Abstract: In order to implement high speed and high surface quality machining of free-form surface, the smooth compression interpolation algorithm is proposed. Based on the angles and lengths evaluated from the adjacent command points, the machining path of free-form can be divided into two region types. For those regions composed of discontinuous micro-line blocks, the line interpolation is performed between the adjacent command points. For those regions composed of continuous micro-line blocks, firstly the shape-defining point is selected by the bend direction of the machining path; secondly the shape-defining points are fitted into smooth spline curve to compress blocks and smooth contours; lastly the curve interpolation is performed on the fitted smooth spline curve. The experimental results show that the proposed algorithm can improve machining efficiency and surface quality.

Key words: CNC machining, Interpolation algorithm, Smooth compression, Spline curve