FAST主动反射面随动关节的研究
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摘要
FAST (Five-hundred-meter Aperture Spherical Telescope 500m射电望远镜)是1994年中国天文学家准备在贵州喀斯特地形上建造的世界上最大的主动反射球面射电望远镜。主动变形反射面是FAST主要创新点之一,中国天文界公认整体索网支撑是作为大射电望远镜(FAST)主动反射面的最佳支承结构。随动关节是整体索网结构实现主动反射的关键部件之一,对FAST主动反射精度及运动灵活性起着举足轻重的作用。
本文首先考虑整体索网支撑结构的特点以及FAST主动反射运动要求,采用直线导轨和球面关节轴承组合的形式,设计了一种新型随动关节结构,它具有体积小、重量轻、结构紧凑、强度高、刚度大、便于安装、环境适应能力强等特点。并对随动关节的关键零部件进行了静力学分析和承载性能分析,为随动关节的设计提供了重要的参数指标。
FAST反射面的每个面板都是三自由度的并联机构,基于空间并联机构理论,对随动关节进行了运动学分析,求出了面板单元质心位置的正解和逆解,从而得出了整体索网支撑结构径向拉索长度和面板质心位置关系;计算出了整体索网结构运动到极限位置时,随动关节直线导轨的移动距离,由此得到了面板单元的安装间距;进一步求出了径向拉索长度变化和面板质心速度之间的关系。然后通过SolidWorks软件和ADAMS软件进行仿真,对运动学推导结果进行验证。
针对低速重载的工况,设计并制造了直线滑动轴承往复实验台,最大载荷为325kg,平均线速度范围为0.005m/s~0.12m/s。测试了几种直线滑动轴承在此工况下的摩擦学特性。实验结果显示,PTFE+石墨复合轴承在脂润滑条件下摩擦系数为0.09左右,运行平稳,满足随动关节低速重载工况的要求。
FAST (Five-hundred-meter Aperture Spherical Telescope) is the biggestradio telescope with active spherical main reflector which was built in Karstterrain in Guizhou in 1994. The whole cable-mesh sustentation is acknowledgedas the best support of the active spherical reflector by astronomical group ofChina. Tracking joint is one of the key parts for the whole cable-mesh to reflectactively，which is very important to the precision and flexibility of FAST.
Considering the characteristics of whole cable-mesh structure and themovement demand of active reflector, a new tracking joint was designed. Itsstructure assembles linear bearing and spherical joint bearing, so that it has manyadvantages, such as small volume, little weight, compact structure, high strengthand stiffness, easy to be install and good TadaptabilityT to eTnvironment, etc. Thestatic characteristics and bearing capacity of TprimaryT parts of were analyzed,which provides the important parameters for the optimization of Ttracking joints.
Each panel of FAST reflector is a 3T-DOF parallel mechanism. Based on thetheory of spatial parallel mechanism, the kinematics analysis of the trackingmechanism was done. The Tdirect solution and inverse solution of center of panelmass Twere obtainedT. The relations between radial cable length of cable-meshstructure and the position of center of panel mass were obtained. The movingdistance of linear leader of the tracking joint was figured out, when cable-meshmoving to the ultimate position. So the installation distance among panels wasobtained. The relations between the length variety of radial cable and the velocityof center of panel mass were obtained. The analysis model was established bySolidWorks. And the simulation was carried out with ADAMS. The correctnessof the kinematics calculation was verified.
Aimed at the working conditions of linear sliding under bearings low-speedand high-load, a reciprocating test bench was designed and manufactured. Itsmaximum load is 325kg and average linear velocity is from 0.005m/s to 0.12m/s.The tribological properties of four kinds of linear bearing were tested. Resultsshow the friction coefficient of PTFE+graphite bearings lubricated by grease isabout 0.09, and operates steadily. It meets the demand of tracking joints under low-speed and high-load.
本文首先考虑整体索网支撑结构的特点以及FAST主动反射运动要求,采用直线导轨和球面关节轴承组合的形式,设计了一种新型随动关节结构,它具有体积小、重量轻、结构紧凑、强度高、刚度大、便于安装、环境适应能力强等特点。并对随动关节的关键零部件进行了静力学分析和承载性能分析,为随动关节的设计提供了重要的参数指标。
FAST反射面的每个面板都是三自由度的并联机构,基于空间并联机构理论,对随动关节进行了运动学分析,求出了面板单元质心位置的正解和逆解,从而得出了整体索网支撑结构径向拉索长度和面板质心位置关系;计算出了整体索网结构运动到极限位置时,随动关节直线导轨的移动距离,由此得到了面板单元的安装间距;进一步求出了径向拉索长度变化和面板质心速度之间的关系。然后通过SolidWorks软件和ADAMS软件进行仿真,对运动学推导结果进行验证。
针对低速重载的工况,设计并制造了直线滑动轴承往复实验台,最大载荷为325kg,平均线速度范围为0.005m/s~0.12m/s。测试了几种直线滑动轴承在此工况下的摩擦学特性。实验结果显示,PTFE+石墨复合轴承在脂润滑条件下摩擦系数为0.09左右,运行平稳,满足随动关节低速重载工况的要求。
FAST (Five-hundred-meter Aperture Spherical Telescope) is the biggestradio telescope with active spherical main reflector which was built in Karstterrain in Guizhou in 1994. The whole cable-mesh sustentation is acknowledgedas the best support of the active spherical reflector by astronomical group ofChina. Tracking joint is one of the key parts for the whole cable-mesh to reflectactively，which is very important to the precision and flexibility of FAST.
Considering the characteristics of whole cable-mesh structure and themovement demand of active reflector, a new tracking joint was designed. Itsstructure assembles linear bearing and spherical joint bearing, so that it has manyadvantages, such as small volume, little weight, compact structure, high strengthand stiffness, easy to be install and good TadaptabilityT to eTnvironment, etc. Thestatic characteristics and bearing capacity of TprimaryT parts of were analyzed,which provides the important parameters for the optimization of Ttracking joints.
Each panel of FAST reflector is a 3T-DOF parallel mechanism. Based on thetheory of spatial parallel mechanism, the kinematics analysis of the trackingmechanism was done. The Tdirect solution and inverse solution of center of panelmass Twere obtainedT. The relations between radial cable length of cable-meshstructure and the position of center of panel mass were obtained. The movingdistance of linear leader of the tracking joint was figured out, when cable-meshmoving to the ultimate position. So the installation distance among panels wasobtained. The relations between the length variety of radial cable and the velocityof center of panel mass were obtained. The analysis model was established bySolidWorks. And the simulation was carried out with ADAMS. The correctnessof the kinematics calculation was verified.
Aimed at the working conditions of linear sliding under bearings low-speedand high-load, a reciprocating test bench was designed and manufactured. Itsmaximum load is 325kg and average linear velocity is from 0.005m/s to 0.12m/s.The tribological properties of four kinds of linear bearing were tested. Resultsshow the friction coefficient of PTFE+graphite bearings lubricated by grease isabout 0.09, and operates steadily. It meets the demand of tracking joints under low-speed and high-load.
引文
1. R. D. Nan, B. Peng. A Chinese Concept for the 1 km~2 Radio Telescope. ActaAstronautica. 2000, 46(10~12): 667~675
2. Y. H. Qiu. A Novel Design for Giant Radio Telescopes with a Active SphericalMain Reflector . Chinese Astronomy an Astrophysics. 1998, 22 (3): 361~368
3.南仁东. 500m球反射面射电望远镜FAST.中国科学G辑物理学力学天文学. 2005, 35(5): 449~466
4.吴盛殷,南仁东.射电望远镜的发展和前景.天文学进展. 1998, (9): 169~175
5.过静珺,谢炳福,于子洋. FAST与近代大型射电望远镜介绍.测绘通报.2002, (8): 56~58
6.吴鑫基.观天巨眼400年系列之二十二之世界上口径最大的可跟踪射电望远镜.太空探索. 2003, (12): 36~39
7.行卫国.柔性结构大型射电望远镜天线结构设计与分析.西安电子科技大学硕士学位论文. 2005: 1~8
8.吴鑫基.观天巨眼400年系列之二十三之世界上口径最大的阿雷西博射电望远镜.太空探索. 2004, (1): 40~42
9. G.. X. Ren, Q. H. Lu, N. Hu, et al. On Vibration Control with Stewart ParallelMechanism. Mechatronic. 2004, 14: 1~13
10.李国强,沈黎元,罗永峰等. 500m口径主动球面望远镜反射面支撑结构分析.同济大学学报. 2000, 28(4): 497～501
11.罗永峰,李国强,邓长根等.大射电望远镜反射面支承张拉结构非线性分析.同济大学学报. 2000, 31(1): 1~5
12.邱育海.具有主动反射面的巨型球面射电望远镜.天体物理学. 1998, 18(2):222~227
13. G. Q. Li, L. Y. Shen, F. Luo, et al. Analysis for Reflector Aluminum Mesh Panelsof Five-hundred Meter Aperture Spherical Telescope. Astrophysics and SpaceScience. 2001, 278(1): 225~230
14. Y. H. Qiu. A Novel Design for a Giant Arecibo-type Spherical Radio Telescopewith an Active Main Reflector. MNRAS. 1998, 301: 827~830
15. H. Q. Can, C. J. Jin, H. Y. Zhang, et al. A Way to Improve the Field of LargeAperture Radio Telescopes .Chinese Astronomy and Astrophysics. 2005, (29):343~352
16.钱宏亮,范峰,沈世钊等. FAST反射面支承结构整体索网方案研究.土木工程学报. 2005，(12): 18~23
17.林斌,范峰,钱宏亮.大射电望远镜FAST主动反射面在喀斯特地貌下的绕流数值模拟及其风振响应分析.工业建筑. 2004,增刊: 314~322
18. R. D. Nan, G. X. Ren, W. H. Zhu, et al. Adaptive Cable-mesh Reflector for theFAST. Acta Astronomica Sinica. 2003, (2) : 13~18
19.钱宏亮,范峰,沈世钊. FAST反射面支承结构整体索网研究.工业建筑.2004,增刊: 121~129
20.胡超,施浒立.大型射电望远镜阵列天线结构设计的考虑.电子机械工程.2006, 22 (1): 23~26
21. Hunt. Structural Kinematics of In-Parallel-Actuated Robot-Arms. ASME Journalof Mechnisms, Tranmissions and Automation in Design. 1983, 105: 705~712
22. K. Lee, D. K. Shah. Kinematic Analysis of a Three Degrees of Freedom In-Parallel Actuated Manipulator. Proceedings of IEEE International Conference onRobotics and Automation, Raleigh, NC, 1987, 1: 345~350
23. R. Clavel. A Fast Robot With Parallel Geometry. 18thPPInternational Symposiumon Industrial Robots, Sydney, Australia, 1988: 91~100
24. F. Pierrot, C. Reynaud, A. Fournier, et al. A Simple and Efficient Parallel Robot.Robotics. 1990, 6: 105~109
25. C. M. Gosselin, J. Angeles. The Optimum Icinematic Design of a Planar Threedegree-of-freedom Parallel Manipulator. ASME, J. Mechanisms, TransmissAutomat Design. 1988, 110(1): 35~41
26.齐毓霖.摩擦与磨损.高等教育出版社，1986: 39~41
27. J. M. Herve. Design of Parallel Manipulators Via the Displacement Group. 9thPPWorld Congress on the Theory of Machines and Mechanisms. Milan, Augus,1995: 2079~2082
28. Z. Huang, W. S. Tao, Y. F. Fang. Study on the Kinematic Characteristics of 3-DOF in Parallel Actuated Platform Mechanisms. Mechanism and Machinetheory. 1996, 31(8): 999~1007
29. L.W. Tsai. The Enumeration of a Class of Three-DOF Parallel Manipulators.10th World Congress on the Theory of Machine and Mechanisms. Olulu, Finland,1999, 3: 1121~1126
30.赵铁石，黄真.能实现三维移动的并联3-RRC平台机构运动学分析闭.中国机械工程. 2000, 11 (5): 4~7
31.赵铁石.空间少自由度并联机器人机构分析与综合的理论研究.燕山大学博士学位论文. 2000
32. H. S. Kim, L. W. Tsai. Kinematic Synthesis of Spatial 3-RPS ParallelManipulators. Proc. of DECT'02 ASME 2002 Design Engineering TechnicalConferences. September 29-October 2, Montreal, Canada, 2002: 978~986
33.黄真.少自由度并联机器人机构的型综合原理.中国科学(E辑). 2003, 11:31~38
34. L. W. Tsai. Kinematics of a Three-DOF Platform with Three Extensible Limbs.Recent Advances in Robot Kinematics. Kiuwer Academic Publishers, 1999, 112:401~410
35. J. A. Carretero, M. Nahon, R. P. Podhorodeski. Workspace analysis of a 3-DOFParallel Mechanism. Proceedings of the IEEE/RSJ International Conference onIntelligent Robot and Systems. Innovations in Theory. Practice and Applications.Victoria, British Columbia, Canada, 1998: 1021~1026
36. R. E. Stamper, L. W. Tsai, G. C. Walsh. Optimization of a Three DOFTranslational Platform for Well-Conditioned Workspace. Proceedings of theIEEE International Conference on Robotics and Automation. Albuquerque, NM,1997: 3250~3255
37. R. D. Gregorio, V. Parenti-Castelli. Influence of Leg Flexibility on theKinetostatic Behaviour of a 3-DOF Fully-Parallel Manipulator. 10th WorldCongress on the Theory of Machine and Mechanisms. Olulu, Finland, 1999, 3:532~539
38. L. W. Tsai. The Mechanics of Serial and Parallel Manipulators. Robot Analysis.John Wiley and Sons. 1998, 102 (4): 223~231
39. M. Badescu, J. Morman, C. Mavroidis. Workspace Optimization of Orientational3-legged UPS Parallel Platform. Proceeding of DECT'02 ASME 2002 DesignEngineering Technical Conferences. Montreal, Canada, 2002: 1152~1163
40.周仁和. 3-RPS并联机器人及其变型2-RPS+PSR并联机器人运动学性能研究.南京理工大学硕士学位论文. 2006
41.黄真.空间机构学.机械工业出版社, 1991
42.黄真,孔令富,方跃法.并联机器人机构学理论及控制.机械工业出版社,1997
43. Jorges Angles.机器人机械系统原理—理论.方法和算法.宋伟刚译.机械工业出版社, 2004
44.陆震,杨光,王启明等. FAST望远镜主动反射面促动机构运动学研究.航空航天大学学报. 2006, 32: 233~238
45.陈文凯. 3-RSR并联机器人运动学和动力学建模及仿真.华东交通大学硕士学位论文. 2006
46. C. Gosslin, J. Angeles. A Global Performance Index for the KinematicOptimization of Robotic Manipulators. Journal of Mechanical Design. 1991, 113:220~226
2. Y. H. Qiu. A Novel Design for Giant Radio Telescopes with a Active SphericalMain Reflector . Chinese Astronomy an Astrophysics. 1998, 22 (3): 361~368
3.南仁东. 500m球反射面射电望远镜FAST.中国科学G辑物理学力学天文学. 2005, 35(5): 449~466
4.吴盛殷,南仁东.射电望远镜的发展和前景.天文学进展. 1998, (9): 169~175
5.过静珺,谢炳福,于子洋. FAST与近代大型射电望远镜介绍.测绘通报.2002, (8): 56~58
6.吴鑫基.观天巨眼400年系列之二十二之世界上口径最大的可跟踪射电望远镜.太空探索. 2003, (12): 36~39
7.行卫国.柔性结构大型射电望远镜天线结构设计与分析.西安电子科技大学硕士学位论文. 2005: 1~8
8.吴鑫基.观天巨眼400年系列之二十三之世界上口径最大的阿雷西博射电望远镜.太空探索. 2004, (1): 40~42
9. G.. X. Ren, Q. H. Lu, N. Hu, et al. On Vibration Control with Stewart ParallelMechanism. Mechatronic. 2004, 14: 1~13
10.李国强,沈黎元,罗永峰等. 500m口径主动球面望远镜反射面支撑结构分析.同济大学学报. 2000, 28(4): 497～501
11.罗永峰,李国强,邓长根等.大射电望远镜反射面支承张拉结构非线性分析.同济大学学报. 2000, 31(1): 1~5
12.邱育海.具有主动反射面的巨型球面射电望远镜.天体物理学. 1998, 18(2):222~227
13. G. Q. Li, L. Y. Shen, F. Luo, et al. Analysis for Reflector Aluminum Mesh Panelsof Five-hundred Meter Aperture Spherical Telescope. Astrophysics and SpaceScience. 2001, 278(1): 225~230
14. Y. H. Qiu. A Novel Design for a Giant Arecibo-type Spherical Radio Telescopewith an Active Main Reflector. MNRAS. 1998, 301: 827~830
15. H. Q. Can, C. J. Jin, H. Y. Zhang, et al. A Way to Improve the Field of LargeAperture Radio Telescopes .Chinese Astronomy and Astrophysics. 2005, (29):343~352
16.钱宏亮,范峰,沈世钊等. FAST反射面支承结构整体索网方案研究.土木工程学报. 2005，(12): 18~23
17.林斌,范峰,钱宏亮.大射电望远镜FAST主动反射面在喀斯特地貌下的绕流数值模拟及其风振响应分析.工业建筑. 2004,增刊: 314~322
18. R. D. Nan, G. X. Ren, W. H. Zhu, et al. Adaptive Cable-mesh Reflector for theFAST. Acta Astronomica Sinica. 2003, (2) : 13~18
19.钱宏亮,范峰,沈世钊. FAST反射面支承结构整体索网研究.工业建筑.2004,增刊: 121~129
20.胡超,施浒立.大型射电望远镜阵列天线结构设计的考虑.电子机械工程.2006, 22 (1): 23~26
21. Hunt. Structural Kinematics of In-Parallel-Actuated Robot-Arms. ASME Journalof Mechnisms, Tranmissions and Automation in Design. 1983, 105: 705~712
22. K. Lee, D. K. Shah. Kinematic Analysis of a Three Degrees of Freedom In-Parallel Actuated Manipulator. Proceedings of IEEE International Conference onRobotics and Automation, Raleigh, NC, 1987, 1: 345~350
23. R. Clavel. A Fast Robot With Parallel Geometry. 18thPPInternational Symposiumon Industrial Robots, Sydney, Australia, 1988: 91~100
24. F. Pierrot, C. Reynaud, A. Fournier, et al. A Simple and Efficient Parallel Robot.Robotics. 1990, 6: 105~109
25. C. M. Gosselin, J. Angeles. The Optimum Icinematic Design of a Planar Threedegree-of-freedom Parallel Manipulator. ASME, J. Mechanisms, TransmissAutomat Design. 1988, 110(1): 35~41
26.齐毓霖.摩擦与磨损.高等教育出版社，1986: 39~41
27. J. M. Herve. Design of Parallel Manipulators Via the Displacement Group. 9thPPWorld Congress on the Theory of Machines and Mechanisms. Milan, Augus,1995: 2079~2082
28. Z. Huang, W. S. Tao, Y. F. Fang. Study on the Kinematic Characteristics of 3-DOF in Parallel Actuated Platform Mechanisms. Mechanism and Machinetheory. 1996, 31(8): 999~1007
29. L.W. Tsai. The Enumeration of a Class of Three-DOF Parallel Manipulators.10th World Congress on the Theory of Machine and Mechanisms. Olulu, Finland,1999, 3: 1121~1126
30.赵铁石，黄真.能实现三维移动的并联3-RRC平台机构运动学分析闭.中国机械工程. 2000, 11 (5): 4~7
31.赵铁石.空间少自由度并联机器人机构分析与综合的理论研究.燕山大学博士学位论文. 2000
32. H. S. Kim, L. W. Tsai. Kinematic Synthesis of Spatial 3-RPS ParallelManipulators. Proc. of DECT'02 ASME 2002 Design Engineering TechnicalConferences. September 29-October 2, Montreal, Canada, 2002: 978~986
33.黄真.少自由度并联机器人机构的型综合原理.中国科学(E辑). 2003, 11:31~38
34. L. W. Tsai. Kinematics of a Three-DOF Platform with Three Extensible Limbs.Recent Advances in Robot Kinematics. Kiuwer Academic Publishers, 1999, 112:401~410
35. J. A. Carretero, M. Nahon, R. P. Podhorodeski. Workspace analysis of a 3-DOFParallel Mechanism. Proceedings of the IEEE/RSJ International Conference onIntelligent Robot and Systems. Innovations in Theory. Practice and Applications.Victoria, British Columbia, Canada, 1998: 1021~1026
36. R. E. Stamper, L. W. Tsai, G. C. Walsh. Optimization of a Three DOFTranslational Platform for Well-Conditioned Workspace. Proceedings of theIEEE International Conference on Robotics and Automation. Albuquerque, NM,1997: 3250~3255
37. R. D. Gregorio, V. Parenti-Castelli. Influence of Leg Flexibility on theKinetostatic Behaviour of a 3-DOF Fully-Parallel Manipulator. 10th WorldCongress on the Theory of Machine and Mechanisms. Olulu, Finland, 1999, 3:532~539
38. L. W. Tsai. The Mechanics of Serial and Parallel Manipulators. Robot Analysis.John Wiley and Sons. 1998, 102 (4): 223~231
39. M. Badescu, J. Morman, C. Mavroidis. Workspace Optimization of Orientational3-legged UPS Parallel Platform. Proceeding of DECT'02 ASME 2002 DesignEngineering Technical Conferences. Montreal, Canada, 2002: 1152~1163
40.周仁和. 3-RPS并联机器人及其变型2-RPS+PSR并联机器人运动学性能研究.南京理工大学硕士学位论文. 2006
41.黄真.空间机构学.机械工业出版社, 1991
42.黄真,孔令富,方跃法.并联机器人机构学理论及控制.机械工业出版社,1997
43. Jorges Angles.机器人机械系统原理—理论.方法和算法.宋伟刚译.机械工业出版社, 2004
44.陆震,杨光,王启明等. FAST望远镜主动反射面促动机构运动学研究.航空航天大学学报. 2006, 32: 233~238
45.陈文凯. 3-RSR并联机器人运动学和动力学建模及仿真.华东交通大学硕士学位论文. 2006
46. C. Gosslin, J. Angeles. A Global Performance Index for the KinematicOptimization of Robotic Manipulators. Journal of Mechanical Design. 1991, 113:220~226