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Offline motion planning and simulation of two-robot welding coordination
Tie ZHANG, Fan OUYANG
《机械工程前沿(英文)》 2012年 第7卷 第1期 页码 81-92 doi: 10.1007/s11465-012-0309-4
This paper focuses on the two-robot welding coordination of complex curve seam which means one robot grasp the workpiece, the other hold the torch, the two robots work on the same workpiece simultaneously. This paper builds the dual-robot coordinate system at the beginning, and three point calibration method of two robots’ relative base coordinate system is presented. After that, the non master/slave scheme is chosen for the motion planning, the non master/slave scheme sets the poses versus time function of the point u on the workpiece, and calculates the two robot end effecter trajectories through the constrained relationship matrix automatically. Moreover, downhand welding is employed which can guarantee the torch and the seam keep in good contact condition all the time during the welding. Finally, a Solidworks-SimMechanics simulation platform is established, and a simulation of curved steel pipe welding is conducted. The results of the simulation illustrate the welding process can meet the requirements of downhand welding, the joint displacement curves are smooth and continuous and no joint velocities are out of working scope.
关键词: complex curve seam two robots coordinated welding motion planning
Fei LI,Suocheng DONG,Fujia LI,Libiao YANG
《环境科学与工程前沿(英文)》 2016年 第10卷 第2期 页码 276-287 doi: 10.1007/s11783-014-0700-y
An adaptive sliding mode control technology for weld seam tracking
Jie LIU,Youmin HU,Bo WU,Kaibo ZHOU,Mingfeng GE
《机械工程前沿(英文)》 2015年 第10卷 第1期 页码 95-101 doi: 10.1007/s11465-015-0332-3
A novel adaptive sliding mode control algorithm is derived to deal with seam tracking control problem of welding robotic manipulator, during the process of large-scale structure component welding. The proposed algorithm does not require the precise dynamic model, and is more practical. Its robustness is verified by the Lyapunov stability theory. The analytical results show that the proposed algorithm enables better high-precision tracking performance with chattering-free than traditional sliding mode control algorithm under various disturbances.
关键词: weld seam tracking welding robotic manipulator adaptive control sliding mode control
A review on transport of coal seam gas and its impact on coalbed methane recovery
Geoff G.X. WANG, Xiaodong ZHANG, Xiaorong WEI, Xuehai FU, Bo JIANG, Yong QIN
《化学科学与工程前沿(英文)》 2011年 第5卷 第2期 页码 139-161 doi: 10.1007/s11705-010-0527-4
关键词: mass transport coal seam gas (CSG) coalbed methane (CBM) coal CBM recovery carbon dioxide storage
Learning curve of totally thoracoscopic pulmonary segmentectomy
Weibing Wu, Jing Xu, Wei Wen, Yue Yu, Xinfeng Xu, Quan Zhu, Liang Chen
《医学前沿(英文)》 2018年 第12卷 第5期 页码 586-592 doi: 10.1007/s11684-017-0566-z
Totally thoracoscopic pulmonary segmentectomy (TTPS) is a feasible and safe technique that requires advanced thoracoscopic skills and knowledge of pulmonary anatomy. However, data describing the learning curve of TTPS have yet to be obtained. In this study, 128 patients who underwent TTPS between September 2010 and December 2013 were retrospectively analyzed to evaluate the learning curve and were divided chronologically into three phases, namely, ascending phase (A), plateau phase (B), and descending phase (C), through cumulative summation (CUSUM) for operative time (OT). Phases A, B, and C comprised 39, 33, and 56 cases, respectively. OT and blood loss decreased significantly from phases A to C (P <0.01), and the frequency of intraoperative bronchoscopy for target bronchus identification decreased gradually (A, 8/39; B, 4/33; C, 3/56; P = 0.06). No significant differences were observed in demographic factors, conversion, complications, hospital stay, and retrieved lymph nodes among the three phases. Surgical outcomes and techniques improved with experience and volume. CUSUMOT indicated that the learning curve of TTPS should be more than 72 cases.
高明中,王列平
《中国工程科学》 2007年 第9卷 第11期 页码 142-146
针对淮南某矿急倾斜煤层开采复杂的采矿地质条件,运用概率积分法对优化后的开采方案所引起 的地表沉陷进行研究,总结出急倾斜煤层开采重复采动所引起的厚冲积层地表沉陷的相关参数。所得结果 对现场开采及地表沉陷治理具有一定的指导作用,对于同类地质和开采条件的矿区具有重要参考价值。
秦书玉,秦伟瀚
《中国工程科学》 2003年 第5卷 第10期 页码 52-55
应用正交设计优化煤层注水工艺参数的组合,对地质条件稳定的煤层是实现最佳注水效果的一种较好的方法。但是,对于地质条件不断变化的煤层,采用该方法,其效果不一定能满足注水工程要求。为此,针对地质因素为不稳定状态下的煤层及影响煤层注水的地质因素既有定性变量又有定量变量的特征,提出利用数量化理论与正交设计2种方法确定注水工艺参数的最优组合,并进行了工程试验优化研究。试验结果表明,此法节省注水试验工程量,接近实际工程要求。
Numerical investigation of circle defining curve for two-dimensional problem with general boundaries
Chung Nguyen VAN
《结构与土木工程前沿(英文)》 2019年 第13卷 第1期 页码 92-102 doi: 10.1007/s11709-018-0472-8
关键词: exact geometry circular defining curve general boundaries SBFEM
GID complex regulates the differentiation of neural stem cells by destabilizing TET2
《医学前沿(英文)》 doi: 10.1007/s11684-023-1007-9
关键词: TET2 GID complex neural stem cells differentiation of neurons
陈志祥
《中国工程科学》 2007年 第9卷 第7期 页码 82-88
学习曲线是一种通过生产者行为学习与经验积累而得到改进的生产产出的特征函数,利用学习曲线可以科学地制定成本计划,改善作业计划、劳动定额与劳力规划,质量改善等。对国际上的研究文献、学习曲线的表现形式及其特点进行分析,探讨了几个新的应用动向。
Research on physical shape preserving curve reconstruction
TANG Kelun, ZHANG Xiangwei, CHENG Siyuan, XIONG Hanwei, ZHANG Hong
《机械工程前沿(英文)》 2007年 第2卷 第3期 页码 305-309 doi: 10.1007/s11465-007-0054-2
关键词: information CMM Numerical simulation effective coordinate measuring
刘泽功,袁亮,戴广龙,石必明,卢平,涂敏
《中国工程科学》 2004年 第6卷 第5期 页码 32-38
开采煤层工作面的瓦斯主要来源于该煤层、采空区和邻近层的卸压解吸瓦斯。由于煤层松软,顺层钻孔施工难,不便钻孔抽放瓦斯。若对采空区实施大面积抽放,工程难度大,而且抽不出高浓度瓦斯。因此,寻找瓦斯运移的裂隙通道和瓦斯富集区,实施有效的瓦斯抽放工程是实现高效瓦斯抽放的技术关键。采用实验室相似材料试验、数值模拟计算和工业性试验研究方法,研究寻找采场上覆岩层中环形裂隙圈形成机理和位置,把抽放钻孔布置在环形裂隙圈内,进行“环形裂隙圈内走向长钻孔法”瓦斯抽放。这种瓦斯抽放技术使低透气性高瓦斯煤层的开采和瓦斯抽放分层区进行,在开采层工作面采煤,在顶板层裂隙区抽放卸压瓦斯,对流向工作面上隅角的瓦斯起到了截流作用,解决了松软低透气性高瓦斯煤层群开采瓦斯抽放困难的关键技术难题。该瓦斯抽放技术在淮南矿区高瓦斯工作面的应用结果表明,采煤工作面瓦斯抽放率达到60%以上,实现煤层群首采煤层安全、高效、集约化开采。
Interpolation of a spline developable surface between a curve and two rulings
Alicia CANTÓN,Leonardo FERNÁNDEZ-JAMBRINA
《信息与电子工程前沿(英文)》 2015年 第16卷 第3期 页码 173-190 doi: 10.1631/FITEE.14a0210
Principle and curve of planetary indexing cam mechanisms
LIU Ming-tao, ZHANG Ce, YANG Yu-hu
《机械工程前沿(英文)》 2006年 第1卷 第4期 页码 475-478 doi: 10.1007/s11465-006-0063-6
关键词: continuity planetary average transmission symmetry intermittent
张忠温,吴吉南
《中国工程科学》 2011年 第13卷 第11期 页码 107-112
针对平朔矿区4号煤层条件,采用理论分析方法研究了浅埋深两硬条件下4号煤层顶煤的冒放性及合理采煤方法。以提高顶煤冒放性为目标,采用数值模拟的方法进行了综放工作面参数及设备选型配套研究。实践表明,浅埋深两硬煤层条件下通过加大综放工作面长度与割煤高度,可以实现安全、高效、高回收率开采。
标题 作者 时间 类型 操作
Is there an inverted U-shaped curve?Empirical analysis of the Environmental Kuznets Curve in agrochemicals
Fei LI,Suocheng DONG,Fujia LI,Libiao YANG
期刊论文
An adaptive sliding mode control technology for weld seam tracking
Jie LIU,Youmin HU,Bo WU,Kaibo ZHOU,Mingfeng GE
期刊论文
A review on transport of coal seam gas and its impact on coalbed methane recovery
Geoff G.X. WANG, Xiaodong ZHANG, Xiaorong WEI, Xuehai FU, Bo JIANG, Yong QIN
期刊论文
Learning curve of totally thoracoscopic pulmonary segmentectomy
Weibing Wu, Jing Xu, Wei Wen, Yue Yu, Xinfeng Xu, Quan Zhu, Liang Chen
期刊论文
Numerical investigation of circle defining curve for two-dimensional problem with general boundaries
Chung Nguyen VAN
期刊论文
Research on physical shape preserving curve reconstruction
TANG Kelun, ZHANG Xiangwei, CHENG Siyuan, XIONG Hanwei, ZHANG Hong
期刊论文
Interpolation of a spline developable surface between a curve and two rulings
Alicia CANTÓN,Leonardo FERNÁNDEZ-JAMBRINA
期刊论文