Real-Time NURBS Interpolator with an Optimal Feed for High-Speed Machining

2009 ◽  
Vol 69-70 ◽  
pp. 461-465 ◽  
Author(s):  
Jing Chun Feng ◽  
Yu Han Wang ◽  
Ming Chen ◽  
Jin Sen Wang
Keyword(s):  
Real Time ◽  
High Speed ◽  
Interpolation Method ◽  
High Speed Machining ◽  
Chord Error ◽  
Look Ahead ◽  
Nurbs Interpolation ◽  
Optimal Feed ◽  
Error Constraint ◽  
Circular Interpolation

NURBS interpolation has many advantages over the traditional linear or circular interpolation in high-speed machining. The existing work in this regard focuses on adaptive feed interpolation considering the chord error constraints and tangent acceleration limits. However, regardless of the dynamic characteristics of individual axis, performance will inevitably suffer when the system is called upon to execute a complex trajectory beyond the range of its capabilities. The intent of the present work is to provide an optimal feed interpolation method respecting both the chord error constraint and the drive constraint of each axis. A look-ahead scheme is applied with a moving window to augment the calculation efficiency for real-time application. Simulations are performed to verify the resulting feedrate, acc/dec profiles and the real-time performance of the proposed interpolator.

A Pipeline Designed Reconfigurable CNC Architecture

2011 ◽  
Vol 697-698 ◽  
pp. 288-291
Author(s):  
Jing Chuan Dong ◽  
Tai Yong Wang
Keyword(s):  
Real Time ◽  
High Speed ◽  
Reconfigurable Architecture ◽  
Experimental Results ◽  
High Speed Machining ◽  
Control Software ◽  
The Real ◽  
Look Ahead ◽  
Reconfigurable Structure

This paper proposed a pipeline based reconfigurable architecture for CNC controllers. The architecture consists of an upper controller and a NC Microcode Processor (NCMP). The control software in the upper controller is a multi-thread program, including a management thread and a NC pipeline thread. The NC pipeline thread in the upper controller converts the machining program into NC Microcode (NCM), which is optimized for the real-time execution in NCMP. A pipelined feedrate plan algorithm is developed for the proposed architecture. The algorithm features a reconfigurable structure and look-ahead ability for high speed machining. Two prototype systems were built to demonstrate the feasibility of the proposed architecture. The experimental results indicate that the NC pipeline is highly reconfigurable and flexible in design compared to the classic implementation.

A feedrate pre-schedule NURBS interpolation method for high-speed machining

2010 ◽  
Author(s):  
Zongtao Luan ◽  
Gedong Jiang ◽  
Bing Bai ◽  
Yun Zhang ◽  
Xuesong Mei
Keyword(s):  
High Speed ◽  
Interpolation Method ◽  
High Speed Machining ◽  
Nurbs Interpolation

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.

Development of Real-Time Look-Ahead Methodology Based on Quintic PH Curve with G2 Continuity for High-Speed Machining

2013 ◽  
Vol 464 ◽  
pp. 258-264 ◽  
Author(s):  
Jing Shi ◽  
Qing Zhen Bi ◽  
Yu Han Wang ◽  
Gang Liu
Keyword(s):  
Real Time ◽  
High Speed ◽  
Tool Path ◽  
Approximation Error ◽  
Machining Process ◽  
Transition Curve ◽  
Look Ahead ◽  
Cad Cam ◽  
Feedrate Fluctuation ◽  
Ph Curve

Curving tool paths composed of straight lines, which are often represented as G01 blocks, are still the most widespread format form in the machining process chain of CAD/CAM/CNC. At the junctions between consecutive segments, the tangency and curvature discontinuities may lead to feedrate fluctuation and acceleration oscillation, which would deteriorate the machining efficiency and quality. In this paper, a real-time look-ahead interpolation methodology is proposed, which adopts a curvature-continuous PH curve as a transition to blend corner at the junction of adjacent lines in the tool path. The blending algorithm can guarantee the approximation error exactly, and the control points of the curve can be calculated analytically. On the other hand, the arc length and the curvature of the transition curve, which are important items in speed planning, also have analytical expressions. All the advantages are the guarantee of calculation efficiency during the interpolation. Except for a curvature-continuous tool path, our look-ahead algorithm adopts a speed planning window strategy to achieve a balance between the calculation capabilities and the real-time interpolation requirements. In this window, the corner transition algorithm and speed planning are implemented simultaneously and dynamically during the interpolation. By defining the width of this window, which is actually the number of linear segments contained in this window, can adjust the time consuming of speed planning. Simulation and experiments on our own developed CNC platform are conducted. The results demonstrate the feasibility and efficiency of the proposed algorithms.

Interpolation Algorithm on Numerical Control Technology

2011 ◽  
Vol 467-469 ◽  
pp. 247-251
Author(s):  
Zhen Yu Zhao ◽  
Ming Jun Liu ◽  
Yong Shan Xiao ◽  
Bai Liu
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Linear Interpolation ◽  
Numerical Control ◽  
Machining Accuracy ◽  
B Spline ◽  
Curve Interpolation ◽  
Nurbs Interpolation ◽  
High Flexibility ◽  
Circular Interpolation

High speed machining (HSM) features in high efficiency, high precision, high flexibility and high quality. The key techniques on HSM such as linear interpolation, circular interpolation, cubic B-spline curve interpolation, non-uniform rational B-spline (NURBS) curve interpolation and their respective characteristics are paid more attention and expatiated. Circle arcs are approximated by using intersecting polygons instead of general inscribed polygons. NURBS interpolation algorithms can reduce feedrate fluctuation and improve machining accuracy.

Real-time NURBS interpolation using FPGA for high speed motion control

2006 ◽  
Vol 38 (10) ◽  
pp. 1123-1133 ◽  
Author(s):  
Hong-Tzong Yau ◽  
Ming-Tzong Lin ◽  
Meng-Shiun Tsai
Keyword(s):  
Real Time ◽  
Motion Control ◽  
High Speed ◽  
Nurbs Interpolation
Sign in / Sign up

Export Citation Format

Share Document