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Dexterity Analysis for Omni-directional Wheeled Mobile Manipulator Based on Double Quaternion

Chinese Journal of Mechanical Engineering 2013年第3期26卷 585-593页

作者： DU Bin ZHAO Jing song chunyu College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology

The unified analysis of omni-directional wheeled mobile manipulator(OWMM) through the dimensionally nonhomogeneous Jacobian matrix may lead to unreliable results. The existing researches focus on the integrated performance evaluation of OWMM, without taking the influence of velocity difference into consideration. This paper presents a new approach to formulate the dimensionally homogeneous Jacobian matrix and a new index for OWMM. First, the universal transformational matrix of the link coordinate frame is derived based on double quaternion. The degree of locomotion of a mobile platform and the degrees of manipulation of a manipulator are treated equally as the joints of a redundant composite robot. Then the integrated modeling of OWMM is established, and the non-dimensional Jacobian matrix is obtained from the above matrix. Next, by examining the concept of directional manipulability, a new index is proposed to evaluate the directional manipulability of OWMM along the specified task direction. Furthermore, for the same task and the time of simulation, the kinematic performance of the fixed base operation of the manipulator and the operation of OWMM are analyzed by numerical simulation. The results suggest that the proposed approach is equivalent to the method of traditional kinematic modeling, with the error of numerical solution being 10-7 , and the varying frequency of DMTR is higher than that of the condition number. This indicates that DMTR is more effective to reflect the variation of the task direction. The proposed method can be used to analyze the manipulating capability of OWMM, and has a simple structure and generality in the unified analysis of OWMM.

关键词： double quaternion homogeneous Jacobian mobile manipulator manipulability task direction

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Mollisols Properties and Changes in Ukraine and China

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Chinese Geographical Science 2011年第3期21卷 257-266页

作者： Yuri S KRAVCHENKO ZHANG Xingyi LIU Xiaobing song chunyu Richard M CRUSE Key Laboratory of Mollisols Agroecology Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Harbin 150081 China National University of Life and Environmental Sciences of Ukraine Kyiv 03041 Ukraine Department of Agronomy Iowa State University Ames 500011 IA USA

Soils are the foundation of civilizations and the basis for human food *** in Ukraine and Northeast China are two out of the four major Mollisol regions in the *** natural areas from which Mollisols developed are the prairies and steppes that experience temperate and freezing *** review paper introduces the general climate,vegetation,and topography of Mollisols regions in Ukraine and Northeast China,analyzes their properties,including soil texture,soil organic matter content,soil bulk density,pH,cation exchange capacity and other chemical properties,and compares the property changes and management practices of Mollisols in relation to sustainable grain production.

关键词： Mollisols soil properties soil organic matter tillage Mollisols management

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Research on the dynamic response of connecting rod bearing bush wear of reciprocating machine under variable working conditions

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High Technology Letters 2023年第2期29卷 148-158页

作者：张进杰 song chunyu LEI Fuchang WANG Yao ZHI Haifeng LIU Fengchun Beijing Key Laboratory of Health Monitoring and Self-Healing of High-end Mechanical Equipment Beijing University of Chemical TechnologyBeijing 100029P.R.China China North Engine Research Institute(Tianjin) Tianjin 300400P.R.China

As a type of reciprocating machine, the reciprocating compressor has a compact structure and many excitation *** the small end bearing of the connecting rod is worn, it is easy to cause the sintering of the bearing and the abnormal vibration of the *** on the characteristics of poor lubrication state and complex force of connecting rod small head bearing, a mixed lubrication model considering oil groove feed was established, and the dynamic simulation of the reciprocating compressor model with lubricated bearings was carried out;considering different speeds and gas load conditions, the law of the impact of the eigenvalues changing with working conditions was *** fault simulation experiment was carried out by selecting representative working conditions, which verified the correctness of the simulation *** study found that two contact collisions between the pin and the bearing bush occurred in one cycle, the collision impact was more severe under the wear fault, and the existence of the gap made the dynamic response more sensitive to the change of working *** research provides ideas for the location and feature extraction of fault symptom signal angular segments in the process of complex measured signal processing.

关键词： small head tile wear lubrication variable working condition impact

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Field Tests for Investigating the Extraction Rate of Piles Using a Vibratory Technique

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Journal of Shanghai Jiaotong university(Science) 2018年第4期23卷 482-489页

作者： QIN Zhaohui CHEN Longzhu song chunyu ZHANG Jingyi School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China Sichuan Institute of Building Research Chengdu 610081 China

Factors directly affecting the extraction rate of the piles pulled out by a vibratory pulling system are summarized and classified into five categories(excitation force,resistance,vibration amplitude,pile plumbness keeping,and slowing down at the later stage) from the mechanics and engineering *** tests on steel sheet piles extracted by vibratory technique in different soil conditions are conducted to ascertain how these factors affect the extraction rate of a pile with regard to three major actors of vibratory pile pulling:the pile to be extracted,the selected pulling system,and the imposed soil *** extraction rates of three different sheet pile types(having up to four different lengths) pulled out by two different vibratory pulling systems are *** piles with different lengths and types,pulled out with or without a clutch,have different extraction *** working parameters governing the vibratory hammer,such as excitation force and vibration amplitude,exert significant influences on the rate of pile extraction,especially in the early stages of up-lift *** extraction rate of the piles driven in different soil conditions is uniform because different extraction resistances mainly refer to shaft *** properties of the pile-soil interface influence the extraction rate of the piles,and the extraction rate decreases with the time for which the piles have been buried in the earth.

关键词： field tests steel sheet pile vibratory pile pulling extraction rate

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Binary encoding-inspired generation of vector vortex beams

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Science China(Physics,Mechanics & Astronomy) 2023年第5期66卷 139-154页

作者： Hui Li Chenglong Zheng Jingyu Liu Hang Xu chunyu song Fan Yang Jitao Li Zhen Yue Wei Shi Yating Zhang Yan Zhang Jianquan Yao Key Laboratory of Opto-Electronics Information Technology(Tianjin University) Ministry of EducationSchool of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China Beijing Key Laboratory for Metamaterials and Devices Key Laboratory of Terahertz OptoelectronicsMinistry of EducationBeijing Advanced Innovation Center for Imaging TechnologyDepartment of PhysicsCapital Normal UniversityBeijing 100048China

Vortex and vector terahertz(THz)beams with inhomogeneous polarization states have become a considerable hot topic in the last decade due to their important roles in multiplexed wireless data ***,the technical instruments to form and evaluate such beams are rather limited,as they are mainly collected in the visible *** emergence of coded metasurfaces has reinvigorated the design of functional devices with multiple degrees of ***,we demonstrate a versatile design inspired by a binary encoding approach for generating off-axis vectorial THz beams on all-silicon ***,simultaneous manipulation of the encoding method within the orthogonal circularly polarized(CP)channel provides strong support for developing versatility in vector THz beams,including the generation of arbitrary polarization profiles and the directional emission of multiplexed vector vortex beams(VVBs)with specified polarization *** introduction of the latitudinal polarization control factor guarantees that continuously rotating or independently designed vector polarization profiles can be obtained on a pre-defined focal ***,a universal parametric theoretical model is developed to analyze the evolutionary trend of off-axis VVB in ***,the proposed monolayer vector metasurface bypasses the requirement of multiple cascaded optical elements,further inducing the advancement of ultra-thin vector THz sources,and also facilitating the generation of vector fields with tailored polarization distributions in 3D space.

关键词： metasurfaces vector beams spin-orbit interactions polarization optics

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A novel nondestructive detection approach for seed cotton lint percentage using deep learning

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Journal of Cotton Research 2024年第2期7卷 148-162页

作者： GENG Lijie YAN Pengji JI Zhikun song chunyu song Shuaifei ZHANG Ruiliang ZHANG Zhifeng ZHAI Yusheng JIANG Liying YANG Kun School of Electronic and Information Henan Key Laboratory of Magnetoelectronic Information Functional MaterialsZhengzhou University of Light IndustryZhengzhou 450002HenanChina

Background The lint percentage of seed cotton is one of the most important parameters for evaluating seed cotton quality and affects its *** traditional measuring method of lint percentage is labor-intensive and time-consuming;thus,an efficient and accurate measurement method is *** recent years,classification-based deep learning and computer vision have shown promise in solving various classification *** In this study,we propose a new approach for detecting the lint percentage using MobileNetV2 and transfer *** model is deployed on a lint percentage detection instrument,which can rapidly and accurately determine the lint percentage of seed *** evaluated the performance of the proposed approach using a dataset comprising 66924 seed cotton images from different regions of *** results of the experiments showed that the model with transfer learning achieved an average classification accuracy of 98.43%,with an average precision of 94.97%,an average recall of 95.26%,and an average F1-score of 95.20%.Furthermore,the proposed classification model achieved an average accuracy of 97.22%in calculating the lint percentage,showing no significant difference from the performance of experts(independent-sample t-test,t=0.019,P=0.860).Conclusion This study demonstrated the effectiveness of the MobileNetV2 model and transfer learning in calculating the lint percentage of seed *** proposed approach is a promising alternative to traditional methods,providing a rapid and accurate solution for the industry.

关键词： Neural network MobileNetV2 Nondestructive detection Smart agriculture Seed cotton lint percentage

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Racemic dielectric metasurfaces for arbitrary terahertz polarization rotation and wavefront manipulation

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Opto-Electronic Advances 2024年第10期7卷 41-50页

作者： Jie Li Xueguang Lu Hui Li chunyu song Qi Tan Yu He Jingyu Liu Li Luo Tingting Tang Tingting Liu Hang Xu Shuyuan Xiao Wanxia Huang Yun Shen Yan Zhang Yating Zhang Jianquan Yao College of Optoelectronic Engineering Chengdu University of Information TechnologyChengdu 610225China School of Precision Instruments and Opto-Electronics Engineering Tianjin UniversityTianjin 300072China College of Materials Science and Engineering Sichuan UniversityChengdu 610065China School of Information Engineering Nanchang UniversityNanchang 330031China Department of Physics School of Physics and Materials ScienceNanchang UniversityNanchang 330031China Key Laboratory of Terahertz Optoelectronics Ministry of EducationDepartment of PhysicsCapital Normal UniversityBeijing 100048China.

Dielectric chiral metasurface is a new type of planar and efficient chiral optical device that shows strong circular dichroism or optical activity,which has important application potential in optical sensing and ***,the two types of chiral optical responses in conventional chiral metasurfaces are often interdependent,as their modulation of the amplitudes and phases of orthogonal circularly polarized components is correlated,which limits the further progress of chiral *** we propose a new scheme for independently designing the circular dichroism and optical activity of chiral metasurfaces to further control the polarization and wavefront of transmitted *** by mixtures of chiral molecular isomers,we use the dielectric isomer resonators to form“super-units”instead of single meta-atoms for chiral responses in terahertz band,which is called racemic *** introducing two levels of Pancharatnam-Berry phases between meta-atoms and“super-units”,the polarization rotation angle and wavefront of the beam can be designed without the far-field circular *** demonstrate the strong control ability on terahertz waves of this scheme through simulation and *** addition,this new type of device with near-field chirality but no far-field circular dichroism may also have important value in optical sensing and other technologies.

关键词： racemic dielectric metasurfaces terahertz waves chirality

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动态背景下图像的分割

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计算机应用与软件 2014年第4期31卷 247-249页

作者：宋春玉黑龙江科技学院计算机与信息工程学院黑龙江哈尔滨150027

动态背景下运动图像的分割是一个重要问题。采用时空联合的分割方法,先对视频图像进行空域单帧分割,采用基于图论的分割技术,即找出一个包含最大面积的最小周长的边界;再根据运动图像间的变换信息,利用背景运动估计和补偿技术,得到全局... 详细信息

动态背景下运动图像的分割是一个重要问题。采用时空联合的分割方法,先对视频图像进行空域单帧分割,采用基于图论的分割技术,即找出一个包含最大面积的最小周长的边界;再根据运动图像间的变换信息,利用背景运动估计和补偿技术,得到全局运动参数。通过全局运动补偿,去除背景区域得到运动目标。实验证明,该方法有效地解决了过分割的问题,得到精确的分割效果。

关键词：时空联合等周算法超松弛迭代

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基于人体工程学的仿人机械臂构型

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机械工程学报 2013年第11期49卷 16-21页

作者：赵京宋春雨杜滨北京工业大学机械工程与应用电子技术学院北京100124

针对仿人机械臂构型问题,提出一种新的筛选方法,并确定串联结构方式下最符合人臂特征的仿人机械臂构型。从人体解剖学的角度出发,分析人臂的运动机理,并结合人体测量学和机器人学相关原理构建6种不同的仿人机械臂构型。提出全局相对可... 详细信息

针对仿人机械臂构型问题,提出一种新的筛选方法,并确定串联结构方式下最符合人臂特征的仿人机械臂构型。从人体解剖学的角度出发,分析人臂的运动机理,并结合人体测量学和机器人学相关原理构建6种不同的仿人机械臂构型。提出全局相对可操作度指标对不同构型进行灵活性分析,并采用可视化方法绘制出各构型的运动灵活性性能分布图。根据人臂的运动特性分析人臂的运动工作空间,将各构型仿人机械臂工作空间与其对比,从而筛选出串联方式下的最佳仿人机械臂构型。该结果为仿人机械臂的设计提供了理论依据,并为后续运动规划奠定了基础。

关键词：人体工程学人臂仿人机械臂构型工作空间

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黑龙江省籽用南瓜高产稳产栽培技术体系

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农业系统科学与综合研究 1999年第3期15卷 221-224页

作者：宋春雨中国科学院黑龙江农业现代化研究所哈尔滨150040

黑龙江省籽用南瓜面积已达200万hm^2,但因栽培技术上的不完善,而严重影响产量和效益.根据实践经验,提出了籽用南瓜高产稳产的合理栽培技术体系.参6.

关键词：籽用南瓜栽培南瓜技术体系黑龙江

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