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

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 tasks.However,when faced with a complex operation,the traditional proportional-integral-derivative(PID)control may not meet requirements for high control performance.Model-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 measurement.Considering 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 system.To 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 measurement.Specifically,a nonlinear adaptive observer is first designed to handle the lack of velocity measurement with the consideration of parametric uncertainties.Then,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 errors.Finally,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

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Mesenchymal stem cell-derived exosomes: Versatile nanomaterials for skin wound treatment

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Nano Research 2024年第4期17卷 2836-2856页

作者： Yuzhen Xiao Hexi Li junhui zhang Songyun Yang Chunsen zhang Yizhou Huang Xin Tang Huiqi Xie Department of Orthopedic Surgery and Orthopedic Research Institute Laboratory of Stem Cell and Tissue EngineeringState Key Laboratory of BiotherapyWest China HospitalSichuan UniversityChengdu 610041China West China School of Basic Medical Sciences and Forensic Medicine Sichuan UniversityChengdu 610041China West China School of Public Health and West China Fourth Hospital Sichuan UniversityChengdu 610041China Sports Medicine Center West China HospitalSichuan UniversityChengdu 610041China

Accumulating studies reveal that mesenchymal stem cells(MSCs)promote skin wound healing mainly through the paracrine effects.Exosomes,one of the crucial paracrine mediators in wound healing,are cell-derived nanosized membranous vesicles containing diverse bioactive cargoes.With the potent ability of modulating skin cell behaviors,MSC-derived exosomes(MSC-Exos)are regarded as a promising nanomaterial for regenerative wound therapy.Under hostile conditions,MSC-Exos are efficient in protecting skin cells from severe damage and restoring their function.According to recent studies,MSC-Exos possess remarkable pro-healing effects in a variety of skin wounds,typically resulting in increased wound closure,inhibited scar tissue formation,and better restoration of skin function.To further enhance the therapeutic potential of MSC-Exos,the development of applicable pretreatment strategies and the optimization of exosome delivery are under intensive investigation.Herein,we summarize current research progress of MSC-Exos for skin wound treatment,with an emphasis on the biological effects of these nanovesicles,the repair mechanisms,and future challenges in clinical translation.

关键词： exosomes mesenchymal stem cells diabetic wounds burn wounds scar wound healing

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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 robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As 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 design.Inspired 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 LLU.We 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 rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.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 muscle.The 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

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Rapid testing and prediction of soil–water characteristic curve of subgrade soils considering stress state and degree of compaction

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第12期15卷 3305-3315页

作者： junhui Peng Huiren Hu junhui zhang National Engineering Research Center of Highway Maintenance Technology Changsha University of Science and TechnologyChangsha410114China

The subgrade soil is generally in saturated or unsaturated condition. To analyze complex thermo-hydro-mechanical-chemical (THMC) behaviors of subgrade, it is essential to determine the soil–water characteristic curve (SWCC) that represents the relationship between matric suction and moisture content. In this study, a full-automatic rapid stress-dependent SWCC pressure-plate extractor was developed. Then, the influences of overburden stress and degree of compaction on the SWCC of subgrade soil such as high liquid limit silt (MH) and low liquid limit clay (CL) were analyzed. Accordingly, a new model taking into account the influences of overburden stress and degree of compaction based on the well-known Van Genuchten (VG) SWCC fitting model was presented and validated. The results show that with the increase of the degree of compaction and overburden stress, the saturated moisture content of subgrade soil decreases, while the air-entry value increases and the transition section curve becomes flat. The influences of the degree of compaction and overburden stress on the SWCC of MH is greater than that of CL. Meanwhile, there was a satisfactory agreement between the prediction and measurement, indicating a good performance of the new model for predicting the SWCC.

关键词： Subgrade soil Soil–water characteristic curve(SWCC) Overburden stress Degree of compaction Prediction mode

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Influence of Piston Number on Churning Losses in Axial Piston Pumps

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 194-207页

作者： Ying Li Xing Chen Hao Luo junhui zhang Jin zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Fluid Power Transmission and Control Zhejiang UniversityHangzhou 310027China

Raising the rotational speed of an axial piston pump is useful for improving its power density;however,the churning losses of the piston increase significantly with increasing speed,and this reduces the performance and efficiency of the axial piston pump.Currently,there has been some research on the churning losses of pistons;however,it has rarely been analyzed from the perspective of the piston number.To improve the performance and efficiency of the axial piston pump,a computational fluid dynamics(CFD)simulation model of the churning loss was established,and the effect of piston number on the churning loss was studied in detail.The simulation analysis results revealed that the churning losses initially increased as the number of pistons increased;however,when the number of pistons increased from six to nine,the torque of the churning losses decreased because of the hydrodynamic shadowing effect.In addition,in the analysis of cavitation results,it was determined that the cavitation area of the axial piston pump was mainly concentrated around the piston,and the cavitation became increasingly severe as the speed increased.By comparing the simulation results with and without the cavitation model,it was observed that the cavitation phenomenon is beneficial for the reduction of churning losses.In this study,a piston churning loss test rig that can eliminate other friction losses was established to verify the accuracy of the simulation results.A comparative analysis indicated that the simulation results were consistent with the actual situation.In addition,this study also conducted a simulation study on seven and nine piston pumps with the same displacement.The simulation results revealed that churning losses of the seven pistons were generally greater than those of the nine pistons under the same displacement.In addition,regarding the same piston number and displacement,reducing the pitch circle radius of piston bores is effective in reducing the churning loss.This research analyzes the effect of piston number on the

关键词： Axial piston pumps Churning losses Pistons CFD simulations Experimental study

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Piecewise model-based adaptive compensation control for high-speed trains with unknown actuator failures

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Transportation Safety and Environment 2023年第4期5卷 172-181页

作者： Chang Tan junhui zhang Hui Yang Leilei zhang School of Electrical and Automation Engineering East China Jiaotong UniversityNanchangJiangxi 330013China State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure NanchangJiangxi 330013China

In order to deal with the uncertainties caused by different operation conditions and unknown actuator failures of high-speedtrains,an adaptive failures compensation control scheme is designed based on the piecewise model.A piecewise constant model is introduced to describe the variable system parameters caused by the variable operation environments,and a multiple-particle plecewise model of high-speed trains,with unknown actuator failures,is then established.An adaptive failure compensation controller is developed for the multiple-particle piecewise constant model,by using a direct model refering to the adaptive control method.Such an adaptive controller can not only compensate the uncertainties from unknown actuator failures,but also effectively deal with the uncertainties caused by different operating conditions.Finally,a CRH380A high-speed train model is taken as the controlled object for the simulation study.The simulation results show that the proposed controller ensures the desired system performance in the presence of unknown actuator failures and uncertain operation conditions.

关键词： actuator failures adaptive compensation piecewise model high-speed train multiple-particle model

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Synoptic-Scale Analysis on Development and Maintenance of the 19–21 July 2021 Extreme Heavy Rainfall in Henan,Central China

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Journal of Meteorological Research 2023年第2期37卷 174-191页

作者： Dorina CHYI Xiuming WANG Xiaoding YU junhui zhang China Meteorological Administration Training Centre China Meteorological AdministrationBeijing 100081 Department of Meteorology Service Yantai International AirportYantai 265617

In this paper,synoptic-scale analyses of frontogenesis,moisture budget,and tropospheric diabatic heating are performed to reveal the development and maintenance mechanisms for the extreme heavy rainfall in Henan Province of central China from 19 to 21 July 2021,based on station observations and the ECMWF Reanalysis version 5(ERA5)data.The results demonstrate that owing to the blocking effect of local topography,low-level wind convergence in Henan appeared underneath high-level divergence,conducive to development and maintenance of a midtropospheric low-pressure system saddled by the Asian continental high and the western Pacific subtropical high(WPSH),during the extreme heavy rainfall.In the lower troposphere,frontogenesis occurred in the θ_(se) intensive region,as a result of the divergence and horizontal deformation(which play equally important roles),generating frontal secondary circulation with strong vertical motion favorable to heavy rainfall.Moisture budget analysis reveals that 1)with the continuous strengthening of the easterly wind from the north side of Typhoon In-Fa(2106),strong wind shear and orographic uplift led to abnormally strong convergence of water vapor flux in the boundary layer in Henan;2)there occurred extremely strong net inflow of moisture in the boundary layer from the east.Horizontally,both the apparent heat source and the moisture sink coincided with the area of heavy rainfall;vertically,however,Q_(1)exhibited a single peak with the heating center in the middle and upper troposphere,while large Q_(2)values evenly resided over 850–400 hPa;and Q_(1)(Q_(2))was dominated by vertical(horizontal)transport of potential temperature(moisture).These indicate that the latent heat release from condensation of initial heavy rainfall provided a positive feedback,leading to increasingly heavy precipitation.All these synoptic settings sustained the extreme rainfall process.

关键词： extreme heavy rainfall frontogenesis apparent heat source moisture sink water vapor budget

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Effects of specific doses of E-beam irradiation which inactivated SARS-CoV-2 on the nutrition and quality of Atlantic salmon

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Food Science and Human Wellness 2023年第4期12卷 1351-1358页

作者： Huilin Yu junhui zhang Yan Zhao Honghao Li Yixuan Chen Jiajin Zhu Department of Food Science and Nutrition Zhejiang UniversityHangzhou 310058China

The contamination of Atlantic salmon with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has impeded the development of the cold-chain food industry and posed possible risks to the population.Electron beam(E-beam)irradiation under 2,4,7,and 10 kGy can effectively inactivate SARS-CoV-2 in cold-chain seafood.However,there are few statistics about the quality changes of salmon exposed to these irradiation dosages.This work demonstrated that E-beam irradiation at dosages capable of killing SARS-CoV-2 induced lipid oxidation,decreased vitamin A content,and increased some amino acids and ash content.In addition,irradiation altered the textural features of salmon,such as its hardness,resilience,cohesiveness,and chewiness.The irradiation considerably affected the L*,a*,and b*values of salmon,with the L*value increasing and a*,b*values decreasing.There was no significant difference in the sensory evaluation of control and irradiated salmon.It was shown that irradiation with 2−7 kGy E-beam did not significantly degrade quality.The inactivation of SARS-CoV-2 in salmon is advised at a dose of 2 kGy.

关键词： E-beam irradiation Atlantic salmon SARS-CoV-2 Physicochemical properties

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What is an effective cardiopulmonary resuscitation training mode?

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Chinese Medical Journal 2022年第9期135卷 1131-1132页

作者： Xiaojun He Yuefeng Ma Zilong Li junhui zhang Jinjun zhang Jun Liang Chinese Journal of Emergency Medicine Second Affiliated Hospital of Zhejiang University School of MedicineHangzhouZhejiang 310009China China County Hospital Emergency Alliance HangzhouZhejiang 310009China Department of Emergency Yuyao People's HospitalNingboZhejiang 315400China SunLife Medical Technology Co. Ltd.Shanghai 200233China Beijing Emergency Medical Center Beijing 100031China

To the Editor:Out-of-hospital cardiac arrest(OHCA)is a serious threat to people's lives and safety.The annual incidence of OHCA in North America is approximately 55/100,000,and it is approximately 59/100,000 in Asia.[1,2]How can the success rate of resuscitation be improved in patients with cardiac arrest?The American Heart Association(AHA)and the European Resuscitation Council have put forward their own cardiopulmonary resuscitation(CPR)guidelines,which are constantly updated with the latest research evidence.CPR training is also an important part of the guidelines.[3,4]Chinese colleagues also try to improve the success rate of rescuing patients with cardiac arrest based on the experience of their international counterparts and combine it with Chinese characteristics.CPR training is in full swing,which includes the training of first responders and medical staff.

关键词： resuscitation cardiac combine

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Modeling and Parameter Sensitivity Analysis of Valve‑Controlled Helical Hydraulic Rotary Actuator System

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 257-274页

作者： Kun zhang junhui zhang Minyao Gan Huaizhi Zong Ximeng Wang Hsinpu Huang Qi Su Bing Xu State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China Shanghai Marine Equipment Research Institute Shanghai 200031China

As a type of hydraulic rotary actuator,a helical hydraulic rotary actuator exhibits a large angle,high torque,and compact structure;hence,it has been widely used in various fields.However,its core technology is proprietary to several companies and thus has not been disclosed.Furthermore,the relevant reports are primarily limited to the component level.The dynamic characteristics of the output when a helical rotary actuator is applied to a closed-loop system are investigated from the perspective of driving system design.Two main aspects are considered:one is to establish a reliable mathematical model and the other is to consider the effect of system parameter perturbation on the output.In this study,a detailed mechanical analysis of a helical rotary hydraulic cylinder is first performed,factors such as friction and load are considered,and an accurate dynamic model of the actuator is established.Subsequently,considering the nonlinear characteristics of pressure flow and the dynamic characteristics of the valve,a dynamic model of a valve-controlled helical rotary actuator angle closed-loop system is described based on sixth-order nonlinear state equations,which has never been reported previously.After deriving the system model,a sensitivity analysis of 23 main parameters in the model with a perturbation of 10%is performed under nine operating conditions.Finally,the system dynamics model and sensitivity analysis results are verified via a prototype experiment and co-simulation,which demonstrate the reliability of the theoretical results obtained in this study.The results provide an accurate mathematical model and analysis basis for the structural optimization or control compensation of similar systems.

关键词： Helical hydraulic rotary actuator Dynamic model Closed-loop system Sensitivity analysis Prototype experiment Co-simulation

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