of Impact and Safety engineering Ministry of EducationNingbo UniversityNingbo315201China Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou310027China

Self-propelled particles are commonly found in a large number of planktonic organisms such as bacteria,fungi,and algae in nature,and researchers have taken a long interest in exploring their swimming mechanisms for more than a *** in the past 20 years,with the development of computational fluid dynamics and flow display technology,as well as the need for the design of synthetic self-propelled particles and micro-swimming devices,self-propelled particles have become the forefront and hotspot of current research in the field of fluid *** paper first introduces the swimming characteristics of common self-propelled particles,leading to a classic“squirmer”type self-propelled particle *** this basis,a systematic introduction and summary of the theoretical and numerical simulation research of“squirmer”will be ***,the main challenges and opportunities faced by the current research will be summarized.

关键词： Self-propelled particles multiphase flow hydrodynamic interaction

Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

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Bio-Design and Manufacturing 2024年第1期7卷 1-13页

作者： Huaizhi Zong Junhui Zhang Lei Jiang Kun Zhang Jun Shen Zhenyu Lu Ke Wang Yanli Wang Bing Xu The State Key Laboratory of Fluid Power and mechatronic systems Zhejiang UniversityHangzhou 310058China Unmanned Vehicle Research and Development Center China North Vehicle Research InstituteBeijing 100072China School of mechatronic engineering Nanchang UniversityNanchang 330031China Auclean High-Tech Ltd. Wuxi 214108China

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped *** various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large *** the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight *** by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an *** propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston *** addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the *** mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah *** mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

关键词： Additive manufacturing Bionic lightweight design Limb leg unit Quadruped robot Trajectory tracking

Numerical and experimental investigation on hydraulic-electric rock fragmentation of heterogeneous granite

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International Journal of Mining Science and Technology 2024年第1期34卷 15-29页

作者： Xiaohua Zhu Ling He Weiji Liu Yunxu Luo Youjian Zhang Wuji Tang School of mechatronic engineering Southwest Petroleum UniversityChengdu 610500China School of Mechanical engineering Sichuan University of Science and EngineeringYibin 643002China

Hydraulic-electric rock fragmentation(HERF)plays a significant role in improving the efficiency of high voltage pulse rock ***,the underlying mechanism of HERF remains *** this study,considering the heterogeneity of the rock,microscopic thermodynamic properties,and shockwave time domain waveforms,based on the shockwave model,digital imaging technology and the discrete element method,the cyclic loading numerical simulations of HERF is achieved by coupling electrical,thermal,and solid mechanics under different formation temperatures,confining pressure,initial peak voltage,electrode bit diameter,and loading ***,the HERF discharge system is conducive to the laboratory experiments with various electrical parameters and the resulting broken pits are numerically reconstructed to obtain the geometric *** results show that,the completely broken area consists of powdery rock *** the pre-broken zone,the mineral cementation of the rock determines the transition of type CⅠcracks to type CⅡand type CⅢ***,the peak pressure of the shockwave increased with initial peak voltage but decreased with electrode bit diameter,while the wave front time ***,increasing well depth,formation temperature and confining pressure augment and inhibit HERF,but once confining pressure surpassed the threshold of 60 MPa for 152.40,215.90,and 228.60 mm electrode bits,and 40 MPa for 309.88 mm electrode bits,HERF is ***,for the same kind of rock,the volume and width of the broken pit increase with higher initial peak voltage and rock fissures will promote ***,the electrode drill bit with a 215.90 mm diameter is more suitable for drilling pink *** research contributes to a better microscopic understanding of HERF and provides valuable insights for electrode bit selection,as well as the optimization of circuit parameters for HERF technology.

关键词： Hydraulic-electric rock fragmentation Shockwave Thermodynamics Microcracks Weak Linear Parallel Bond Model