Look-Ahead NURBS-PH Interpolation for High Speed CNC Machining

2010 ◽  
Author(s):  
Behnam Moetakef Imani ◽  
Amirmohammad Ghandehariun
Keyword(s):  
High Speed ◽  
Cnc Machining ◽  
Corner Detection ◽  
Nurbs Curves ◽  
Look Ahead ◽  
Approximation Errors ◽  
Pythagorean Hodograph ◽  
Approximate Nature ◽  
Sharp Corners ◽  
Parametric Interpolation

Various methods for parametric interpolation of NURBS curves have been proposed in the past. However, the errors caused by the approximate nature of the NURBS interpolator were rarely taken into account. This paper proposes an integrated look-ahead algorithm for parametric interpolation along NURBS curves. The algorithm interpolates the sharp corners on the curve with the Pythagorean-hodograph (PH) interpolation. This will minimize the geometric and interpolator approximation errors simultaneously. The algorithm consists of four different modules: a sharp corner detection module, a PH construction module, a jerk-limited module, and a dynamics module. Simulations are performed to show correctness of the proposed algorithm. Experiments on an X-Y table confirm that the developed method improves tracking and contour accuracies significantly when compared to previously proposed adaptive-feedrate and curvature-feedrate algorithms.

High speed interpolation for micro-line trajectory and adaptive real-time look-ahead scheme in CNC machining

2011 ◽  
Vol 54 (6) ◽  
pp. 1481-1495 ◽  
Author(s):  
LiXian Zhang ◽  
RuiYong Sun ◽  
XiaoShan Gao ◽  
HongBo Li
Keyword(s):  
Real Time ◽  
High Speed ◽  
Cnc Machining ◽  
Look Ahead ◽  
Line Trajectory

A Parametric Interpolator with Smooth Kinematic Profiles for High Speed Machining

2006 ◽  
Vol 315-316 ◽  
pp. 169-173 ◽  
Author(s):  
You Peng You ◽  
Jun He
Keyword(s):  
High Speed ◽  
Contour Error ◽  
Interpolation Algorithm ◽  
Tracking Accuracy ◽  
Parametric Curve ◽  
Chord Error ◽  
Feedrate Planning ◽  
Profile Matching ◽  
Look Ahead ◽  
Parametric Interpolation

Smooth kinematic profiles are very important for high speed curve machining. During parametric interpolation, simple adaptive feedrate with confined contour error may cause acceleration and jerk to fluctuate acutely. To avoid the undesirable influence, an interpolation algorithm for parametric curves with smooth kinematic profiles is presented. The interpolator consists of three parts, look-ahead module, feedrate planning module and interpolation module. In look-ahead module, a pre-interpolator is designed to produce the required feedrate profile considering chord error. By feedrate planning, a smooth feedrate profile with confined acceleration and jerk is schemed based on bell-shape ACC/DEC profile by feedrate profile matching and feedrate profile synthesis. Then the parametric curve can be interpolated with the planned feedrate in interpolation module. Simulation results have been also provided to illustrate that the proposed interpolator can generate smooth kinematic profiles required for the high tracking accuracy at high speed with confined chord error, acceleration and jerk, and can be used for high speed and precision curve machining.

Review of Research on Hydrostatic Bearings

2020 ◽  
Vol 13 ◽  
Author(s):  
Xiaodong Yu ◽  
Yu Wang ◽  
Junfeng Wang ◽  
Wenkai Zhou ◽  
Hongwei Bi ◽  
...  
Keyword(s):  
High Speed ◽  
Static Pressure ◽  
Development Trend ◽  
Cnc Machining ◽  
Pressure Effects ◽  
Cnc Machine Tools ◽  
Future Research ◽  
Theoretical Formula ◽  
Hydrostatic Bearing ◽  
Hydrostatic Bearings

Background: Hydrostatic bearings have the advantages of strong bearing capacity, good stability, small friction coefficient and long life. The performance of liquid hydrostatic bearings directly affect the accuracy and efficiency of CNC machining equipment. The performance is conducive to the development of CNC machine tools towards high speed and heavy load, so it is necessary to sort out and summarize the existing research results. Objective: This study summarizes the current development status of hydrostatic bearings and explains the development trend of hydrostatic bearings. Methods: According to the recently published journal articles and patents, the recent experimental research on hydrostatic thrust bearings is summarized. This paper summarizes many factors that affect the performance of hydrostatic bearings, and discusses the causes of various factors on hydrostatic bearings. Finally, future research on hydrostatic bearings is presented. Results: The study discusses experimental methods, simulation processes, and experimental results. Conclusion: This study can produce dynamic and static pressure effects by changing the structure of the oil cavity of the hydrostatic bearing. This effect can make up for the static pressure loss. By improving the theoretical formula and mathematical model and proposing a new simulation method, the accuracy of the hydrostatic bearing simulation is satisfied; the future development trend of the hydrostatic bearing is proposed.

High-speed corner detection based on fuzzy ID3 decision tree

2012 ◽  
Vol 19 (9) ◽  
pp. 2528-2533 ◽  
Author(s):  
Ru-jiao Duan ◽  
Wei Zhao ◽  
Song-ling Huang ◽  
Kuan-sheng Hao
Keyword(s):  
Decision Tree ◽  
High Speed ◽  
Corner Detection

Research on Virtual Grinding for Indexable Inserts

2014 ◽  
Vol 703 ◽  
pp. 163-166
Author(s):  
Yuan Yuan Wang ◽  
Jun Zhao ◽  
Fei Li
Keyword(s):  
Virtual Environment ◽  
High Speed ◽  
3D Models ◽  
Cutting Edge ◽  
Cnc Machining ◽  
Boolean Operation ◽  
Nc Code ◽  
Virtual Machining ◽  
High Speed Grinding ◽  
Testing Efficiency

The cutting location of cutting-edge curves is obtained by the mathematic models of indexable inserts, and based on the softwares of UG and NCSIMUL, The virtual machining platform is realized to simulate the whole processing of grinding. The Entity modelings of indexable inserts are obtained by Boolean operation in virtual environment, and the basis is presented for analyzing accuracy of the mathematic models and the virtual machining platform. Testing efficiency of NC code and reliability of high speed grinding are improved. This method provides precise 3D models which can be used in the followed works such as finite analysis, CNC machining and so on.

Multi-Period Turning Interpolation Algorithm for High-Speed Machining of Continuous Line Segments With Limited Acceleration, Jerk and Chord Error

2012 ◽  
Author(s):  
Lixian Zhang ◽  
Xiao-shan Gao ◽  
Hongbo Li
Keyword(s):  
Real Time ◽  
High Speed ◽  
Control Method ◽  
Dynamic Performance ◽  
Interpolation Algorithm ◽  
Cnc Machine ◽  
Look Ahead ◽  
Geometric Precision ◽  
S Curve ◽  
Accumulated Error

In this paper, a multi-period turning interpolation algorithm, with real-time look-ahead scheme based on S-curve control method, is presented. In this interpolation algorithm, the geometric precision and the dynamic performance are both satisfied. The machining efficiency is improved by multi-period turning transition, and the precision is also improved by S-curve control method. The computational efficiency of this algorithm meets the need of real-time machining. In addition, there is no accumulated error. At last, this algorithm is verified the validation by the experiments on 3-axis CNC machine.

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