NURBS Piecewise Interpolation Algorithm Based on Discrete S-Type Velocity Planning

Abstract

In order to make the 6-axis robot capable of processing NURBS curves, this paper firstly analyzes the recursive expressions of the NURBS curve and the calculation method of interpolation points, and proposes a new discrete S-type speed planning algorithm. In addition, to achieve the contour accuracy of NURBS and overcome the shortcomings of the feed-speed oscillation and hysteresis in the adaptive algorithm based on chord error, a segmented discrete S-type velocity planning algorithm for NURBS curve is proposed. The algorithm segmented the NURBS curve at the point of extreme curvature, and discrete S-type velocity planning algorithm was applied to the segmented curve respectively, thus achieving a better control of the chord error under continuous acceleration. Finally, the NURBS Trident curve is used as an example to simulate and compare different interpolation algorithms in Matlab.