Real-time smoothing of G01 commands for five-axis machining by constructing an entire spline with the bounded smoothing error. (July 2021)

• Record Type: Journal Article
• Authors: Xiao, Qun-Bao; Wan, Min; Qin, Xue-Bin; Liu, Yang; Zhang, Wei-Hong
• Is Part Of: Mechanism and machine theory. Volume 161(2021)
• Publication Date: 2021-07
• Subjects: Real-time -- Five-axis machining -- Tool path smoothing -- Cubic uniform B-spline; Machine theory -- Periodicals; Machinery -- Periodicals; Machines -- Périodiques; Génie mécanique -- Périodiques; Machine theory; Machinery; Periodicals; 621.81
• DOI: 10.1016/j.mechmachtheory.2021.104307
• Languages: English
• ISSNs: 0094-114X

Abstract

Highlights: A real-time five-axis tool path smoothing algorithm is proposed for CNC machining of short line segments. The uniform smoothing of adjacent two corners is developed for different lengths of G01 commands. All the G01 commands are smoothed by an entire B-spline through connecting pieces of B-splines. The smoothing error of the locally asymmetrical B-spline is theoretically proved to be constrained. Experiments verify that the machining efficiency can be significantly improved by more than 26%. Abstract: G01 commands generated by computer-aided manufacturing (CAM) software need to be smoothed to eliminate the tangential discontinuities at corners. Although the smoothing methods for five-axis tool paths have been widely studied, it is still challenging to realize the high machining efficiency of short, dense G01 commands with real-time processing. This article proposes a real-time five-axis tool path smoothing algorithm for short G01 commands. The uniform smoothing of adjacent two corners with cubic uniform B-spline is developed. Through connecting the pieces of splines, all the G01 commands are smoothed by an entire B-spline. Therefore, the curvature increment induced by the avoidance of the intersection of adjacent micro-splines is prevented, and thus, high allowable feedrate and high machining efficiency can be achieved. Especially, the smoothing errors are theoretically proved to be constrained by using the convex polyhedron method. At the same time, the required number of control points is greatly reduced by sharing the control points with the adjacent G01 commands. Simulation and experimental results demonstrate that the proposed method can significantly reduce the machining time by more than 26% for short linear trajectories.