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A method for the length-pressure hysteresis modeling of pneumatic artificial muscles

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Science China(Technological Sciences) 2020年第5期63卷 829-837页

作者： XIE ShengLong liu haitao &WANG Yu School of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China Key Laboratory of Mechanism Theory and Equipment Design Ministry of EducationTianjin UniversityTianjin 300072China

This paper presents a method for the length-pressure hysteresis modeling of pneumatic artificial muscles(PAMs)by using a modified generalized Prandtl-Ishlinskii(GPI)*** from the approaches for establishing the GPI models by replacing the linear envelope functions of operators with hyperbolic tangent and exponential envelop functions,the proposed model is derived by modifying the envelope functions of operators into arc tangent functions,which shows an improvement in the modeling *** effectiveness of the proposed model is verified by the experimental data of a ***,its capacity in capturing the hysteresis relationship between length and pressure is testified by giving different input pressure *** regard to the computational efficiency,the influence of the number of operators on the modeling accuracy is ***,the inversion of the GPI model is *** capability of compensating the hysteresis nonlinearities is confirmed via the simulation and experimental study.

关键词： modified generalized Prandtl-Ishlinskii model pneumatic artificial muscle hysteresis envelope function control

Statistical properties of Chinese semantic networks

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Chinese Science Bulletin 2009年第16期54卷 2781-2785页

作者： liu haitao Institute of Applied Linguistics Communication University of China Beijing 100024 China

Almost all language networks in word and syntactic levels are small-world and scale-free. This raises the questions of whether a language network in deeper semantic or cognitive level also has the similar properties. To answer the question, we built up a Chinese semantic network based on a treebank with semantic role (argument structure) annotation and investigated its global statistical properties. The results show that although semantic network is also small-world and scale-free, it is different from syntactic network in hierarchical structure and K-Nearest-Neighbor correlation.

关键词：语义网络统计性质汉语参数结构统计特性层次结构小世界标度

Influence of the finish rolling temperatures on the microstructure and texture evolution in the ferritic stainless steels

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Acta Metallurgica Sinica(English Letters) 2011年第5期24卷 343-350页

作者： Fei GAO Zhenyu liu haitao liu Guodong WANG The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 China

The influence of the finish rolling temperature on the microstructure and texture evolution of Nb and B micro-alloyed ultra purified Cr17 ferritic stainless steels was investigated. The hot rolled bands were produced by conventional rolling process and the finish rolling at relatively low temperatures or ＂warm rolling＂. The microstructure was observed by optical microscopy, scanning electron microscopy and transmission electron microscopy, and X-ray diffraction was used to characterize the texture evolution processes. The results showed that as compared to conventional hot rolling process, the warm rolling has led to the refined and homogeneous microstructure and uniform recrystallization texture along γ-fiber in final sheets, indicating that the finish rolling at relatively low temperatures can be the effective way to improve significantly the formability of final sheets.

关键词： Ultra purified Cr17 ferritic stainless steel Finish rolling temperature Microstructure Texture

Modeling and analysis for time-varying dynamics of thin-walled workpieces in mirror milling considering material removal

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Science China(Technological Sciences) 2023年第7期66卷 1883-1898页

作者： MA ShiJun XIAO JuLiang liu haitao liu SiJiang TIAN Yu Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300354China

To reduce the vibration and deformation of large thin-walled workpieces during the milling process,mirror milling is widely used due to its point-to-point support and strong *** influence of the support head on the workpiece’s dynamic characteristics is crucial in determining whether the mirror milling process is reliable and ***,this study establishes a time-varying dynamic model for mirror milling of thin-walled workpieces with various boundary conditions to accurately analyze and predict the dynamic characteristics and response of the ***,a new analytical method for material removal with extensive applicability and high precision is *** this method,the Ritz mode shape is used to approximate the workpiece’s mode shape as it changes during material ***,the Hertz contact theory is adopted to establish a tool-workpiece-support head coupling model,which considers the jump-off phenomenon between ***,the dynamic model is solved using the Newmark-β numerical integration method to obtain the workpiece’s time-domain acceleration and displacement responses under the forced ***,the measured frequency response function(FRF)and vibration signals of workpieces verify the correctness of the proposed mirror milling model for thin-walled workpieces considering material *** addition,this paper analyzes the dynamic characteristics and forced vibration law of workpieces in mirror milling,which lays the foundation for high precision mirror milling.

关键词： thin-walled workpiece mirror milling dynamic model material removal machining vibration

Language clusters based on linguistic complex networks

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Chinese Science Bulletin 2010年第30期55卷 3458-3465页

作者： liu haitao LI WenWen School of International Studies Zhejiang University Hangzhou 310058 China Institute of Applied Linguistics Communication University of China Beijing 100024 China

To investigate the feasibility of using complex networks in the study of linguistic typology,this paper builds and explores 15 linguistic complex networks based on the dependency syntactic treebanks of 15 languages. The results show that it is possible to classify human languages by means of the following main parameters of complex networks:(a) average degree of the node,(b) cluster coefficients,(c) average path length,(d) network centralization,(e) diameter,(f) power exponent of degree distribution,and (g) the determination coefficient of power law distributions. The precision of this method is similar to the results achieved by means of modern word order typology. This paper tries to solve two problems of current linguistic typology. First,the language sample of a typological study is not real text; second,typological studies pay too much attention to local language structures in the course of choosing typological parameters. This study performs better in global typological features of language and not only enhances typological methods,but it is also valuable for developing the applications of complex networks in the humanities,social,and life sciences.

关键词：人类语言复杂网络集群类型学发展中国家路径长度指数分布分布系数

Residual Vibration Reduction of High-Speed Pick-and-Place Parallel Robot Using Input Shaping

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Chinese Journal of Mechanical Engineering 2022年第1期35卷 62-69页

作者： Xianlei Shan Yuhang Li haitao liu Tian Huang Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300354China School of Engineering The University of WarwickCoventry CV47ALUK.

Because of their elastic links and joints,high-speed parallel robots for pick-and-place operations inevitably suffer from residual vibrations that significantly degrade their positioning *** effective approach based on the input shaping technique is presented in this paper for suppressing the residual vibration in these parallel *** addressing the design principle of an input shaper for a parallel robot with flexible actuated joints,a robust optimal input shaper is developed by considering the configuration-dependent flexible modes and minimizing the maximum percentage of residual vibration at the *** input shaper allows a good overall performance to be achieved throughout the entire *** results on a 4-DOF SCARA-type parallel robot show that the residual vibration of the end-effector is dramatically reduced and the dynamic positioning accuracy of the robot significantly improved.

关键词： Pick-and-place parallel robot Residual vibration reduction Input shaping

Modeling and analysis for material removal and surface roughness in fluid jet polishing of optical glass

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Friction 2024年第7期12卷 1548-1563页

作者： Zhongchen CAO Ming WANG haitao liu Tian HUANG Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300072China School of Engineering The University of WarwickCoventry CV47ALUK

luid jet polishing(FJP)is a non-contact polishing technology that can fabricate free-form optical surfaces with sub-micron-level form accuracy and nano-level surface roughness,especially for hard and brittle *** surface generation model of FJP can be used to guide the determination and optimization of process parameters and is of great significance for understanding the evolution mechanism of surface ***,predictive models for the microscopic topography of polished surfaces are still *** study established a macroscopic surface profile model for predicting 3D material removal characteristics and surface texture by combining the 3D computer fluid dynamics(CFD)simulation model and single-particle erosion mechanism.A fractal theory-based erosion model has been built to calculate the material removal caused by the erosion of a single abrasive particle on the rough surface;thus,it predicts the micro-topography and surface roughness of the polished samples.A series of polishing experiments were conducted to analyze the feasibility and accuracy of the model quantitatively and study the influence mechanism of process parameters on the material removal characteristics and surface *** indicated that the models could well predict material removal and surface *** prediction accuracy of the surface roughness Ra and maximum removal depth is better than 91.6%and 90%,*** is also found that the material removal rate of FJP could reach 0.517 mm3/min,and the surface roughness convergence rate could reach 62.9%.

关键词： fluid jet polishing(FJP) computational fluid dynamics(CFD) material removal mechanism surface roughness theoretical model

Base placement optimization of a mobile hybrid machining robot by stiffness analysis considering reachability and nonsingularity constraints

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Chinese Journal of Aeronautics 2023年第11期36卷 398-416页

作者： Zhongyang ZHANG Juliang XIAO haitao liu Tian HUANG Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300340China School of Engineering The University of WarwickCoventry CV47ALUK

The mobile hybrid machining robot has a very bright application prospect in the field of high-efficiency and high-precision machining of large aerospace ***,an inappropriate base placement may make the robot encounter a singular configuration,or even fail to complete the entire machining task due to *** addition to considering the two constraints of reachability and non-singularity,this paper also optimizes the robot base placement with stiffness as the goal to improve the machining *** of all,starting from the structure of the robot,the reachability and nonsingularity constraints are transformed into a simple geometric constraint imposed on the base placement:feasible base placement ***,genetic algorithm is used to search for the base placement with near optimal stiffness(near optimal base placement for short)in the feasible base placement ***,multiple controlled experiments were carried out by taking the milling of a protuberance on the spacecraft cabin as an *** is found that the calculated optimal base placement meets all the constraints and that the machining quality was indeed *** addition,compared with simple genetic algorithm,it is proved that the feasible base placement area method can shorten the running time of the whole program.

关键词： Aerospace industry Base placement optimization Hybrid machining robot Mobile robot Robot application Singularity avoidance Stiffness optimization

Determination of the Fracture Toughness of Glasses via Scratch Tests with a Vickers Indenter

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Acta Mechanica Solida Sinica 2022年第1期35卷 129-138页

作者： haitao liu Jianwei Zhang Minghao Zhao Chunsheng Lu lSchool of Mechanics and Safety Engineering Zhengzhou UniversityZhengzhou 450001China School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450001China Henan Key Engineering Laboratory for Anti-fatigue Manufacturing Technology Zhengzhou 450001China School of Civil and Mechanical Engineering Curtin UniversityPerth 6845Western AustraliaAustralia

Fracture toughness is an important index in safety evaluation for materials and *** convenient and accurate characterization has attracted extensive *** small specimens,traditional testing methods of fracture toughness are not suitable due to limitations in sample size and *** this work,a new formula is proposed to determine the fracture toughness of glasses using scratch tests with a Vickers indenter based on dimensional analysis and finite element *** toughness of glasses could be calculated with elastic modulus,crack depth of scratched materials and normal force applied during the scratch *** effects of plastic deformation and interfacial friction between the Vickers indenter and scratched materials are considered,and the crack shape is consistent with experimental *** proposed formula is verified by comparing the fracture toughness of soda-lime and borosilicate glasses obtained from scratch tests with those obtained via indentation *** work provides an alternative method to determine the fracture toughness of glass materials.

关键词： Scratch test Fracture toughness Glass Dimensional analysis Finite element analysis