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

Abstract

Since their ability to machine complex curved surface, five-axis CNC machine tools have been widely used in the machining field. To guarantee the accuracy of the complex surface machining, multi-axis linkage performance detection of five-axis machine tools is necessary. RTCP (rotation tool center point) is one of the basic essential functions for five-axis machine tools, which could effectively reduce the nonlinear errors caused by rotation axes when five axes move synchronously. On the basis of RTCP function, a way to detect multi-axes linkage performance of five-axis machine tools is introduced in this paper. Some simulations that exhibit the relationship between the tool center error trajectories and the factors influencing the linkage performance of the machine tool are established based on the linkage error model. Analyzing the rule of tool center error trajectories, a linkage error tracing method is proposed based on feature extraction and trajectory similarity. The experiments based on RTCP are carried out, and the tool center point error variation is shown to be consistent with the simulation result. Furthermore, the error of the error tracing method is less than 5%, which means the error tracing method could find the mismatch parameters effectively. This attempt provides a theoretical support for linkage performance detection and error tracing of five-axis CNC machine tools.

Dynamic performance optimization of five-axis machine tools based on S-specimen and servo dynamics matching degree indexes

“…Eq. (20) shows that when the command trajectory is specified, TEA is determined by 𝑤 𝑦 (𝜏)/𝑤 𝑥 (𝜏) . As indicated by Eq.…”

“…Flohic et al analysed the influence of SDMD on dual ball bar test results, identified the servo parameters that affect SDMD, and optimized the dynamic performance of the machine tool by adjusting the identified servo parameters [18]. Jiang et al identified the factors that influence the SDMD based on the results of a rotation tool centre point (RTCP) test, which is one of the most effective experimental methods for testing the dynamic performance of five-axis machine tools [19,20], and achieved preliminary tracing of the machine axis system to be optimized without considering other error factors [21]. Ding et al optimized the RTCP test process to improve the identifiability of tracking errors based on their influence on SDMD [22].…”

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

“…Another method is synchronous measurement, 20 which means synchronously measuring the tool tip error and corresponding tool posture. By the inverse kinematic transform, the position, velocity and acceleration of each motion axis can be calculated from tool posture angles and device time series, as equation (17) shows:…”

“…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.…”

Research on Error Tracing of Synchronizer Gear Hub Based on Variable Step Fa-Rbf Neural Network

“…In the machining process, there are many influence factors that cause the machining error, including tool wear, machine tool motion error, cutting force, thermal deformation of machine tool, and position error, etc. In addition, the errors of the machine tool are dynamic, and it is a difficult problem in actual production to find the error source corresponding to the processing quality error [1,2]. Therefore, it is of great significance to trace the error source of machining quality of gear hub, to improve the machining quality of parts in intelligent manufacturing process.…”