Path smoothing for five-axis machine tools using dual quaternion approximation with dominant points

Abstract

Nowadays, G01 blocks are still the most widely utilized representation form for the tool paths in the five-axis machine tools. Tangency and curvature discontinuities of the linear tool paths may lead to frequent feedrate fluctuation and acceleration variation, which inevitably deteriorate the machining efficiency and quality. To solve this problem, this paper proposed a dual quaternion B-spline approximation method of dominant points to generate smooth tool paths for five-axis CNC machine tools. First, the dominant points, which can characterize the shape of the linear path, are selected for the tool tip location and the tool orientation simultaneously. Such scheme can significantly compress the number of the control points and release the computational load. Then, the linear tool paths are converted to dual quaternions and approximated to dual quaternion B-spline, which can realize the parameter synchronization for the tool tip and tool orientation, and avoid the fitting oscillatory as well. To verify the proposed method, a trajectory generation method for the dual quaternion B-spline is developed. Simulations and experiments on a five-axis machine tool are conducted, and the results demonstrate the feasibility and efficiency of the proposed method.