PC-based Controller with Real-time Look-ahead NURBS Interpolator

AbstractThis paper presents a real-time look-ahead NURBS interpolator implemented on a PC-based controller to solve the problems of traditional linear short NC segments. Taking advantage of the designs of the look-ahead function and multi-threads, the NURBS interpolator can obtain enough NC block information and complete feedrate planning before interpolation. Consequently, the computational load is reduced during an interpolation period and unnecessary feedrate acceleration and deceleration can be avoided. The continuous short blocks conforming to the CSB criterion can be fitted into NURBS curves in real-time. S-shaped federate profile for ACC/DEC planning can make the single block achieve C1 continuity and jerk-limited capability. The simulation and experimental results show that the output contour profiles approach the input NC program models. This indicates that the proposed real-time look-ahead NURBS interpolator is able to provide a satisfactory performance

[1]  Tae Jo Ko,et al.  NURBS interpolator for constant material removal rate in open NC machine tools , 2004 .

[2]  Min-Yang Yang,et al.  A study on a generalized parametric interpolator with real-time jerk-limited acceleration , 2004, Comput. Aided Des..

[3]  Mi-Ching Tsai,et al.  A real-time NURBS surface interpolator for precision three-axis CNC machining , 2003 .

[4]  Les A. Piegl,et al.  The NURBS book (2nd ed.) , 1997 .

[5]  Hong-Tzong Yau,et al.  Development and implementation for real-time lookahead interpolator by using Bezier curve to fit CNC continuous short blocks , 2005, IEEE International Conference on Mechatronics, 2005. ICM '05..

[6]  X. Zhiming,et al.  Performance Evaluation of a Real-Time Interpolation Algorithm for NURBS Curves , 2002 .

[7]  Ranga Narayanaswami,et al.  A parametric interpolator with confined chord errors, acceleration and deceleration for NC machining , 2003, Comput. Aided Des..

[8]  M. Mori,et al.  Adaptive interpolation scheme for NURBS curves with the integration of machining dynamics , 2005 .

[9]  Rida T. Farouki,et al.  Exact Taylor series coefficients for variable-feedrate CNC curve interpolators , 2001, Comput. Aided Des..

[10]  Rida T. Farouki,et al.  Variable-feedrate CNC interpolators for constant material removal rates along Pythagorean-hodograph curves , 1998, Comput. Aided Des..

[11]  Hyo-Gyu Kim,et al.  A high speed machining algorithm for CNC machine tools , 1999, IECON'99. Conference Proceedings. 25th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.99CH37029).

[12]  Yusuf Altintas,et al.  High speed CNC system design. Part I: jerk limited trajectory generation and quintic spline interpolation , 2001 .

[13]  Syh-Shiuh Yeh,et al.  Adaptive-feedrate interpolation for parametric curves with a confined chord error , 2002, Comput. Aided Des..

[14]  Mi-Ching Tsai,et al.  Real-time NURBS command generators for CNC servo controllers , 2002 .

[15]  Ming-Jen Kuo,et al.  NURBS machining and feed rate adjustment for high-speed cutting of complex sculptured surfaces , 2001 .

[16]  Syh-Shiuh Yeh,et al.  The speed-controlled interpolator for machining parametric curves , 1999, Comput. Aided Des..