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Adaptive sampling for corrugated plate digitization using a laser displacement sensor

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Science China(Technological Sciences) 2024年第5期67卷 1510-1523页

作者： WU ChengXing QI Qi CHEN BaiJin YANG JiXiang ding han State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China

The surface quality of a corrugated plate directly determines the heat transfer property of the thermal power mechanical apparatus.Traditional detection methods are impractical for real-world production,being slow and destructive.In contrast,the point laser displacement sensor,employing the optical triangle method,emerges as a promising device for assessing parts with variable curvature and highly reflective surfaces.Despite its benefits,high-density sampling by an innate frequency introduces challenges such as data redundancy and a poor signal-to-noise ratio,potentially affecting the efficiency and precision of subsequent data processing.To address these challenges,adjustable frequency data sampling has been developed for this sensor,allowing adaptive sampling for corrugated plate digitization.The process begins with surface digitization to extract discrete points,which are transformed into intersection curves using the B-spline fitting technique.Subsequently,dominant points are identified,considering multigeometric constraints for curvature and arch height.Finally,the sampling signal is adjusted based on the distribution information of dominant points.Comparative results indicate that the proposed method effectively minimizes redundant sampling without compromising the accurate capture of essential geometric features.

关键词： corrugated plate laser displacement sensor adaptive sampling dominant point curvature arch height

Water modeling on fluid flow and mixing phenomena in a BOF steelmaking converter

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Journal of Iron and Steel Research(International) 2024年第3期31卷 595-607页

作者： Xin-yu Cai Hao-jian Duan ding-han Li Anjun Xu Li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

A 1∶8 physical water model was constructed to investigate the fluid flow and mixing phenomena in the basic oxygen furnace(BOF)converter.The particle image velocimetry was employed to measure the velocity distribution of the bath and the high-speed camera was applied to capture the cavity shape in the combined blowing BOF converter.The mixing time for varied operating conditions was measured by the stimulus-response approach.The cavity depth increased with the decrease in the lance height and the increase in the top gas flow rate while the bottom blowing gas had little influence on the cavity depth.The minimum cavity depth was obtained under the condition of a 69.8 m^(3)/h top gas flow rate,a 287.5 mm lance height and a 0.93 m^(3)/h bottom blowing gas flow rate,which was 161.2 mm.The mixing time decreased as the lance height decreased and the top blowing gas flow rate increased.The mixing time was first decreased and then increased with the increase in the bottom gas flow rate.With the condition of 69.8 m^(3)/h gas flow rate of top blowing,the 287.5 mm lance height and the 0.93 m^(3)/h gas flow rate of bottom blowing,the mixing time in the converter was 48.65 s.The empirical formula between the stirring power and the mixing time in the converter was calculated.

关键词： Water model Fluid flow Particle image velocimetry Mixing time BOF converter

Atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction

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Nuclear Science and Techniques 2024年第3期35卷 40-52页

作者： ding-han Zhu Xiong Zhang Xiao-Qiang Li Peng Li Yan-Bin Wang Shuang Zhang State Key Laboratory of NBC Protection for Civilian Beijing 102205China

In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such events.These pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric transmission.To quantitatively analyze the effects of different satellite detection altitudes,burst heights,and transmission angles on the physical processes of X-ray transport and energy fluence,we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction.The proposed method is an improvement over the traditional analytical method that only computes direct-transmission X-rays.The traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo method.Our improved method reduces this error to within 10% under the same conditions,even reaching 1% in certain scenarios.Moreover,its computation time is 48,000 times faster than that of the Monte Carlo method.These results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors,inverting nuclear detonation source terms,and assessing ionospheric effects.

关键词： High-altitude nuclear detonation Atmospheric transmission Pulsed X-rays Scattering correction Analytical method Monte Carlo method

Human umbilical cord mesenchymal stem cell-derived exosomes loaded into a composite conduit promote functional recovery after peripheral nerve injury in rats

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Neural Regeneration Research 2024年第4期19卷 900-907页

作者： Haoshuai Tang Junjin Li Hongda Wang Jie Ren han ding Jun Shang Min Wang Zhijian Wei Shiqing Feng Department of Othopaedics Tianjin Medical University General Hospital International Science and Technology Cooperation Base of Spinal Cord Injury Tianjin Key Laboratory of Spine and Spinal Cord InjuryDepartment of OrthopedicsTianjin Medical University General Hospital Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment Tianjin Lung Cancer InstituteTianjin Medical University General Hospital Department of Othopaedics Qilu Hospital of Shandong UniversityShandong University Centre for OthopedicsAdvanced Medical Research InstituteShandong University Orthopedic Research Center of Shandong University&Advanced Medical Research Institute Cheeloo College of MedicineShandong University

Complete transverse injury of peripheral nerves is challenging to treat.Exosomes secreted by human umbilical cord mesenchymal stem cells are considered to play an important role in intercellular communication and regulate tissue regeneration.In previous studies,a collagen/hyaluronic acid sponge was shown to provide a suitable regeneration environment for Schwann cell proliferation and to promote axonal regeneration.This three-dimensional(3D)composite conduit contains a collagen/hyaluronic acid inner sponge enclosed in an electrospun hollow poly(lactic-co-glycolic acid)tube.However,whether there is a synergy between the 3D composite conduit and exosomes in the repair of peripheral nerve injury remains unknown.In this study,we tested a comprehensive strategy for repairing long-gap(10 mm)peripheral nerve injury that combined the 3D composite conduit with human umbilical cord mesenchymal stem cell-derived exosomes.Repair effectiveness was evaluated by sciatic functional index,sciatic nerve compound muscle action potential recording,recovery of muscle mass,measuring the cross-sectional area of the muscle fiber,Masson trichrome staining,and transmission electron microscopy of the regenerated nerve in rats.The results showed that transplantation of the 3D composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes promoted peripheral nerve regeneration and restoration of motor function,similar to autograft transplantation.More CD31-positive endothelial cells were observed in the regenerated nerve after transplantation of the loaded conduit than after transplantation of the conduit without exosomes,which may have contributed to the observed increase in axon regeneration and distal nerve reconnection.Therefore,the use of a 3D composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes represents a promising cell-free therapeutic option for the treatment of peripheral nerve injury.

关键词： axon growth collagen exosome human umbilical cord mesenchymal stem cells hyaluronic acid muscular atrophy nerve guidance conduits peripheral nerve regeneration

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稀土发光纳米材料在手印显现中的应用进展

光谱学与光谱分析 2024年第6期44卷 1501-1511页

作者：丁寒中国政法大学刑事司法学院北京102249

自2000年起,研究人员陆续将一系列新型纳米材料应用到手印显现中,由此衍生了手印纳米显现技术。显现材料的推陈出新和显现方法的借鉴创新共同促进了手印纳米显现技术的迅速发展。近十年来,将稀土发光纳米材料应用于手印纳米显现技术的... 详细信息

自2000年起,研究人员陆续将一系列新型纳米材料应用到手印显现中,由此衍生了手印纳米显现技术。显现材料的推陈出新和显现方法的借鉴创新共同促进了手印纳米显现技术的迅速发展。近十年来,将稀土发光纳米材料应用于手印纳米显现技术的研究报道日益增多,已经逐渐成为该领域的研究热点之一。基于稀土发光纳米材料的手印显现技术具有对比度强、灵敏度高、选择性佳、毒害性低等突出优势,因此具备重要的理论研究价值和广阔的实践应用前景。目前,该研究领域的文献报道形式主要为研究类文章,鲜有涉及综述类文章。该文从显现材料的推陈出新和显现方法的借鉴创新两个方面综述了稀土发光纳米材料在手印显现中的研究进展。在显现材料的推陈出新方面,总结了基于稀土下转换发光纳米材料、稀土上转换发光纳米材料、复合型稀土发光纳米材料的手印显现应用;在显现方法的借鉴创新方面,总结了基于静电吸附原理、疏水作用原理、化学键合原理、适配体识别原理的手印显现方法。基于稀土发光纳米材料的手印显现研究呈现出如下发展趋势:显现材料由下转换发光材料向上转换发光材料发展,由单一发光材料向多重发光材料发展,由光致发光材料向功能复合材料发展;显现方法由非特异显现向靶向性显现发展,由痕迹物证的定性显现向遗留物质的定量检测发展,由物理显现向化学显现发展;显现效果由痕迹特征的宏观无损向生物物证的微观无损发展;显现操作由潜在毒害向绿色环保发展;显现评估由主观、片面、定性描述向客观、全面、定量分析发展。该综述对基于稀土发光纳米材料的手印显现技术提出了如下展望:首先是纳米材料的物理性质对手印显现效果的影响研究,其次是纳米材料的诸多性质对生物物证检验的影响研究,最后是显现原理的广泛借鉴与显现方法的深度开发研究。

关键词：手印显现潜在手印纳米材料稀土发光

Real time tool path smoothing of short linear commands for robot manipulator by constructing asymmetrical Pythagoran-hodograph(PH)splines

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Science China(Technological Sciences) 2023年第3期66卷 674-688页

作者： YANG JiXiang ADILI Abulikemu ding han School of Mechanical Science and Engineering State Key Laboratory of Digital Manufacturing Equipment and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

Tool path smoothing of linear commands is important to guarantee the high-order motion continuity of multi-axis motion control systems.The existing local tool path smoothing methods mainly construct symmetrical splines at transition corners of linear segments.When the linear segments are short,the symmetrical splines must be shrunk to avoid overlapping,which gives rise to relatively high curvature and low machining efficiency.This paper proposes a tool-path smoothing algorithm for serial industrial robots with 6 rotary(6R)joints by constructing asymmetrical Pythagorean-hodograph(PH)splines.Firstly,symmetrical PH splines are initially constructed at transition corners to realize the third-order differential continuity of tool path position and tool orientation.Tool tip position smoothing errors are constrained by directly evaluating the control polygon length of spline according to the error tolerance in the workpiece coordinate system,while the tool orientation smoothing errors are constrained by adjusting control polygon length after converting tool orientation error to Euler angles using Jacobian matrix.Then asymmetrical splines are constructed by dealing with the spline overlapping problem,while guarantying the fully utilization of error tolerance to reduce spline curvature.The position and orientation are synchronized to the arc-length of the tool tip position to ensure the continuity of acceleration and jerk commands.The control points and arc-length of the constructed asymmetrical splines can all be solved analytically,which makes it suitable for on-line tool path smoothing.Experiments demonstrate that the proposed method achieves higher motion efficiency and lower tracking error than the existing symmetrical and asymmetrical tool path smoothing methods,which validates the advantages of the proposed method in high speed machining.

关键词： robot tool path real time interpolation spline

Nonlinear impedance control with trajectory adaptation for collaborative robotic grinding

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Science China(Technological Sciences) 2023年第7期66卷 1928-1936页

作者： han FengTao TAM SikYuen CAO ZhiHong ZHAO XingWei TAO Bo ding han State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Intelligent Manufacturing System Technology for Complex Products Beijing Institute of Electronic System EngineeringBeijing 100854China ROKAE(Beijing)Technology Co. Ltd.Beijing 100193China

Stiffness adjustment is an important feature of human arm control.The adaptive variable impedance control can adapt to the robotic stiffness,but may result in a large overshoot.In this paper,nonlinear impedance control is proposed for collaborative robotic grinding,where nonlinear force feedback is designed to compensate for the nonlinear stiffness of the environment.Thus,the interaction system can be linearization to ensure the system stability.Moreover,a target trajectory adaptation strategy is studied to ensure the force tracking requirement.Then,switching law between trajectory tracking and force tracking is proposed when the robot performs a complex grinding task.The stability of the switch control as well as the trajectory adaptation law is proved.Experiments are conducted in a robotic grinding test rig,where the robot is used to grind a turbine blade.Experimental results show that the nonlinear impedance control can obtain stable grinding force,and have better grinding quality than the linear impedance control.

关键词： impedance control robotic grinding trajectory adaptation force tracking

Pneumatic and tendon actuation coupled muti-mode actuators for soft robots with broad force and speed range

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Science China(Technological Sciences) 2022年第9期65卷 2156-2169页

作者： ZHU JiaQi PU MengHao CHEN han XU Yi ding han WU ZhiGang State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Broad output force and speed ranges are highly desired for actuators to endow soft robots with high performance,thereby increasing the range of tasks they can accomplish.However,limited by their low structural stiffness and single actuation method,most of the existed soft actuators are still difficult to achieve a broad force and speed range with a relatively compact body structure.Here,we propose a pneumatic and tendon actuation coupled soft actuator(PTCSA)with multiple actuation modes,mainly composing of a multi-joint thermoplastic polyurethanes(TPU)-made skeleton sealed in a film sleeve.The TPU skeleton with certain structural stiffness combined with soft joints allows PTCSA to output small force and respond rapidly under pneumatic actuation,as well as output high force and flexibly regulate response speed under tendon actuation,therefore achieving a broad force and speed range with a compact structure.The multiple modes constructed from the two actuation methods with different force and speed properties can cover diverse application scenarios.To demonstrate its performance,PTCSA is further used to construct a soft robotic arm(with a maximum lifting speed of 198°/s and can easily lift a load of 200 g),an inchworm-inspired wheel-footed soft robot(moves at a high speed of 2.13 cm/s when unload or pulls a load of 300 g forward),and a soft gripper(can grasp diverse objects,from 0.1 g potato chips to an 850 g roll of Sn-0.7 Cu wire,from a high-speed moving tennis ball to an upright pen).This work indicates the potential of combining multiple complementary actuation methods to improve the force and speed range of soft actuators,and may provide inspiration for related research.

关键词： soft actuator tendon actuation pneumatic actuation broad force and speed range multiple modes

Robotic cluster machining:Manufacturing revolution for large and complex components

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Science China(Technological Sciences) 2022年第9期65卷 2215-2217页

作者： TAO Bo GONG ZeYu &ding han State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Large complex components, such as aircraft skins, aerospace hulls, ship and high-speed train shells, are key components for aviation, aerospace, marine and transportation industries.The high-efficiency and high-quality manufacturing of these products is not only a major need for industry, but also a frontier hotspot in the field of intelligent manufacturing.

关键词： frontier cluster aviation