混联机床并联机构几何参数辨识研究及内球面加工试验
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摘要
混联机床是近年来发展起来的一种新型机床,该类机床采用了串并联复合机构,不仅继承了并联机床高刚度、高精度和高进给速度等优点,还具备了串联机床大移动行程和大旋转运动角的特点。混联机床的出现是机床产业的一次重大革命,代表了新一代机床的发展方向,但加工精度仍是制约混联机床商品化和在工业生产中推广应用的重要因素,如何提高混联机床的加工精度已经成了其能否投入工业运行的关键。
运动学标定是提高混联机床几何精度的一种高效、低成本的方法。本文结合6PM2六轴混联数控镗铣床,分析了混联机床并联机构的几何误差来源;建立了空间坐标系,采用坐标变换的方法对动平台的位姿进行了描述;应用逆解模型构造动平台的位姿误差与结构几何误差之间的关系,建立了几何参数辨识模型;以并联杆初始杆长参数的标定为例,测量动平台的位姿信息,将结构参数作为未知数对辨识方程进行求解,得到了并联杆初始杆长的真实值。最后,对并联机构的控制模型参数进行修正,初步完成了混联机床的运动学标定。
以内球面加工为例,验证了混联机床运动学标定的有效性。分析内球面的生成原理,采用圆柱铣刀插补内球面截面圆弧与工件绕其自身轴线旋转的运动配合方法进行加工。论述了内球面加工时铣刀与已加工表面发生干涉的可能性,推导了主轴倾角的最小值公式。应用数据采样法内接弦线圆弧插补的方法对内球面截面圆弧进行粗插补运算,精插补则由多轴运动控制器PMAC自身的插补运动模式来实现。
The hybrid machine tool is a novel type machine tool developed in the recent years. It is combined serial mechanism with parallel mechanism so that it can obtains the advantages of great travel and rotational angle of the serial parts, as well as high stiffness, high accuracy and high feed speed of the parallel parts. The birth of the hybrid machine tool is a great revolution of the machine tool industry, which also represents the development trend of the new generation machine tool. However, the machining accuracy still is an important factor which restricts the commercialization of the hybrid machine tool and its popularization and application in industrial production. In this case, how to improve the machining accuracy of the hybrid machine tool has become the key that relates to that whether it can be put into practice or not.
The Kinematic Calibration is a high-efficiency and low-cost method that can improve the geometric accuracy of the hybrid machine tool. In this thesis, the Geometric error sources of the six-axis hybrid boring and milling NC machine tool 6PM2's parallel mechanism are analyzed. Space coordinate systems are established, and then the posture of the motion platform is described with the solution of coordinate transformation. Then, the geometric parameters' identification model is constructed according to the relationship between the posture errors of the motion platform and the geometric errors that is given out by the inverse model. With the calibration of parallel bars' original length being taken for instance, the posture information of the motion platform is measured and the identification equations are solved by considering the structural parameters as unknowns so that the real value of the parallel bars' original length can be obtained. Finally, the control model parameters of the parallel mechanism are corrected. In this way, the kinematic calibration of the hybrid machine tool is preliminarily accomplished.
With the machining of internal spherical surface being taken for example, the kinematic calibration of the hybrid machine tool is proved effectively. The generating principle of internal spherical surface is analyzed, based on which the machining method of combining the motion of cylinder milling cutter interpolating the section circular arc of the internal spherical surface with the motion of the workpiece rotating on its own axis is chosen. As it is possible that the milling cutter would interfere with the machined surface while machining the internal spherical surface, the minimum value formula of the spindle's inclination angle is deduced. The time-slicing circular interpolating method is used to accomplish the rough interpolation of the section circular arc of the internal spherical surface, while a certain motion mode of the multi-axis motion controller PMAC is used for the precise interpolation.
运动学标定是提高混联机床几何精度的一种高效、低成本的方法。本文结合6PM2六轴混联数控镗铣床,分析了混联机床并联机构的几何误差来源;建立了空间坐标系,采用坐标变换的方法对动平台的位姿进行了描述;应用逆解模型构造动平台的位姿误差与结构几何误差之间的关系,建立了几何参数辨识模型;以并联杆初始杆长参数的标定为例,测量动平台的位姿信息,将结构参数作为未知数对辨识方程进行求解,得到了并联杆初始杆长的真实值。最后,对并联机构的控制模型参数进行修正,初步完成了混联机床的运动学标定。
以内球面加工为例,验证了混联机床运动学标定的有效性。分析内球面的生成原理,采用圆柱铣刀插补内球面截面圆弧与工件绕其自身轴线旋转的运动配合方法进行加工。论述了内球面加工时铣刀与已加工表面发生干涉的可能性,推导了主轴倾角的最小值公式。应用数据采样法内接弦线圆弧插补的方法对内球面截面圆弧进行粗插补运算,精插补则由多轴运动控制器PMAC自身的插补运动模式来实现。
The hybrid machine tool is a novel type machine tool developed in the recent years. It is combined serial mechanism with parallel mechanism so that it can obtains the advantages of great travel and rotational angle of the serial parts, as well as high stiffness, high accuracy and high feed speed of the parallel parts. The birth of the hybrid machine tool is a great revolution of the machine tool industry, which also represents the development trend of the new generation machine tool. However, the machining accuracy still is an important factor which restricts the commercialization of the hybrid machine tool and its popularization and application in industrial production. In this case, how to improve the machining accuracy of the hybrid machine tool has become the key that relates to that whether it can be put into practice or not.
The Kinematic Calibration is a high-efficiency and low-cost method that can improve the geometric accuracy of the hybrid machine tool. In this thesis, the Geometric error sources of the six-axis hybrid boring and milling NC machine tool 6PM2's parallel mechanism are analyzed. Space coordinate systems are established, and then the posture of the motion platform is described with the solution of coordinate transformation. Then, the geometric parameters' identification model is constructed according to the relationship between the posture errors of the motion platform and the geometric errors that is given out by the inverse model. With the calibration of parallel bars' original length being taken for instance, the posture information of the motion platform is measured and the identification equations are solved by considering the structural parameters as unknowns so that the real value of the parallel bars' original length can be obtained. Finally, the control model parameters of the parallel mechanism are corrected. In this way, the kinematic calibration of the hybrid machine tool is preliminarily accomplished.
With the machining of internal spherical surface being taken for example, the kinematic calibration of the hybrid machine tool is proved effectively. The generating principle of internal spherical surface is analyzed, based on which the machining method of combining the motion of cylinder milling cutter interpolating the section circular arc of the internal spherical surface with the motion of the workpiece rotating on its own axis is chosen. As it is possible that the milling cutter would interfere with the machined surface while machining the internal spherical surface, the minimum value formula of the spindle's inclination angle is deduced. The time-slicing circular interpolating method is used to accomplish the rough interpolation of the section circular arc of the internal spherical surface, while a certain motion mode of the multi-axis motion controller PMAC is used for the precise interpolation.
引文
[1]范守文.混联结构并联机床的研究[D].成都:四川大学,2002:1-3.
[2]关浩,胡萍,于云满.21世纪新兴机床--虚拟轴并联机床[J].江苏机械制造与自动化,2001,(4):17-18.
[3]Manfred Weck,Michael Damnoer.Design,calculation and control of machine tools based on parallel kinematics[A].In:Proc.of the ASME[C].MED-vol.8,1998:715-721.
[4]Bruno Siciliano.The Tricept robot:Inverse kinematics,manipulability analysis and closed-loop direct kinematics algorithm[J].Robotica,1999,17(4):437-445.
[5]Tetsuro Shhibukawa,et al.Development of parallel mechanism based milling machine[HexaM][A].In:Proc.of theASME[C].MED-Vol.8,1998:691-698.
[6]Keum-Shik Hong,Jeom-Goo Kim.Manipulability Analysis of a Parallel Machine Tool:Application to Optimal Link LengthDesign[J].J.Robotic Systems,2000,17(8):403-415.
[7]夏广岚,胡晓平,李彩花,赵国福.并联机器人发展现状与展望[J].中国科技信息,2005,(22)
[8]邬昌峰,高荣慧.并联机床的特点、研究现状及展望[J].机械,2003,30(1):1-6.
[9]汪劲松,黄田.并联机床--机床行业面临的机遇与挑战[J].中国机械工程,1999,10(10):1103-1107.
[10]马琳.3-HSS并联机床精度设计与误差补偿方法研究[D].天津:天津大学,2001
[11]史长虹,张同庄,丁洪生.变轴数控机床精度研究进展[J].组合机床与自动化技术,2001(4):8-10.
[12]唐有桥.混联机床精度检测与误差补偿研究[D].西安:西安理工大学,2005:30.
[13]何小妹,丁洪生,付铁,孙厚芳.并联机床运动学标定研究综述[J].机床与液压,2004,(10):9-11.
[14]高猛,李铁民,叶佩青,段广洪.面向精度评价的并联机床参数辨识技术[J].机械工程学报,2005,41(5):79-82.
[15]王冰.五轴混联机床的关键技术研究[D].秦皇岛:燕山大学,2005:9-10.
[16]Wang J.,Masory O..On The Accuracy of a Stewart Platform-Part I,The Effect of Manufacture Tolerances.IEEE International Conference on Robotics and Automation,1993:114-120.
[17]T.Ropponen,T.Arai.Accuracy Analysis of a Modified Stewart Platform Manipulator.IEEE Int.Conf.on Robotics and Automation,1995:521-525.
[18]赵俊伟.串并联机床精度分析及检测装置研究[D].武汉:华中科技大学,2001
[19]毛新华,游红伟,刘新昌.基于数控加工中圆弧插补的改进方法[J].河南科技学院学报(自然科学版),2006:95-97.
[20]于信伟,麻晓红.内球面加工及其误差分析[J].煤矿机械,2004,(2):93.
[21]乔雁龙.混联机床的数控加工程序处理方法的研究及其模块的开发[D].西安:西安理工大学,2006:9,28,51-52.
[22]彭中波.混联机床运动学标定及其开放式数控系统研究[D].西安:西安理工大学,2004
[23]杜振辉,蒋诚志,桂垣,王斌.激光干涉仪测量长度[J].河北建筑工程学院学报,2003,21(2):11-13.
[24]黎捷.Maple 9.0符号处理及应用[M].北京:科技出版社,2004:1.
[25]李宏胜,黄尚先.机床数控技术及应用[M].北京:高等教育出版社,2001:97-98.
[26]周慧.数据采样法圆弧插补的新算法[J].组合机床与自动化加工技术,2004,(2):38-42.
[27]任玉田,焦振学,王宏甫.机床计算机数控技术(第二版)[M].北京:北京理工大学出版社,2002:138.
[28]田相克.PMAC多轴运动控制器研究[D].兰州:兰州理工大学,2004:13-32.
[29]北京钧义志成科技发展有限公司责任公司.PMAC用户手册,2003
[30]宓方伟,陈功福.PMAC多轴运动控制器应用研究[J].机床与液压,2004,(12):129-131.
[31]程祥.新型复合加工中心创新设计方法研究[D].西安:西安理工大学,2006
[32]李金泉,丁洪生,付铁,庞思勤.并联机床的历史、现状及展望[J].机床与液压,2003,(13):3-8.
[33]黄玉美,高 峰,史文浩.混联式数控机床的发展[J].制造技术与机床,2001(8):8-9.
[34]顾锋,汪通悦,康志军,刘远伟.并联机床的研究与技术进展[J].机床与液压,2002,(16):14-16.
[35]李强,闫洪波,张桂霞.并联机床发展的历史、研究现状与展望[J].机床电器,2006,(13):5-9.
[36]张学良,温淑花,王培霞.并联机床及其前景展望[J].太原重型机械学院学报,2003,24(3):195-200.
[37]黄玉美.数控机床总体方案的创新设计[J].世界制造技术与装备市场,2001,(1):41-244.
[38]于鹏.并联机床的研究[D].成都:四川大学,2002:2.
[39]彭用新.并联机床结构及误差分析研究[D].昆明:昆明理工大学,2006:6.
[40]魏世民,周晓光,廖启征.六轴并联机床运动精度的标定研究[J].中国机械工程,2003,14(23):1981-1985.
[41]邢登鹏.并联机床运动学标定与实验方法的研究[D].天津:天津大学,2006:4-5.
[42]徐礼钜,范守文,马咏梅.一种新型并联机床的精度建模与误差分析[J].四川大学学报(工程科学版),2003,35(4):1-5.
[43]孙浩.5-UPS/PRPU并联机床的误差标定研究[D].秦皇岛:燕山大学,2004:10.
[44]A.J Patel et al.Volumetric Error Analysis of a Stewart Platform Based Machine Tool.Annals of the CIRP,1997,46(1):287-290.
[45]刘文涛.并联杆系机床工作空间与精度分析[J].制造技术与机床,1998,(11):9-11.
[46]高建设.新型五自由度并联机床驱动输入选择与运动学标定研究[D].秦皇岛:燕山大学,2006:16.
[47]黄田,李亚,李思维,唐国宝,赵兴玉.一种三自由度并联机构几何误差建模、灵敏度分析及装配工艺设计[J].中国科学(E辑),2002,32(5):628-635.
[48]周芳青.5-UPS并联机床结构参数标定及加工技术研究[D].秦皇岛:燕山大学,2004:1-3,16.
[2]关浩,胡萍,于云满.21世纪新兴机床--虚拟轴并联机床[J].江苏机械制造与自动化,2001,(4):17-18.
[3]Manfred Weck,Michael Damnoer.Design,calculation and control of machine tools based on parallel kinematics[A].In:Proc.of the ASME[C].MED-vol.8,1998:715-721.
[4]Bruno Siciliano.The Tricept robot:Inverse kinematics,manipulability analysis and closed-loop direct kinematics algorithm[J].Robotica,1999,17(4):437-445.
[5]Tetsuro Shhibukawa,et al.Development of parallel mechanism based milling machine[HexaM][A].In:Proc.of theASME[C].MED-Vol.8,1998:691-698.
[6]Keum-Shik Hong,Jeom-Goo Kim.Manipulability Analysis of a Parallel Machine Tool:Application to Optimal Link LengthDesign[J].J.Robotic Systems,2000,17(8):403-415.
[7]夏广岚,胡晓平,李彩花,赵国福.并联机器人发展现状与展望[J].中国科技信息,2005,(22)
[8]邬昌峰,高荣慧.并联机床的特点、研究现状及展望[J].机械,2003,30(1):1-6.
[9]汪劲松,黄田.并联机床--机床行业面临的机遇与挑战[J].中国机械工程,1999,10(10):1103-1107.
[10]马琳.3-HSS并联机床精度设计与误差补偿方法研究[D].天津:天津大学,2001
[11]史长虹,张同庄,丁洪生.变轴数控机床精度研究进展[J].组合机床与自动化技术,2001(4):8-10.
[12]唐有桥.混联机床精度检测与误差补偿研究[D].西安:西安理工大学,2005:30.
[13]何小妹,丁洪生,付铁,孙厚芳.并联机床运动学标定研究综述[J].机床与液压,2004,(10):9-11.
[14]高猛,李铁民,叶佩青,段广洪.面向精度评价的并联机床参数辨识技术[J].机械工程学报,2005,41(5):79-82.
[15]王冰.五轴混联机床的关键技术研究[D].秦皇岛:燕山大学,2005:9-10.
[16]Wang J.,Masory O..On The Accuracy of a Stewart Platform-Part I,The Effect of Manufacture Tolerances.IEEE International Conference on Robotics and Automation,1993:114-120.
[17]T.Ropponen,T.Arai.Accuracy Analysis of a Modified Stewart Platform Manipulator.IEEE Int.Conf.on Robotics and Automation,1995:521-525.
[18]赵俊伟.串并联机床精度分析及检测装置研究[D].武汉:华中科技大学,2001
[19]毛新华,游红伟,刘新昌.基于数控加工中圆弧插补的改进方法[J].河南科技学院学报(自然科学版),2006:95-97.
[20]于信伟,麻晓红.内球面加工及其误差分析[J].煤矿机械,2004,(2):93.
[21]乔雁龙.混联机床的数控加工程序处理方法的研究及其模块的开发[D].西安:西安理工大学,2006:9,28,51-52.
[22]彭中波.混联机床运动学标定及其开放式数控系统研究[D].西安:西安理工大学,2004
[23]杜振辉,蒋诚志,桂垣,王斌.激光干涉仪测量长度[J].河北建筑工程学院学报,2003,21(2):11-13.
[24]黎捷.Maple 9.0符号处理及应用[M].北京:科技出版社,2004:1.
[25]李宏胜,黄尚先.机床数控技术及应用[M].北京:高等教育出版社,2001:97-98.
[26]周慧.数据采样法圆弧插补的新算法[J].组合机床与自动化加工技术,2004,(2):38-42.
[27]任玉田,焦振学,王宏甫.机床计算机数控技术(第二版)[M].北京:北京理工大学出版社,2002:138.
[28]田相克.PMAC多轴运动控制器研究[D].兰州:兰州理工大学,2004:13-32.
[29]北京钧义志成科技发展有限公司责任公司.PMAC用户手册,2003
[30]宓方伟,陈功福.PMAC多轴运动控制器应用研究[J].机床与液压,2004,(12):129-131.
[31]程祥.新型复合加工中心创新设计方法研究[D].西安:西安理工大学,2006
[32]李金泉,丁洪生,付铁,庞思勤.并联机床的历史、现状及展望[J].机床与液压,2003,(13):3-8.
[33]黄玉美,高 峰,史文浩.混联式数控机床的发展[J].制造技术与机床,2001(8):8-9.
[34]顾锋,汪通悦,康志军,刘远伟.并联机床的研究与技术进展[J].机床与液压,2002,(16):14-16.
[35]李强,闫洪波,张桂霞.并联机床发展的历史、研究现状与展望[J].机床电器,2006,(13):5-9.
[36]张学良,温淑花,王培霞.并联机床及其前景展望[J].太原重型机械学院学报,2003,24(3):195-200.
[37]黄玉美.数控机床总体方案的创新设计[J].世界制造技术与装备市场,2001,(1):41-244.
[38]于鹏.并联机床的研究[D].成都:四川大学,2002:2.
[39]彭用新.并联机床结构及误差分析研究[D].昆明:昆明理工大学,2006:6.
[40]魏世民,周晓光,廖启征.六轴并联机床运动精度的标定研究[J].中国机械工程,2003,14(23):1981-1985.
[41]邢登鹏.并联机床运动学标定与实验方法的研究[D].天津:天津大学,2006:4-5.
[42]徐礼钜,范守文,马咏梅.一种新型并联机床的精度建模与误差分析[J].四川大学学报(工程科学版),2003,35(4):1-5.
[43]孙浩.5-UPS/PRPU并联机床的误差标定研究[D].秦皇岛:燕山大学,2004:10.
[44]A.J Patel et al.Volumetric Error Analysis of a Stewart Platform Based Machine Tool.Annals of the CIRP,1997,46(1):287-290.
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[46]高建设.新型五自由度并联机床驱动输入选择与运动学标定研究[D].秦皇岛:燕山大学,2006:16.
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