Feedrate blending method for five-axis linear tool path under geometric and kinematic constraints

Abstract

To tackle the bottlenecks of the linear interpolation and two-step geometry-based corner smoothing methods in five-axis machining, an analytical one-step corner smoothing method based on feedrate blending is proposed in this paper. In the proposed algorithm, the maximum kinematics adjustments scheme together with the variable acceleration and jerk optimization algorithms are first adopted to determine the dynamic performances along the linear segments. Meanwhile, the smooth feedrate profiles of the tool tip position in the workpiece coordinate system (WCS) and tool orientation in the machine coordinate system (MCS) are generated by the tool tip mastered jerk-limited feedrate scheduling scheme, with which the tool tip feedrate and angular feedrate in the WCS, together with the translational and rotatory feedrate in the MCS are well bounded. Then, the blending time is calculated based on the specified tool tip error and tool orientation error in the WCS, and the feedrate profiles are blended to generate the smooth trajectories under axial kinematic constraints along the whole paths in both the WCS and MCS. Since the proposed method can generate the smooth corner trajectory by directly blending the feedrate profiles, it eliminates the construction and interpolation process of parametric splines in two-step corner smoothing algorithms and shows better tracking and real-time performances. Finally, simulation and experimental results validate the effectiveness and feasibility of the proposed method.