Development of Novel Tool Center Point Velocity Planning Algorithm for Five Axis Machine Tool

Abstract

In this paper, a tool center point (TCP) feedrate scheduling algorithm for 5-axis machine tool is developed to generate the axes interpolation commands. The proposed algorithm considers not only the constraints of TCP velocity, acceleration and jerk, but also the velocity differences of each axes at the junction of each block. First, the proposed method determines the maximum speed for each block segment at the TCP coordinate based on the computed length. Then the kinematics of the five axis machine tool is employed to derive the five-axis corner velocity difference (FCVD) formulation. The FCVD utilizes the axis velocity difference at the junction of blocks as the designed variable. As the starting and end velocities of each block are determined, the S-shape acceleration/deceleration (Acc/Dec) method is adopted to generate both smooth TCP and rotary axis profile based on the given interpolation parameters. The servo dynamics of the five axis machine tool are utilized to evaluate the performances of the FCVD. Simulation results demonstrate that the FCVD can achieve better contour accuracy with less machining time as compared to the five-axis feedrate regulation formulation (FFRF) algorithm. Furthermore, the FCVD are compared with Heidenhain CNC controller and the results show that the FCVD has similar behaviors as the Heidenhain controller, but it can achieve less machining time.