标题: CNC控制器速度及加减速规划之研究
Study on Velocity and Acceleration/Deceleration Planning for CNC Controller
作者: 曾旭生
Tseng, Hus-Sheng
李安谦
Lee, An-Chen
机械工程学系
关键字: CNC工具机;路径误差
公开日期: 1996
摘要: CNC工具机产生路径误差的原因相当复杂,输入伺服系统的参考
命令直接影响路径误的产生。参考命令包含了路径插值与加减速的计
算。路径插值主要是获得精确的路径,为了更精确有效的计算复杂的
曲线,所以发展更高次的曲线插值。但若速度命令变化过大时,马远
瞬间大扭力输出,会造成系统的振动,所以为了提高精度并使运动更
加平滑,必需加入适当的加减速规则。
本论文中对于路径插值方面,藉由已经发展的Linear、 Parabolic
DDA插值法则进而提出 Cubic DDA插值法则。应用高次的DDA插值,对
高次复杂的曲线能产生更精确的路径。在加减速规则方面,发展前加
减速和多段混合(Blended)的速度曲线,规则出数种更平滑的速度曲
线并且讨论由于混合(Blended)速度曲线规划所产生的转角误差。最后
利用电脑模拟以上所提的方法,验证方法具有可行性。
In the motion control, the reference command to the servo system directly influences the contouring error. The generation of the reference command includes path planning and the acceleration/deceleration planning. In order to obtain more accurate contouring path, we have to develop a higher order interpolation curve rather than a simple linear one. On the other hand, when the speed command varies drastically, the servo motor will consequently provide large torque to meet the change, and that will always cause the system to vibrate because of large jerk is induced. Therefore, it is necessary to develop an appropriate acceleration/deceleration planning for smooth and accurate motion.
According to the concept of pre-acceleration/deceleration scheme, several kinds of acceleration/deceleration curve including linear curve, S-curve, and linear plus S-curve are discussed and compared. Considering the planning of speed curves within every two consecutive blocks together, we also examine several kinds of blended speed curves. The performance of different blended curves are compared in the view of corner error; an error control strategy is also developed by adjusting the acceleration time or the time-delay between two consecutive blocks. At last, every algorithm is simulated to verify its feasibility. In this thesis, we also extend the algorithm of liner and parabolic DDA to a new higher order one, called cubic DDA.
URI: http://140.113.39.130/cdrfb3/record/nctu/#NT853489023
http://hdl.handle.net/11536/62371
显示于类别:Thesis