Asymmetrical Pythagorean-hodograph spline-based $C^4$ continuous local corner smoothing method with jerk-continuous feedrate scheduling along linear toolpath

In computer numerical control systems, linear segments generated by computer-aided manufacturing software are the most widely used toolpath format. Since the linear toolpath is discontinuous at the junction of two adjacent segments, the fluctuations on velocity, acceleration and jerk are inevitable. Local corner smoothing is widely used to address this problem. However, most existing methods use symmetrical splines to smooth the corners. When any one of the linear segments at the corner is short, the inserted spline will be micro to avoid overlap. This will increase the curvature extreme of the spline and reduce the feedrate on it. In this article, the corners are smoothed by a continuous asymmetric Pythagorean-hodograph (PH) spline. The curvature extreme of the proposed spline is investigated first, and $K = 2.5$ is determined as the threshold to constrain the asymmetry of the spline. Then, a two-step strategy is used to generate …

The International Journal of Advanced Manufacturing Technology 121 (9), 5731-5754