Traditional working platforms for the maintenance work of large vertical storage tank such as scaffolding, rail and wall-climbing robots have many disadvantages like difficulty on disassembly, complex system or the low moving speed etc. These affect the efficiency of maintenance and limit the payload of working platform. Wire-driven parallel mechanism is new kind of robots with the advantages of large workspace, modular structure and big load capacity, which mean that it is promising to use it as working platform of large vertical storage tank. A new modular wire-driven parallel mechanism is proposed. Depending on the basic theory of parallel mechanism and modular design, the robot has eight wires and four modular rods. The position of each wire on rod is adjustable. After establishing the kinematic model, the influence on workspace by each parameter is given, which make it possible to optimize structure parameters for vertical storage tank of 20 m diameter. While the platform moves along different trajectory, analysis on the change of wire length and wire force shows better motion planning trajectory.
[1] 范继光. 油罐[M]. 北京：中国石化出版社,2007.
FAN Jiguang. Tank[M]. Beijing：China Petrochemical Press,2007.
[2] 中国石油天然气集团公司. GB 50341-2003,立式圆筒形钢制焊接油罐设计规范[S]. 北京：中国计划出版社,2003.
China National Petroleum Corporation. GB50341-2003,Vertical cylindrical steel welded oil tank design specification[S]. Beijing：China Planning Press,2003.
[3] 张清林. 国内外石油储罐典型火灾案例剖析[M]. 天津：天津大学出版社,2014.
ZHANG Qinglin. Typical domestic oil tank fire case analysis[M]. Tianjin：Tianjin University Press, 2014.
[4] 关卫和,沈纯厚,陶元宏,等. 大型立式储罐在线生发射检测与安全评估[J]. 压力容器,2005,22(1)：40-44.
GUAN Weihe, HEN Chunhou,TAO Yuanhong,et al. On-line detection and safety assessment of large-scale above ground storage tanks by acoustic emission[J]. Pressure Vessel Technology,2005,22(1)：40-44.
[5] 薛胜雄,任启乐,陈正文,等. 磁隙式爬壁机器人的研制[J]. 机械工程学报,2012,47(21)：37-42.
XUE Shengxiong,REN Qile,CHEN Zhengwen,et al. Design on magnetic gap adhesion typed crawler[J]. Journal of Mechanical Engineering,2012,47(21)：37-42.
[6] 闻靖. 罐壁爬行机器人本体设计及其特性研究[D]. 上海：上海交通大学,2011.
WEN Jing. System design and characteristics research of oil tank crawling robot[D]. Shanghai：Shanghai Jiaotong University,2011.
[7] 邵珠峰, 唐晓强, 王立平, 等. 平面柔性3-RRR并联机构自标定方法[J]. 机械工程学报, 2009, 45(3)： 150-155.
SHAO Zhufeng, TANG Xiaoqiang, WANG Liping, et al. Self-calibration method of planar flexible 3-RRR parallel manipulator[J]. Journal of Mechanical Engineering, 2009, 45(3)：150-155.
[8] ALBUS J,BOSTELMAN R,DAGALAKIS N. The NIST robocrane[J]. Journal of Robotic Systems,1993,10(5)： 709-724.
[9] SHAO Zhufeng,TANG Xiaoqiang,CHEN Xu,et al. Research on the inertia matching of the Stewart parallel manipulator[J]. Robotics and Computer Integrated Manufacturing,2012,28(6)：649-659.
[10] YAO Rui,TANG Xiaoqiang,WANG Jinsong,et al. Dimensional optimization design of the four-cable-driven parallel manipulator in FAST[J]. IEEE/ASME Transactions on Mechatronics,2010,15(6)：932-941.
[11] TANG Xiaoqiang,SHAO Zhufeng. Trajectory generation and tracking control of a multi-level hybrid support manipulator in FAST[J]. Mechatronics,2013,23(8)：1113-1122.
[12] 汤奥斐,仇原鹰,段宝岩,等. 一种柔索并联机器人的刚度解析[J]. 中国机械工程,2006,17(2)：345-349.
TANG Aofei,QIU Yuanying,DUAN Baoyan,et al. Analysis of reachable workspace of a wire driven parallel robot and its stiffness estimation[J]. China Mechanical Engineering,2006,17(2)：345-349.
[13] 姚蕊,唐晓强,李铁民,等. 大型射电望远镜馈源定位 3T 索牵引并联机构分析与设计[J]. 机械工程学报,2007,43(11)：105-109.
YAO Rui,TANG Xiaoqiang,LI Tiemin,et al. Analysis and design of 3T cable-driven parallel manipulator for the feedback's orientation of the large radio telescope[J]. Chinese Journal of Mechanical Engineering,2007,43(11)：105-109.
[14] 唐乐为,唐晓强,汪劲松,等. 七索并联对接机构作业空间分析及索力优化设计[J]. 机械工程学报,2012,49(21)：1-7.
TANG Lewei,TANG Xiaoqiang,WANG Jinsong,et al. Workspace analysis and tension optimization design in docking parallel mechanismdriven by seven cables[J]. Journal of Mechanical Engineering,2012,49(21)：1-7.
[15] 刘雄伟,郑亚青. 六自由度绳牵引并联机构的运动学分析[J]. 机械工程学报,2002,38(z1)：126-134.
LIU Xiongwei,ZHENG Yaqing. Kinematic analysis of a 6-DOF wire-drivenparallel kinematic manipulator[J]. Chinese Journal of Mechanical Engineering,2002,38(z1)：126-134.
[16] 郑亚青. 绳牵引并联机构若干关键理论问题及其在风洞支撑系统中的应用研究[D]. 泉州：华侨大学,2004.
ZHENG Yaqing. The key problems about cable-driven parallel mechanism and application on wind tunnel[D]. Quanzhou, Huaqiao University,2004.
[17] CONE L L. Skycam-an aerial robotic camera system[J]. Byte,1985,10(10)：122-132.
[18] SHAO Zhufeng,TANG Xiaoqiang,YI Wangmin. Optimum design of a 3-DOF cable-driven upper arm exoskeleton [EB/OL]. [2014-04-24]. http：//ade.sagepub.com/content/6/157096.
[19] VERHOEVEN R. Analysis of the workspace of tendon-based Stewart platforms [D]. Duisburg：University of Duisburg-Essen,2004.
[20] TANG Xiaoqiang,TANG Lewei,WANG Jinsong,et al. Workspace quality analysis and application for completely restrained 3-DOF planar cable-driven parallel manipulators[J]. Journal of Mechanical Science and Technology,2013,27(8)：2391-2399.
[21] KAWAMURA S,KINO H,WON C. High-speed manipulation by using parallel wire-driven robots [J]. Robotica,2000,18(1)：13-21.
[22] BARRETTE G,GOSSELIN C. Kinematic analysis and design of planar parallel mechanisms actuated with cables [C/CD]// Proceedings of the ASME 26th Biennial Mechanisms and Robotics Conference,Baltimore,Maryland,USA,2002.
[23] POTT A,BRUCKMANN T,MIKELSONS L. Closed-form force distribution for parallel wire robots [C]// Proceedings of the 5th International Workshop on Computational Kinematics. Duisburg, Germany,2009：25-34.
[24] BRUCKMANN T,POTT A,HILLER M. Calculating force distributions for redundantly actuated tendon-based Stewart platforms [EB/OL]. [2014-04-24]. http：//link.springer.com/chapter/10.1007%2F978-1-4020-4941-5_44.
[25] WANG Weifang,TANG Xiaoqiang,SHAO Zhufeng,et al. Design and analysis of a wire-driven parallel mechanism for low-gravity environment simulation [EB/OL].[ 2014-04-24]. http：//ade.sagepub.com/content/ 6/810606.
[26] LAFOURCADE P,LIBRE M,REBOULET C. Design of a parallel wire-driven manipulator for wind tunnels [C]// Workshop on Fundamental Issues and Future Research Directions for Parallel Mechanisms and Manipulators,Quebec,Canada,2002：187-194.
