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Sliding mode controller by using adaptive exponential reaching law based on nonlinear disturbance observer

ISA Transactions 2025年

作者： Liu, Ying Li, Gongfa Du Jiang Yun, Juntong Tao, Bo Jiang, Guozhang Kong, Jianyi Chen, Baojia Key Laboratory of Metallurgical Equipment and Control Technology of Ministry of Education Wuhan University of Science and Technology Wuhan430081 China Research Center for Biomimetic Robot and Intelligent Measurement and Control Wuhan University of science and Technology Wuhan430081 China Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of science and Technology Wuhan430081 China Precision Manufacturing Research Institute Wuhan University of Science and Technology Wuhan430081 China Hubei Longzhong Laboratory Xiangyang441000 China Hubei Key Laboratory of Hydroelectric Machinery Design& Maintenance China Three Gorges University Yichang443002 China

Aiming at the position tracking control problem of flexible jointed manipulator in the uncertainties and external disturbances, this paper proposes an integrated nonlinear disturbance observer (NDOB) and a non-singular fast terminal sliding mode (NFTSM) control method based on adaptive exponential reaching law (AERL). The NDOB is designed to ensure that the time-varying disturbance is suppressed in finite time. The AERL is designed to improve the track tracking speed and reduce the chattering of the control input. Simulation results show that compared with the optimal ARL, the proposed method reduces the trajectory tracking error by 1.3 %, improves the trajectory tracking convergence speed. Experimental results show that the proposed method reduces the trajectory tracking error by 0.545 %. © 2025 ISA

关键词： Sliding mode control

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Residual Stress in 347H Weldments: Influence of Various Thermal Treatment on Residual Stress Reduction

Residual Stress in 347H Weldments: Influence of Various Ther...

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ASME 2024 Pressure Vessels and Piping Conference, PVP 2024

作者： Yang, Yi Gao, Yanfei Feng, Zhili Bunn, Jeffrey R. Payzant, E. Andrew Penso, Jorge Department of Materials Science and Engineering University of Tennessee KnoxvilleTN37996 United States Materials Science and Technology Division Oak Ridge National Laboratory P.O BOX 2008 Oak RidgeTN37831 United States Neutron Scattering Division High Flux Isotope Reactor Oak Ridge National Laboratory P.O BOX 2008 Oak RidgeTN37831 United States Shell Projects and Technology P.O. Box 4327 HoustonTX77210 United States

ISBN: (纸本)9780791888513

Residual stresses play a pivotal role in influencing the structural integrity of welded structures, a consequence inherent to the welding process itself. In scenarios involving cyclic thermal and mechanical loading during operation, the dynamic transformation of residual stress patterns arises from multiple influencing factors. In addition to thermomechanical considerations, the evolution of the microstructure significantly contributes to this intricate and interconnected phenomenon. The selection of 347H austenitic stainless steel stands out as an optimal choice due to its exceptional resistance to creep and corrosion. Nonetheless, unforeseen failures continue to pose significant challenges in meeting design criteria. Residual stress remains the primary factor for predicting the lifetime of welded components, and a reliable measurement method for this purpose is still lacking. In this research paper, we present a comprehensive series of measurements conducted on lab-made plate welds subjected to different thermal treatment conditions. Simultaneously, we employ and compare two distinct calculation methodologies to assess the disparities and the feasibility of applying the plane stress methodology to thick service pipe welds. Through a meticulous measurement plan encompassing both As-Welded and post-weld heat treatment (PWHT) lab-made plate welds, which aim to determine the impact of PWHT on the redistribution and relaxation of the residual stress field. Additionally, both plate welds undergo 361.5 hours of thermal aging (TA) at 650℃ to mimic as practical as possible service conditions. The validation of both methodologies is subsequently established across four distinct thermal treatment conditions. Consequently, the reliable application of the plane stress methodology to service-grade thin/thick pipes becomes apparent. © 2024 by The United States Government and Shell Global Solutions.

关键词： Austenitic stainless steel

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In situ SR-CT Experimental Study on the Directional Sintering of High-Temperature Superconductor YBCO Materials in the Microwave Fields

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Acta Metallurgica Sinica(English Letters) 2022年第1期35卷 67-77页

作者： Liangyuan Wang Lei Shen Yongcun Li Yuanjie Wang Yu Xiao Xingyi Zhang Feng Xu Xiaofang Hu CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsCAS Center for Excellence in Complex System MechanicsUniversity of Science and Technology of ChinaAnhui230027China Key Laboratory of Mechanics on Disaster and Environment in Western China Attached to the Ministry of Education of China Lanzhou UniversityLanzhou730000China Shanxi Key Lab of Material Strength&Structural Impact College of Mechanical and Vehicle EngineeringTaiyuan University of TechnologyTaiyuan030024China

YBa_(2)Cu_(3)O_(7-x)(YBCO)is a kind of high-temperature superconducting material that has important application in information,energy,medical treatment,etc.,and the superconducting properties of YBCO are closely related to its internal *** this study,the microwave heating method was adopted to prepare the YBCO *** internal 3 D online evolution observation based on the synchrotron radiation computed tomography technology shows that there was directional grain growth phenomenon of YBCO during microwave sintering *** local regions with special microstructure,these particles grew to the same ***,the theoretical models of single and multiple particles in the microwave electromagnetic fields were *** on these theoretical models and finite element analysis,it shows that the YBCO particles can modulate the distribution of electromagnetic fields,resulting in the significantly higher electric field intensity at the particle junctions than other ***,there were very high electric field intensity and temperature gradients in the directions of particle *** factors were crucial in directional *** results will provide theoretical basis and technical guidance for the controllable preparation and performance optimization of the internal microstructure of superconducting materials in the preparation process.

关键词： Synchrotron radiation computed tomography Microwave sintering Microstructure In situ

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Direct ink writing of programmable functional silicone-based composites for 4D printing applications

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Interdisciplinary Materials 2022年第4期1卷 507-516页

作者： Zhiyang Lyu J.ustin Koh Gwendolyn J.H.Lim Danwei Zhang Ting Xiong Lei Zhang Siqi Liu Junfei Duan Jun Ding John Wang Jinlan Wang Yunfei Chen Chaobin He Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments School of Mechanical EngineeringSoutheast UniversityNanjingChina Department of Materials Science and Engineering National University of SingaporeSingaporeSingapore Agency for Science Technologyand Research(A*STAR)Institute of Materials Research and EngineeringSingaporeSingapore School of Materials Science and Engineering Changsha University of Science and TechnologyChangshaChina School of Physics Southeast UniversityNanjingChina

Polydimethylsiloxane(PDMS)has been widely used in flexible electronics,soft robotics,and ***,the fabrication of PDMS-based devices has mostly relied on conventional approaches,such as casting and molding,thereby limiting their *** we fabricate PDMS-based composites with programmable microstructures by direct ink writing and realize their practical functionalities of four-dimensional(4D)*** mechanical,thermomechanical and magnetic properties of the three-dimensional-printed composites can be well tailored by using carbon,metal,or ceramic functional *** taking advantage of the printable,flexible,and magnetic PDMS composites,we demonstrate new practical functionalities of 4D printing by designing programmable architectures,including magnetic-field-driven battery cases and patchworks,as well as arbitrary morphing ceramic *** particular,4D-printed batteries are constructed by PDMS-based battery cases for the first time,which can be actuated via external magnetic *** study broadens the paradigm of 4D printing for prospective applications,such as implant batteries,biomimetic engineering,and customized biomedical devices.

关键词： 4D printing 4D-printed batteries direct ink writing PDMS polymer-derived ceramics

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Development and Validation of Integral Algorithms Based on Data Resampling Techniques 9

Development and Validation of Integral Algorithms Based on D...

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9th International Conference on Intelligent Computing and Signal Processing, ICSP 2024

作者： Ma, Xiang Wu, Yongshun Yu, Haoliang Wang, Donghui Yang, Sujun Shen, Song Shanghai Haixun Mechanical & Electrical Engineering Co. Ltd Shanghai China Marine Design & Research Institute of China Shanghai China Shanghai Key Laboratory of Ship Engineering Shanghai China Laboratory of Science and Technology on Water Jet Shanghai China China Orient Institute of Noise & Vibration Beijing China

ISBN: (纸本)9798350376548

Accurate acquisition of displacement signals is of great importance in the field of engineering research, but displacement transducers have harsh requirements for testing conditions, which cannot be implemented in many cases, and it is relatively convenient to adopt the method of using acceleration transducer testing and integrating twice to obtain displacement signals. In the acceleration integration, the trend interference term will appear, which leads to a serious reduction in the integration accuracy. To address this problem, this paper proposes a full calculus algorithm based on data reconstruction technology to achieve real-time calculus conversion in the dynamic signal measurement process, and a comparison test is carried out in the laboratory through actual experiments to verify the effectiveness and reliability of the integration algorithm. Based on the above, the algorithm is used to conduct field tests on a bridge and the vertical motion of wave floats, and the test results show that the algorithm can effectively solve the integral signal offset, and the actual results are in good conformity. Based on this technology, the acceleration, velocity and displacement signals of vibration can be obtained continuously and in real time for a long time with only acceleration sensors, which solves the problem of signal calculus conversion in engineering, and can be widely applied to the motion of ships in waves, displacement of vibrating objects and other test scenarios. © 2024 IEEE.

关键词： Software design

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Mechanistic investigation of highly bendable magnesium alloy sheet fabricated by short-process manufacturing

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Journal of Magnesium and Alloys 2024年第10期12卷 4289-4310页

作者： Shiwei Xu Peijie Xiao Xiaofan Wu John Holmes Frédéric Mompiou Zhenyu Xiao Chen Jin Tianjiao Li Kuaishe Wang Zhuoran Zeng College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan UniversityChangsha 410082China Suzhou Research Institute of Hunan University Suzhou 215131China College of Engineering Computing and CyberneticAustralian National UniversityACT 2601Australia CEMES-CNRS Universitéde Toulouse29 rue J.MarvigToulouse 31055France Qinghai Salt Lake Teli Magnesium Co. Ltd.Xining 810000China International Joint Laboratory for Light Alloys(Ministry of Education) College of Materials Science and EngineeringChongqing UniversityChongqing 400044China School of Metallurgical Engineering Xi’an University of Architecture&TechnologyXi’an 710055China College of Materials Science and Engineering Hunan UniversityChangsha 410082China

In this study,a commercial magnesium alloy AZ31(Mg-3Al-1Zn-0.3Mn)sheet through a short manufacturing process was found to be ductile and highly formable in *** possessing a strong basal texture,the short-processed sheet without any annealing can be bent at a small radius,only 0.2 times its thickness in the 90°bending ***,it could withstand direct deformation by repeated *** in-situ microstructural characterization reveals that extension twin bands with strain localization appear in the bending *** subsequent flattening,these twin bands underwent detwinning,reducing local strain concentrations and enabling further bending *** outstanding bend formability originated from the significant-type dislocation loops slipping on the prismatic crystal planes within dynamic-recrystallized *** grains underwent a uniform refinement to several microns in the short manufacturing process and exhibited low residual *** active prismatic dislocation slip within refined grains was due to its much lower relative activation stress to basal slip(CRSSprism/CRSSbasal of only∼1.6)owing to the effective grain boundary ***,the prismatic dislocation activity was further enhanced when bypassing Al-Mn nano-particles during motion,leaving debris and loops that facilitated easy multiplication.

关键词： Magnesium Deformation Texture In-situ characterization Dislocation slip.

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Multi-scale design and optimization for solid-lattice hybrid structures and their application to aerospace vehicle components

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Chinese Journal of Aeronautics 2021年第5期34卷 386-398页

作者： Chuang WANG Jihong ZHU Manqiao WU Jie HOU Han ZHOU Lu MENG Chenyang LI Weihong ZHANG State IJR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical UniversityXi'an 710072China MIIT Lab of Metal Additive Manufacturing and Innovative Design Northwestern Polytechnical UniversityXi'an 710072China Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle TechnologyBeijing 100076China

By integrating topology optimization and lattice-based optimization,a novel multi-scale design method is proposed to create solid-lattice hybrid structures and thus to improve the mechanical performance as well as reduce the structural *** achieve this purpose,a two-step procedure is developed to design and optimize the innovative ***,the classical topology optimization is utilized to find the optimal material layout and primary load carrying ***,the solid-lattice hybrid structures are reconstructed using the finite element mesh based modeling *** lattice-based optimization is performed to obtain the optimal crosssection area of the lattice ***,two typical aerospace structures are optimized to demonstrate the effectiveness of the proposed optimization *** numerical results are quite encouraging since the solid-lattice hybrid structures obtained by the presented approach show remarkably improved performance when compared with traditional designs.

关键词： Aerospace vehicle components Lattice-based optimization Multi-scale Solid-lattice hybrid structure Topology optimization

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Analytical Formulation for the Quantum Radar Scattering of the semi-Cylinder Surface

Analytical Formulation for the Quantum Radar Scattering of t...

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2022 International Applied Computational Electromagnetics Society Symposium, ACES-China 2022

作者： Fang, Chonghua Shi, Xinyang Science and Technology on Electromagnetic Compatibility Laboratory China Ship Development and Design Centre Wuhan China Wuhan Maritime Communication Research Institute Wuhan China

ISBN: (纸本)9781665452366

In this paper, the photon backscattering of quantum radar from the semi-cylinder surface is considered. A uniform and analytical solution derived from an asymptotic evaluation of the high-frequency approximation is shown. So, for a typical monostatic scene, you can analytically calculate the QRCS for different elevation angles. Finally, we also analyzed the scattering mechanism difference of the analytical formulations between QRCS and CRCS the semi-cylinder surface. © 2022 IEEE.

关键词： Radar cross section

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A new class of crystalline X-ray induced photochromic materials assembled from anion-directed folding of a flexible cation

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Chinese Chemical Letters 2024年第8期35卷 554-557页

作者： Hong-Jin Liao Zhu Zhuo Qing Li Yoshihito Shiota Jonathan P.Hill Katsuhiko Ariga Zi-Xiu Lu Lu-Yao Liu Zi-Ang Nan Wei Wang You-Gui Huang CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China Institute for Materials Chemistry and Engineering Kyushu UniversityFukuoka 819-0395Japan World Premier International(WPI)Center for Materials Nanoarchitectonics(MANA) National Institute for Materials Science(NIMS)Ibaraki 305-0044Japan

Electron-deficient viologens are widely used as ligands or structure-directing agents(SDAs)to synthesize crystalline X-ray induced photochromic ***,a new rational strategy of anion-directed fold-ing a flexible cation(H_(2)imb)^(2+)((H_(2)imb)^(2+)=di-protonated 2,3-bis(imidazolin-2-yl)-2,3-dimethylbutane)has been ***-donating Cl−and(ZnCl4)2−are used to direct folding a flexible electron-deficient(H_(2)imb)^(2+)*** complexes(H_(2)imb)(NO_(3))2(1),(H_(2)imb)Cl2·H_(2)O(2),and(H_(2)imb)ZnCl4(3)have been synthesized in which(H_(2)imb)^(2+)crystallize in an anti-conformation,88.8°-gauche,and 51.8°-gauche,*** contrary to X-ray silent complex 1,X-ray induced photochromism has been achieved in both complex 2 and *** intermolecular charge-transfer mechanism has been elucidated and the anion directed folding of(H_(2)imb)^(2+)has been validated to be critical to yield colored long-lived charge-separated states.

关键词： Supramolecular Photochromic X-ray induced Anion-directed folding Electron-deficient viologens

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Research on pipe crack detection based on image processing algorithm

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International Journal of Wireless and Mobile Computing 2021年第4期20卷 328-335页

作者： Huang, Licheng Tao, Bo Chen, Donghai Zhang, Xun Li, Gongfa Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of Science and Technology Hubei Wuhan China Key Laboratory of Metallurgical Equipment and Control Technology Ministry of Education Wuhan University of Science and Technology Hubei Wuhan China Changjiang Survey Planning Design and Research Limited Company Hubei Wuhan China

Pipe cracks detection based on machine vision is a new and effective technology. However, it requires high quality of the image. Moreover, images with adequate lighting, evident cracks, clean backgrounds are difficult to obtain in practice. This paper proposes an algorithm for pipe cracks detection in natural background. The algorithm performs filtering, background segmentation, edge detection, threshold segmentation, morphological contour extraction and annotation on the image. This paper also proposes an adaptive threshold segmentation method to obtain the clear crack. By comparing the proposed algorithm with the DEE algorithm, the result shows that the proposed algorithm has certain advantages in experiments. The experiment results show that the algorithm proposed can be used in significant pipe cracks detection. Copyright © 2021 Inderscience Enterprises Ltd.

关键词： Image segmentation

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