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面向多联体叶片的机器人喷涂无干涉路径规划

机械工程学报 2024年第1期60卷 210-219页

作者：漆琪刘礼祥杨吉祥丁汉华中科技大学智能制造装备与技术全国重点实验室武汉430074 中国航发沈阳黎明航空发动机有限责任公司沈阳110043

多联体叶片存在曲面复杂、叶片间距小等结构特点。等离子喷涂为铸造多联体叶片的重要工序,可使叶片表面强化与改性,其喷涂质量直接决定叶片的成品率与性能。现有的机器人等离子喷涂的路径生成主要依靠手动示教,而喷涂过程中的喷涂距离... 详细信息

多联体叶片存在曲面复杂、叶片间距小等结构特点。等离子喷涂为铸造多联体叶片的重要工序,可使叶片表面强化与改性,其喷涂质量直接决定叶片的成品率与性能。现有的机器人等离子喷涂的路径生成主要依靠手动示教,而喷涂过程中的喷涂距离与喷涂夹角无法量化导致喷涂质量不均且示教方法繁琐、效率低。基于此,提出一种面向多联体叶片的工业机器人等离子喷涂无干涉路径生成及光顺方法。首先,根据CAD模型,将多联体叶片型面转为非均匀有理B样条(NURBS)曲面,利用NURBS曲面解析特性,生成约束喷涂行距与喷涂叶片边缘距离的初始路径点;然后将喷涂焰流简化为方向包围盒,将干涉曲面转为三角面片,采用基于分离轴检测的方法进行碰撞干涉检测,生成考虑最小喷涂倾角约束的喷涂姿态。采用基于球面样条四元数插值变步长姿态优化方法进行姿态光顺,生成无干涉且路径光顺的喷涂路径。经过仿真与实验验证,提出干涉避免算法能有效避免喷涂过程中的干涉现象。对比未光顺路径,所提出算法机器人运行效率提高52.6%,机器人振动下降,运行更加平稳,其中关节加速度最大下降55.8%,最小下降2.9%,末端瞬时加速度最大下降39.6%,最小下降14.4%。

关键词：多联体叶片机器人喷涂干涉检测路径光顺

湖滨绿洲土壤有机碳含量的支持向量机估算模型

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新疆农业科学 2024年第6期61卷 1477-1486页

作者：杨吉祥李新国新疆师范大学地理科学与旅游学院/新疆干旱区湖泊环境与资源实验室乌鲁木齐830054

【目的】利用高光谱数据快速估算土壤有机碳含量,为干旱区湖滨绿洲合理开发土地资源提供科学依据。【方法】以新疆博斯腾湖北岸湖滨绿洲为研究区,将实测的土壤有机碳含量数据与高光谱数据相结合,对原始光谱进行SG平滑(SavitzkyGolay smo... 详细信息

【目的】利用高光谱数据快速估算土壤有机碳含量,为干旱区湖滨绿洲合理开发土地资源提供科学依据。【方法】以新疆博斯腾湖北岸湖滨绿洲为研究区,将实测的土壤有机碳含量数据与高光谱数据相结合,对原始光谱进行SG平滑(SavitzkyGolay smoothing,SG)、连续统去除(Continuum Removal,CR)、连续小波变换(Continuous Wavelet Transform,CWT)预处理,采用连续投影算法(Successive Projections Algorithm,SPA)筛选特征波段;应用支持向量机(Support Vector Machines,SVM)模型估算土壤有机碳含量。【结果】(1)研究区土壤有机碳含量为0.69~50.32 g/kg,平均值为14.15 g/kg,标准差为9.51 g/kg,呈中等变异性,变异系数为67.20%。(2)土壤原始光谱反射率在350~750 nm,光谱反射率呈上升趋势,在750~2150 nm,光谱反射率呈相对平稳趋势,在2150~2500 nm,光谱反射率逐渐下降;连续小波变换对土壤原始光谱预处理后随着分解尺度的增加,光谱局部特征明显,吸收峰和反射峰越来越平滑;采用连续投影算法筛选的光谱特征波段集中于350~952 nm、1007~1742 nm、2082~2381 nm,且特征波段仅占可见光-近红外光谱波段的0.30%。(3)连续小波变换结合连续投影算法构建的SVM模型,其训练集和验证集分别R^(2)=0.76,RMSE=4.78和R^(2)=0.94,RMSE=3.30,RPD=2.50。【结论】CWT-SPA-SVM可有效估算研究区土壤有机碳含量。

关键词：土壤有机碳含量连续小波变换连续投影算法支持向量机模型高光谱数据

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康有为“三世说”对董子《春秋》学之阐发

衡水学院学报 2024年第3期26卷 20-27,43页

作者：杨济襄中山大学中文系中国台湾高雄80402

康有为在戊戌政变游走海外后,对公羊学里所主张之“三世”说有了新的阐释。他不从“事与文”来解经,而从董子“《春秋》无达辞,以义为尚”去发挥《春秋》大义,对《礼记》谓《春秋》之教为“属辞比事”不以为然。康有为以孔子之仁为核心... 详细信息

康有为在戊戌政变游走海外后,对公羊学里所主张之“三世”说有了新的阐释。他不从“事与文”来解经,而从董子“《春秋》无达辞,以义为尚”去发挥《春秋》大义,对《礼记》谓《春秋》之教为“属辞比事”不以为然。康有为以孔子之仁为核心,畅论三世之变,不拘泥于“事与文”之解经方式,而落实在仁治的文明进化。在西汉董仲舒、东汉何休二人不同的解经路线上,康有为无疑倾向于董仲舒。聚焦于康有为的三世新诠与董子《春秋》学之关联,厘清康有为“三世说”的特殊见解与相关争议。

关键词：董仲舒康有为三世说公羊学《春秋》

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 *** existing local tool path smoothing methods mainly construct symmetrical splines at transition corners of linear *** the linear segments are short,the symmetrical splines must be shrunk to avoid overlapping,which gives rise to relatively high curvature and low machining *** paper proposes a tool-path smoothing algorithm for serial industrial robots with 6 rotary(6R)joints by constructing asymmetrical Pythagorean-hodograph(PH)***,symmetrical PH splines are initially constructed at transition corners to realize the third-order differential continuity of tool path position and 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 *** asymmetrical splines are constructed by dealing with the spline overlapping problem,while guarantying the fully utilization of error tolerance to reduce spline *** position and orientation are synchronized to the arc-length of the tool tip position to ensure the continuity of acceleration and jerk *** control points and arc-length of the constructed asymmetrical splines can all be solved analytically,which makes it suitable for on-line tool path *** 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

大型煤化工低温甲醇洗工艺的尾气处理技术研究

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煤化工 2024年第4期52卷 45-48页

作者：何鹏杨吉祥国家能源集团宁夏煤业有限责任公司煤制油分公司宁夏银川750001

针对不同气化技术配套低温甲醇洗装置尾气组分的区别,分析了如何选择合适的尾气处理技术。对比研究了水煤浆气化技术和干煤粉气化技术配套低温甲醇洗装置尾气中甲醇、总硫、CO、H_(2)、CO_(2)等污染物的处理技术,并分析了这些处理技术... 详细信息

针对不同气化技术配套低温甲醇洗装置尾气组分的区别,分析了如何选择合适的尾气处理技术。对比研究了水煤浆气化技术和干煤粉气化技术配套低温甲醇洗装置尾气中甲醇、总硫、CO、H_(2)、CO_(2)等污染物的处理技术,并分析了这些处理技术的优缺点及未来的发展前景。

关键词：低温甲醇洗尾气污染物有效气

An on-line tool path smoothing algorithm for 6R robot manipulator with geometric and dynamic constraints

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Science China(Technological Sciences) 2021年第9期64卷 1907-1919页

作者： SUN HongWei yang jixiang LI DingWei DING Han School of Mechanical Science and Engineering State Key Laboratory of Digital Manufacturing Equipment and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

The tool path smoothness of the industrial robot directly influences the dynamic performance of its motion control. Therefore, it is important to smooth the path that is composed of small linear segments, in order to achieve continuous and smooth *** paper uses the FIR filter interpolation method to generate the smooth tool tip position and tool orientation trajectory for robot manipulators with 6 rotational(6R) joints. The geometric smoothness and motion interpolation are achieved in one *** maximum velocity and acceleration of joints are constrained when calculating the time parameters of the FIR filter. By specially designing the overlapping time at transition corners, the tool tip position and tool orientation deviations are all constrained in the workpiece coordinate system. Considering the complexity of the inverse kinematics of the robot, in order to constrain the velocity and acceleration of robot joints, this paper proposes a simplified method which directly establishes the relationship between joint motion and tool motion through the derivative of joint motion to tool motion without considering the inverse kinematics. Simulation and experiment results show that the algorithm can generate continuous acceleration commands of the tool tip position and tool orientation within the corner error tolerance. The preset velocity and acceleration limitations of six joints are all constrained well. Comparisons with existing algorithms demonstrate advantages of the proposed method.

关键词： robots tool path corner smooth FIR filter kinematics

Fiber Optic Hydrogen Sensors： a Review

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Photonic Sensors 2014年第4期4卷 300-324页

作者： Minghong yang jixiang DAI National Engineering Laboratory for Optical Fiber Sensing Technologies Wuhan University of Technology Wuhan430070 China

Hydrogen is one of the next generation energies in the future, which shows promising applications in aerospace and chemical industries. Hydrogen leakage monitoring is very dangerous and important because of its low ignition energy, high combustion efficiency, and smallest molecule. This paper reviews the state-of-art development of the fiber optic hydrogen sensing technology. The main developing trends of fiber optic hydrogen sensors are based on two kinds of hydrogen sensitive materials, i.e. palladium-alloy thin films and Pt-doped WO3 coatings. In this review work, the advantages and disadvantages of these two kinds of sensing technologies will be evaluated.

关键词： Optical fiber sensors hydrogen sensing thin films coatings

基于多尺度特征提取-改进天鹰算法-长短时神经网络的有载分接开关故障诊断方法

维普期刊数据库评论

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现代电力 2024年第4期41卷 793-800页

作者：龚禹璐崔龙飞王典浪陈静须雷皮天满谢正波杨继翔中国南方电网有限责任公司超高压输电公司曲靖局云南省曲靖市655000 南京南瑞继保工程技术有限公司江苏省南京市210000

为实现有载分接开关(on-load tap changer)在复合故障下的精准故障诊断,提出一种基于多尺度特征提取与改进天鹰算法(improved aquila optimizer,IAO)和长短时记忆神经网络(long short-term memory networks,LSTM)的变压器OLTC故障诊断... 详细信息

为实现有载分接开关(on-load tap changer)在复合故障下的精准故障诊断,提出一种基于多尺度特征提取与改进天鹰算法(improved aquila optimizer,IAO)和长短时记忆神经网络(long short-term memory networks,LSTM)的变压器OLTC故障诊断方法。首先提取OLTC振动信号时域尺度、频域尺度和能量熵尺度特征组成特征向量;通过混合初始化策略和精英解保留策略对天鹰优化算法(aquila optimizer,AO)进行改进,以提高收敛性;利用改进天鹰算法对LSTM的隐含层节点数和学习率进行优化,得到最优LSTM模型;以单一故障和复合故障融合特征向量为输入,以故障状态作为输出,在最优网络模型中训练,完成后进行故障诊断。结果表明,文中所述方法平均准确率达97.2%,适用于OLTC的故障诊断。

关键词：有载分接开关多尺度特征提取优化LSTM神经网络改进天鹰算法故障诊断

Porous graphene:Properties,preparation,and potential applications

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Chinese Science Bulletin 2012年第23期57卷 2948-2955页

作者： XU PengTao yang jixiang WANG KeSai ZHOU Zhen SHEN PanWen Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Institute of New Energy Material Chemistry ComputationalCenter for Molecular Science College of Chemistry Nankai University Tianjin 300071 China

Graphene has recently emerged as an important and exciting *** by its outstanding properties,many researchers have extensively studied graphene-related materials both experimentally and *** graphene is a collection of graphene-related materials with nanopores in the *** graphene exhibits properties distinct from those of graphene,and it has widespread potential applications in various fields such as gas separation,hydrogen storage,DNA sequencing,and *** this review,we summarize recent progress in studies of the properties,preparation,and potential applications of porous graphene,and show that porous graphene is a promising material with great potential for future development.

关键词： graphene porous graphene electronic structure gas separation DNA sequencing