Development of a CCD-Based Multifunctional Measuring System for Pre-Machining Error Calibration in Five-Axis Machine Tools

Geometric and tool setting errors are the most critical, accounting for about 70% of the total errors. Currently, various devices for measuring geometric errors, rotation tool center point (RTCP) trajectory errors, and tool parameter settings errors have been developed for calibrating the pre-machining process. However, measuring each type of error requires different instruments, resulting in significant costs incurred for purchasing these devices and considerable time spent setting up each instrument. Therefore, in this study, an image-based multifunctional measuring system has been developed using two charge coupled device (CCD) sensors and two laser sources for three types of the measuring scenario in the pre-machining. In the first measuring scenario, eccentric geometric errors (such as $E_{XOC}$ , $E_{YOC}$ , $E_{YOA}$ , and $E_{ZOA}$ ) of five-axis machine tools are measured and compensated using the system’s static measurement function. In the second measuring scenario, the RTCP simultaneous motion performance of five-axis machine tools is evaluated through the system’s dynamic measurement function. In the final measuring scenario, the tool contour is reconditioned using the system’s 3-D image sensing module, with various tool parameters, such as tool length and tool diameter, obtained by analyzing the tool contour. The measurement results indicate that the system achieves a standard deviation of up to $\pm 2~\mu $ m for geometric error measurement and $\pm 1.5~\mu $ m for tool parameter measurement. These three measurement functions are integrated through a C# human-machine interface (HMI) and incorporate the Internet of Things (IoT) technology for error compensation. In the future, the costs associated with purchasing multiple instruments can be reduced by applying this system to various measurement scenarios.