Evaluation of the Dynamic Performance for Five-Axis CNC Machine Tools Based on RTCP

Abstract

RTCP (rotation tool center point), which is one of the necessary functions for high-grade CNC machine tools, can effectively decrease nonlinear errors caused by the motion of the rotation axis and improve the accuracy of the machinery. Based on the characteristic that the cutting tool tip point is relative to the manufacturing workpiece, the RTCP trajectory is proposed to conveniently measure the displacement of the tool tip point. The scheme is utilized to study the dynamic performance of machine tools, and a simulation that shows the relationship between the tool tip error trajectory and the factors influencing the dynamic performance of the machine tool is presented based on the servo system model. Then, the experiment is carried out, and the tool tip point error variation is found to be consistent with the simulation result. This study provides theoretical support for dynamic performance detection of five-axis CNC machine tools.

Research on error tracing method of five-axis CNC machine tool linkage error

“…RTCP function is one of the basic functions of the five-axis machine tool, which can simplify post-processing and significantly reduce the nonlinear errors that is caused by the motion of rotary axes, thus improving the coincidence between the actual tool center motion and ideal tool center motion. The detection method of linkage performance of the five-axis machine tool is proposed based on the characteristic of RTCP function, and the details of the detection are mentioned in previous research [20]. When RTCP function is ON, NC instruction represents the position of the tool center and orientation of the tool.…”

“…A more effectively detection trajectory named '8' shape trajectory, which has an advantage in linkage performance detection of five-axis machine tool compared with the common trajectory, is presented in Ref. [20]. Therefore, '8' shape trajectory is taken as the detection trajectory to measure the linkage performance of machine tool in this study.…”

“…With the developed servo tuning process under ISO measuring trajectories, the contour errors caused by Kpp mismatch are reduced remarkably. Compared with circle trajectory, a more effective detection trajectory named '8' shape trajectory is presented by Jiang Zhong [20], which has advantages in linkage performance detection of the five-axis machine tool. However, linkage error can be identified only by classifying the difference of tool center error trajectories artificially [16,20].…”

“…Compared with circle trajectory, a more effective detection trajectory named '8' shape trajectory is presented by Jiang Zhong [20], which has advantages in linkage performance detection of the five-axis machine tool. However, linkage error can be identified only by classifying the difference of tool center error trajectories artificially [16,20]. Therefore, the error identification nowadays is just studied on geometric error or dynamic error based on the artificial classification of the five-axis machine tool.…”

An attempt to relate dynamic tracking error to occurring situation based on additional rectilinear motion for five-axis machine tools

“…Zhong et al 15 designed a new S trajectory according to the standard S-shaped test piece to evaluate the dynamic performance. Jiang et al [16][17][18] designed an eight-shape RTCP trajectory and proposed a dynamic tracking error tracing method based on feature extraction.…”