Real-Time B-Spline Interpolator with Look-Ahead Scheme for High-Speed CNC Machine Tools

Abstract:

NC tool paths of digital CAD models are currently generated as a set of discrete data points. The CNC interpolator must convert these points into continuous machine tool axis motions. In order to achieve high-speed and high-accuracy machining, the development of a real-time interpolation algorithm is really indispensable, which can deal with a large number of short blocks and still maintain smooth interpolation with an optimal speed. In this paper, a real-time local cubic B-spline interpolator with look-ahead scheme is proposed for consecutive micro-line blocks interpolation. First, the consecutive micro-line blocks that satisfy the bi-chord error constraints are fitted into a C1 continuous cubic B-spline curve. Second, machining dynamics and tool path contour constrains are taken into consideration. Third, local cubic B-spline interpolator with an optimal look-ahead scheme is proposed to generate the optimal speed profile. Simulation and experiment are performed in real-time environment to verify the effectiveness of the proposed method. Compared with the conventional interpolation algorithm, the proposed algorithm reduces the machining time by 70%.

• Periodical: Key Engineering Materials (Volume 455)
• Pages: 599-605
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.455.599
• Online since: December 2010
• Authors: Yong Qiao Jin, Yu Han Wang, Jian Guo Yang
• Keywords: B-Spline Interpolator, Consecutive Micro-Line, High-Speed CNC Machine Tool, Look-Ahead, Real-Time

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