A B-spline surface interpolator for precision machining of free-form surfaces

This paper presents a B-spline surface interpolator aiming to generate tool path for precision machining of free-form surfaces. For simplicity of implementation of the proposed surface interpolator, iso-parametric machining method is adopted. Parametric interpolation based on Taylor´s expansion is used along the tool path and also in the path interval direction for better surface quality and improving machining efficiency. However, scallop heights between two adjacent CC paths generated when using iso-parametric machining method are non-constant, which could cause degradation in machining quality and precision. As an attempt to address this problem, this paper presents an algorithm for on-line or off-line scheduling CC path satisfying that the maximum scallop height between two adjacent CC paths will not exceed specified scallop height value to ensure the desired machining precision. Simulation results indicate the feasibility of the proposed interpolator and CC path scheduling algorithm.