高速高精加工轨迹间速度平滑方法的研究与应用
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摘要
随着现代数控技术的不断发展,高速高精加工已经成为新的趋势。而轨迹间的转接速度严重影响着机床效率和精度,当相邻轨迹间形成的转角较大时,会造成运动速度矢量变化过大,对机床产生较大冲击,因此实现相邻轨迹间的速度平滑转接,减小转角处速度突变对机床的冲击,是提高加工效率和精度的关键因素。
目前数控系统处理轨迹间速度平滑的方法多局限于对无拐点的相邻轨迹段的研究,而且基于简单的直线加减速曲线,存在电机连续启停,加工效率低,加工表面不光滑等问题。针对上述速度平滑方法的不足,为实现数控加工轨迹间的速度平滑转接,满足数控系统对高速高精加工的需求,并考虑一个加工工件的轮廓通常有普通曲面(非小线段)和复杂曲面(小线段)组成,本文分别对数控加工中非小线段轨迹间和小线段轨迹间的速度平滑方法进行了研究。首先,本文介绍了蓝天数控平台的体系结构,并对相关的运动规划流程进行了研究。
其次,本文论述了用于非小线段速度平滑处理的矢量转接方法的原理。该方基于S曲线加减速,通过把相邻轨迹段同时进行加减速规划来实现速度平滑转接。再次,本文论述了用于小线段速度平滑处理的小线段动态转接规划方法的实现原理。该方法通过聚集多个轨迹段为加工链,然后求解加工链之间的衔接速度来实现小线段的速度平滑转接。
最后,把以上两种方法初步应用到蓝天数控平台的运动规划器中,针对不同的加工轨迹,进行实验测试和分析。
本文所设计的方法简单、可靠,能够实现加工轨迹段间的高速平滑转接,满足现代数控系统对高效率、高精度的需求。
With the development of modern CNC technology, high-speed and high-accuracy machining has become a new trend. While the transfer speed of inter-trajectory influences the efficiency and accuracy of machine seriously, when the corner angle of inter-trajectory is bigger, larger changes in speed at the corner will cause greater impact on the machine. So realizing the smoothing transfer of speed of inter-trajectory and reducing the impact of machine caused by sudden change of speed at corner is a key factor to improve the efficiency and accuracy of machining.
At present, the studies of speed smoothing of inter-trajectory for NC system are mostly limited to non-turning point of the adjacent trajectory segment and based on simple trapezoidal accelection and decelection, which have the shortcoming of frequent stops of motor, lower efficiency, not-smoothing surface and etc. For the drawbacks of above-mentioned method, in order to realize the speed smoothing of inter-trajectory and satisfy the need of high-speed and high-accuracy of CNC, and considering that the contour of a special part commonly consists of common surface (non-micro segments) as well as the complicated surfaces (micro segments), this paper has mainly studied the speed smoothing method for non-micro segments and micro segments respectively.
Firstly, the architecture of Lantian NC Platform and design scheme of related motion plan were introduced.
Secondly, the principle of vector transfer method for speed smoothing of non-micro segments was discussed. The method was based on the s-curve and had achieved the speed smoothing by planning the adjacent segments at the same time.
Thirdly, the principle of dynamic transfer planning method for micro segments was discussed. The method had achieved the speed smoothing by forming multiple segments into machining chain, and then solving the transfer speed of the machining chains.
Finally, the application on the Lantian NC Platform of the two methods was given. For different trajectories, a large number of tests were carried out and the results were analyzed.
The methods designed are simple, reliable, and able to achieve smooth and high-speed transfer of inter-trajectory, so can meet the requirement of modern CNC system for high-efficiency and high-accuracy.
目前数控系统处理轨迹间速度平滑的方法多局限于对无拐点的相邻轨迹段的研究,而且基于简单的直线加减速曲线,存在电机连续启停,加工效率低,加工表面不光滑等问题。针对上述速度平滑方法的不足,为实现数控加工轨迹间的速度平滑转接,满足数控系统对高速高精加工的需求,并考虑一个加工工件的轮廓通常有普通曲面(非小线段)和复杂曲面(小线段)组成,本文分别对数控加工中非小线段轨迹间和小线段轨迹间的速度平滑方法进行了研究。首先,本文介绍了蓝天数控平台的体系结构,并对相关的运动规划流程进行了研究。
其次,本文论述了用于非小线段速度平滑处理的矢量转接方法的原理。该方基于S曲线加减速,通过把相邻轨迹段同时进行加减速规划来实现速度平滑转接。再次,本文论述了用于小线段速度平滑处理的小线段动态转接规划方法的实现原理。该方法通过聚集多个轨迹段为加工链,然后求解加工链之间的衔接速度来实现小线段的速度平滑转接。
最后,把以上两种方法初步应用到蓝天数控平台的运动规划器中,针对不同的加工轨迹,进行实验测试和分析。
本文所设计的方法简单、可靠,能够实现加工轨迹段间的高速平滑转接,满足现代数控系统对高效率、高精度的需求。
With the development of modern CNC technology, high-speed and high-accuracy machining has become a new trend. While the transfer speed of inter-trajectory influences the efficiency and accuracy of machine seriously, when the corner angle of inter-trajectory is bigger, larger changes in speed at the corner will cause greater impact on the machine. So realizing the smoothing transfer of speed of inter-trajectory and reducing the impact of machine caused by sudden change of speed at corner is a key factor to improve the efficiency and accuracy of machining.
At present, the studies of speed smoothing of inter-trajectory for NC system are mostly limited to non-turning point of the adjacent trajectory segment and based on simple trapezoidal accelection and decelection, which have the shortcoming of frequent stops of motor, lower efficiency, not-smoothing surface and etc. For the drawbacks of above-mentioned method, in order to realize the speed smoothing of inter-trajectory and satisfy the need of high-speed and high-accuracy of CNC, and considering that the contour of a special part commonly consists of common surface (non-micro segments) as well as the complicated surfaces (micro segments), this paper has mainly studied the speed smoothing method for non-micro segments and micro segments respectively.
Firstly, the architecture of Lantian NC Platform and design scheme of related motion plan were introduced.
Secondly, the principle of vector transfer method for speed smoothing of non-micro segments was discussed. The method was based on the s-curve and had achieved the speed smoothing by planning the adjacent segments at the same time.
Thirdly, the principle of dynamic transfer planning method for micro segments was discussed. The method had achieved the speed smoothing by forming multiple segments into machining chain, and then solving the transfer speed of the machining chains.
Finally, the application on the Lantian NC Platform of the two methods was given. For different trajectories, a large number of tests were carried out and the results were analyzed.
The methods designed are simple, reliable, and able to achieve smooth and high-speed transfer of inter-trajectory, so can meet the requirement of modern CNC system for high-efficiency and high-accuracy.
引文
[1] Chuan Shi,Peiqing Ye,Kaiming Yang,etc.The look ahead Based Adaptive Motion Control for high-speed maching of complicated contours[C]. Proceedings of the 2007 IEEE International Symposium on Assembly and Manufacturing. 2007:31~37.
[2]杨开明,石川,叶佩青等.数控系统轨迹段光滑转接控制方法[J].清华大学学报,.2007,47(8):1295~1299.
[3]叶佩青,赵慎良.微小直线段的连续插补控制方法研究[J].中国机械工程.2004,15(15):1354~1356.
[4]张得礼,周来水.数控加工运动的平滑处理[J].航空学报.2006(1):125~130.
[5]黄志宏.CNC工具机之进给速度控制[学位论文].台北,国立中央大学.2002.
[6]吕强,张辉,叶佩青等.数控连续加工中提高轨迹转接速度的方法研究[J].制造技术与机床.2008(7):79~83.
[7]王宇晗,肖凌剑,曾水生等.小线段高速加工速度衔接数学模型[J].上海交通大学学报.2004,38(6):901~904.
[8]冯庆枝,刘少君,裴海龙.高速加工中微线段的最佳转角速度的研究[J].制造业自动化.2007,29(1):38~40.
[9] Jun Hu,Lingjian Xiao,Yuhan Wang,etc. An optimal federate model and solution algorithm for a high-speed machine of small line blocks with look-ahead[J].Int Adv Manuf Technol,2006(28):930~935.
[10] Haifeng Xu, Yuhan Wang, Yuhao Li. Research on Feedrate Model of Look-ahead and Solution Algorithm for High-speed Machining of Small Line Segments[J].Mechanical Engineer.2005(4): 9~13.
[11]徐夏民,邵泽强.数控原理与数控系统[M].北京理工大学出版社.2006.
[12]周凯.数控原理、系统及应用[M].机械工业出版社.2006:1~3.
[13]俞鸿斌,翁献进.基于高速加工的加减速控制方法研究及实现[J].组合机床与动化加工技术.2008(2):50~54.
[14]OCEAN(Open Controller Enabled by an Advanced real-time Network).On line at:http://www.fidia.it/english/research_ocean_fr.htm.
[15]Open System Architecture for Controls within Automation Systems.OSACA final report.1996.
[16]Hemin, Golden. Open architecture who defines it and who benefits.Manufacturing Engineering. 1998.
[17] RTAI实现原理与分析.[EB/OL].Online at: http://hi.baidu.com/ilbx/blog/item/717feed17870d5da562c845a.html.2009.
[18]何波,罗磊.高速数控加工轨迹拐角的速度平滑方法[J].上海交通大学学报.2008, 42(1):83~86.
[19]黄艳,李家霁,于东等. CNC系统S型曲线加减速方法的设计与实现[J].制造技术与机床. 2005(03):55~58.
[20]林一松,汤兆江,区锐相等.一种S形曲线加减速计算方法[J].制造技术与机床.2005(11):74~75.
[21]曹宇男,王田苗,陈友东等.插补前S加减速在CNC前瞻中的应用[J].北京航空航天大学学报.2007,33(5):594~599.
[22] Kaan Eekorkmaz, Yusuf Altintas. High speed CNC system design. Part I:Jerk limited trajectory generation and quintic spine interpolation. International Journal of Machine Tools & Manufacture 2001(41):1323~1345.
[23]Jingyan Donga, P.M. Ferreiraa, J.A. Stori. Feed-rate optimization with jerk constraints for generating minimum-time trajectories. International Journal of Machine Tools & Manufacture . 2007(47): 1941~1955.
[24]石川,赵彤,叶佩青等.数控系统S曲线加减速规划研究[J].中国机械工程.2007, 18(12):1421~1425.
[25]宋宝,周云飞.高速高精运动中的平滑抑振运动规划[J].制造技术与机床.2005(2):32~35.
[26] Roque Alfredo Osornio-Rios, Rene de Jesus Romero-Troncoso. Computationally effcient parametric analysis of discrete-time polynomial based acceleration–deceleration pro?le generation for industrial robotics and CNC machinery. R.A. Osornio-Rios Mechatronics .2007(17): 511~523.
[27]周雷.开放式数控系统复杂曲线运动规划方法的研究与实现[学位论文],沈阳.中国科学院研究生院.2006.
[28] J.Dong, J.A.Stori, Optimal Feed-Rate Scheduling for High-Speed Contouring.Journal of Manufacturing Science and Engineering.2007(129):63~76.
[29] Todd J. Schuett. A Closer Look At Look-Ahead Speed and Accuracy Benefits[J].Modern Machine Shop, March,1996:20~26.
[2]杨开明,石川,叶佩青等.数控系统轨迹段光滑转接控制方法[J].清华大学学报,.2007,47(8):1295~1299.
[3]叶佩青,赵慎良.微小直线段的连续插补控制方法研究[J].中国机械工程.2004,15(15):1354~1356.
[4]张得礼,周来水.数控加工运动的平滑处理[J].航空学报.2006(1):125~130.
[5]黄志宏.CNC工具机之进给速度控制[学位论文].台北,国立中央大学.2002.
[6]吕强,张辉,叶佩青等.数控连续加工中提高轨迹转接速度的方法研究[J].制造技术与机床.2008(7):79~83.
[7]王宇晗,肖凌剑,曾水生等.小线段高速加工速度衔接数学模型[J].上海交通大学学报.2004,38(6):901~904.
[8]冯庆枝,刘少君,裴海龙.高速加工中微线段的最佳转角速度的研究[J].制造业自动化.2007,29(1):38~40.
[9] Jun Hu,Lingjian Xiao,Yuhan Wang,etc. An optimal federate model and solution algorithm for a high-speed machine of small line blocks with look-ahead[J].Int Adv Manuf Technol,2006(28):930~935.
[10] Haifeng Xu, Yuhan Wang, Yuhao Li. Research on Feedrate Model of Look-ahead and Solution Algorithm for High-speed Machining of Small Line Segments[J].Mechanical Engineer.2005(4): 9~13.
[11]徐夏民,邵泽强.数控原理与数控系统[M].北京理工大学出版社.2006.
[12]周凯.数控原理、系统及应用[M].机械工业出版社.2006:1~3.
[13]俞鸿斌,翁献进.基于高速加工的加减速控制方法研究及实现[J].组合机床与动化加工技术.2008(2):50~54.
[14]OCEAN(Open Controller Enabled by an Advanced real-time Network).On line at:http://www.fidia.it/english/research_ocean_fr.htm.
[15]Open System Architecture for Controls within Automation Systems.OSACA final report.1996.
[16]Hemin, Golden. Open architecture who defines it and who benefits.Manufacturing Engineering. 1998.
[17] RTAI实现原理与分析.[EB/OL].Online at: http://hi.baidu.com/ilbx/blog/item/717feed17870d5da562c845a.html.2009.
[18]何波,罗磊.高速数控加工轨迹拐角的速度平滑方法[J].上海交通大学学报.2008, 42(1):83~86.
[19]黄艳,李家霁,于东等. CNC系统S型曲线加减速方法的设计与实现[J].制造技术与机床. 2005(03):55~58.
[20]林一松,汤兆江,区锐相等.一种S形曲线加减速计算方法[J].制造技术与机床.2005(11):74~75.
[21]曹宇男,王田苗,陈友东等.插补前S加减速在CNC前瞻中的应用[J].北京航空航天大学学报.2007,33(5):594~599.
[22] Kaan Eekorkmaz, Yusuf Altintas. High speed CNC system design. Part I:Jerk limited trajectory generation and quintic spine interpolation. International Journal of Machine Tools & Manufacture 2001(41):1323~1345.
[23]Jingyan Donga, P.M. Ferreiraa, J.A. Stori. Feed-rate optimization with jerk constraints for generating minimum-time trajectories. International Journal of Machine Tools & Manufacture . 2007(47): 1941~1955.
[24]石川,赵彤,叶佩青等.数控系统S曲线加减速规划研究[J].中国机械工程.2007, 18(12):1421~1425.
[25]宋宝,周云飞.高速高精运动中的平滑抑振运动规划[J].制造技术与机床.2005(2):32~35.
[26] Roque Alfredo Osornio-Rios, Rene de Jesus Romero-Troncoso. Computationally effcient parametric analysis of discrete-time polynomial based acceleration–deceleration pro?le generation for industrial robotics and CNC machinery. R.A. Osornio-Rios Mechatronics .2007(17): 511~523.
[27]周雷.开放式数控系统复杂曲线运动规划方法的研究与实现[学位论文],沈阳.中国科学院研究生院.2006.
[28] J.Dong, J.A.Stori, Optimal Feed-Rate Scheduling for High-Speed Contouring.Journal of Manufacturing Science and Engineering.2007(129):63~76.
[29] Todd J. Schuett. A Closer Look At Look-Ahead Speed and Accuracy Benefits[J].Modern Machine Shop, March,1996:20~26.